Gene A Giacomelli

Interests

Teaching

controlled environment agriculture

Research

controlled environment agriculture, and extending information to the commercial community.

Courses

Scholarly Contributions

Books

• Bickel, A. K., Duval, D. F., Frisvold, G. B., Cuello, J. L., Didan, K., Farrell-Poe, K. L., Giacomelli, G. A., Li, H., & Kacira, M. (2023). The Bioeconomy & Circular Economy in Southern Arizona. https://www.mapazdashboard.arizona.edu/bioeconomy-circular-economy-southern-arizona: University of Arizona.

Chapters

• Giacomelli, G. A. (2020). Controlled Environment Agriculture. In Ball Redbook, 19th Edition. GrowerTalks/Green Profit magazine.
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  Controlled-Environment AgricultureChris Beytes, with Gene GiacomelliChris Beytes is editor of GrowerTalks/Green Profit magazine, West Chicago, Illinois. Gene A. Giacomelli, Professor of Agricultural and Biosystems Engineering, University of Arizona, Tucson, Arizona
• Giacomelli, G. A. (2021). Preface [updated]. In "Basic Principles of Growing by Plant Empowerment" by P.A.M. Geelan, J.O. Voogt, P.A. van Weel Foreword by Gene A. Giacomelli.
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  Foreward updated for second edition by Gene Giacomelli for the book authored by Peter Geelan, Jan Voogt, and Peter. van Weel
• Giacomelli, G. A. (2020). Afterward. In 10th anniversary edition, The Vertical Farm by Dickson Despommier.
• Giacomelli, G. A. (2018). Preface. In "Basic Principles of Growing by Plant Empowerment" by P.A.M. Geelan, J.O. Voogt, P.A. van Weel Foreword by Gene A. Giacomelli.
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  Foreward by Gene Giacomelli for the book authored by Peter Geelan, Jan Voogt, and Peter. van Weel

