Three separate Upland cotton variety evaluations were conducted in southeastern Arizona during the 2005 cotton growing season. Two locations were in Graham County, Thatcher and Ashurst, while the third location was in Cochise County in the community of Kansas Settlement. Eleven varieties were selected for both the Thatcher and Kansas Settlement locations while seven were planted at the Ashurst location. Varieties ranged in maturity from early to full at each of the three locations. All plots were arranged in a randomized complete block design with four replications. All three locations were planted on grower-cooperator fields and were managed in accordance to the individual grower styles. Plant measurements were collected over the course of the season at both the Thatcher and Ashurst locations. Lint yield was determined by harvesting the entire plot at each location and weighing the resultant seedcotton. Sub-samples were also collected at the time of harvest for percent lint estimates and fiber quality analysis. Lint yield levels at both the Ashurst and Thatcher locations were high. Due to poor initial germination, the Kansas Settlement location had to be replanted and was later maturing. Thus, lint yield was down some from the normal average in that area. At the Thatcher location lint yield ranged from 1200 to just over 1600 lbs. lint/acre with ST5242BR producing the highest lint yield and the highest crop value. In Ashurst the yields ranged from 950 to nearly 1350 lbs. lint/acre with Fiber Max FM960RR producing the highest lint yield. However, due to some fiber quality discounts it did not produce the highest crop value. Fiber Max FM989RR had excellent fiber quality and produced the highest crop value even though it produced a slightly lower yield. In Kansas Settlement lint yields ranged from 460 to approximately 850 lbs. lint/acre with the highest lint yield and total crop value being produced by Deltapine DP444BR. This is consistent with the earlier nature of this variety.

A single field trial was conducted in 2005 at the University of Arizona Safford Agricultural Center as part of the regional Extra Long Staple (ELS) cotton variety testing program. This trial was conducted to evaluate nine different ELS varieties under growing conditions of the Upper Gila River Valley. These nine varieties were planted in a randomized complete block design with four replications on 26 April 2005. All plots were managed in an optimum fashion with respect to general agronomic practices. Plot size was four rows 36” wide and 40’ in length. Lint yield was determined on 10 November by harvesting the center two rows of each plot and weighing the resultant seed cotton. Sub-samples were collected for percent lint determination and fiber quality analysis at the time of harvest. Lint yield averaged 1375 lbs/acre with a range of just over 1150 to nearly 1570 lbs lint/acre. Several experimental CPCSD varieties performed extremely well with E503 and E105 placing in the top three. The standard DP340 also placed in the top three. By comparison to the Pima S-7 variety significant advances in terms of yield are being made with the newer varieties being developed. Significant advances in fiber quality were also observed. Phytogen PHY800 performed very well with respect to fiber quality properties, particularly in comparison to the Pima S-7 standard of exceptional quality.

A single trial was conducted during the 2005 cotton growing season at The University of Arizona Safford Agricultural Center to evaluate the effects of the selective herbicide Envoke in combination and alone with the plant growth regulator (Pix). Combining applications of chemical inputs in a crop production system has the potential to help reduce costs by eliminating a trip across the field with equipment. The effects of these applications on growth, development, yield, and fiber quality was investigated. The trial was arranged with seven treatments including 1) control, 2) broadcast Envoke, 3) post-direct Envoke, 4) broadcast Pix, 5) broadcast Envoke + Pix, 6) post-direct Envoke followed by broadcast Pix, and 7) broadcast Pix followed by post-direct Envoke. These treatments were imposed in both normal and high soil moisture regimes. Plots were arranged in a randomized complete block design with four replications in two separate studies (normal and high soil moisture). Plots were monitored for effects on plant growth and development throughout the season by collecting a series of plant measurements from each treatment. Effects on final lint yield and fiber quality was determined by harvesting the center two rows of each four-row plot and weighing the resultant seed cotton. A sub-sample was collected for lint turnout and fiber quality analysis. Results indicated very little differences in plant growth and development among any of the treatments in both the normal and high moisture regimes. Significant differences were observed among lint yield and fiber quality parameters. Analysis of variance indicated significant effects due to treatment in lint yield, fiber length, strength, and uniformity. Significant differences were also observed due to soil moisture with respect to micronaire and fiber strength. Significant interaction between treatment and moisture regime was observed in micronaire, fiber length, strength, and uniformity. Results indicate that even though plant growth and development did not appear to be significantly impacted by the application of Pix + Envoke, lint yield was impacted. In both the normal and high soil moisture regimes the treatment receiving the combined application of Pix and Envoke produced the lowest yield.

