Glenn C Wright
- Associate Specialist
- Associate Professor, Plant Sciences
- Ph.D. Horticulture
- Texas A&M University, College Station, Texas
- Effects of Salinity and Additional Calcium on Rabbiteye Blueberry (Vaccinium ashei Reade)
- M.S. Horticulture
- Texas A&M University, College Station, Texas
- Pre-harvest Pecan Yield Estimation in Texas
- B.S. Major: Horticulture, Minor: Spanish
- Colorado State University, Fort Collins, Colorado, USA
No activities entered.
Citrus ProductionPLS 403 (Spring 2020)
Citrus ProductionPLS 403 (Spring 2018)
Citrus ProductionPLS 403 (Spring 2016)
- Wright, G. C. (2016). Citrus Care. In Arizona Master Gardener Handbook.More infoThis is finished, and in press.
- Stover, E., & Wright, G. C. (2019). Walter Tennyson Swingle: A Relentless Intellect that Transformed American Pomology. Journal of the American Pomological Society, 73(2), 129-138.More infoWalter Tennyson Swingle grew up outside of Manhattan, Kansas, attended classes at Kansas State Agricultural College (now KSU) at 15, and when he graduated at 20 he had already published 27 scientific papers in plant pathology, plant breeding and genetics. Swingle joined the United States Department of Agriculture (USDA) in 1891, and was sent to Florida to investigate diseases in orange trees. He established a USDA laboratory and began a comprehensive program to breed disease- and frost-resistant citrus. He proposed testing all known wild relatives for disease-resistance and other advantageous traits that could be introduced to improve citrus. While conducting comprehensive studies of the comparative anatomy and systematics of the orange subfamily, he discovered some new species and several new genera. His breeding originated several new categories of citrus: the tangelos, citranges and citrumelos (now critical as rootstocks), and many other intergeneric hybrids. He was an early advocate for permanent, living collections of economically important plants and their close relatives. In 1897-98, in collaboration with David Fairchild, he established the USDA's Office of Foreign Seed and Plant Introduction, and new plant introduction research facilities were set up in Miami. He was a champion for ensuring that introduced plants were disease and pest free. He conducted plant exploration, mainly in countries surrounding the Mediterranean, and among many other accessions introduced date palms, figs, table grapes, and ‘Clementine’ mandarins. He also brought in the Blastophaga wasp to pollinate Smyrna-type figs. After his retirement from the USDA, Swingle moved to Miami in 1943 and completed his treatise on the taxonomy of the citrus subfamily. “Even in his retirement, Swingle inspired a generation of students with his knowledge, curiosity of nature, and insights into plants. His simple advice to students was ‘Look and look, again and again,’ words still relevant today”.
- Bidabadi, S. S., Dehghanipoodeh, S., & Wright, G. C. (2017). Vermicompost leachate reduces some negative effects of salt stress in pomegranate. International Journal of Recycling of Organic Waste in Agriculture, 6, 1-9. doi:10.1007/s40093-017-0173-7
- Wright, G. C. (2016). The Commercial Date Industry in the United States and Mexico. HORTSCIENCE, 51(11), 1333-1338.
- Kahn, T. L., Samons, V., & Wright, G. C. (2015). When life gives you lemons, it's time to make a profit.. Citrograph, 6(3), 48-59.
- Kahn, T., & Wright, G. (2015). Update on Evaluations of Lemon Selections for the California Desert. HortScience, 50(9), S189 (Abstr.).
- Wright, G. C., & Schuch, U. K. (2015). Pomegranate Variety Trial in Arizona. HortScience, 50(9), S309 (Abstr.).
- Wright, G., & Caravetta, G. (2014). Response of Government and the Citrus Industry to the Discovery of Asian Citrus Psyllid in Arizona. Journal of Citrus Pathology, 1(1), 80.
- Schuch, U. K., Wright, G. C., & Mahato, T. (2013). Pomegranate Variety Trial in Southern Arizona.. HortScience, 48(9), 396.
- Wright, G. (2012). Date Cultivation in Arizona and the Bard Valley. J. Amer. Pom. Soc, 66(3), 110-117.