Journals/Publications

• Valencia Islas, J. O., Kacira, M., Lopez-Cruz, I., Giacomelli, G. A., Ruiz-Garcia, A., & Li, P. (2022). Controller Design for a Greenhouse-Type Solar Dryer Based on Product Temperature Model. https://ssrn.com/abstract=4183397.
• Parrish, C. H., Giacomelli, G. A., Bergren, M., McDaniel, H., Herbert, D., & Ramaswamy, K. (2021). Optimizing spectral quality with quantum dots to enhance crop yield in controlled environments. Commun Biol 4, 124 (2021). https://doi.org/10.1038/s42003-020-01646-1, Commun Biol 4, 124. doi:https://doi.org/10.1038/s42003-020-01646-1
• Tollefson, S. J., Giacomelli, G. A., Hawes, M. C., & Curlango-Rivera, G. (2016). Effect of a Compost Water Extract on Growth and Root Disease Suppression in Pea Grown in Different Substrates.. Compost Science and Utilization..
• Tollefson, S. J., Giacomelli, G. A., Hawes, M. C., Curlango-Rivera, G., Huskey, D. A., & Thomas, P. (2015). Altered Carbon Delivery from Roots: Rapid, Sustained Inhibition of Border Cell Dispersal in Response to Compost Water Extracts.. Plant and Soil, 389(1-2), 145-156.
• Giacomelli, G. A. (2014). Altered Carbon Delivery from Roots: Rapid, Sustained Inhibition of Border Cell Dispersal in Response to Compost Water Extracts. Plant and Soil, doi: 10.1007/s11104-014-2350-z..
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  Tollefson, S. J., Curlango-Rivera, G., Huskey, D. A., Pew, T., Giacomelli, G., & Hawes. M.C. (2014). Altered Carbon Delivery from Roots: Rapid, Sustained Inhibition of Border Cell Dispersal in Response to Compost Water Extracts. Plant and Soil. doi: 10.1007/s11104-014-2350-z.
• Proietti, S., Moscatello, S., Giacomelli, G. A., & Battistelli, A. (2013). Influence of the interaction between light intensity and CO₂ concentration on productivity and quality of spinach (Spinacia oleracea L.) grown in fully controlled environment. Advances in Space Research, 52(6), 1193-1200.
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  Abstract: The effects of the factorial combination of two light intensities (200 and 800 μmol m-2 s-1) and two CO2 concentrations (360 and 800 ppm) were studied on the productivity and nutritional quality of spinach (Spinacia oleracea L.) grown under controlled environment. After 6 weeks within a growth chamber, spinach plants were sampled and analyzed for productivity and quality. There were no statistically significant interactions between the effects of light and CO2 for all of the variables studied, except for the nitrate and oxalic acid content of the leaves. High light and high CO2 independently one from the other, promoted spinach productivity, and the accumulation of ascorbic acid, while their interactive effect limited the accumulation of nitrate and oxalic acid in the spinach leaves. The results highlight the importance of considering the effects of the interaction among environmental variables on maximizing production and the nutritional quality of the food when cultivating and modeling the plant response in controlled environment systems such as for bioregenerative life support. © 2013 COSPAR. The Authors. Published by Elsevier Ltd. All rights reserved.
• Villarreal-Guerrero, F., Kacira, M., Fitz-Rodríguez, E., Linker, R., Giacomelli, G. A., Arbel, A., & Kubota, C. (2013). Implementation of a greenhouse cooling strategy with natural ventilation and variable fogging rates. Transactions of the ASABE, 56(1), 295-304.
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  Abstract: A control strategy for greenhouse cooling with natural ventilation and variable high-pressure fog was evaluated via computer simulation and verified experimentally. Two set points were used, one based on air specific enthalpy (56 kJ kg-1) for determining the vent openings, and the other based on vapor pressure deficit (VPD) of the air (1.0 kPa) for controlling the fogging rate. These set points would maintain the greenhouse air at a temperature of 24°C and a relative humidity of 67%. Achieving the VPD set point was the priority, and excessive air exchange was avoided through adjustments of the vent openings when fogging demands were beyond the operational capacity of the fogging system. Results of simulations and experiments from four different days (18, 19, 29 June and 3 July 2011) were in good agreement. The performance of the control strategy developed was satisfactory to maintain the greenhouse indoor climate close to the set points with 1.1 ±0.4 kPa and 26°C ±1.7°C for inside air VPD and temperature, respectively (with relative humidity of 67% ±8%). The implementation results demonstrated that the control strategy was capable of reducing the air VPD by an average of 4.2 kPa when the average outside air VPD was 5.4 kPa and reducing the air temperature by an average of 10.5°C when the average outdoor air temperature was 37°C, and the greenhouse relative humidity was increased by an average of 52% compared to outside during the four experiment days. Deviations between the simulated and measured variables inside the greenhouse were attributed to a prevailing high and variable-magnitude outside wind speed during the experiments as well as to the time delay on the retrieval of climate data needed for computations of the strategy. Real-time climate parameters with no delay are preferable for effective computations of ventilation rates and desired fogging rates. The strategy that was developed in this study maintained the VPD close to the selected set point for all the experimental periods evaluated. Finally, the control strategy developed effectively maintained desirable climate conditions inside the greenhouse, and the simulation results were experimentally validated. © 2013 American Society of Agricultural and Biological Engineers ISSN 2151-0032.
• Boscheri, G., Kacira, M., Patterson, L., Giacomelli, G., Sadler, P., Furfaro, R., Lobascio, C., Lamantea, M., & Grizzaffi, L. (2012). Modified energy cascade model adapted for a multicrop lunar greenhouse Prototype. Advances in Space Research.
• Giacomelli, G. A., Kacira, M., Villarreal-Guerrero, F., Kubota, C., Fitz-Rodriquez, E., & Linker, R. (2011). Comparison of three evapotranspiration models for a greenhouse cooling strategy with natural ventilation and variable high pressure fogging.. Scientia Horticulturae, 134, 210-221.
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  Villarreal-Guerrero, F., M. Kacira, E. Fitz-Rodríguez, C. Kubota, G.A. Giacomelli, R. Linker, A. Arbel. 2012a. Comparison of three evapotranspiration models for a greenhouse cooling strategy with natural ventilation and variable high pressure fogging. Scientia Horticulturae, 134: 210-221.
• Giacomelli, G. A., Sase, S., Cramer, R., Hoogeboom, J., MacKenzie, A., Parbst, K., Scarascia-Mugnozza, G., Selina, P., Sharp, D. A., Voogt, J. O., Weel, P. V., & Mears, D. (2012). Greenhouse production systems for people. Acta Horticulturae, 927, 23-38.
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  Abstract: Environmentally sound greenhouse production requires that: demand for market products is understood; greenhouse design addresses the climate circumstances; input resources are available and consumed efficiently, and; there must be a reasonable balance of production products to the environmental impacts from system. Engineering greenhouse production systems to meet these requirements must include: a cost-effective and structurally sound facility; various sub-systems controlled to interact harmoniously together; and educated and experienced system operators. The major components of the environmentally sound greenhouse are: Super-structure and glazing (for a specific location and climate conditions); Climate control sub-systems (ventilation, heating, cooling, CO2 control, pest protection, energy conservation, shading/lighting); Monitoring and control (for system operations data; decisionsupport systems; and, operations control procedures); Automation systems (for quality control, and effective resource utilization); and Crop nutrient delivery system (for control of plant root zone environment). Effective greenhouse engineering design, operations and management, must incorporate input from academic, private and public sectors of society. Therefore this team of researchers, educators, industry/ business, and experienced crop production operators has cooperated to include a current real-world applications perspective to the presentation. Greenhouse production systems are described that not only include the fundamentals for success, but also the combination of sub-systems, at appropriate technological levels to meet the design requirements and restrictions for success. The collaborators on this presentation have capabilities and experiences of successful greenhouse production systems from around the world that range from simple, low-input systems to highly complex production systems. Our goal is to emphasize the current basics of greenhouse design, and to support the symposium about greenhouse production systems for people.
• Giacomelli, G. A., Villarreal-Guerrero, . F., Kacira, ., , R., Linker, ., Giacomelli, ., & Kubota, C. (2012). Implementation of a Greenhouse Cooling Strategy with Natural Ventilation and Variable Fogging Rates. Transactions of ASABE.
• Giacomelli, G. A., Villarreal-Guerrero, F., Fitz-Rodriquez, E., Kacira, M., Kubota, C., Linker, R., & Arbel, A. (2012). Comparison of three evapotranspiration models for a greenhouse cooling strategy with natural ventilation and variable high pressure fogging. Scientia Horticulturae, 134, 210-221.
• Giacomelli, G. A., Villarreal-Guerrero, F., Kacira, E., , R., Linker, C., Kubota, G., & Giacomelli, A. (2012). Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling. Biosystems Engineering, 111, 217-228.
• Lobascio, C., Boscheri, G., Lamantea, M., Pascale, S. D., Giacomelli, G., Sadler, P., & Wheeler, R. (2012). Review and perspectives of plant cultivation facilities and technologies for space exploration. Proceedings of the International Astronautical Congress, IAC, 1, 565-572.
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  Abstract: Future habitation of space will necessitate engineering of complex systems capable of performing critical tasks for life support, including atmosphere revitalization, water purification and food production. Bio-regenerative Life Support Systems represent an integrated solution to these problems, with higher plants cultivation facilities as a key element capable of providing a variable percentage of the astronauts' diet. A Food Complement Unit is a potential solution for providing fresh crops and dietary supplements for the crew on the International Space Station (ISS) and future space exploration vehicles. Larger greenhouses are envisaged on planetary surfaces for longer missions, providing percentages of astronauts' diet up to 40 - 50%. Safe, sustainable and reliable operations of such systems in their relevant environment, mission and associated spacecraft is challenging and requiring an organized technological development approach. Critical subsystems necessitating further technological development include: Nutrient Delivery System - with root zone interactions, multi-phase flows, bio-contamination issues, and optimization of growth substrates Plant Illumination System - with associated high energy consumption, to be reduced via alternative light delivery strategies and technologies - Air Management - featuring trace contaminants removal, gas exchange with the crew quarters Exploitation of the ISS and of Earth analogues are opportunities to be pursued for such critical technologies demonstration, to provide a solid baseline for exploration architectural studies. This paper reports a brief summary of existing plant growth facilities, a review of the most critical plant production technologies and a roadmap for necessary further developments, focusing on the potential of ISS and of Earth analogues exploitation for their demonstration. ©(2012) by the International Astronautieal Federation.
• Patterson, R. L., Giacomelli, G. A., Kacira, M., Sadler, P. D., & Wheeler, R. M. (2012). Description, operation and production of the south pole food growth chamber. Acta Horticulturae, 952, 589-596.
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  Abstract: The South Pole Food Growth Chamber (SPFGC) is an automated hydroponic climate controlled chamber located inside the Amundsen-Scott South Pole station, which produces fresh vegetables and herbs, as well as a psychologically pleasurable environment for station personnel. The objective of this study was to document the SPFGC automated control practices, telepresence support, and resource utilization and crop production. Resource inputs included energy, water, plant nutrients, carbon dioxide, labor and the outputs included food, condensate water and oxygen. Data collected from January through October 2006 were used to evaluate the performance. Various plants (e.g. leafy greens, fruit crops, herbs and edible flowers) were grown within a hydroponic polyculture cropping system within the same controlled environment. Consumed resources included 1.1 kg d-1 of carbon dioxide, 0.21 kg d-1 of dry plant fertilizer salts, 1012 MJ d-1 (281 kWh d-1) of electrical energy, and production included 0.52 kg d-1 of oxygen and 2.8 kg d-1 of edible vegetables (fresh mass). The SPFGC system components and the control elements were described, and an energy balance analysis of the SPFGC was completed, and comparisons were made to various ALS food and oxygen production results.
• Villarreal-Guerrero, F., Kacira, M., Fitz-Rodríguez, E., Giacomelli, G. A., Linker, R., Kubota, C., & Arbel, A. (2012). Neural network predictive control in a naturally ventilated and fog cooled greenhouse. Acta Horticulturae, 952, 45-52.
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  Abstract: Passive ventilation in greenhouse production systems is predominant worldwide, limiting its usability and profitability to specific regions or for short production cycles. Evaporative fogging systems have increasingly been implemented in Arid and Semi-Arid regions to extend the production cycle during the warmest season, and also to achieve near-optimum environments for year-round production. However, appropriate control strategies for evaporative fogging systems are still lacking or limited despite its reported benefits in terms of environmental uniformity and potential savings in water and energy usage, when compared to fan and pad systems. The present research proposes a neural network predictive control approach for optimizing water and energy usage in a naturally ventilated and fog cooled greenhouse while providing a near-optimum and uniform environment for plant growth. As a first step the dynamic behavior of the greenhouse environment, defined by air temperature and relative humidity, was characterized by means of system identification using a recurrent dynamic network (NARMX). The multi-step ahead prediction capability of NARMX allows for the optimization of the control actions (vent configuration and fogging rate) for its implementation in the NN predictive control scheme. Greenhouse environmental data from a set of experiments consisting of several vent configurations (0/50, 0/100, 50/50, 50/100 and 100/100, percent opening of the side/roof vents) and three fogging rates (17.5, 22.3 and 27.0 g m-2 min-1) during several days throughout the year were used in the system identification process. The resulting NN model accurately predicted the dynamic behavior of the greenhouse environment, having coefficients of determination (R2) of 0.99 for each parameter (air temperature and relative humidity). These NN model will be incorporated into the NN predictive control scheme and its feasibility is in a naturally ventilated greenhouse equipped with a variable-rate fogging system is discussed, while achieving a greenhouse environment within defined permissible ranges of air temperature and relative humidity.
• Villarreal-Guerrero, F., Kacira, M., Fitz-Rodríguez, E., Giacomelli, G. A., Linker, R., Kubota, C., & Arbel, A. (2012). Simulation of fixed and variable fogging rates in a naturally ventilated greenhouse: Water and energy savings and stability of climate. Acta Horticulturae, 952, 37-44.
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  Abstract: Cooling must be supplied for greenhouses located in semiarid climates most of the year to provide desired climate conditions for year-round crop production. High-pressure fogging systems have shown promising results for cooling, however the lack of effective control strategies, especially under passive ventilation, have limited their use. In this study, a new proposed climate control strategy, which considers the contribution on cooling and humidification from plants, is tested through simulation. The developed strategy using variable pressure fogging (VPF) and variable vent configurations was compared to a constant pressure fogging (CPF), fixed vents cooling strategy. In both cases, the control of fog was based on vapor pressure deficit (VPD) set points. Results showed that on average, VPF based system was able to save 15.2% of water and consumed 10.1% less energy. Pump cycling was reduced by 78.5% and lower temperature and relative humidity fluctuations were achieved by adjusting fog rates through manipulating the system working pressure. Finally, simulations also showed that by reducing the number of nozzles, a smaller fogging rate was achieved and the system performance and savings on water and energy were enhanced during morning hours of operation.
• Villarreal-Guerrero, F., Kacira, M., Fitz-Rodríguez, E., Kubota, C., Giacomelli, G. A., Linker, R., & Arbel, A. (2012). Comparison of three evapotranspiration models for a greenhouse cooling strategy with natural ventilation and variable high pressure fogging. Scientia Horticulturae, 134, 210-221.
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  Abstract: Even though several models to predict evapotranspiration (ET) of greenhouse crops have been developed, previous studies have evaluated them under fixed greenhouse conditions. It is still not clear which model is more appropriate, accurate, and best suited for applications such as inclusion in greenhouse cooling strategies for different crops, climatic conditions and greenhouse cooling settings. This study evaluated three theoretical models (Stanghellini, Penman-Monteith and Takakura) to simulate the ET of two crops (bell pepper and tomato), under two greenhouse cooling settings (natural ventilation with fog cooling and mechanical ventilation with pad and fan), and for three growing seasons (spring, summer, fall). Predictions of ET from the models were compared to measured values obtained from sap flow gauges. Inputs of internal and external crop resistances for Stanghellini and Penman-Monteith models were calibrated separately by crop and by model. Even though Stanghellini model produced the smallest deviations of the predicted ET from the measured ET, having the best overall performance under all conditions evaluated, an analysis of variance of the daily mean square errors did not show significant differences (α= 0.05) between the three models. This suggested that any of the three models could be used for inclusion in a greenhouse cooling climate control strategy. However, parameter adjustments such as stomatal and aerodynamic resistances, and the need of leaf area index (LAI) in the models of Penman-Monteith and Stanghellini represent a limitation for this application. The Takakura model was found to be easier to implement; however as the crop grows, careful adjustments on the height of the solarimeter used for this approach are required. Such adjustments determine the field of view of the solarimeter and play a significant role on the determination of radiation balances and the average apparent temperature of the evaporative surface. © 2011.
• Villarreal-Guerrero, F., Kacira, M., Fitz-Rodríguez, E., Linker, R., Kubota, C., Giacomelli, G. A., & Arbel, A. (2012). Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling. Biosystems Engineering, 111(2), 217-228.
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  Abstract: In addition to ventilation, daily cooling must be provided for greenhouses located in semiarid climates to maintain the desired climate conditions for year-round crop production. High-pressure fogging systems have been successfully developed for greenhouse cooling. However the lack of control strategies, in combination with ventilation systems, especially passive ventilation, has limited their capabilities. A new cooling control strategy, which considered the contribution of humidification and cooling from the crop, was evaluated by computer simulations. The strategy controlled the amount of fog introduced into the greenhouse, as well as the percentage of vent openings to maintain desired values of greenhouse atmospheric vapour pressure deficit (VPD) and enthalpy, respectively, which would consequently affect air temperature. The performance was compared to constant fogging rate strategy, which was based on VPD. On average, the new strategy saved 36% water and consumed 30% less electric energy. Smaller air temperature and relative humidity fluctuations, and more consistent control, were achieved by varying the fog system operating pressure to provide a more optimum amount of fog for evaporative cooling. It was demonstrated by simulations that dynamically varying the fog rate and properly selecting the number of nozzles, savings of water and electric energy were increased, while still maintaining acceptable VPD and temperature. The improvements in the greenhouse climate achieved by the new strategy were due to its ability to dynamically manipulate fog rates, as well as, the vent configurations. © 2011.
• Giacomelli, G. A. (2011). HortiFair Special with focus on greenhouse water use efficiency. Groenten & Fruit Magazine.
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  Presented at Amsterdam, the Netherlands, 11/21/2011.
• Giacomelli, G. A. (2011). Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling.. Not applicable.
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  Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling. Villarreal-Guerrero, F., M. Kacira, e. Fitz-Rodriguez, R. Linker, C. Kubota, G. giacomelli, A. Arbel. 2011. Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling. Biosystems Engineering. Published.
• Sabeh, N. C., Giacomelli, G. A., & Kubota, C. (2011). Water use in a greenhouse in a semi-arid climate. Transactions of the ASABE, 54(3), 1069-1077.
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  Abstract: Greenhouse crop production in semi-arid climates is desirable because high solar radiation levels are consistent year round. The use of evaporative cooling will further increase yields and crop consistency. However, these regions typically receive less than 500 mm of rain annually, making water use management a critical concern. This study evaluated water use for irrigation (WU I) and pad-and-fan (WU PF) evaporative cooling systems in a single-span, polyethylene-covered greenhouse in Tucson, Arizona, from March to October 2006. A single-use, non-recirculating irrigation system delivered water to hydroponically grown tomatoes. The pad-and-fan system was computer controlled to maintain day/night air temperatures of 24°C/18°C. The total eight-month WU I and WU PF were 780 and 1450 L m -2, respectively. WU I increased steadily from 4.3 L m -2 d -1 during crop establishment to 7.2 L m -2 d -1 when the plants were mature. WU PF increased from 1.1 L m -2 d -1 during early spring to a peak of 11 L m -2 d -1 during the hottest, driest outside conditions. The water use efficiency (WUE, kg yield per m 3 water use) of the irrigation and pad-and-fan cooling systems was 30 and 16 kg m -3, respectively. When WUE was calculated by combining WU I and WU PF, the total greenhouse WUE was 11 kg m -3. Theoretically, using a 100% recirculating irrigation system could have produced a greenhouse WUE of 13 kg m -3. This study demonstrates that although greenhouses achieve high annual yields with low irrigation rates, using an evaporative cooling system reduces greenhouse WUE to field WUE levels. To minimize greenhouse water use while maintaining high crop yields, this study recommends further examination of the use of recirculating irrigation systems, variable-speed fans to improve climate control, alternative cooling systems, and drought-tolerant crops. © 2011 American Society of Agricultural and Biological Engineers.
• Fitz-Rodríguez, E., Kacira, M., Guerrero, F. V., Kubota, C., Giacomelli, G., Linker, R., & Arbel, A. (2010). Dynamic response and environmental uniformity of a naturally ventilated greenhouse cooled with a variable-pressure fogging system. American Society of Agricultural and Biological Engineers Annual International Meeting 2010, 6, 4727-4742.