Two rates of the ethylene blocker ReTain® were evaluated on four varieties of cotton in the Palo Verde Valley during the summer of 2005. Data indicated that responses to ReTain® varied greatly by variety. Application of ReTain® to DPL 555BR resulted in significant increases in numbers of fruiting structures per plant, however, these increases were not realized at harvest, as ReTain® treatments resulted in numerically reduced yields for this variety. Bolls per plant at harvest were not signficantly different for DPL 449BR, DPL 5415R or STV 5599BR. Both rates of ReTain® significantly increased uniformity of DPL 555BR cotton lint, but the lower rate of ReTain® evaluated usually resulted in slightly higher cotton lint quality for most components measured than did the higher rate. Quality and yield data were not collected for DPL 449BR, DPL 5415R or STV 5599BR.

Eight varieties were evaluated under field conditions for resultant plant populations after field infection with Rhizoctonia solani. Highest plant populations were noted in Delta and PineLand 454BR, followed by three other Delta and PineLand (DPL) varieties. Stoneville and Phytogen cotton varieties had reduced plant stands compared to DPL varieties at approximately 30 days after planting. DPL 454BR, which had the highest plant population, also had earlier growth and establishment than other varieties which is thought to have helped plant survival. Although all seed was treated with multiple fungicides, seed of DPL varieties was treated with several fungicide active ingredients (thiram, tridimenol) not present on seed from other varieties. Comparative increased stand on DPL varieties may be in part due to plant genetics as well as fungicide. Stand loss was noted in all varieties however. Data indicate that in-furrow application of fungicides or applications to small cotton plants may be necessary for heavier soils under cool and moist early season growing conditions in the low desert.

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.

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.

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.

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.

This study was conducted in 2005 at the University of Arizona Maricopa Agricultural Center. The objective was to compare the performance of various PPO inhibitors [Aim (carfentrazone-ethyl), ET (pyraflufen-ethyl), Blizzard (fluthiacet-methyl) and Resource(flumiclorac)] as stand-alone defoliation treatments either as a single or sequential application, or tank mixed with Ginstar or CottonQuik. Plots were arranged in a randomized, complete block design with four replicates. Each plot was composed of four, 40 inch rows that measured 25 feet long. Delta and Pine variety DP 449BR was planted on 12 April 2005. Treatments included: Ginstar @ 6 oz/A, Ginstar @ 8 oz/A, Aim @ 1 oz/A, ET @ 1.5 oz/A, Resource @ 8 oz/A and Blizzard @ 0.5 oz/A, Aim followed by Aim, ET followed by ET, Blizzard followed by Blizzard, Resource followed by Resource, Ginstar @ 6 oz/A plus Aim, Ginstar plus ET, Ginstar plus Resource, Ginstar plus Blizzard, CottonQuik at 32 oz/A plus Aim, CottonQuik plus ET, CottonQuik plus Resource, and CottonQuik plus Blizzard. All treatments receiving a PPO inhibitor also contained a Crop Oil Concentrate at 1% v/v. None of the PPO inhibitors applied as a single application performed as well as Ginstar at either the 6 oz/A or 8 oz/A rates. At 14 days after treatment (DAT), both Aim and Blizzard achieved 74% defoliation, Resource 69% and ET 60%. For sequential applications at 14 DAT, Aim at 1.5 oz/A followed eight days later by a second application of Aim performed as well as the standalone applications of Ginstar at 6 oz/A and 8 oz/A. Two applications of Blizzard at 0.5 oz/A eight days apart defoliated as well as Ginstar at 6 oz/A. Tank mixing any of the four PPO inhibitors with Ginstar did not improve defoliation over Ginstar alone, at either rate nor did defoliation rates decrease as a result of the mixes. A mixture of Aim + CottonQuik (75%) defoliated as well as a standalone treatment of Ginstar (82%).