- Wright, G. (2012). Nitrogen Fertilization Guidelines for Non- bearing Medjool Date Palms. HortScience, 47(9), S305.More infoHortSci
- Wright, G. C. (2008). Evaluation of ten navel orange (Citrus sinensis) selections under Arizona desert conditions. Acta Horticulturae, 773, 77-82.More infoAbstract: A navel orange (Citrus sinensis) trial was established at the University of Arizona Citrus Agriculture Center, Waddell, AZ in 1999. This trial consists of the following selections: 'Beck-Earli', 'Cara Cara', 'Chislett', 'Fisher', 'Fukumoto', 'Lane Late', 'Powell', 'Spring', 'Washington' and 'Zimmerman', all on Carrizo citrange rootstock. 'Washington' is the standard cultivar selection for the local industry. Yield, packout and fruit quality data have been collected since the first harvest in 2001. 'Fisher', 'Lane Late', 'Beck-Earli' and 'Washington' have had the greatest 5-year cumulative yield, and those selections as well as 'Cara Cara' had good annual yields in 2005-06. 'Beck-Earli' and 'Chislett' have had good yields for the 2004-05 seasons. 'Beck-Earli', 'Chislett', and 'Lane Late' generally have had large fruit size over the course of the experiment. 'Zimmerman', 'Cara Cara' and 'Washington' had large fruit size in 2004-05. 'Beck-Earli' has had characteristically elongated fruit, while the rest of the selections have had more rounded fruit. Among the early-harvest fruit, 'Fisher' is the least colored, and 'Fukumoto' colors the best. 'Spring' fruit has the best color among those selections harvested late. 'Cara Cara' fruit typically has had the highest level of solids, while the late navels have lower levels of solids. Peel thickness and granulation of the selections varies depending on the year. Based on the data collected so far, 'Beck-Earli', 'Cara Cara', 'Chislett', 'Fisher', 'Fukumoto' and 'Lane Late' appear to be suitable alternatives to 'Washington' in the desert.
- Wright, G. C. (2007). An overview of the changing date industry in the United States. Acta Horticulturae, 736, 47-52.More infoAbstract: The commercial date industry in the United States is located primarily in the Sonoran Desert of southeast California and southwest Arizona. The industry comprises about 3800 hectares, of which 78% is found in California and the rest in Arizona. While date palms were introduced to the United States by the Spaniards, small quantities were imported for experimental purposes beginning in the late 1800's, and commercial quantities were imported in the early 1900's. During this period, most imported offshoots originated from Algeria, Egypt, Tunisia and Iraq. Important varieties that were imported include 'Deglet Noor', 'Khadrawi', 'Zahidi', 'Hayany' and 'Halawy'. More recently, the 'Medjool' from Morocco was introduced. This variety is becoming increasingly popular because of its large size and high sugar content. Date palm operations are moving from areas that are under pressure from urbanization to more remote locales. Low volume drip and microjet irrigation is beginning to replace the tradition flood and basin irrigation methods. Some dates are produced using organic methods because of consumer demand. Farm operations begin in January when the trees are dethorned. Operations that occur later in the year include pollination, training the fruit arms, strand thinning, fruit thinning, supporting the arms, spreading the strands, bagging the developing fruit and harvest. Individual growers are increasingly forming cooperatives to pack the fruit at a centrally located packinghouse. At the house, fruit are graded, then packed, and placed in storage until shipment. Dates from the region are marketed by individual growers, and by the grower cooperatives, and sold to customers around the world. Palm trees are also sold for landscape purposes to customers across the United States.