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  Abstract: Greenhouse crop production systems have been established throughout the world, including arid and semi-arid regions, to fulfill a market demand of locally grown produce consistently through the year. In these particular regions while they have the advantage of sunshine year-round, production during the summer is a challenge due to elevated air temperatures. Fog systems have proven to be a good economical alternative for evaporative cooling while potentially providing a more uniform environment when compared to fan and pad systems. High-pressure fogging systems equipped with variable frequency drives can be operated at different pressures to meet the varying cooling demands during the day. This feature adds the flexibility of varying the fog flow rate by operating at lower pressures or by changing the number of working fog lines accordingly to the cooling demands. These systems may offer the potential advantage of energy and water saving by operating at a low frequency while providing the proper amount of fog accordingly to the cooling loads. A variable pressure fogging systems operating in the range of 4.8 to 10.3 MPa (700 to 1500 psi) was recently installed in a greenhouse at the University of Arizona Controlled Environment Agriculture Center (UA-CEAC) for the purpose of developing advanced control strategies for optimum greenhouse environments. This study experimentally evaluated the dynamics of air and canopy temperatures, crop evapotranspiration rates, and climate uniformity in the greenhouses working under various fogging system operational pressures and greenhouse side/roof vent opening configurations.
• Fitz-Rodríguez, E., Kubota, C., Giacomelli, G. A., Tignor, M. E., Wilson, S. B., & McMahon, M. (2010). Dynamic modeling and simulation of greenhouse environments under several scenarios: A web-based application. Computers and Electronics in Agriculture, 70(1), 105-116.
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  Abstract: Greenhouse crop production systems are located throughout the world within a wide range of climatic conditions. To achieve environmental conditions favorable for plant growth, greenhouses are designed with various components, structural shapes, and numerous types of glazing materials. They are operated differently according to each condition. To improve the pedagogy and the understanding of the complexity and dynamic behavior of greenhouse environments with different configurations, an interactive, dynamic greenhouse environment simulator was developed. The greenhouse environment model, based on energy and mass balance principles, was implemented in a web-based interactive application that allowed for the selection of the greenhouse design, weather conditions, and operational strategies. The greenhouse environment simulator was designed to be used as an educational tool for demonstrating the physics of greenhouse systems and environmental control principles. Several scenarios were simulated to demonstrate how a specific greenhouse design would respond environmentally for several climate conditions (four seasons of four geographical locations), and to demonstrate what systems would be required to achieve the desired environmental conditions. The greenhouse environment simulator produced realistic approximations of the dynamic behavior of greenhouse environments with different design configurations for 28-h simulation periods.
• Guerrero, F. V., Kacira, M., Fitz-Rodriguez, E., Linker, R., Arbel, A., Kubota, C., & Giacomelli, G. A. (2010). Developing a control strategy for greenhouses equipped with natural ventilation and variable pressure fogging: Evapotranspiration models and simulated comparison of fixed and variable pressure fog cooling. American Society of Agricultural and Biological Engineers Annual International Meeting 2010, 6, 4513-4527.
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  Abstract: Previous studies on high pressure fogging have shown their capability for maintaining temperature and humidity in acceptable ranges most of the year in greenhouses located in semiarid regions. The heat load, and therefore cooling demand, inside the greenhouse vary during the day and throughout the seasons. Thus, it may be advantageous to use a variable pressure fogging (VPF) system, where specific fog rates can be supplied based on the cooling demand. However, the absence of effective cooling strategies is one of the drawbacks limiting the extensive use of these systems. A well defined control strategy should account for plant's contribution on cooling and humidification in the control algorithm. This study compared the accuracy of three evapotranspiration models using measured values from greenhouse grown pepper plants. The results showed that Stanghellini model (R2=0.93) predicted measured evapotranspiration rates slightly better than Penman-Monteith (R2=0.84) and Takakura models (R2=0.79). Furthermore, a computer simulation was developed to compare a proposed control algorithm for VPF to a typical on/off fixed pressure fogging system based on vapor pressure deficit (VPD). Results showed that VPD based fixed pressure fogging strategy consumed more water and energy compared to the VPF system. Cycling of the pump was smaller and higher stability of temperature and relative humidity were achieved by the operation of the VPF system.
• Fitz-Rodríuez, E., & Giacomelli, G. A. (2009). Yield prediction and growth mode characterization of greenhouse tomatoes with neural networks and fuzzy logic. Transactions of the ASABE, 52(6), 2115-2128.
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  Abstract: Despite the technological advances implemented in greenhouse crop production, greenhouse operation relies on human expertise to decide on the optimum values of each environmental control parameter. Most importantly, the selected values are determined by human observation of the crop responses. Greenhouse tomatoes often show a pattern of cycling between reproductive and vegetative growth modes. The growth mode is a practical visual characterization of the source-sink relationships of the plants resulting from the greenhouse environment (aerial and root zone). Experienced reenhouse tomato growers assess the growth mode based on morphological observations, including quantitative (length, diameter, elongation rates) and qualitative (shape and color) features of the plant head, stems, flowers, trusses, and leaves. Data from greenhouse environments and crop records from an experimental production in Tucson, Arizona, and from a large-scale commercial operation in Marfa, Texas, were used for modeling the growth mode of tomato plants with fuzzy logic. Data from the commercial operation were used to model weekly fluctuations of harvest rate, fruit size, and fruit developing time with dynamic neural networks (NN). The NN models accurately predicted weekly and seasonal fluctuations of the fruit-related parameters, having coefficients of determination(R 2) of 0.92, 0.76, and 0.88, respectively, for harvest rate, fruit fresh weight, and fruit developing time, when compared with a dataset used for independent validation. The fuzzy modeling of growth mode allowed discrimination of the reproductive and balanced growth modes in the experimental system, and modeling of the seasonal growth mode variation in the commercial application. Both modeling results might be applicable to commercial operations for making decisions on greenhouse climate control and overall crop management practices. Copyright © 2009 American Society of Agricultural and Biological Engineers ISSN 2151-0032.
• Giacomelli, G. A. (2009). Engineering principles impacting high-tunnel environments. HortTechnology, 19(1), 30-33.
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  Abstract: High tunnels are a special type of greenhouse with primary operational goals of season extension, crop quality improvement, and new crop production opportunities to reach unique markets. From an engineering viewpoint, high tunnels have many of the same design concerns as larger, more complex greenhouses. They capitalize on the greenhouse effect as do all enclosed plant growth structures. However, less automated environmental control systems are required for the desired crop production. Tunnel designs are less complex and less expensive than large high-technology greenhouse ranges, but they must be designed and constructed with the fundamental assurance of structural stability, safety, efficient layout, appropriate environmental control, and effective crop management in mind.
• Takakura, T., Kubota, C., Sase, S., Hayashi, M., Ishii, M., Takayama, K., Nishina, H., Kurata, K., & Giacomelli, G. A. (2009). Measurement of evapotranspiration rate in a single-span greenhouse using the energy-balance equation. Biosystems Engineering, 102(3), 298-304.
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  Abstract: The energy-balance equation was used to estimate evapotranspiration in a greenhouse, and an instrument was developed to collect data for this purpose. The values estimated by this method were in good agreement with the measured data. It was shown that the net solar radiation term was the largest and cannot be neglected, and that long-wave radiation exchange had a relatively small effect. As usual, soil heat flux can be neglected but the sensible heat transfer term cannot be neglected since the maximum of the possible range of values is large and significant. It was concluded that the method used was simple and suitable for irrigation control in greenhouses. It was also concluded that normal radiation sensor measurements on a horizontal surface are not adequate for measuring radiation received by a plant canopy in a single-span greenhouse. © 2009 IAgrE.
• Giacomelli, G. A. (2008). Procedding of International Workshop on Greenhouse Ebviromental Control and Crop Production in Semi-Arid Regions: Foreword. Acta Horticulturae, 797, 5-.
• Giacomelli, G., Castilla, N., Henten, E. V., Mears, D., & Sase, S. (2008). Innovation in greenhouse engineering. Acta Horticulturae, 801 PART 1, 75-88.
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  Abstract: Innovations in greenhouse engineering are technical developments which help evolve the state-of-the-art in CEA (Controlled Environment Agriculture). They occur in response to the operational demands on the system, and to strategic changes in expectations of the production system. Influential operational factors include availability of labor, cost for energy, logistics of transport, etc. Influential strategic factors result from broader, regional issues such as environmental impact, product safety and consistency, and consumer demand. These are industry-wide concerns that have the effect of changing the production system in the long term. Global issues are becoming more influential on greenhouse production sustainability, and include less tangible issues such as social acceptance, political stability, quality of life benefits, and environmental stewardship. These offer much more complex challenges and are generally beyond the realm of engineering. However global issues do affect greenhouse engineering innovation. The most effective innovations in greenhouse engineering design, operations and management, will incorporate input from partnerships with the academic, private and public sectors of society. Furthermore, successful applications include, at least to some degree a multi-disciplinary approach of the sciences, engineering and economics, while for ultimate success and sustainability, societal and political support must also be attained. For this overview of innovation in greenhouse engineering a list of influential factors, or "driving forces" affecting the development, application, evolution and acceptance of greenhouse systems have been described. The factors are similar for all greenhouse systems around the world, as they include the plant biology of the crop, the physical components of the structure and production system hardware, the management and logistics of labor and materials, and the mechanism of marketing the crop. Each greenhouse system, wherever located, must resolve similar problems for its specific application. The magnitude of the factors and their relative local importance are different for the specific sites. The design response will be introduced and related to the factors, as examples of innovation.
• Kacira, M., Sase, S., Ikeguchi, A., Ishii, M., Giacomelli, G., & Sabeh, N. (2008). Effect of vent configuration and wind speed on three-dimensional temperature distributions in a naturally ventilated multi-span greenhouse by wind tunnel experiments. Acta Horticulturae, 801 PART 1, 393-400.
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  Abstract: This study was conducted to determine the effects of vent configuration and external wind speed on three-dimensional distribution of air temperature in a naturally ventilated multi-span greenhouse using wind tunnel experiments. The experiments were conducted with the scale models in a wind tunnel with four different vent configurations and at four external wind speeds ranging from 0 to 3 m/s at full scale, with 1 m/s increments. Three dimensional temperature distributions were analyzed and the airflow patterns were observed based on temperature distributions. The highest air temperatures were found to be in spans close to the leeward side vent when the side vents were closed at zero wind speeds in the case when the roof vents were fully open and side vents were closed. The air temperature, measured by thermocouples, was higher on the windward side of the greenhouse than on the leeward side for all wind speeds when only roof vents were used. The distribution of air temperature was more uniform when both side and roof vents were used. As the wind speed increased, the average internal air temperature decreased for all cases. Contribution of side vents for greenhouse ventilation and reduction of air temperature were significant for the particular greenhouse design used in this study.
• Kim, K., Yoon, J., Kwon, H., Han, J., Son, J. E., Nam, S., Giacomelli, G. A., & Lee, I. (2008). 3-D CFD analysis of relative humidity distribution in greenhouse with a fog cooling system and refrigerative dehumidifiers. Biosystems Engineering, 100(2), 245-255.
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  Abstract: The distribution of humidity in a greenhouse was studied using three-dimensional (3-D) computational fluid dynamics (CFD). The calculations were validated using experimental data from a single-span greenhouse without plants. Two types of humidity distribution were considered: humidifying using a fog cooling system, and dehumidifying using refrigerative dehumidifiers in addition to a fog cooling system. The simulation errors of RH were 0.1-18.4% with a fog cooling system and 1.1-13.1% with a fog cooling system and refrigerative dehumidifiers at each observation point. Contour maps were obtained from the 3-D CFD simulations to locate any non-uniformity in humidity distribution. The use of refrigerative dehumidifiers reduced the overall difference of humidity between the middle and bottom zones of a greenhouse, but the local distribution of humidity was uneven, especially close to the dehumidifiers. This study suggests that the developed 3-D CFD model can be a useful tool in designing and evaluating greenhouses with various configurations. © 2008 IAgrE.
• Patterson, R. L., Giacomelli, G. A., & Sadler, P. D. (2008). Resource and production model for the south pole food growth chamber. SAE Technical Papers.
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  Abstract: NASA scientists have previously researched biomass production units for the purpose of bioregenerative life support systems (BLSS). The University of Arizona, Controlled Environment Agriculture Center (UA-CEAC) in cooperation with Sadler Machine Company (SMC) designed, constructed and assisted real-time operations of the South Pole Food Growth Chamber (SPFGC). The SPFGC is a semi-automated, hydroponic, multiple salad crop production chamber located within the U.S. National Science Foundation New Amundsen-Scott South Pole Station. Fresh vegetables are grown for the Station crew during the annual eight-month period of isolation in one of the most extreme and remote environments on Earth. An empirical mathematical model was developed from data monitored onsite and remotely by Internet and telecommunications during the winter of 2006. The SPFGC model was based on a mass balance, whereby all carbon dioxide and water were monitored within the system and biomass generated by the crops was recorded. Edible production yields within the 21.90 m2 SPFGC Plant Production Room averaged 2.8 kg day-1 (± 1.0 kg day-1) with 12 kW of installed high intensity discharge lighting and a 17-hour photoperiod. Other operational resources were monitored including labor, energy, and plant nutrients. The data generated from the remote and isolated location of the SPFGC includes information for future BLSS applications. Copyright © 2008 SAE International.
• Giacomelli, G. A., Patterson, R. L., & Sadler, P. D. (2007). Telepresence technologies and practices for enabling remote semi-autonomous CEA food production. Acta Horticulturae, 761, 21-31.
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  Abstract: CEA (Controlled Environment Agriculture) is an advance technology for the production of biological materials, such as, food, flowers, and plant byproducts for commercial application. To establish successful operations, education, training, and experience for the system operators are required. In fact, assuming good system design, it is experience which may be the most important factor in the success of a CEA operation. Decision support from off-site consultants or other support groups can be beneficial to help the operation, but to provide an effective response, they require environmental information and plant status, as well as easy access to sufficient data about the current and recent history of operations of the mechanical systems and the biological components. Telepresence procedures, which can be defined as practices which provide a representative environment for humans who then control devices and hardware within distant, hostile, or unique environments, can improve remote decision support of CEA facilities. The CEAC (Controlled Environment Agriculture Center) at the University of Arizona in Tucson not only includes CEA classes for the on-campus education of undergraduate and graduate students, as well as postgraduate growers and industry professionals, but also technologies for telepresence activities. To leverage educational reach, to complement research goals, and to utilize collective expertise which is not always onsite or available, a number of non-traditional decision-support activities have been established. Telepresence practices can substantially sustain or improve distant production systems through environmental monitoring, controlling, decision-support of operations, crop diagnostics, system diagnostics, and distance education, by using web cameras, climate control computers, and email. These procedures provide the information that grower operators often omit or overlook, and provide experiences and information for improvements of distance-education and support practices. Furthermore, these practices have provided effective support despite the inter-personal challenges of remote operations where operator (on site) and advisors (located elsewhere in the world) may have never met, nor have previously developed a level of mutual confidence and trust.
• Kurata, K., Matsuda, R., Kubota, C., Ikeguchi, A., Sabeh, N., Giacomelli, G. A., Sase, S., Ishii, M., & Yokoi, S. (2007). Light quality in and between tomato plant rows in a greenhouse. Acta Horticulturae, 761, 227-234.
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  Abstract: Recently in some large scale greenhouses, young tomato seedlings have been planted between mature crop rows to enable year-round production. Young seedlings receive light intercepted and transmitted/reflected by leaves of mature crops. Light quality (spectrum) changes by these procedures and affects the seedling growth. In particular, red/far red ratio is of main concern, because this ratio affects the stem extension rate via the change in the phytochrome photostationary state (Pfr/Ptotal)-However, there have been no reports on the light quality in and between tomato crop rows. Measurements of light quality in and between mature tomato crop rows were conducted in a semi-arid greenhouse in Tucson, Arizona on a clear day and profiles of R/FR ratio and Pfr/Ptotal were calculated. When the direct solar radiation penetrated into the canopy in parallel to the row, photon flux density (PFD) in FR at the height of 2.20 m in the passage between the rows was larger than that at the canopy height (3.10 m). Gradual decrease of R/FR with the depth into the canopy was observed in the passage, but in the rows, R/FR took the minimum value at the middle of the height. In the passage, Pfr/Ptotal was almost constant with regard to the height when the direct solar radiation ran parallel to the row, but at other periods slightly decreased with the depth into the canopy from 0.7 at the canopy height to 0.6 at the ground. In the rows, Pfr/Ptotal took the minimum at the middle of the height.
• Sabeh, N. C., Giacomelli, G. A., & Kubota, C. (2007). Water use by greenhouse evaporative cooling systems in a semi-arid climate. 2007 ASABE Annual International Meeting, Technical Papers, 8 BOOK.
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  Abstract: Water availability is a common concern in semi-arid regions, such as Southern Arizona, USA, where greenhouse crop production is popular due to high solar radiation. Hydroponic greenhouse crop production greatly reduces irrigation water use; however, water use by evaporative cooling systems has never been quantified. This project investigated water use by two evaporative cooling systems: pad-and-fan (P&F) and high-pressure-fog (HPF) with fan ventilation and a central overhead line. Water use data were collected from a double-layer polyethylene film-covered greenhouse (28 × 9.8 × 6.3 m) with mature tomato plants (1.7 plants m -2) from 08:00-17:00 for each ventilation rate tested under semi-arid climate conditions (T Out,Avg=35°C, RH Out,Avg=10%, Solar Avg=900 W m -2). Total daily water use by P&F was 3.2, 6.4, 8.5, and 10.3 L m -2 for ventilation rates of 0.016, 0.034, 0.047, 0.061 m 3 m -2 s -1 respectively. Total daily water use by the HPF system was 7.9, 7.4, and 9.3 L m -2 for fan ventilation rates of 0.01, 0.016, 0.034 m 3 m -2 s -1, respectively. Total greenhouse WUE (water use efficiency) was calculated using hydroponie irrigation (4.5 L m -2) and evaporative cooling water use. Total WUE values were comparable to sprinkler-irrigated WUE (15-19 L m -2) and flood-irrigated WUE (
• Sase, S., Ishii, M., Moriyama, H., Kurata, K., Kubota, C., Hayashi, M., Sabeh, N., Romero, P., & Giacomelli, G. A. (2007). Transpiration of tomato plant canopy and water use for a fog cooled greenhouse in semiarid climate. Acta Horticulturae, 761, 63-69.
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  Abstract: The ultimate goal of this collaborative project is to develop an effective environmental control strategy to cool the greenhouses for plant production and minimize the water use in semiarid climate. Using a single-span double-polyethylene greenhouse with tomato plant canopy at The University of Arizona, the canopy transpiration rate and the water balance of greenhouse were investigated. The greenhouse was equipped with high-pressure fog nozzles, roll-up side vents with insect screens, and a roof vent. Fogging was operated cyclically with an air temperature set point of 24°C. Under different vent configurations, the transpiration rate was measured using a stem gage. The amounts of generated fog and non-evaporated water droplets were collected and measured. The natural ventilation rate was measured continuously using SF 6 gas as a tracer. Preliminary results showed that the transpiration rate increased linearly with an increase in vapor pressure deficit (VPD) of the air. When the ventilation rate was decreased by reducing the vent openings, the total water use in the greenhouse decreased by 13% and relative humidity increased as expected from simulation based on the steady-state energy balance. The decrease in canopy transpiration was driven by the decrease in VPD, and was at a greater magnitude than that of fog evaporation rate under the present experimental conditions with relatively high humidity ranging 70-94%. These results suggest that by optimizing natural ventilation rate, we could effectively cool the greenhouse with less water use.
• Takakura, T., Kubota, C., Sase, S., Hayashi, M., Ishii, M., Takayama, K., Nishina, H., Kurata, K., & Giacomelli, G. A. (2007). Evapotranspiration rate measurement by energy-balance equation in a single-span greenhouse. 2007 ASABE Annual International Meeting, Technical Papers, 8 BOOK.
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  Abstract: An energy balance equation was used to estimate evapotranspiration in a greenhouse, and an instrument for this purpose was developed. It was found that the present method is simpler than that using the Penman-Monteith equation and the estimated values by this method were in good agreement with measured data. It is also reported that normal radiation sensor measurements on a horizontal surface are not adequate for measuring radiation received by a plant canopy in a greenhouse.
• Tignor, M. E., Wilson, S. B., Giacomelli, G. A., Kubota, C., Fitz-Rodriguez, E., Irani, T. A., Rhoades, E. B., & McMahon, M. J. (2007). Multi-institutional cooperation to develop digital media for interactive greenhouse education. HortTechnology, 17(3), 397-399.
• Giacomelli, G. A., Patterson, L., Nelkin, J., Sadler, P. D., & Kania, S. (2006). CEA in Antarctica. Resource: Engineering and Technology for Sustainable World, 13(1), 3-5.
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  Abstract: The Controlled Environment Agriculture (CEA) technologies are helping in producing vegetables in the icy areas of Antarctica. The CEA-based hydroponic crop production processes used the abundant frozen fresh water, as an alternative food growth chamber to produce vegetables. University of Arizona and Sadler Machine Company, under the Controlled Environment Agriculture Program (UA-CEAC) designed and built the new South Pole Food Growth Chamber (SPFGC) under the direction of the National Science Foundation, which manages the US Antarctic Program. Antarctica provides an unique application for CEA technologies, which can grow plants anywhere, any time, with planning and resources.
