• Comparative Responses of Three Cotton Varieties to Mid-July 2005 Application of Chaperone™ in the Palo Verde Valley

      Rethwisch, Michael D.; Milke, Jose; Wellman, Jessica J.; Luna, Manuel; Ramos, D. Michael; Van Dyke, Joe; Tronstad, Russell; Norton, E. Randy (College of Agriculture, University of Arizona (Tucson, AZ), 2006-07)
      Chaperone™ was applied in mid-July to three different cotton varieties (DPL 449BR, DPL 555BR, STV 5599BR) being grown in the same field. Varieties differed in their responses, with application of Chaperone™ resulting in fewer fruiting structures per plant than untreated DPL 449BR or STV 5599BR, but more such structures in DPL 555BR. Seed cotton yields were increased in DPL 555BR by almost 300 lbs./acre by application of Chaperone™, but were only about 20 lbs./acre greater in the other two varieties. A higher percentage of lint in seed cotton was associated with Chaperone™ application in both DPL 449BR and STV 5599BR, but a lower percentage in DPL 555BR. Calculated lint yields increased in both DPL 449BR and STV 5599BR, but yields were almost identical for treated/untreated DPL 555BR in this experiment. Application of Chaperone™ resulted in a slight increase in fiber uniformity in all three varieties.
    • Comparison of Three Plant Growth Regulator Products on April Planted DPL 555BR Cotton, 2005

      Rethwisch, Michael D.; Swan, Ron; Luna, Manuel; Ramos, D. Michael; Wellman, Jessica; Tronstad, Russell; Norton, E. Randy (College of Agriculture, University of Arizona (Tucson, AZ), 2006-07)
      Three plant growth enhancement treatments were applied to April-planted DPL 555BR cotton on the morning of July 2, 2005. Plant parameter data were obtained during July, and yield and quality data were obtained at harvest in December. Usage of ChaperoneTM resulted in decreased potassium and phosphorus levels in petioles, as well as increased amounts of leaf chlorophyll. Treatments initially resulted in less fruiting structure/plant but had more than the untreated cotton at 26 days post treatment, with highest numbers per plant noted from the HappyGroTM + PhotoGro treatment. Each treatment resulted in less seed cotton and lint per acre than the untreated cotton. Less spotting associated with treated cotton increased the lint strength and increased trash levels. The AuxiGro® WP + CalMax® + Foliar Pride treatment resulted in the highest fiber strength per pound and lint value.
    • Effects of Goëmar® BM86 and Mepiquat Chloride on DPL 449BR/DPL 494R Cotton

      Rethwisch, Michael D.; Cox, Tim; Ramos, D. Michael; Luna, Manuel; Wellman, Jessica; Tronstad, Russell; Norton, E. Randy (College of Agriculture, University of Arizona (Tucson, AZ), 2006-07)
      A field experiment compared several rates of mepiquat chloride and Goëmar® BM86 on Upland cotton in the Palo Verde Valley during 2005 for their effects on cotton growth and yields. Leaf chlorophyll levels were significantly increased in DPL 449BR by usage of mepiquat chloride on initial samples dates after applications, and these treatments also effected cotton heights. Retention percentages and numbers of fruiting structures per plant were initially increased by treatments which contained Goëmar® BM86, although late in the season significant differences existed between Goëmar® BM86 treatments as a result of interaction with mepiquat chloride. All treatments resulted in a slight (0.01 inch) increase in fiber length as well as staple, resulting in increased lint value. The combination treatment of Goëmar® BM86 plus 12 oz./acre of mepiquat chloride had highest cotton value ($1,035/ acre), and was worth $178/acre more than the untreated check.
    • Field Comparison of Various Plant Growth Enhancement Products on DPL 449BR Cotton, 2005

      Rethwisch, Michael D.; Luna, Manuel M.; Ramos, D. Michael; Wellman, Jessica J.; Reay, Mark; Tronstad, Russell; Norton, E. Randy (College of Agriculture, University of Arizona (Tucson, AZ), 2006-07)
      Three plant growth enhancement chemistries (AuxiGro®, ChaperoneTM, HappyGroTM) were evaluated on DPL 449BR cotton during the summer of 2005, Application were made during mid-July to late planted cotton to evaluate and compare effects of these products on cotton growing under severe heat and growth stress to determine if such chemistries could overcome this stress. Two foliar fertilizers were included with two formulations of AuxiGro® to determine if differences associated with these treatments existed. Usage of HappyGroTM = PhotoGroTM resulted in the most fruiting structures/plant while treatments that included ChaperoneTM resulted in reduced numbers of structures when compared with the untreated check on August 24. Highest yields among products tested were noted for the formulations of AuxiGro® 518 which were slightly higher than the untreated check. Quality was improved in comparative formulations of AuxiGro® by inclusion of CalMax® + First Choice® Foliar Pride when compared with First Choice® Bollster.
    • Pistil and Style Elongations Beyond the Anthers: Results From 2005 Field Experimentation

      Rethwisch, Michael D.; Luna, Manuel M.; Ramos, D. Michael; Wellman, Jessica J.; Williams, Michael T.; Tronstad, Russell; Norton, E. Randy (College of Agriculture, University of Arizona (Tucson, AZ), 2006-07)
      A rapid heat increase from the high 80s-low 90s to high temperatures of 110o F on May 21 and 22, 2005, was recorded in the Blythe, CA, area, resulting in abnormal cotton flowers in mid-June, being especially characterized by elongated styles and stigmas being beyond the anthers. Two different cotton variety trials conducted in the Palo Verde Valley allowed data to be collected semi-weekly beginning June 17-20, with 100+ flowers per plot examined in each plot (four replications) of each of the 14 cotton variety entries. Every cotton variety had an average of 90+% of flowers expressing heat stress abnormalities (elongated styles) at the beginning of data collection even though the trials varied by planting date and location. Abnormal flowers were noted for several weeks, with some stigmas 21 mm beyond the anthers. Varieties differed in their responses to heat stress as measured by elongation later in the summer. Limited data were also collected for fruit retention and correlated with length of stigma extension beyond anthers. Retention percentages decreased as distance between anthers/stigmas increased, however boll size increased with less retention, possibly through nutrient partitioning. Various foliar fertilizers containing calcium were also evaluated for their effect on stigma elongations of DPL 449BR cotton. Significant differences existed for stigma elongations, with 2.5 qts./acre of CalMax resulting in statistical reduction of elongation when compared with the untreated check at 3 weeks after application. Statistical differences did not exist at four weeks although statistical differences did exist at this date for the percentage of flowers affected, with the highest percentage (81.7%) noted in untreated cotton.