- Kusakabe, A., White, S. A., Walworth, J. L., Wright, G. C., & Thompson, T. L. (2006). Response of microsprinkler-irrigated navel oranges to fertigated nitrogen rate and frequency. Soil Science Society of America Journal, 70(5), 1623-1628.More infoAbstract: Microsprinklers allow precise control of irrigation water applications and offer the potential for higher efficiency of water and fertilizer use compared with flood irrigation. A field experiment was conducted during 1999-2002 in central Arizona (AZ) to evaluate effects of various N rates and fertigation frequencies on fruit yield and quality, leaf N concentration, and residual soil N of 'Newhall' navel oranges (Citrus sinensis) on 'Carrizo' citrange (Porcirus trifoliata x Citrus sinensis) rootstock (planted in 1997) grown in a Gilman (coarse-loamy, mixed, superactive, calcareous, hyperthermic Typic Torrifluvents) fine sandy loam. The experiment included nonfertilized control plots and factorial combinations of three fertigation frequencies (27, 9, and 3 applications annually) and three N rates (68, 136, and 204 g N tree-1 yr-1). Maximum yields occurred at N rates of 105 to 153 g N tree-1 yr-1 for the fourth to the sixth growing seasons. The yield-maximizing N rates were equivalent to 17 to 34% of currently recommended N rates for citrus grown in AZ. Fruit and juice quality did not show significant response to N rate or fertigation frequency. Leaf N concentrations at yield-maximizing N rates were above the critical leaf tissue N range of 25 to 27 mg g-1, indicating that this range may be too low for these 'Newhall' navel orange trees. During all three seasons, higher residual soil NO3 concentrations resulted from the highest N rate. Our results suggest that optimum N rates for microsprinkler-irrigated 'Newhall' navel oranges in AZ are lower than currently recommended N rates. © Soil Science Society of America.
- Wright, G. C., McCloskey, W. B., & Taylor, K. C. (2003). Managing orchard floor vegetation in flood-irrigated citrus groves. HortTechnology, 13(4), 668-677.More infoAbstract: Several orchard floor management strategies were evaluated beginning in Fall 1993 in a 'Limoneira 8A Lisbon' lemon (Citrus limon) grove on the Yuma Mesa in Yuma, Ariz. and in a 'Valencia' orange (Citrus sinensis) grove at the University of Arizona Citrus Agricultural Center, Waddell, Ariz. At Yuma, disking provided acceptable weed control except underneath the tree canopies where bermudagrass (Cynodon dactylon), purple nutsedge (Cyperus rotundus), and other weed species survived. Mowing the orchard floor suppressed broadleaf weed species allowing the spread of grasses, primarily bermudagrass. Preemergence (norflurazon and oryzalin) and postemergence (glyphosate and sethoxydim) herbicides were used to control weeds in the clean culture treatment in Yuma. After three harvest seasons (1994-95 through 1996-97), the cumulative yield of the clean culture treatment was 385 kg (848.8 lb) per tree, which was significantly greater than the 332 kg (731.9 lb) and 320 kg (705.5 lb) per tree harvested in the disking and mowing treatments, respectively. In addition, the clean culture treatment had a significantly greater percentage of fruit in the 115 and larger size category at the first harvest of the 1995-96 season than either the disk or mow treatments. At Waddell, the management strategies compared were clean culture (at this location only postemergence herbicides were used), mowing of resident weeds with a vegetation-free strip in the tree row, and a 'Salina' strawberry clover (Trifolium fragiferum) cover crop with a vegetation-free strip. The cumulative 3-year yield (1994-95 through 1996-97) of the clean culture treatment was 131 kg (288.8 lb) per tree, which was significantly greater then the 110 kg (242.5 lb) per tree yield of the mowed resident weed treatment. The yield of the strawberry clover treatment, 115 kg (253.5 lb) of oranges per tree, was not significantly different from the other two treatments. The presence of cover crops or weeds on the orchard floor was found to have beneficial effects on soil nitrogen and soil organic matter content, but no effect on orange leaf nutrient content. The decrease in yield in the disked or mowed resident weed treatments compared to the clean culture treatment in both locations was attributed to competition for water.
- Demetriou, M. C., Thompson, G. A., Wright, G. C., & Taylor, K. C. (2000). A molecular approach for the diagnosis of wood rotting disease in desert citrus. Mycologia, 92(1-6), 1214-1219.More infoAbstract: Brown heartwood rot is an increasingly important problem in southwestern deserts, affecting numerous native tree species, and commercial lemon production. Two fungal pathogens, Coniophora eremophila and Antrodia sinuosa, have been identified as causal agents of brown heartwood rot in citrus. Development of effective disease management strategies relies on the ability to readily identify and distinguish between the pathogens; therefore we have developed molecular markers as an alternative to morphometric methods to differentiate these two economically important pathogens. Random amplified polymorphic DNA analysis identified four primers that revealed fungal polymorphisms. Polymorphic DNA fragments were cloned, sequenced, and used to create a 700 bp sequence characterized amplified region (SCAR) in C. eremophila isolates using sequence-specific primers, Conio7 and Conio8. Three fragments (300, 650, and 1000 bp) were amplified with Conio7 and Conio8 in A. sinuosa isolates. A rapid, small scale method for DNA extraction from fungus was developed to expedite the technique. With this method, the usefulness of the Conio7 and Conio8 was verified using new Coniophora eremophila and Antrodia sinuosa isolates from citrus.