• Ishii, M., Sase, S., Moriyama, H., Kurata, K., Ikeguchi, A., Kubota, C., Hayashi, M., Sabeh, N., Romero, P., & Giacomelli, G. A. (2006). The effect of evaporative fog cooling in a naturally ventilated greenhouse on air and leaf temperature, relative humidity and water use in a semiarid climate. Acta Horticulturae, 719, 491-498.
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  Abstract: Under two combinations of roof and side vent openings of a semiarid greenhouse located in Tucson, Arizona, U.S.A, air and leaf temperatures, relative humidity, ventilation rate and water use (fog injection and plant water uptake) were measured. The natural ventilation rate was continuously measured by using SF6 as the tracer gas. Plant water uptake rate was measured using a sap flow gage. When the roof and side vents open, the inside temperature and ventilation rate were larger than when only the roof vent open. The inside air temperature increased with increasing ventilation rate. Converse responses were found for inside relative humidity and leaf temperature. Therefore, it follows that the vertical distribution of inside air temperature and relative humidity were increased with increasing ventilation rate. Water use in the greenhouse was reduced with decreasing ventilation rate and increasing internal relative humidity. Future work will be to develop the fog and vent control method to make air temperature and relative humidity uniform in the greenhouse and to reduce water use.
• Romero, P., Giacomelli, G. A., Choi, C. Y., & Lopez-Cruz, I. (2006). Ventilation rates for a naturally-ventilated greenhouse in Central Mexico. Acta Horticulturae, 719, 65-72.
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  Abstract: The design and operation of greenhouse structures suitable for specific climate conditions is critical, especially when greenhouse cooling is expected to depend entirely on natural ventilation. The ultimate goal of this study was to investigate the potential enhancement of overall ventilation rates by optimizing greenhouse design parameters such as the area of inlet and outlet vents as well as the type of the insect screen utilized and its area. The Computational Fluid Dynamics (CFD) approach was used, verified by experimental data. Numerical simulations showed that the area of the ventilation openings has a significant effect on the air exchange rate, which increased about 25% when the vent area was enlarged from 6 to 15% of the greenhouse ground area. Another potential design change, the removal of the insect screen from the roof vents, increased the ventilation rates by 25% as compared to the current design. Enlarging the area of the insect screen on the side walls showed no significant improvement in ventilation.
• Sabeh, N. C., Giacomelli, G. A., & Kubota, C. (2006). Water use for pad and fan evaporative cooling of a greenhouse in a semi-arid climate. Acta Horticulturae, 719, 409-416.
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  Abstract: Water availability is a common concern in semi-arid regions, such as Southern Arizona, USA, where more greenhouses are operating due to high solar radiation. Hydroponic greenhouse crop production greatly reduces irrigation water use; however, there is currently no information demonstrating water use of an evaporative cooling system. This project investigated water use by a pad and fan (P&F) cooling system under semi-arid climate conditions. Data were collected for two physically identical, side-by-side, double-layer polyethylene film-covered arched-roof greenhouses (28 m x 9.8 m x 6.3 m) during summer conditions (38.5°C, 15% RH, 845 W m-2). One greenhouse had mature tomato plants (2.3 plants m-2) and the other had no plants. Water use was primarily affected by air exchange rate. The average water use by the P&F system was 0.145, 0.182, 0.265, 0.325, and 0.387 g m-2 s -1 for greenhouse air exchange rates of 0.017, 0.037, 0.051, 0.067, and 0.079 m3 m-2 s-1, respectively. In the empty greenhouse, the lowest ventilation rate produced the highest average greenhouse air temperature (Tin=33.8°C) and lowest RH (40%). Tin and RH were nearly equal for the three highest air exchange rates. In the greenhouse with plants, the lowest ventilation rate produced the highest Tin (31.1°C) but also the highest RH (69.4%). In general, RH decreased with increasing air exchange rate and the minimum Tin of 27.6°C (RH: 52%) was achieved at the middle air exchange rate (0.051 m3 m-2 s-1). It is believed that the lower cooling efficiency of the P&F system at higher ventilation rates caused a reduction in cooling. However, the lower ventilation rates limited air exchange and effectively reduced cooling. If a higher pad cooling efficiency could be maintained at high ventilation rates, a cooler air temperature and higher relative humidity may be achieved, though water use would increase. Finally, when the air exchange rate was controlled to maintain the GH at 24°C/18°C during day and night, water use by the P&F cooling system (14.8 L m-2 day-1) was greater than the tomato irrigation system (8.9 L m-2 day-1) assuming 100% drainage recovery, which is typical for many high-technology greenhouse facilities.
• Sase, S., Ishii, M., Moriyama, H., Kurata, K., Sabeh, N., Romero, P., Giacomelli, G. A., Kubota, C., & Hayashi, M. (2006). Effect of natural ventilation rate on relative humidity and water use for fog cooling in a semiarid greenhouse. Acta Horticulturae, 719, 385-392.
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  Abstract: Using a single-span double-polyethylene greenhouse without plants, the effect of natural ventilation rate on humidity and water use for fog cooling was investigated. A simple and unique control algorithm for fog cooling was proposed and tested. The greenhouse was equipped with high-pressure fog nozzles, roll-up side vents with insect screens and a roof vent. Fogging was operated cyclically with an air temperature set point of 24.5°C. Under several configurations of vent openings, the greenhouse environmental conditions and the outside weather conditions were monitored. The natural ventilation rate was measured continuously by the tracer gas method. The fog generated was collected and measured at 15-min intervals. Results showed that the inside relative humidity decreased with an increase in ventilation rate as expected from simulations based on the steady-state energy balance equations using a software Visual VETH, while the water used for fog cooling increased. For example, the humidity decreased from approximately 80 to 65% on a clear day when the ventilation rate was increased from 1 to 3.5 m3 m-2 min-1, while the water use increased from 18 to 21 g m-2 min-1. There was good agreement between the measured 45-min averages of ventilation rate and the predicted ventilation rates by Visual VETH. The control algorithm which incorporated the adjustment of vent openings demonstrated the possibility of maintaining relative humidity and air temperature simultaneously within a desirable range (65-75% and 24-25°C, respectively) while reducing the water used for fog cooling.
• Son, J. E., Oh, M. M., Lu, Y. J., Kim, K. S., & Giacomelli, G. A. (2006). Nutrient-flow wick culture system for potted plant production: System characteristics and plant growth. Scientia Horticulturae, 107(4), 392-398.
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  Abstract: To compliment the current subirrigation systems used for production of potted plants, a nutrient-flow wick culture (NFW) system was developed and compared with other subirrigation systems, such as an ebb and flow culture (EBB) system and a nutrient-stagnant wick culture (NSW) system in relation to their system characteristics and plant growth. Kalanchoe (Kalanchoe blossfeldiana cv. New Alter) was cultivated in a 6 cm pot for 10 weeks in each subirrigation system. The water-absorption pattern of the medium, water content of the medium, water loss, algal growth, salt-buildup and plant growth under various culture systems were observed. The water contents of medium under the NFW and EBB systems showed fluctuations from 30 to 40% and from 50 to 60% (by volume), respectively, whereas the water content under the NSW system gradually increased to over 40% without fluctuation. Relative to other systems, the water loss in the NFW system was 50-70% due to the reduction in the evaporation from the surfaces of the trough and medium. Algae appeared in the NSW system because the nutrient solution was always stagnant in the trough, while it was not observed under the NFW system. The dissolved oxygen in the nutrient solution was the highest during the irrigation period and the salinity in the medium was the lowest in the NFW system. With regard to system characteristics, the NFW system was simple, water-saving and efficient. In addition, the growth of kalanchoes in the NFW system was similar to those in the NSW and EBB systems at an irrigation frequency of five times a day. © 2005 Elsevier B.V. All rights reserved.
• Tignor, M. E., Giacomelli, G. A., Kubota, C., Fitz, E., Wilson, S. B., Irani, T. A., Rhoades, E., & McMahon, M. J. (2006). Development of a web-based multi-media resource for environmental control modeling and greenhouse education. Acta Horticulturae, 719, 303-310.
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  Abstract: A publicly accessible multimedia instrument for greenhouse education was developed for global use. The instrument consists of (1) greenhouse videos produced on site in Arizona. Vermont. Ohio and Florida that emphasize state-specific production, environmental control, labor, and marketing issues; (2) an interactive Flash-based greenhouse environment simulator that allows users to model greenhouse environments based on climate data from each of the four video locations; (3) a searchable digital repository containing hundreds of useful greenhouse images, videos, and lectures, and (4) a web-based method for instructors to evaluate perceived student learning of greenhouse concepts. The Interactive Greenhouse Environment Simulator is driven bv a mathematical model developed bv engineers which is linked to a Flash-based graphical user interface (GUI). Following user selection of climate, structure and environmental control choices, dynamic environmental information is shown graphically during the simulation, allowing users to model changes in the greenhouse environment.
• Giacomelli, G. A., Kubota, C., & Jensen, M. (2005). Design considerations and operational management of greenhouse for tomato production in semi-arid region. Acta Horticulturae, 691, 525-532.
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  Abstract: An overview of the design considerations and the operational characteristics for production of tomato in a greenhouse in a semi-arid region is provided. The integration of the automation, culture and environment requires an understanding of the production needs of the crop, and the specialized weather conditions of the Arizona climate. The demand on the plant imposed by the greenhouse climate, including air temperature and humidity, or atmospheric vapor pressure deficit (VPD), leaf temperature, and solar radiation must be balanced with the water availability within the plant root zone, as affected by the electrical conductivity of the nutrient solution and the irrigation frequency. The crop production system requires that nutrient delivery be automated to provide a consistent availability of nutrient formulation and concentration in proportion to the general daily fluctuating water demand. An automatic means to determine water demand that will vary the irrigation frequency and the nutrient concentration is important to provide the desired stress for crop production. The climate control includes monitoring and feedback mechanisms to firstly, minimize the potentially harsh diurnal fluctuating desert conditions of low air humidity, high solar radiation, and water quality with high salts, and then, to secondly, alter the plant microclimate to match the stage of plant growth and its production condition. The greenhouse structure should be of sufficient height for buffer volume needed to offset the large daily environmental fluctuations. The structure system must also offer air exchange capacity, shading, and evaporative cooling to help maintain the desired air temperature and relative humidity for crop production. Experiences and research studies within each of these areas of production system, climate control and greenhouse structure will be presented, including: production of greenhouse tomatoes within a high-wire, continuous production system; modulating plant vegetative or reproductive tendency with a combination of root zone and aerial microclimates; improving fruit market quality; and greenhouse structure design variations for improved cooling and reduced water utilization.
• Costa, P., Giacomelli, G. A., Kubota, C., & Jensen, M. (2004). Preliminary study on the effects of environmental conditions and salinity on tomato plants (Lycopersicon esculentum L.) growth status in semi-arid regions. Acta Horticulturae, 659, 557-564.
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  Abstract: Balancing plant growth between vegetative and reproductive status is crucial for producing high quality greenhouse tomatoes while maintaining high productivity. The ability to change plant growth characteristics often associated with vegetative or reproductive growth status was demonstrated. Two greenhouse canopy environments were selected for inducing reproductive growth [high vapor pressure deficit (VPD) (2 kPa) and 27°C / 18°C day-night air temperature], and vegetative growth [low VPD (0.8 kPa) and 24°C / 22°C day-night air temperature]. Plant responses from the treatment environments were contrasted with those from a standard commercial greenhouse environment (24°C / 19°C). All environmental treatments were associated with two electrical conductivities (EC) of the nutrient solution: 2.5 dS m-1 (EC 2.5) and 8 dS m-1 (EC 8). Plants were grown under one of two treatment environmental conditions, until significant differences in plant growth characteristics were observed. Out of the five plant growth characteristics monitored, stem diameters were the most responsive to canopy environment and EC treatments. The major factor in changing plant growth responses was EC, for the range of VPD and day-night air temperature differences achieved in the present study, while canopy environment affected the magnitude of the change. Mean stem diameters (SD) were significantly higher under EC 2.5, than for plants growing under EC 8. IN5 cm and SD 15 cm are the plant growth responses most affected by EC treatments and canopy environment. Single leaf gas exchange measurements had significantly reduced transpiration rate at EC 8 under all canopy environments, while net photosynthetic rate was not affected. This suggests that decreased plant growth responses observed under high salinity treatments resulted from reduced water and nutrient uptake due to suppressed transpiration rate.
• Giacomelli, G. A. (2004). Engineering design of plant nutrient delivery systems. Acta Horticulturae, 648, 71-81.
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  Abstract: Greenhouse plant production systems include the nutrient delivery system, and the plant culture management technique, that are enclosed within a controlled environment. Fundamental engineering design will be inherent in all successful applications. The nutrient delivery system [NDS] consists of those hardware components that transport nutrient solution [water plus fertilizer] from a central location to each individual plant. The plant culture technique includes the procedures that are completed by the grower in order to produce a healthy crop of desired quality. These procedures or culture tasks are crop specific, but they are directly related to the type of NDS. The controlled environment includes the greenhouse, or other structure, and its environmental control systems that are implemented to obtain the desired climate in order to produce a quality crop within a predictable and repeatable time schedule. The paper will focus on the engineering applications of the nutrient delivery systems. The NDS will be described in terms of its mechanism for plant water delivery. Examples of traditional and unique applications of nutrient delivery systems will be discussed.
• Hayden, A. L., Brigham, L. A., & Giacomelli, G. A. (2004). Aeroponic cultivation of ginger (Zingiber officinale) rhizomes. Acta Horticulturae, 659, 397-402.
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  Abstract: Ginger (Zingiber officinale Rosc.) rhizomes are popular as a spice and an herbal dietary supplement. The anti-inflammatory and anti-nausea qualities of ginger have applications in the pharmaceutical industry. Conventionally grown as a tropical field crop, ginger is plagued by soil-borne disease and nematode problems. Aeroponic cultivation of ginger can provide high-quality rhizomes that are free from pesticides and nematodes and can be produced in mild-winter greenhouses. An experiment involving 34 ginger plants grown in aeroponics was performed in a temperature controlled greenhouse in Tucson, Arizona. The unique aeroponic growing units incorporated a "rhizome compartment" separated and elevated above an aeroponic spray chamber. Bottom heat was supplied to one half of the plants. Accelerated growth was observed in plants receiving bottom heat. One third of the plants were grown in units where the rhizome compartment was filled with perlite, one third in sphagnum moss, and one third without any aggregate medium. Those plants grown in perlite matured faster than the other treatments. The aeroponic units without aggregate medium provided an opportunity to photograph the growth habit of rhizomes over a three month period. Those images were incorporated into a 60-second digital movie that dramatically illustrates how underground rhizomes develop and grow.
• Hayden, A. L., Giacomelli, G. A., Hoffmann, J. J., & Yokelson, T. N. (2004). Aeroponics: An alternative production system for high-value root crops. Acta Horticulturae, 629, 207-213.
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  Abstract: An aeroponic system was developed for the production of root crops used in the herbal and phytopharmaceutical industries. The variability in the phytochemical quality of botanical products precludes the ability to administer uniform dosing in clinical studies. Aeroponic systems allow the producer to precisely control root zone nutrient and water regimes and environmental conditions, as well as have complete access to the roots throughout the life of the crop. This control promises a more uniform harvest. An A-frame aeroponic system was designed to maximize root yields and permit free access to the roots for monitoring. Burdock (Arctium lappa L.) plants were grown in aeroponics with controls grown in a greenhouse soilless potting mix for ten weeks in a research greenhouse in Tucson, Arizona. The plants were harvested and the dry weights of aerial parts and roots were determined, as well as the chloro-genic acid concentration in the dried roots. Chlorogenic acid is a caffeoylquinic acid derivative known to have antioxidant activity. The biomass yields of the aerial parts were significantly higher in the aeroponically grown plants compared to the controls. The root biomass yields showed no significant difference between treatments. The chlorogenic acid concentrations were also not significantly different, however the plant-to-plant variability was significantly lower in the aeroponically grown plants, suggesting the potential for more consistent phytochemical yields using this production technique.
• Pagliarulo, C. L., Hayden, A. L., & Giacomelli, G. A. (2004). Potential for greenhouse aeroponic cultivation of urtica dioica. Acta Horticulturae, 659, 61-66.
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  Abstract: Resent studies investigating aeroponic cultivation of medicinal plants have provided encouraging results for increasing yields, shortening time to maturity, and improving consistency and overall quality of produce over field production. The goal of the current study was to determine the applicability of aeroponic technology for the cultivation of the traditionally field grown herbaceous medicinal plant Urtica dioica. In addition, we investigated if control of nutrient delivery and repeated harvesting practices could be utilized to increase and direct yield of desired plant parts. Comparison of root and shoot dry weights between treatments revealed; (1) U. dioica cultivated in soil-less medium yielded equal shoot biomass and greater root biomass than aeroponically cultivated plants, (2) potassium and phosphorus ratios within the nutrient solution had no significant impact on yield or biomass allocation, and (3) multiple harvesting of aeroponic roots and shoots yielded greater total biomass of both roots and shoots than a multi-crop replanting strategy. Results suggest aeroponic technology could be a powerful tool for the cultivation U. dioica as well as a variety of other important herbaceous medicinal plants. However, further optimization of the plant growing environment is required to maximize and direct growth.
• Suárez-Romero, A., Giacomelli, G., Kubota, C., & Jensen, M. (2004). Control strategy and sensors for the climate conditioning in a retractable roof greenhouse in semi-arid regions. Acta Horticulturae, 659, 97-104.
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  Abstract: The different possible positions for the roof and sidewalls of retractable roof greenhouses allow them to behave either as greenhouses, shadehouses or wind barriers. Radiation and wind control must be part of the control strategy along air temperature which proves to be a poor method of control as it is the case currently. Globe temperature is proposed as a viable controller for retractable roof greenhouses in arid regions, for its ability to integrate in one simple data point temperature, radiation, and wind speed. With the use of two globe thermometers it is possible to merge the data between outdoors and indoors to create an improved environment for vegetable cultivation while maximizing light exposure for the plants.
• Fleisher, D. H., Cavazzoni, J., Giacomelli, G. A., & Ting, K. C. (2003). Adaptation of SUBSTOR for controlled-environment potato production with elevated carbon dioxide. Transactions of the American Society of Agricultural Engineers, 46(2), 531-538.
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  PMID: 14552353;Abstract: The SUBSTOR crop growth model was adapted for controlled-environment hydroponic production of potato (Solanum tuberosum L. cv. Norland) under elevated atmospheric carbon dioxide concentration. Adaptations included adjustment of input files to account for cultural differences between the field and controlled environments, calibration of genetic coefficients, and adjustment of crop parameters including radiation use efficiency. Source code modifications were also performed to account for the absorption of light reflected from the surface below the crop canopy, an increased leaf senescence rate, a carbon (mass) balance to the model, and to modify the response of crop growth rate to elevated atmospheric carbon dioxide concentration. Adaptations were primarily based on growth and phenological data obtained from growth chamber experiments at Rutgers University (New Brunswick, N.J.) and from the modeling literature. Modified-SUBSTOR predictions were compared with data from Kennedy Space Center's Biomass Production Chamber for verification. Results show that, with further development, modified-SUBSTOR will be a useful tool for analysis and optimization of potato growth in controlled environments.
• Giacomelli, G. A., Paterson, R. L., Sadler, P., & Barta, D. J. (2003). Development and evaluation of an advanced water-jacketed high intensity discharge lamp. SAE Technical Papers.
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  Abstract: During the period July 2001 to March 2002, the performance of a water-jacketed high intensity discharge lamp of advanced design was evaluated within a lamp test stand at The University of Arizona (UA), Controlled Environment Agriculture Center (CEAC) in Tucson, Arizona. The lamps and test stand system were developed by Mr. Phil Sadler of Sadler Machine Company, Tempe, Arizona, and supported by a Space Act Agreement between NASA-Johnson Space Center (JSC) and UA. The purpose was for long term testing of the prototype lamp and demonstration of an improved procedure for use of water-jacketed lamps for plant production within the close confines of controlled environment facilities envisioned by NASA within Bioregenerative Life Support Systems. The lamp test stand consisted of six, 400 watt water-cooled, high pressure sodium HID lamps, mounted within a framework. A nutrient delivery system consisting of nutrient film technique re-circulation troughs and a storage tank was also included, but plants grown in the system were not evaluated in this time period. The performance of the lamps was quantified in terms of photosynthetic photon flux (PPF), and spectral irradiance during the 9-month testing period. In addition, an energy balance and a series of short term tests were completed on the lamp system. The lamps were operated on a 16 hour 'on' and 8 hour 'off' duty cycle each day. The total operation time for the lamps during the test period was 4208 hour. The following report describes a series of tests performed on the water-cooled high pressure sodium (HPS) lamp system. Copyright © 2003 SAE International.
• Lefsrud, M. G., Giacomelli, G. A., Janes, H. W., & Kliss, M. H. (2003). Development of the microgravity plant growth pocket. Transactions of the American Society of Agricultural Engineers, 46(6), 1647-1651.
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  Abstract: The Microgravity Pocket (MGP) was designed for continuous production of root crops in microgravity within a controlled environment. The MGP is intended to provide NASA with a "Salad Machine" to grow carrot and radish for consumption by astronauts. Attributes of the pocket system, include light weight; ease of planting, monitoring, and harvesting; no free water; and low energy requirements. The MGP system uses porous sheets of plastic to wick water to the plant roots, which are enclosed within a watertight pouch. An experiment was conducted growing carrot and radish root crops in a horizontal orientation adjacent to a water-cooled high-pressure sodium lamp. The hydrophilic property of the porous sheet provided nutrient solution to the root zone of the plants, but the small size of the pores prevented root growth into the sheet. The MGP was successful in growing both carrot and radish to harvestable size.
• Giacomelli, G. A. (2002). Nutrient delivery systems for crop production in the controlled environment. Acta Horticulturae, 578, 207-212.
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  Abstract: The foundation of all plant production systems is the effective, efficient and dependable means of nutrient delivery to the plant. The nutrient delivery system directly influences the physical components and the plant culture tasks of the plant management technique within the controlled environment agriculture system. The nutrient delivery system can be described in terms of its mechanism for water delivery to the plant. Examples of an aeroponic root growth system, and a traditional tomato production system, within the controlled environment facilities at the University of Arizona, Controlled Environment Agriculture Center are provided.
• Sadler, P. D., & Giacomelli, G. A. (2002). Mars inflatable greenhouse analog.. Life support & biosphere science : international journal of earth space, 8(2), 115-123.
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  PMID: 11987303;Abstract: Light intensities on the Martian surface can possibly support a bioregenerative life support system (BLSS) utilizing natural sunlight for hydroponic crop production, if a suitable controlled environment can be provided. Inflatable clear membrane structures offer low mass, are more easily transported than a rigid structure, and are good candidates for providing a suitable controlled environment for crop production. Cable culture is one hydroponic growing system that can take advantage of the beneficial attributes of the inflatable structure. An analog of a Mars inflatable greenhouse can provide researchers data on issues such as crew time requirements for operation, productivity for BLSS, human factors, and much more at a reasonable cost. This is a description of one such design.
• Gottdenker, J. S., Giacomelli, G. A., & Durner, E. (2001). Supplemental lighting strategy for greenhouse strawberry production (Fragaria X ananassa duch. Cv. Sweet charlie). Acta Horticulturae, 559, 307-312.
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  Abstract: Controlled environment, greenhouse cultivation of Sweet Charlie strawberries is technically an effective method to target niche winter markets. Supplemental lighting can help to accelerate fruit maturation, and to encourage a greater number of smaller fruit earlier in the season. Unless yield per plant can be drastically increased, achieving an economically viable system will require a planting density approaching 30 plants m-2.
• Fleisher, D. H., Cavazzoni, J., Giacomelli, G. A., & Ting, K. C. (2000). Adaptation of SUBSTOR for Hydroponic, Controlled Environment White Potato Production. 2000 ASAE Annual Intenational Meeting, Technical Papers: Engineering Solutions for a New Century, 2, 4501-4511.
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  Abstract: SUBSTOR, a process-oriented crop growth and development field model included with DSSAT software, was modified for controlled environment hydroponic production of white potato (cv. Norland) under elevated carbon dioxide concentration. Modifications were primarily based on growth and phenological data obtained via in-house experiments in ebb and flood equipped growth chambers at Rutgers University. Results from published literature were also used for additional modification where appropriate. The adaptations made to SUBSTOR included adjustment of input files for hydroponic cultural conditions, calibration of genetic coefficients, parameter tuning such as for radiation use efficiency, and source code changes. The latter included accounting for the absorption of light reflected from the surface below the canopy, an increased senescence rate, adding a carbon (mass) balance to the model, and a modified response of crop growth rate to CO2 concentration. Modified-SUBSTOR predictions were then compared with data from in-house experiments and Kennedy Space Center's Biomass Production Chamber.
• Lefsrud, M. G., Giacomelli, G. A., Janes, H. W., & Dreschel, T. W. (2000). Crop Production on the Porous Tube. 2000 ASAE Annual Intenational Meeting, Technical Papers: Engineering Solutions for a New Century, 2, 4415-4429.
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  Abstract: The porous tube is a nutrient delivery system that was developed to grow plants in microgravity. Most of the research studies with the porous tubes have been completed with lettuce, radish, wheat and sweet potato. The NJ-NSCORT at Rutgers University has focused on root crops and fruiting plants which can be grown on the porous tube. Carrots were grown to maturity on the porous tube with support methods tested to increase yields. Strawberry plants and fruit were also grown on the porous tube from the successful establishment of transplanted runners, but with marginally successful seed germination.
• Lefsrud, M. G., Giacomelli, G. A., Janes, H. W., & Kliss, M. H. (2000). Development of the Micro Gravity Plant Growth Pocket. 2000 ASAE Annual Intenational Meeting, Technical Papers: Engineering Solutions for a New Century, 2, 4461-4473.
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  Abstract: The micro gravity pocket (MGP) was designed to be used for continuous cropping of root crops in microgravity within a controlled environment. NASA plans for a 'Salad Machine' to grow carrot and radish in microgravity for consumption by the astronauts. The pocket system was designed to be light weight, easy to plant, monitor and harvest, with no free water and low energy requirements. The MGP system was developed using porous sheets of plastic to wick water to the plant roots. The design was tested with radish, growing horizontally facing a metal halide lamp. The hydrophilic property of the porous sheet made water available to the roots, but the small size of the pores prevented root growth into the sheet. The MGP was not significantly different in yield compared to the porous tube.
• Choi, C. Y., & Giacomelli, G. (1999). Freeze and frost protection with aqueous foam - Field experiments. HortTechnology, 9(4), 662-667.
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  Abstract: Newly formulated aqueous foam was tested in the field. The foam demonstrated the longevity necessary for practical field use. Soil temperatures beneath an insulation layer of aqueous foam were measured to determine the effectiveness of foam as soil mulch. Leaf temperature within a canopy was monitored to observe the modification of plant leaf temperature, and to evaluate the phytotoxic effects of foam applied directly to the leaf canopy. Leaves were not damaged after being covered with the foam for two weeks. The foam-protected soil was effectively insulated, and the aqueous foam proved to be an effective radiation shield against the cold night sky. Temperature differences as high as 5 °C (9 °F) were measured between the foam-covered and uncovered copper metal plates, which were used to simulate plant leaves. The foam covered plates were ≃80% as effective as the aluminum foil covered plates in reducing radiation heat transfer.
• Choi, C. Y., Zimmt, W., & Giacomelli, G. (1999). Freeze and frost protection with aqueous foam - Foam development. HortTechnology, 9(4), 654-661.
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  Abstract: Aqueous foam was developed to serve as a barrier to conductive, convective, and radiative heat transfer. Through the use of a bulking agent, the physical properties of gelatin-based foam were more stable, adhesive, biodegradable, and long lasting. The phytotoxicity, possible environmental hazard and removal of the foam were also considered. Resistance to freezing-thawing, heating-evaporation, and wind were evaluated. Studies to determine the foam's long-term stability under field weather conditions were completed. The handling and performance characteristics of the foam necessary for development of this application were determined. Factors that affect the physical properties and the utilization of the foam were quantified. These included the proportions of the foam components, the mixing temperature of the prefoam solution, the application temperature, and the rate of foam generation. The newly developed foam might be ideal for freeze and frost protection in agriculture.
• Giacomelli, G. A., & Ting, K. C. (1999). Horticultural and engineering considerations for the design of integrated greenhouse plant production systems. Acta Horticulturae, 481, 475-481.
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  Abstract: Design and operation of a greenhouse for plant production are challenging tasks even for the most experienced growers or designers, primarily because they are a highly complex system of biological and mechanical subsystems. These subsystems are deeply interrelated and must function together to provide successful crop production. With fundamental understanding and a desire to develop integrated crop production systems, the design of future greenhouses may become less guesswork, less design by "experience", and more methodical and reliant on information databases. The specific greenhouse structure, the crop production system, the environmental control and the labor/management procedures, directly affect the ability of the greenhouse manager to successfully produce high quality crops within the greenhouse. The greenhouse design requires the selection of many individual component systems, within the three primary areas of automation, culture and environment. Having selected the crop or crops, thereby knowing the culture requirements, it becomes necessary to select a water/nutrient delivery system, which when housed within a greenhouse structure, will efficiently incorporate labor requirements and environmental control. The complexity of the dynamic greenhouse system requires that problem solving and planning should not occur with the daily management decisions, but during the design stage of the greenhouse, prior to implementation. A logical procedure of design steps needs to be developed, in order to avoid the trial and error methodologies typically utilized, and whose success or failure depends totally on the past experiences of the designer, with too little input from the grower. Although a detailed design procedure does not currently exist, the basis for its development will be considered in this paper.
• Giacomelli, G. A. (1998). Monitoring plant water requirements within integrated crop production systems. Acta Horticulturae, 458, 21-27.
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  Abstract: Water management is an essential task for all crop production. However, it is difficult to determine short term plant water needs, as the plant does not exhibit readily detectable indicators of stress until well beyond optimum water conditions. The plant utilizes water in several critical ways, such as, to maintain turgidity, for nutrient uptake, and in photosynthesis, all of which vary in proportion to the environmental conditions. The traditional procedure for supplying plant water needs is to provide a storage of water within the root zone which becomes an immediately available source. Soil or soilless mixes for potted plants have moisture contents which can range from field capacity after watering, to high soil water tensions associated with the onset of wilting conditions of the plant. Alternatively, the root zone volume and storage capacity has for some crops been significantly reduced, requiring a more "on-demand" water feeding schedule. Hydroponic crop production systems, for example, ebb and flood, where there is little or no buffer within the root zone for water, require automated watering schemes which are extremely dependable, reasonably accurate, and uniform in distribution for production of quality crops. In theory, the plant transpires water and thus requires replenishment at rates which are dependent on the plant microclimate (leaf temperature, solar radiation, air humidity, wind speed), as well as, the plant age, morphology, health, and the ease at which the water is available within the root zone. Water requirement can be determined in either of two ways: (1) correlated to plant and its environment with physical or mathematical models, or (2) measured directly with an electronic transducer, such as with stem "sap flow" device. Each has been applied to selected plants species with reasonable success, but generally maintaining some margin of safety, through a water storage buffer within the root zone. The most practical application of each procedure has been in minimizing over-watering and minimizing plant stress while utilizing traditional irrigation techniques. The "speaking plant" approach can provide new opportunities for application of water and nutrients, and ultimately for control of plant growth, but such procedures require that one must "listen" to the speaking plant. Tjie challenge is to focus on the development of sensors to interpret the plant indicators, and then to respond to them within a control system. Machine vision which utilizes the spectral features (by reflectance), or morphological features (physical shape or dynamic growth response) of the plant is one relatively new option for determining the real-time plant condition. Real-time sensors that directly monitor the plant and its water requirements, which are non-intrusive, non-invasive, reliably calibrated, and integrated within a microclimate control system will be necessary for the ultimate success of such systems. In this paper, the plant water requirements, the delivery systems and the potential of automated monitoring of plant water status within integrated crop production systems will be discussed.
• Giacomelli, G. A., Ling, P. P., & Kole, J. (1998). Determining nutrient stress in lettuce plants with machine vision technology. HortTechnology, 8(3), 361-365.
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  Abstract: The rate of change of top projected leaf area (TPLA) of lettuce (Lactuca sativa L.) seedlings was determined with machine vision technology. Differences of TPLA between control and treatment plants were detectable with this technique within 48 hours from the onset of an imposed nutrient stress. The nutrient stress treatments were 0%, 50%, 150% of the control (100%). There were no differences for the 50% and 150% treatments compared to the control plants, even after a 6-day observation period. However, the 0% treatment caused different TPLA expansion within 48 hours and required a recovery period of 3 or 4 days after being returned to normal EC levels before again attaining prestressed growth rates.
• Li, Z., Ling, P. P., & Giacomelli, G. A. (1998). Machine vision monitoring of plant growth and motion.. Life support & biosphere science : international journal of earth space, 5(2), 263-270.
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  PMID: 11541685;Abstract: The tomato plant was used as a model to study growth and movement due to temperature changes in the environment. A morphological feature, plant top projection canopy area (TPCA), was used to characterize the plant growth and movement. Three temperature regimes (normal temperature, low temperature, and a step change from normal to low temperature) were used for the study. It is found that the plants have significant cyclic canopy movement. In addition, both plant growth, which is represented by canopy expansion, and canopy movement are affected by air temperature. The response of the plant to a step change of air temperature was also documented.
• Sauser, B. J., Giacomelli, G. A., & Janes, H. W. (1998). Modeling the effects of air temperature perturbations for control of tomato plant development. Acta Horticulturae, 456, 87-92.
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  Abstract: The primary objective of the investigation was to evaluate the effects of selected perturbations in air temperature on the development of the tomato plant, Lycopersicon esculentum (c.v. Laura, DeRuitter Seeds Laura FI, Tm-C2-V-F2). The approach to this investigation was to quantify the plants responses to air temperature and organize this information to develop an environmental control model for tomato plant growth while integrating the information with machine vision technologies. The focus was on the effect of selected air temperature perturbations on crop growth and scheduling. The objectives were accomplished through growth chamber experimentation and model development in coordination with non-destructive machine vision technologies. Three replications were performed at three different air temperatures (high, normal, low). These experiments were used to develop baseline data for calibration of an empirical model and correlation with machine vision images. The model would allow for the quantity of biomass to be predicted at a given air temperature under constant air temperature conditions. Results from the growth chamber studies indicated that the small air temperature differences had the effect of altering the time to first flower for the tomato plant. However, under the three different temperature regimes the dry weight of the aerial portion of the plant at time of flowering was similar for each crop, and seemingly independent of air temperature. Preliminary, results of the plant model indicated that it was capable of predicting developmental rates and changes in the tomato plant based on the dry weight of the aerial portion of the plant. The correlation of the machine vision images with dry weight can be used with the model for plant developmental predictions and development of a control system for maintaining plant scheduling.
• Sauser, B. J., Giacomelli, G. A., & Ling, P. P. (1998). Development of the basis for an automated plant-based environmental control system. SAE Technical Papers.
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  Abstract: The primary objective of the investigation was to evaluate the effects of induced perturbations in air temperature on the development of the tomato plant, while correlating a plant feature for use with machine vision non-contact sensing technologies, and allow for eventual integration into a non-invasive plant-based environmental control system. Real-time information of plant growth responses to steady-state and changing air temperature regimes were measured (i.e. dry weight). There was a positive correlation of the profile machine vision images with dry weight. Therefore, machine vision could be used for plant developmental predictions and development of a control system for maintaining plant schedules. © 1998 Society of Automotive Engineers, Inc.
• Chao, K., Ting, K. C., & Giacomelli, G. A. (1997). Foundation class library design for global BLSS models. Paper - American Society of Agricultural Engineers, 1.
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  Abstract: The successful modeling of Bioregenerative Life Support Systems (BLSS) for deriving answers to system level questions depends mainly on the systems abstraction. ACE_SYS-oriented analysis is performed to identify the essential component modules for the BLSS as well as the interrelationships among them. The object oriented design for the BLSS is performed based on the outcome of the systems analysis. A set of foundation class library and building blocks for the BLSS models have been developed by translating the object classes and relationships developed during the object oriented design.
• Fleisher, D. H., Ting, K. C., & Giacomelli, G. A. (1997). Computer model for full-scale phytoremediation systems using rhizofiltration processes. Paper - American Society of Agricultural Engineers, 1.
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  Abstract: Microcomputer software was developed to provide decision support information for design and operation of a rhizofiltration system, a phytoremediation based technology utilizing plant roots to remove heavy metals and radionuclides from contaminated waters. A Michaelis-Menton based model was developed and incorporated into a series of algorithms which process information relevant to the system design of the rhizofiltration process. Physical components of the phytoremediation system - plant production, rhizofiltration, pre and post treatment of water, and post treatment of spent plant materials are coupled with engineering and biological aspects of systems design. An engineering economic analysis tool within the software allowed for analysis of the impact of critical design variables on system efficiency.
• Morden, R. E., Ling, P. P., & Giacomelli, G. A. (1997). Automated plant growth monitoring system using machine vision. Paper - American Society of Agricultural Engineers, 3.
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  Abstract: A noncontact plant-monitoring system for measuring the top projected canopy area (TPCA) of lettuce plants (cv. `Ostinata') was developed using machine vision. It makes automatic hourly measurements of the plants and is capable of detecting the effect of nutrient stress only 17 hours after application, based on the average 24-hour change in TPC. The combined growth and motion of the plants is detectable directly from the hourly measurements. The natural cycles of both growth and motion of the plant are synchronized to the light/dark cycles; thus a sliding 24-hour early in TPCA was selected as the test for detecting stress. Furthermore the plant grows very slowly during the early light period and grows at its peak rate during the early night period. A measurement interval shorter than 24 hours would require a more detailed analysis due to the variable growth rates. This noncontact sensing system is capable of detecting nutrient stress in 17 hours while tracking the hourly performance of the lettuce plants, thus providing further understanding of plant growth and motion.
• Ting, K. C., Chao, K., & Giacomelli, G. A. (1997). Systems studies of NJ-NSCORT for BLSS: An overview. SAE Technical Papers.
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  Abstract: The New Jersey NASA Specialized Center of Research and Training (NJ-NSCORT) for Bioregenerative Life Support Systems (BLSS) was established at Rutgers University, with participation from Stevens Institute of Technology, in May 1996. Four research teams including Biomass Production, Food Processing and Nutrition, Waste Processing, and Systems Studies and Modeling were assembled to study issues related to human life support associated with long duration space missions. Each team is conducting a number of projects that address specific problems to the design of BLSS. The current tasks of the Systems Studies and Modeling (SSM) team are: to establish communications among NJ-NSCORT research teams, to develop system analysis methodologies, to develop hybrid fundamental/empirical models for individual subsystems of a BLSS, and to develop functional modules to manipulate information related to BLSS. For the systems studies part of SSM team, an integrated automation-culture-environment analysis cyber environment (acesys) is being developed to facilitate the study of BLSS. Preliminary study has been conducted to identify the key components of this systems analysis environment. The acesys consists of an input mechanism for project information, a set of databases for storing information (informational modules), a display capability for data presentation, a discussion forum, and a collection of applets for processing information (functional modules). This paper provides an overview on the development of acesys system analysis methodologies and hardware/software configurations for implementing acesys on the internet. © Copyright 1997 Society of Automotive Engineers, Inc.
• Ting, K. C., Ling, P. P., & Giacomelli, G. A. (1997). Sustaining human lives in outer space. Resource: Engineering and Technology for Sustainable World, 4(3), 7-8.
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  Abstract: A mission aboard a space vehicle to other planets takes time. To sustain life, the space crew's three basic needs including air, water and food need to be replenished. Today, researchers are studying alternatives to meet these needs considering the special circumstances related to space travel. Efforts to develop bioregenerative life support systems (BLSS) are underway. Over the years, NASA has been providing leadership in developing BLSS.