- Fidelibus, M. W., Martin, C. A., Wright, G. C., & Stutz, J. C. (2000). Effect of arbuscular mycorrhizal (AM) fungal communities on growth of 'Volkamer' lemon in continually moist or periodically dry soil. Scientia Horticulturae, 84(1-2), 127-140.More infoAbstract: Citrus volkameriana Tan. and Pasq. ('Volkamer' lemon) seedlings were inoculated with five different communities of arbuscular mycorrhizal (AM) fungi collected from citrus orchards in Mesa and Yuma, AZ, USA, and undisturbed North American Sonoran Desert and Chihuahuan Desert soils. Plants were then grown in a glasshouse for four months under continually moist or periodically dry conditions achieved by altering watering frequency so that before watering events container soil water tensions were approximately -0.01 MPa (continually moist) or -0.06 MPa (periodically dry) one half way down the container profile. Plants grown in continually moist soil had greater shoot growth than plants grown in periodically dry soil. Plant P status did not limit growth, and there was no interaction between watering frequency and AM fungal inoculum treatments. Plants inoculated with AM fungi from the Yuma orchard soil had significantly less root dry weight and total root length, and lower photosynthetic fluxes than plants treated with inoculum from the other soils. Specific soil respiration and an estimated carbon cost to benefit ratio were also higher for plants inoculated with AM fungi from the Yuma orchard soil than for plants treated with inoculum from the other soils. The Yuma orchard inoculum was distinctive in that > 80% of the total number of AM fungal spores were from a single species, Glomus occultum. These data showed that root growth suppression of plants treated with the Yuma inoculum, compared with plants treated with inoculum from all other sites, was substantial and greater in magnitude than the effect of periodic soil drying. Suppression of root growth might have resulted from increased AM fungal activity resulting in higher carbon costs to the plant. (C) 2000 Elsevier Science B.V.
- Wright, G. C. (1999). The carbohydrate economy of horticultural crops: Introduction to the colloquium. HortScience, 34(6), 1014-1015.
- Wright, G. C., Patten, K. D., & Drew, M. C. (1995). Labeled sodium (22Na+) uptake and translocation in rabbiteye blueberry exposed to sodium chloride and supplemental calcium. Journal of the American Society for Horticultural Science, 120(2), 177-182.
- Wright, G. C., Patten, K. D., & Drew, M. C. (1994). Mineral composition of young rabbiteye and southern highbush blueberry exposed to salinity and supplemental calcium. Journal of the American Society for Horticultural Science, 119(2), 229-236.
- Wright, G. C. (2018, March). The Date Industry in the United States and Mexico. In Sixth International Date Palm Conference, 117-122.
- Wright, G., & Kahn, T. (2012, Fall). Evaluation of Lemon Selections for the deserts of the United States. In Proc. Intl. Citrus Congress, 312.
- Wright, G. C. (2018, March). The Date Industry in the United States and Mexico. Sixth International Date Palm Conference. Abu Dhabi, United Arab Emirates.
- Wright, G. C., & Schuch, U. K. (2015, October). Pomegranates - The Arizona Story. Florida Pomegranate Society Conference. Lake Alfred, FL: Florida Pomegranate Society.
- Wright, G. C. (2014, February). Manejo de huertos de mandarinas en ambientes desérticos. Citrica 2014, Lima Peru. Lima, Peru: Informaccion/Lima -Peru and UNALM - Universidad Nacional Agraria La Molina / Lima - Perú.
- Wright, G. C., Johnson, D., & El Houmaizi, M. A. (2014, March). Medjool- the King of Dates, and elite date cultivar. Fifth International Date Palm Congress, Abu Dhabi. Abu Dhabi, United Arab Emirates: UAE University.
- Hoddle, M., & Wright, G. C. (2018, March). The South American Palm Weevil. Sixth International Date Palm Conference. Abu Dhabi, United Arab Emirates.