• Chiu, H. C., Ting, K. C., Giacomelli, G. A., & Mears, D. R. (1996). Simulation of supplemental light control strategies in a single truss tomato production system. Acta Horticulturae, 440, 141-146.
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  Abstract: In the single truss tomato production system (STTPS), plants are grown hydroponically in a greenhouse with a single cluster of fruit per plant. One major advantage of STTPS is the ability to achieve uniform fruit quality on a planned schedule with predictable yield. To achieve high levels of greenhouse space utilization and a consistent harvest, several generations of plants are grown simultaneously with the plants being spaced periodically to maintain maximum plant canopy cover of the growing area, thereby maximizing utilization of space and supplemental lighting. As the production period varies with the light received by the crop it is essential to control the amount of supplemental light provided the crops so that each will have a predictable harvest date. Simulation of the cropping cycle has been programmed in Visual Basic to provide a management tool for the scheduling of lighting and the design of the lighting system. This program is based on a previously determined relationship between light received by the crop between germination and first flower development and the time to harvest. It accepts location specific solar radiation data as a variable input and has been used to optimize scheduling for the New Brunswick, New Jersey location.
• Giacomelli, G. A., Ling, P. P., & Morden, R. E. (1996). An automated plant monitoring system using machine vision. Acta Horticulturae, 440, 377-382.
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  PMID: 11541581;Abstract: A plant growth chamber equipped with a machine vision (MV) system was developed for the continuous, non-contact sampling and near-real-time evaluation of the top projected leaf area (TPLA) of lettuce (Lactuca sativa, cv. Ostinata) seedlings. A rotary table enabled automatic, individual presentation of the lettuce plants to the imaging system. Hourly measurements were continuously made for 16 plants from the first true leaf stage through 30 days from seeding. A near-infrared radiation source illuminated the plants during the dark period, permitting measurements without interrupting the 12 hour photoperiod. Daily minimum hourly change of TPLA for the plants occurred from 3 to 4 hours after the start of the light period. Most rapid increase in TPLA occurred from 4 to 5 hours after the onset of the dark period. The machine vision system was capable of determining a plant physiological response to the nutrient stress within 24 hours of the change of the nutrient regime.
• Ling, P. P., Giacomelli, G. A., & Russell, T. (1996). Monitoring of plant development in controlled environment with machine vision. Advances in Space Research, 18(4-5), 101-112.
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  PMID: 11538786;Abstract: Information acquisition is the foremost requirement for the control and continued operation of any complex system. This is especially true when a plant production system is used as a major component in a sustainable life support system. The plant production system not only provides food and fiber but is a means of providing critically needed life supporting elements such as O2 and purified H2O. The success of the plant production system relies on close monitoring and control of the production system. Machine vision technology was evaluated for the monitoring of plant health and development and showed promising results. Spectral and morphological characteristics of a model plant were studied under various artificially induced stress conditions. From the spectroscopic studies, it was found that the stresses can be determined from visual and non-visual symptoms. The development of the plant can also be quantified using a video image analysis base approach. The correlations between the qualities of the model plant and machine vision measured spectral features were established. The success of the research has shown a great potential in building an automated, closed-loop plant production system in controlled environments.
• Ting, K. C., Ling, P. P., & Giacomelli, G. A. (1996). Research on flexible automation and robotics for plant production at Rutgers University. Advances in Space Research, 18(1-2), 175-180.
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  PMID: 11538960;Abstract: This is an overview of research activities in the areas of flexible automation and robotics (FAR) within controlled environment plant production systems (CEPPS) in the Department of Bioresource Engineering, Rutgers University. In the past thirty years, our CEPPS research has dealt with the topics including structures and energy, environmental monitoring and control, plant growing systems, operations research and decision support systems, flexible automation and robotics, and impact to natural (i.e. surrounding) environment. Computer and modeling/simulation techniques have been utilized extensively. Mechanized systems have been developed to substitute human's physical labor and maintain uniformity in production. Automation research has been directed towards adding, to the mechanized systems, the capabilities of perception, reasoning, communication, and task planning. Computers, because of their programmability, provide flexibility to automated systems, when incorporated with generic hardware devices. Robots are ideal hardware tools to be employed in flexible automation systems. Some technologies developed in our CEPPS research may be readily adaptable to Closed Bioregenerative Life Support Systems (CBLSS).
• Ling, P. P., Russell, T. P., & Giacomelli, G. A. (1995). Plant health monitoring with machine vision. Proceedings of SPIE - The International Society for Optical Engineering, 2345, 247-256.
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  Abstract: Spectral and dynamic morphological features were investigated for plant health monitoring using machine vision techniques. The plants were stressed by withholding all nutrient salts. The spectral reflectance of healthy and stressed lettuce leaves (Latuca sativa cv. `Ostinata') was measured to determine at which wavelength(s) a stressed condition would be apparent. The measured wavebands were between 400 and 1000 nm. A reference waveband was utilized to account for photometric variables such as lighting and surface geometry differences during image acquisition. The expansion of the top projected leaf area (TPLA) was found to be an effective feature to identify stressed plants. The nutrient stressed plant was identifiable within two days after nutrients were withheld from a healthy plant. This was determined by a clearly measurable reduction in TPLA expansion.
• Giacomelli, G. A., Ting, K. C., & Ling, P. P. (1994). Systems approach to instrumenting and controlling plant growth systems. Advances in Space Research, 14(11), 191-197.
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  PMID: 11540180;Abstract: Acquisition and analysis of sensory information are foremost for the control and continued operation of any complex system. The sensors and their attributes must be selected by understanding the biological and physical parameters which, first, can describe, and second, when linked to control systems, can modulate, the plant growth system. These parameters are not all understood, or known, and practical sensors may not even exist for their measurement. A systematic analysis of the general plant system would: focus without prejudice on all the descriptive parameters, as well as, their interrelationships within the biophysical system; highlight the significance of each parameter; expose the areas of weakness and strength of current knowledge; expand the knowledge base; provide the platform for the development of operational models for real-time monitoring and control requirements; and support the longer term tactical and strategic planning needs. Components of such a procedure of systematic analysis which is in development for intensive plant production systems within controlled environments will be discussed. © 1994.
• Takakura, T., Manning, T. O., Giacomelli, G. A., & Roberts, W. J. (1994). Feedforward control for a floor heat greenhouse. Transactions of the American Society of Agricultural Engineers, 37(3), 939-945.
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  Abstract: Floor heating is a promising technique to heat greenhouses using low quality energy. The large thermal inertia of floor heating systems requires some form of predictive control. To analyze the effectiveness of feedforward logic, first a prediction model has been developed and then an experiment using a controlled-environment chamber has been conducted. Basic control logic has been established and verified for controlling air temperature by energy input only to the floor. The combination of feedforward and feedback control should be the next step.
• Kabala, W. P., & Giacomelli, G. A. (1992). Transportation and elevation system for greenhouse crops. Applied Engineering in Agriculture, 8(2), 133-139.
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  Abstract: A closed loop transportation and elevation system for greenhouse crop production benches was designed and tested. Its purpose was to improve access to tomato plants in production. The system met two major design criteria: (1) benches could be elevated, and (2) benches could be interchanged between any two rows within a greenhouse bay. The system consisted of aluminum transportable benches, a pipe track system, transfer-elevation device (TED), and two rear transfer mechanisms (RTM). The centralized work station within the bench transport system, provided the possibility of performing labor studies to evaluate the system/labor interactive performance of the overall production process. The relative comparison of the operation times required for each operation for an elevated versus a non-elevated bench was evaluated and a measure of the relative bench transport time was determined.
• Yang, Y., Ting, K. C., & Giacomelli, G. A. (1991). Factors affecting performance of sliding-needles gripper during robotics transplanting of seedlings. Applied Engineering in Agriculture, 7(4), 493-498.
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  Abstract: Transplanting tests with commercially grown seedling plugs were conducted using a Sliding-Needles with Sensor (SNS) gripper operated by a SCARA type robot. A total of 11 plug trays, with 600 cells each, were tested. Many mechanical and horticultural factors were found to affect the percentage of successful transplanting, which were analyzed to understand their influence on the effectiveness of the gripper. The mechanical factors were 1) the angles of gripper needles; 2) plug extraction acceleration; and 3) the sensor sensitivity. The horticultural factors included 1) empty cells on the plug trays; 2) plant species; 3) root connections; 4) adhesion between roots and cell walls; 5) root zone moisture; and 6) the number of seedlings in one cell.
• Fang, W., Ting, K. C., & Giacomelli, G. A. (1990). Animated simulation of greenhouse internal transport using SIMAN/CINEMA. Transactions of the American Society of Agricultural Engineers, 33(1), 336-340.
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  Abstract: An animated computer model has been developed using a simulation language SIMAN/CINEMA to simulate greenhouse internal transport systems. The model can be used as a tool to study the performance of materials handling operations within a greenhouse. The potential bottleneck of a transport system can be visually detected on the computer monitor. Statistical analyses on the system parameters, such as the status and utilization of machines, workers and waiting lines, and throughput time of an operation, are performed during the simulation. From these data, the interaction between machines and workers within a greenhouse system can be studied.
• Fang, W., Ting, K. C., & Giacomelli, G. A. (1990). Optimizing resource allocation for greenhouse potted plant production. Transactions of the American Society of Agricultural Engineers, 33(4), 1377-1382.
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  Abstract: A procedure for studying the profitability of greenhouse potted plant production systems subject to resource constraints was developed. The constrained condition and resources were the crop production schedule, greenhouse space, labor, and budget. A database containing the information for determining the required resources and operating costs for growing various crops was established. The database also provides the estimated revenue from sales of the crops, on a per pot basis. An algorithm was developed to determine first the feasibility of a given production plan and then determine the quantities of crops to be grown in order to yield an optimum profit. The result of this algorithm may serve to optimize allocation of resources for year-round production. The algorithm along with the crop database was incorporated into a user-friendly micro-computer program.
• Ting, K. C., Giacomelli, G. A., & Shen, S. J. (1990). Robot workcell for transplanting of seedlings. Part I. Layout and materials flow. Transactions of the American Society of Agricultural Engineers, 33(3), 1005-1010.
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  Abstract: The transplanting of seedlings from high density plug trays into low density growing flats, as currently practiced in the bedding plant production systems, was the operation studied within a prototype workcell utilizing a Selective Compliance Assembly Robot Arm (SCARA) type robot. The concept of a multi-stop local work trajectory surrounding each seedling was incorporated into the workcell design consideration. The trays and flats were envisioned to flow across each other's path at different heights within the workcell. A straight-line robot wrist motion was used between the locations on a tray and a flat. A computer program for checking the interactions of the workcell layout, the robot motions and the flows of materials was developed. The average robot wrist horizontal travel distance per transplanting (AHT) for a given workcell could be readily calculated using this computer program. The AHT was evaluated for its use as an indication of the performance of any given workcell design. For the 12 cases studied, the AHT ranged from 0.381 m to 0.993 m which was found to correlate well with the average cycle time per transplanting.
• Ting, K. C., Giacomelli, G. A., Shen, S. J., & Kabala, W. P. (1990). Robot workcell for transplanting of seedlings. Part II. End-effector development. Transactions of the American Society of Agricultural Engineers, 33(3), 1013-1017.
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  Abstract: The successful integration of a robot with seedling transplanting requires an operational end-effector. Two types of grippers were designed in this study for seedling picking, holding, and planting during robotic transplanting. They were called 'Swinging Needles' and 'Sliding Needles', respectively. The Sliding Needles gripper was found to be functionally superior to the Swinging Needles for seedling transplanting. Further study was done to incorporate a seedling sensing capability to the Sliding Needles gripper. A capacitive proximity sensor was selected and its sensing capability tested on plant materials. The sensor was found to have satisfactory performance in terms of detecting seedlings held by the gripper. The sensor and the gripper were then integrated to become a final end-effector design called 'Sliding Needles with Sensor'. A prototype of the final design version was tested. The gripper was adaptable to a wide range of seedling sizes and shapes. The sensor on the gripper assured that the growing flats were transplanted, with seedlings of satisfactory quality.
• Giacomelli, G. A., Ting, K. C., & Panigrahi, S. (1988). Solar PAR vs. solar total radiation transmission in a greenhouse. Transactions of the American Society of Agricultural Engineers, 31(5), 1540-1543.
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  Abstract: The availability of solar radiation in a bow-type, air-inflated, double polyethylene covered greenhouse was studied. Solar total radiation (0.285 to 2.8 μm waveband) transmittance and the transmittance of photosynthetically active radiation (solar PAR, 0.4 to 0.7 μm) were compared. The comparisons were reported for measurements made both at the glazing and the plant canopy levels. A relationship was previously determined for the available solar total radiation (W m-2) and solar PAR (μmol s-1 m-2), transmitted through the atmosphere. This report focuses on the effects of glazing and structure on transmitting ambient solar radiation and the development of a relationship for transmittance of solar total radiation (W m-2) versus solar PAR (μmol s-1 m-2) between the two wavebands.
• Giniger, M. S., McAvoy, R. J., Giacomelli, G. A., & Janes, H. W. (1988). COMPUTER SIMULATION OF A SINGLE TRUSS TOMATO CROPPING SYSTEM.. Transactions of the American Society of Agricultural Engineers, 31(4), 1176-1179.
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  Abstract: The development of a computer simulation model for greenhouse tomato crop management is discussed. The management model, based on a crop production model, will determine a production schedule designed to provide a continuous yield, optimize greenhouse space utilization, and predict production rates throughout the year.
• Ting, K. C., & Giacomelli, G. A. (1987). AVAILABILITY OF SOLAR PHOTOSYNTHETICALLY ACTIVE RADIATION.. Transactions of the American Society of Agricultural Engineers, 30(5), 1453-1457.
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  Abstract: Experiments have been conducted to determine the correlations between the available hourly and daily photosynthetically active radiation (PAR) and total solar radiation. PAR was measured in the photon flux density unit of mol s** minus **1 m** minus **2 and total radiation was in the radiant flux density of W m** minus **2. Regression equations are presented in this paper for two purposes: (a) to show the predictability of PAR using available total solar radiation data, and (b) to provide empirical equations for estimating direct and diffuse PAR based on total radiation values.
• Ting, K. C., & Giacomelli, G. A. (1987). Solar photosynthetically active radiation transmission through greenhouse glazings. Energy in Agriculture, 6(2), 121-132.
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  Abstract: One critical factor for crop energy conversion for plant growth is photosynthetically active radiation (PAR) received by the plant. While it is important to know their total solar radiation transmission characteristics in the design of greenhouse for thermal environment management, it is also essential to understand their PAR transmission capability, especially over the winter period for high-latitude regions. This paper presents the results of PAR transmission of four different greenhouse glazings, measured at both the glazing and crop canopy levels. The glazings studied were single glass, double glass, twin-walled acrylic and air-inflated double polyethylene. The first three materials were tested at a commercial rose greenhouse range (gable type) in Connecticut and the double polyethylene greenhouse (bow type) was located at Cook College, Rutgers University. Also reported is the comparison between total solar radiation transmission and PAR transmission in the double polyethylene greenhouse. The glazing level PAR transmission showed mainly the effects of glazing materials, sky clearness and solar angle of incidence, whereas PAR received at the canopy level was strongly influenced by the greenhouse geometric configuration and internal structures. It was found that air-inflated double polyethylene transmitted a higher percentage when measured in the total solar radiation range than in the PAR range. © 1987.
• Ting, K. C., & Giacomelli, G. A. (1986). AVAILABILITY OF SOLAR PHOTOSYNTHETICALLY ACTIVE RADIATION.. Paper - American Society of Agricultural Engineers.
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  Abstract: Photosynthetically active radiation (PAR) is a portion (0. 4-0. 7 micrometer wavelength) of the total radiation spectrum directly related to plant photosynthetic productivity. Experiments have been conducted to determine the correlations between the available hourly and daily PAR and total solar radiation. PAR was measured in micro-mol/s m**2 and total radiation was in W/m**2. Regression equations are presented in this paper for two purposes: (1) to show the predictability of PAR using available total solar radiation data, and (2) to provide empirical equations for estimating direct and diffuse PAR based on total radiation values.
• Giacomelli, G. A., & Giniger, M. S. (1985). MICROCOMPUTER CONTROL OF WARM FLOOR HEATED GREENHOUSE.. ASAE Publication, 126-135.
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  Abstract: An 11 by 15 meter free span, gutter connected, double polyethylene clad greenhouse was equipped with a porous concrete warm floor heating system. The warm floor heating system consisted of a 30 cm deep, vinyl swimming pool liner, filled with 20 cm of bluestone and capped with a 10 cm layer of porous concrete. It was filled with water to a depth of 20 cm and heated by a hot water boiler through a network of 1. 3 cm diameter pipes embedded within the bluestone. Supplemental heating was supplied by a water to air heat exchanger connected to the boiler. Cooling was achieved by forced air ventilation. There were three stages of ventilation with a maximum capacity of one air change per minute. This paper discusses tests conducted in the greenhouse, along with instrumentation hardware, the software program, and system operation.
• Giacomelli, G. A., & Krass, A. E. (1985). GREENHOUSE FOG EVAPORATIVE COOLING USING A MOVABLE BOOM.. Paper - American Society of Agricultural Engineers.
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  Abstract: An evaporative cooling system was designed and evaluated. The system utilized high pressure fog nozzles mounted on a movable frame which travelled the width of a greenhouse bay. The system effectiveness (measured as absolute cooling and spatial temperature uniformity) as influenced by the spraying rate, the rate of frame movement and the greenhouse volume air change rate was determined. Effectiveness values ranged from 50 to 70% with instantaneous temperature reductions as large as 9 degree C.
• Giacomelli, G. A., Giniger, M. S., & Krass, A. E. (1985). UTILIZATION OF THE ENERGY BLANKET FOR EVAPORATIVE COOLING OF THE GREENHOUSE.. Paper - American Society of Agricultural Engineers.
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  Abstract: The ability to cool greenhouse air is essential in growing many warm weather greenhouse crops. Present methods, such as fan-and-pad cooling are lacking in both the amount of cooling at high humidity and the uniformity of distribution of cooled air within the greenhouse. One method, a wetted overhead energy-saving blanket, was devised and tested. The blanket (open weave, 55% shading) acted as an evaporative cooling surface when wetted by mist nozzles placed in the greenhouse attic above the blanket. Results have shown good uniformity as well as temperature reduction of up to 8 degree C.
• Giniger, M. S., Stine, C. B., Giacomelli, G. A., & Mears, D. R. (1985). MICROCOMPUTER CONTROL OF GREENHOUSES. I. DEVELOPING CONTROL STRATEGIES FOR A LARGE THERMAL MASS.. Paper - American Society of Agricultural Engineers.
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  Abstract: Work is underway to maximize the use of a warm floor heating system as the primary greenhouse heating source. To date, simple thermostats control the floor temperature which can lead to an undesirable climate for plant growth. Because of the large thermal inertia of the system, temperature changes of the floor for a given heat input are relatively slow. Initial research has yielded equations which describe the temperature response of the floor to constant heat inputs. These equations incorporated into existing computer software offer improved overall greenhouse temperature control. Results from simulation studies and measured data indicate that classical control strategies will be effective in maintaining optimum climates for plant growth.
• Giacomelli, G. A., & Studer, H. E. (1980). ORIENTING AND STEMMING MATURE GREEN, FRESH MARKET TOMATOES.. Paper - American Society of Agricultural Engineers.
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  Abstract: Mature green fresh market tomatoes have been machine harvested on a commercial scale in California since 1978. The harvesting and handling process results in some damage to the fruit, and the incidence of puncture injury is a function of the percentage of fruits which retain their stems. This paper reports on a study to identify concepts for mechanically stemming the tomato fruits, concepts which, preferably, might be incorporated in the harvesting machine, so that machine productivity could be increased while maintaining or possibly reducing the size of crew required in the field. Parallel rollers were used to study fruit stem orientation and stemming of mature green fresh market tomatoes. Stemming efficiencies of more than 95% were achieved by using a padded, tri-roller assembly with a fruit constraining bracket.