- Wright, G. C. (2017, August). Application of plant growth regulators and calcium to reduce skin separation in ‘Medjool’ dates. XIII International Symposium on Plant Bioregulators in Fruit Production. Chiba, Japan: International Society for Horticultural Science.More infoSummary: ‘Medjool’ is one of the world’s most expensive and profitable dates. However, costs to grow the fruit are also high, so the highest quality must be maintained. Exterior appearance is an important quality parameter. Skin separation (Figs. 1 and 2) is a defect that can downgrade the fruit and reduce profits. Skin separation occurs when the epicarp separates from the mesocarp; a phenomenon that appears only once the fruit dries to the rutab to the tamar stage, not in the khalal (colored) stage. Calcium, GA, and ABA have all been proposed to reduce skin separation. Applications of CaCl2(625 mg/l), S-ABA (500 ppm), CaCl2 (625 mg/l) + S-ABA (500 ppm), ProGibb® 40% at 24 g a.i., ProGibb® 40% at 32 g a.i., CalTrac (Ca fertilizer mfg. by Yara North America) at 4.7 l/ha and Powerbor CA (Calcium-boron fertilizer mfg. by Yara North America) at 4.7 l/ha were made to individual bunches of date fruit on 20 trees in two orchards in late July 2016. Two sequential harvests for each orchard occurred in September 2016, then the fruit was sorted by color, dehydrated to a uniform moisture content and resorted for quality. There was no consistent effect of treatments upon fruit color in the first harvests. However, applications of ProGibb led to significantly more fruit in the yellow khalal stage for the second harvests in both orchards. Applications of ABA, and sometimes ABA + CaCl2 led to a 5 to 10% increase in fruit of the higher quality, but these increases were trends, and were not significant. Subsequent experiments should take application timing into consideration.
- Wright, G. C., & Kahn, T. L. (2016, September). LEMON CULTIVAR EVALUATION FOR THE CALIFORNIA AND ARIZONA DESERTS. International Society of Citriculture Conference. Foz do Iguassu, Brazil: International Society of Citriculture.
- Wright, G. C., Matheron, M. E., & Martin, P. (2016, September). ANTRODIA SINUOSA – A WOOD ROTTING FUNGUS THAT ADVERSELY AFFECTS LEMONS IN ARIZONA. International Society of Citriculture Conference. Foz do Iguassu, Brazil: International Society of Citriculture.
- Wright, G. C., & Schuch, U. K. (2015, Aug). Pomegranate Variety Trial in Arizona. American Society for Horticultural Sciences Conference. New Orleans: American Society for Horticultural Sciences.
- Schuch, U. K., Wright, G. C., & Mahato, T. (2014, May 9). Pomegranate Variety Trial in Southern Arizona. Desert Horticulture Conference, Tucson. Tucson.
- Schuch, U. K., Wright, G. C., & Mahato, T. (2014, November 10). Pomegranate Variety Trial in Southern Arizona. CALS Annual Research Poster Forum, Tucson. Tucson.
- Wright, G. C. (2014, August). Mechanization and Innovation In The High-Value ‘Medjool’ Date Palm Orchard - Moving Into The Future. International Horticultural Congress, Brisbane. Brisbane, Australia: International Society for Horticultural Sciences.
- Wright, G. C., & Kahn, T. L. (2014, August). Evaluation of 12 Lemon Selections in The California Desert. International Horticultural Congress, Brisbane. Brisbane, Australia: International Society for Horticultural Sciences.
- Hu, J., & Wright, G. C. (2019, July). Coupling Spore Traps and Quantitative PCR Assays for Detection and Quantification of Airborne Spores of Antrodia sinuosa in Lemon Orchards of Yuma - 2018. Arizona Citrus Research Council Website https://agriculture.az.gov/arizona-citrus-research-council-previously-funded-research-projects. https://agriculture.az.gov/sites/default/files/documents/Coupling%20Spore%20Traps%20and%20Quantitative%20PCR%20Assays%20for%20Detection%20and%20Quantification%20of.......%20-%202018.pdf
- Hu, J., & Wright, G. C. (2019, June). Huanglongbing of Citrus. University of Arizona Cooperative Extension Publication AZ 1795. https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1795-2019.pdf
- Wright, G. C., & Poe, S. E. (2019, July). Citrus Rootstock Acquisition and Evaluation — 2018. Arizona Citrus Research Council Website https://agriculture.az.gov/arizona-citrus-research-council-previously-funded-research-projects. https://agriculture.az.gov/sites/default/files/documents/Citrus%20Rootstock%20Acquisition%20and%20Evaluation%20%20-%202018.pdf
- Wright, G. C. (2018, March). Control of Brown Wood Rot in Lemons - 2017. Arizona Citrus Research Council Website.More infofile:///C:/Users/Glenn%20Wright/Downloads/Control%20of%20brown%20wood%20rot%20in%20lemons%20-%202017.pdf
- Wright, G. C., & Poe, S. E. (2018, March). Citrus Rootstock Acquisition and Evaluation — 2017. Arizona Citrus Research Council Website.More infofile:///C:/Users/Glenn%20Wright/Downloads/Citrus%20Rootstock%20Acquisition%20and%20Evaluation%20New%20%20%202017.pdf
- Wright, G. C. (2015, February). Area-Wide Spraying for Asian Citrus Psyllid in Texas and Florida. Commodity Research Report. http://extension.arizona.edu/pubs/area-wide-spraying-asian-citrus-psyllid-texas-and-floridaMore infoRealizing that the Arizona citrus industry might someday have to deal with widespread ACP control, the Arizona Citrus Research Council approved a trip to Florida and Texas to investigate how ACP control was accomplished in those two states. The trips were to McAllen, Texas on 9-12 Nov 2011 and to Immokalee Florida on 17-18 Nov. 2011. In McAllen, I interviewed Dr. Mamoudou Setamou, extension entomologist for Texas A&M – Kingsville and his staff, and Mr. Ray Prewitt, president of Texas Citrus Mutual. In Florida, I interviewed Mr. Ron Hamel, manager of the Gulf Citrus Growers, and Dr. Mongi Zekri, southwest Florida Multi-County Citrus Agent, housed at the Hendry County Extension Office in LaBelle., FL. The author hopes that some of this information can be used in the development of an Area Wide Spray Plan in Arizona.
- Wright, G. C. (2015, February). Control of Brown Wood Rot in Lemons with Low Pressure Injection 2012. Commodity Research Report. http://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1652-2015.pdfMore infoAbstract We injected AGRA PHOS (Potassium Phosphite) 0-2.4-2, Propaconizole – 0.05%, Propaconizole plus Azoxystrobin – 0.117 and 0.135% respectively, Zn, Mn and Fe 0.105, 0.112, and 0.10% respectively, and Azoxystrobin – 0.137% using a low pressure injection system for the control of Antrodia sinuosa in lemon trees. The Propaconizole + Azoxystrobin treatment, the Azoxystrobin treatment, and the Zn + Mn + Fe treatment led to significantly less fungal lesion growth when applied prior to the introduction of the fungus, as compared to their application after fungal introduction.
- Wright, G. C. (2015, February). Evaluation of Nitrogen Fertilization Practices for Surface-Irrigated Lemon Trees – 2012. Commodity Research Report. http://extension.arizona.edu/pubs/evaluation-nitrogen-fertilization-practices-surface-irrigated-lemon-trees-2012More infoAbstract: Lisbon lemons were treated with N levels ranging from 0.5 to 3.0 lbs. N per tree annually. Fourth–season yield results from the trial show significant effects of the treatments upon overall yield and leaf N concentrations, but no effect upon fruit packout. Treatments did lead to a significant effect upon leaf nutrient concentration. Total cumulative yields from 2008 to 2012 (not including the freeze-affected 2011-12 season) were significantly affected by the treatments. Trees treated annually with 2.0 lbs N had the greatest yield, which represented a 12% increase over the yield of trees treated with just 0.5 lbs. N annually.
- Wright, G. C. (2015, July). Citrus Fertilization Chart for Arizona. CALS Extension Publication #AZ1671. http://extension.arizona.edu/pubs/citrus-fertilization-chart-arizona
- Wright, G. C. (2015, September). Control of Brown Wood Rot in Lemons with Low Pressure Injection 2013-14. Commodity Research Report. http://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1680-2015.pdf