Proceedings Publications

• Alcorn, J. R., Giacomelli, G. A., & Scott, B. T. (2022, August). Sustained Growth and Yield in Elevated Greenhouse Air Temperatures through Control of VPD
  
  . In IHC.
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  Thesis research study of Joe Alcorn
• Blum, M. A., Parrish, C. H., Hebert, D., Giacomelli, G. A., & Bergren, M. R. (2022, August). Enhancing light use efficiency and tomato fruit yield with quantum dot films to modify the light spectrum. In IHC.
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  Thesis research study of Michael Blum
• Giacomelli, G. A., van Weel, P., & Blok, C. (2020, June 2019). Ebb and Flood Nutrient Delivery System for Sustainable Automated Crop. In GreenSys2019, 1296, 1129-1136.
• Gallenbeck, S., Giacomelli, G. A., & Pryor, B. M. (2019, July). Mushrooms on Mars: A Subsystem for Human Life Support. In 49th International Conference on Environmental Systems ICES-2019, 1-11.
• Gellenbeck, S., Furfaro, R., Giacomelli, G. A., & LePore, R. (2019, 2019). A Predictive Model For The Production Rates Of A Bioregenerative Life Support System. In ICES-2019-258.
• Gellenbeck, S., Pryor, B., & Giacomelli, G. A. (2019, 2019). Mushrooms on Mars: A Subsystem for Human Life Support. In ICES-2019-259.
• Kacira, M., Jensen, M., Robie, T., Tollefson, S., & Giacomelli, G. A. (2015, December). Use resources wisely: Waste Management and Organic Liquid Fertilizer Use in Greenhouse Production System. In III International Symposium on Organic Greenhouse Horticulture.
• Staats, K., Milovanov, L., Adams, J., Schoberth, G., Curry, T., Morgan, K., Deleeuw, J., & Giacomelli, G. A. (2019, 2019). An agent-based model for high-fidelity ECLSS and bioregenerative simulation. In International Conference on Environmental Systems.
• Furfaro, R., Gellenbeck, S., Giacomelli, G. A., & Sadler, P. D. (2017, 16-20 July 2017). Mars-Lunar Greehouse (MLGH) Prototype for Bioregenerative Life Support Systems In Future Planetary Outposts. In 47th International Conference on Environmental Systems ICES-2017-347.
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  In this paper, we describe an on-going effort called Mars-Lunar Greenhouse (MLGH) which aims at designing, constructing and testing a semi-closed, poly-cultivation hydroponic system for food production, air revitalization and water recycling as part of Bioregenerative Life Support Systems (BLSS) for future planetary outposts. Funded by the NASA Ralph Steckler Program, our team has designed and constructed a set of four innovative, cylindrical 5.5 m long by 2.1 m diameter membrane MLGHs with a cable-based hydroponic crop production system in a controlled environment that exhibits a high degree of future Lunar and/or Mars mission fidelity. This paper illustrates the research goals and objectives, a summary of the past research effort during Phase I & II as well as the status of the current research effort, including 1) evaluate MLGH food production capabilities, 2) evaluate water balance (from liquid irrigation water, biomass and water vapor), carbon balance (from gaseous carbon dioxide and biomass) and energy balance (from electrical, heat, light and food calories produced); 3) provide an analysis of the fertilizer consumption (kg per are per time) and of the required environmental control (spatial/temporal climate uniformity); 4) develop a model for crop production simulation and control; 5) develop a solar energy plant lighting-based power system; 6) develop a Remote Expert Network Decision Systems (RENDSys) and enhanced telepresence, 7) development of innovative water-cooled Chip-On-Board LED lighting systems for space-based poly-cultivation systems as well as 8) promote the STEM education access & outreach. Future effort includes the development and deployment of an analog Deep Space Habitat (DSH) within the University of Arizona’s Biosphere 2.
• Giacomelli, G. A. (2015, April). 2015 High-Level International Forum on Protected Horticulture. In 2015 High-Level International Forum on Protected Horticulture.
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  Proceedings of the 2015 High-Level Internaitonal Forum on Protected Horticulutre edited by QiChang Yand and Toyolki Kozai, Shouguang, China, Chinese Agricultural Sicence and Technology Press, April 2015chairman of the Scientific Committee
• Giacomelli, G. A., Kacira, M., Furfaro, R., Patterson, L., & Sadler, P. (2014, 08/2014). Plant production, energy balance and monitoring-control-telepresence in a recirculating hydroponic vegetable crop production system: prototype lunar greenhouse. In International Symposium on Innovation and New Technologies in Protected Cropping, 53-60.
• Giacomelli, G. A., Kacira, M., Furfaro, R., Patterson, L., & Sadler, P. (2015, November). Plant production, energy balance and monitoring-control-telepresence in a recirculating hydroponic vegetable crop production system: prototype lunar greenhouse. In International Symposium on Innovation and New Technologies in Protected Cropping, 1107, 53-60.
• Kacira, M., Jensen, M., Robie, T., Tollefson, S., & Giacomelli, G. A. (2015, April). Use resources wisely: waste management and organic liquid fertilizer use in greenhouse production system. In III International Symposium on Organic Greenhouse Horticulture.
• Giacomelli, G., Furfaro, R., Kacira, M., Patterson, L., Story, D., Boscheri, G., Lobascio, C., Sadler, P., Pirolli, M., Remiddi, P., Thangavelu, M., & Catalina, M. (2012, July). Bio-Regenerative Life Support System Development for Lunar/Mars Habitats. In 42nd ICES.
• Giacomelli, G., Harrington, M., Sotala, A., & Wilson, S. (2012, Fall). Comparison of two delivery methods used to produce an online lecture entitled worldwide technology for controlled environment plant production. In Not provided in APROL, 47.
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  HortScience
• Sadler, P., Giacomelli, G., Patterson, R., Kacira, M., Furfaro, R., Lobascio, C., Boscheri, G., lamantea, M., Grizzaffi, L., Rossignoli, S., Pirolli, M., & DePascale, S. (2011, July). Bio-regenerative Life Support Systems for Space Surface Applications. In 41st ICES.
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  Conference Presentation - ICES. "Bio-regenerative Life Support Systems for Space Surface Applications".

Presentations

• Alcorn, J. R., Giacomelli, G. A., & Scott, B. T. (2022, August). Sustained Growth and Yield in Elevated Greenhouse Air Temperatures through Control of VPD. IHC. Angers, France.: ISHS.
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  Oral presentation by Joe Alcorn from his MS resreach program and prepared a manuscript in review for publication.
• Blum, M. A., Parrish, C. H., Hebert, D., Giacomelli, G. A., & Bergren, M. R. (2022, August). Enhancing light use efficiency and tomato fruit yield with quantum dot films to modify the light spectrum. IHC. Angers, France.: ISHS.
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  Oral presentation by Mmichael Blumfrom his MS resreach program and prepared a manuscript in review for publication.
• Gellenbeck, S., Giacomelli, G. A., & Pryor, B. M. (2019, October). Mushrooms on Mars. MBR Space Settlement Challenge. Dubai, UAE: UN Office for Outer Space Affairs, UAE Space Agency and the MBR Space Center.
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  MBR Space Settlement Challenge at conference we will be holding on 13-15th November. The purpose of the conference will be to discuss 7 of the projects done for the Challenge that focus specifically on Space Research & Technologies for Food and Water Security on Earth. Of course we will be happy to cover the associated expenses of course, including airfare and a 3-4 day hotel stay of your visit. The event will be held with the support of the UN Office for Outer Space Affairs and our national stakeholders including the UAE Space Agency and the MBR Space Center.
• Giacomelli, G. A., Santi, G., Moscatello, S., Proietti, S., Stefanoni, W., Brizi, F., Sadler, P., & Battistelli, A. (2015, May). Waste Biomass Characterization for the Planning of Recycling Loops in BLSS. ISLSWG Torino 2015. Turin, Italy: ISLSWG.
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  A biorefinery approach to waste recycling is becoming more and more relevant on earth and it may represent an interesting approach to increase the efficiency of bioregenerative life support systems (BLSS) for space. In this sense, a precise characterization (in terms of proteins, lipids, non structural carbohydrates (NSC), organic acids, structural carbohydrates, lignin and ash) of waste biomass produced by higher plants used in BLSS is a pre-requisite in order to plan the destination of such biomass in recycling loops. In fact, biomass composition is influenced by several factors like plant species, the type of tissues and the environmental growth conditions (i.e. light intensity, which also affects the overall energy consumption). For a correct biorefinery approach to space waste biomass, it must be considered that only some of its components can be digested by humans, or easily degraded into inorganic components in recycling systems, while others are recalcitrant to most biological degradation systems. However, some of these indigestible components, like cellulose and hemicellulose, can be recovered as food with simple methods.The aim of the present study was to characterize plant tissues (sweet potato and strawberry leaves, shoots and leaf disks) collected at two different light intensity ranges (800-1000 and 20-40 μmol quanta m-2 s-1: high and low light, respectively) in the Lunar Greenhouse at the Controlled Environment Agriculture Center (CEAC, University of Arizona, Tucson, AZ) in November 2013, and to demonstrate how it is possible to increase the digestible fraction of waste biomass. In particular, the effect of light intensity on the composition of sweet potato and strawberry leaves was evaluated and, after a two–way analysis of variance (ANOVA), with species and light intensity as main factors, it was evident that light intensity mostly affected total proteins, total carbohydrates and malic acid content (with the higher values being detected in leaves collected under high light intensity). Moreover, potato leaves were chemically characterized before and after a simple acid hydrolysis. Results showed that it was possible to increase the digestible fraction from about 50% to about 70% of the dry matter, as a consequence of the conversion of the indigestible structural polysaccharides (cellulose and hemicellulose) into monomeric sugars. In conclusion, our study demonstrates the importance of biomass characterization in view of the optimization of plant-growth conditions (e.g. light intensity), and might help to organize a biorefinery approach for a correct use of waste biomass in order to maximize its value in BLSS.
• Giacomelli, G. A. (2014, August). Plant Production, Energy Balance and Monitoring-Control-Telepresence in a Recirculating Hydroponic Vegetable Crop Production System: Prototype Lunar Greenhouse. IHC Australia.
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  G. Giacomelli, M. Kacira, R. Furfaro, R.L. Patterson and P. Sadler. 2014. Plant Production, Energy Balance and Monitoring-Control-Telepresence in a Recirculating Hydroponic Vegetable Crop Production System: Prototype Lunar Greenhouse, ACTA Horticulturae ??? IHC 2014 New Technologies in Protected Cropping Symposium in Australia in 2014.
• Giacomelli, G. (2012). State of the Art of Greenhouse Developments. 5th Workshop Internationale AGROSPAZIO2012 Agricoltura e Spazio. ex Chiesa. Sperlonga, Italy.
• Giacomelli, G. (2012). Technological Opportunities in Indoor Food Growing Systems: Working examples of South Pole and Moon Applications. NSF Workshop on Challenges in Vertical Farming.
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  Internet/intranet
• Giacomelli, G. (2012). Technology Challenges Now and in Future for Water Use in CEA -- Applying knowledge of Lessons learned from Mars/Moon. 15th Congreso International en Ciencias Agricolas. Mexicali, Mexico.
• Giacomelli, G. (2012). Urban Agriculture Indoor FarmingExperiences at the South Pole and on the Moon. NSF Workshop on Challenges in Vertical Farming. Tokyo, Japan.
• Giacomelli, G. A. (2012). Greenhouse Control and Plant Production. Taiwan Workshop - Greenhouse Control and Plant Production. Taichung, Taiwan: Taiwan Agricultural Research Institute, Council of Agriculture.
• Giacomelli, G. A. (2012). Greenhouse for Control of Plant Production: Education, Research, Outreach and Industry Collaboration in Controlled Environment Systems at UA-CEAC for Modern Agricultural Food Production Technology. Workshop on Greenhouse Horticulture IV. Taipei, Taiwan.
• Giacomelli, G., Furfaro, R., Kacira, M., Patterson, L., & David, S. D. (2012). Bio-Regenerative Life Support System Development for Lunar/Mars Habitats. 42nd ICES. San Diego.
• Giacomelli, G., Harrington, M., Sotala, A., & Wilson, S. (2012). Comparison of two delivery methods used to produce an online lecture entitled worldwide technology for controlled environment plant production. Annual ASHS Meeting. Miami, FL.
• Giacomelli, G., Kubota, C., Kacira, M., Rorabaugh, P., & Jensen, M. (2012). Education, Research, Outreach and Industry Collaboration in Controlled Environment Systems for Modern Agricultural Food Production Technology. CIPA Conference Plasticulture for a Green Planet. Tel Aviv, Israel.
• Giacomelli, G., Sadler, P., Patterson, R., Kacira, M., & Furfaro, R. (2012, September). Novel Applications in Controlled Environments, Controlled Environments Technology and Practice. 4th International Conference of UK-CEUG, North American NCERA-101 & Australasian ACEWG. Cambridge, UK.
• Giacomelli, G. A. (2011). Food Production Within Extreme Climates: Growing on Moon/Mars Requires Search for the Water. HortiFair Congress International. Amsterdam, The Netherlands.
• Giacomelli, G. A. (2011, November). HortiMax Workshop Facilitator. International HortiFair. Amsterdam, The Netherlands.
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  November 2, 2011: Facilitated panel presentations/discussion at the International HortiFair (November 1-4, 2011).

Poster Presentations

• Giacomelli, G. A., Parrish, C., Gellenbeck, S., & Shasteen, K. (2019, July). Mars-Lunar Greenhouse - Bioregenerative Life Support for Planet Habitation. 50th anniversary of the first moon landing. UA Lunar & Planetary Lab: UA Lunar & Planetary Lab.
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  Booth Display of Mars-Lunar Greenhouse - 50th anniversary of the first moon landing, 19th July, special commemoration event at the UA Lunar & Planetary Lab, with Charles Parrish, Sean Gellenbeck and KC Shasteen
• Giacomelli, G. A. (2014, March). Understanding root-microbe interactions at the leading edge of the rhizosphere: Harnessing the plant's 'white blood cells' to increase efficacy of compost applications. UA Sustainability Conference. Tucson, Arizona.
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  Curlango-Rivera, G. Tollefson, S. Pew, T. Giacomelli, G., & Hawes, M. C. (2014). Understanding root-microbe interactions at the leading edge of the rhizosphere: Harnessing the plant's 'white blood cells' to increase efficacy of compost applications. Poster presentation, UA Sustainability Conference, March 24-25.Tollefson, S.J., Curlango-Rivera, G., Pew, T., Giacomelli, G, and Hawes, M.C. (2013). Factors influencing disease suppression by compost water extracts (CWE) under controlled conditions. Poster presented at the American Phytopathological Society Caribbean and Pacific Division Meeting, June 17-19, Tucson, AZ

Creative Productions

• Giacomelli, G. A., & Furfaro, R. (2017. La coltivazione idroponica e i progetti della Nasa (Hydroponic cultivation and Nasa projects). Formeche Monthly Magazine, translation by Valeria Serpentini. Rome, Italy: Formeche Monthly Magazine, Agricultura 4.0 BRACCIA RUBATE ALL’INNOVAZIONE.
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  Experience and knowledge deriving from spatial projects in the agricultural sector are now also applied on Earth to develop food production activities within greenhouses, growth chambers and multi-level production systems that, compared to Traditional agricultural production systems in the fields, per single unit of cultivated product, use less water resources, nutrients for plants, energy and work. There is a better quality of food products, greater yield of crops, more food security and less waste, as well as a elimination of animal infestation and typical plant diseases
• Giacomelli, G., Kacira, M., Furfaro, R., Sheehy, C., & Sadler, P. (2014. "EARTHLIGHT" Documentary. Tucson Loft Theater viewing; DVD format released; online at CALS website. University of Arizona: College of Agriculture and Life Sciences. http://cals.arizona.edu/earthlight/
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  Earthlight documentary released in July 2014 to bring awareness about the need for sustainable food systems on earth and the possibility of creating such systems in the future on our moon or other planets.This documentary was awarded an Emmy in October, 2015. See Cody Sheehy accepting the award here: https://twitter.com/EarthlightDoc/status/657621949137448960/photo/1

Others

• Giacomelli, G. A., Kacira, M., Patterson, L., Furfaro, R., Sadler, P., Boscheri, G., Lobascio, C., Lamantea, M., Wheeler, R., & Rossignoli, S. (2011, June). System Dynamics and Performance Factors of a Lunar Greenhouse Prototype Bioregenerative Life Support System. GreenSys 2011.
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  Presented at Greece on 06/01/2011.
• Giacomelli, G. A., Kacira, M., Patterson, R. L., & Sadler, P. D. (2011, June). Operation and Production of the South Pole Food Growth Chamber (SPFGC). GreenSys 2011.
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  Presented at Greece 06/01/2011.
• Giacomelli, G. A., Kubota, C., Kacira, M., Villarreal-Guerrero, F., Fitz-Rodriguez, E., Linker, R., & Arbel, A. (2011, June). Simulation of Fixed and Variable Fogging Rates in a Naturally Ventilated Greenhouse: Water and Energy Savings and Stability of Climate. GreenSys 2011.
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  Presented at Greece 06/01/2011.
• Giacomelli, G. A. (2017, summer). Growing Secure, Sustainable, Sensational Foods at Controlled Environment Agriculture Center. Lee Allen, writer, BizTucson, Vol 9(2):108-109.
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  Growing Secure, Sustainable, Sensational Foods at Controlled Environment Agriculture Center, Lee Allen, BizTucson, Vol 9(2):108-109, Summer 2017
• Giacomelli, G. A., Kacira, M., Kubota, C., Fitz-Rodriguez, E., Villarreal-Guerrero, F., Linker, R., & Arbel, A. (2011, June). Neural Network Predictive Control in a Naturally Ventilated and Fog Cooled Greenhouse. GreenSys 2011.
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  Presented at Greece on 06/01/2011.
• Giacomelli, G. A. (2011, December). Prototype Lunar Greenhouse and South Pole Food Growth Chamber. Popular Press Interviews and Writings.
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  Numerous articles prepared by various TV and radio news, science and economic journals, web journals, and popular press outlets.
• Giacomelli, G. A. (2011, November). Food Production Within Extreme Climates: Growing on Moon/Mars Requires Search for the Water.
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  HortiFair Congress International. Invited presentation to opening session. The idea is to open the exhibition with a one day international symposium about water availability and water use worldwide. Presented at Amsterdam, the Netherlands, on 11/01/2011.
• Giacomelli, G. A., & Caulfield, J. (2011, October). Life Support: A greenhouse for growing food on the moon could serve the same purpose for cities on Earth. Builder Magazine.
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  Exact Date: 10/1/2011. Presented at Internet.John Caulfield, Builder Magazine. Hanley Wood, LLC.
• Giacomelli, G. A., & Collins, G. (2011, August). Want Fresher Produce? Leave Dirt Behind. The New York Times.
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  Exact Date: 8/2/2011. by Glenn Collins of The New York Times. Presented at New York Times Newspaper.
• Giacomelli, G. A., MacClellan, L., & Story, D. (2011, Fall). Controlled Environment Agriculture Center. The University of Arizona Controlled Environment Agriculture Center. http://ag.arizona.edu/ceac
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  Revisions in 2011 by Liz MacClellan and David Story.
• Giacomelli, G. A. (2010, Fall). CEAC Newsletter.
• Giacomelli, G. A., Kacira, M., Story, D., & Tevik, A. (2010, Fall). NASA Prototype Lunar Greenhouse. The AZ NASA Steckler Prototype Lunar Greenhouse Program.
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  Page: 10
• Giacomelli, G. A., MacClellan, L., Story, D., Giacomelli, G. A., Stein, D., Story, D., & Tevik, A. (2010, Fall). Controlled Environment Agriculture Center. The University of Arizona Controlled Environment Agriculture Center. http://ag.arizona.edu/ceac
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  Page: 10