• Acala Cotton Variety Trial, Safford Agricultural Center, 2001

      Clark, L. J.; Carpenter, E. W.; Norton, E. R. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      Six New Mexico and California Acala cotton varieties were tested along with three upland varieties with good quality and excellent yield potential in a replicated small plot trial on the Safford Agricultural Center in Graham county at an elevation of 2950 feet. The highest yielding variety in this study was DP 655BR with a yield of 1367 pounds of lint per acre. The next highest variety was Fiber Max 989. This latter variety, while not officially classified as an Acala, produced the longest fiber in the study. Yield and other agronomic data as well as fiber quality data are contained in this paper.
    • Defoliation of Pima and Upland Cotton at the Safford Agricultural Center, 2001

      Clark, L. J.; Coleman, R. D.; Carpenter, E. W.; Norton, E. R. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      Nine defoliation treatments based on standard and reduced rates of Ginstar and Chlorate plus two additives (compounds F and S) were applied to Pima and Upland cotton to compare the treatment effects on percent leaf drop and yields. All of the treatments were beneficial to leaf drop compared to the untreated check with the Ginstar treatments generally performing better than the Chlorate. Both of the additives enhanced the early defoliation effectiveness for the reduced rates of Chlorate and Ginstar over all other treatments, including the full rates of the Chlorate and Ginstar. Generally, this same enhanced effectiveness was seen of the additives plus reduced rates over the full rates of Chlorate and Ginstar throughout the defoliation process. This is the second year of the study.
    • Evaluation of a Twin-Line Cotton Production System in Graham County

      Norton, E. R.; Clark, L. J.; Carpenter, E. W.; Husman, S. H.; McCloskey, W. M.; Clay, P. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      A single field study was established in 2001 at the Safford Agricultural Center to evaluate a twin-line cotton production system. This location was part of a larger, statewide program conducted in 2001. This location consisted of two separate planting dates (PD) in which two separate planting systems were used. Results from this location indicated trends in yield increases with the twin-line production system when compared to the single or conventional production system. Lint yield increases of approximately 200 lbs. lint/acre were observed on the second PD. Lower yields were observed in the twin-line planting with the first PD which was in part due to poor seed placement with the equipment used to plant the twin-line on the first PD. Results indicate the potential for increased yield with the twin-line production system with the caveat that the proper equipment be used to plant the twin-line system to ensure precise and consistent seed placement and spacing.
    • Phosphorus Fertility Evaluation in Graham County

      Norton, E. R.; Silvertooth, J. C.; Clark, L. J. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      A series of three phosphorus (P) fertility experiments were conducted in 2001 in Graham County. These studies follow similar experiments conducted over the past three seasons. Results from 2001 were consistent with previous results indicating a positive relationship between yield and P fertilizer applications in relation to soil test indices. Modest yield increases were observed from a minimum of 25 to 80 lbs. lint per acre with an application of approximately 70 lbs. of P as P₂O₅ per acre. Yield differences from previous years have been as great as 170 lbs. of lint per acre. With the increased use of UAN-32 as a primary fertilizer source and a reduction in the application of P fertilizers, which is typically associated with a rotation of small grains, a depletion of soil P is a potential result. A continuation of this research with varying rates of P fertilizer will take place in 2002 in an attempt to relate soil test P levels to yield increases observed in recent years. The results of this research demonstrate the possible need for a return to use of fertilizers with supplemental P for optimum yields that would be predictable based on soil test results.
    • Pima Cotton Regional Variety Trial, Safford Agricultural Center, 2001

      Clark, L. J.; Carpenter, E. W.; Norton, E. R. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      Twenty long staple varieties were tested in a replicated small plot trial on the Safford Agricultural Center in Graham County at an elevation of 2950 feet. The highest yielding variety in this study was HAZ 195 with a yield of 1408 pounds of lint per acre. This interspecific hybrid possessing a “fuzzy” seed and was tested with the Acala varieties in 2000, but was included in the Pima study this year because of it’s fiber characteristics. OA 345 was the highest yielding nonhybrid variety in the study, it yielded nearly 800 pounds of lint per acre. Yield and other agronomic data as well as fiber quality data are contained in this paper along with estimated values of the lint.
    • Planting Date by Variety Evaluation in Graham County

      Norton, E. R.; Clark, L. J.; Carpenter, E. W. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      A single field study was established in 2001 at the Safford Agricultural Center to evaluate the effects of planting date and variety on crop growth and yield. Ten varieties were selected and planted on three separate planting dates in a split-plot randomized complete block design with four replications. Results from this experiment indicated significant differences due to planting date and variety. The interaction between planting date and variety was not significant. Yield trends were increasing with later planting dates which is thought to be a function of the inclement weather conditions surrounding particularly planting date one but also two. This experiment provides some interesting results with respect to seedling vigor, survivability, and ultimately yield for the different varieties tested.
    • Planting Method and Seeding Rate Evaluation in Graham County

      Norton, E. R.; Clark, L. J.; Carpenter, E. W. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      A single field experiment was established in 2001 at the Safford Agricultural Center to evaluate the effects planting method and seeding rate have on plant population and yield of an Upland cotton cultivar Deltapine DP655BR. Two planting methods; planting into moisture (pre-irrigate) and dry plant/water-up, were main effects with three seeding rates of 10, 20, and 30 lbs./acre as sub-effects. These effects were evaluated with respect to stand establishment and yield. Analysis of variance showed no significant differences with respect to planting method for either plant population or yield, so data was combined across main effects. Significant differences were observed in plant population and yield as a function of seeding rate. A linear increase in yield with plant population was observed. These results are not consistent with previous research performed examining plant population effects on yield. This experiment will be conducted again in 2002 in an effort to validate results observed in 2001.
    • Residual Soil Nitrogen Evaluations in Irrigated Desert Soils, 2001

      Silvertooth, J. C.; Galadima, A.; Norton, E. R. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-03-18)
      Field experiments were conducted in Arizona in 2001 at three locations (Maricopa, Marana, and Safford). The Maricopa and Safford experiments have been conducted for14 consecutive seasons and the Marana site was initiated in 1994. The original purposes of the experiments were to test nitrogen (N) fertilization strategies and to validate and refine N fertilization recommendations for Upland (Gossypium hirsutum L.) and American Pima (G. barbadense L.) cotton. The experiments have each utilized N management tools such as pre-season soil tests for NO₃⁻-N, in-season plant tissue testing (petioles) for N fertility status, and crop monitoring to ascertain crop fruiting patterns and crop N needs. At each location, treatments varied from a conservative to a more aggressive approach of N management. Results at each location revealed a strong relationship between the crop fruit retention levels and N needs for the crop. This pattern was further reflected in final yield analysis as a response to the N fertilization regimes used. The higher, more aggressive, N application regimes did not benefit yields at any location. Generally, the more conservative, feedback approach to N management provided optimum yields at all locations. In 2001, a transition project evaluating the residual N effects associated with each treatment regime was initiated and no fertilizer N was applied. Therefore, all N taken-up by the crop was derived from residual soil N. In 2001 there were no significant differences among the original fertilizer N regimes in terms of residual soil NO₃⁻-N concentrations, crop growth, development, lint yield, or fiber properties. The lint yields were very uniform at each location and averaged 1500, 1100, and 850 lbs. lint/acre for Maricopa, Marana, and Safford, respectively.
    • Short Staple Variety Trial in Cochise County, 2001

      Clark, L. J.; Norton, E. R. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      Twelve varieties were tested including three New Mexico Acalas and one Acala from Buttonwillow Research in California, six Roundup Ready varieties, five of which also contained the Bt gene, along with a couple of other varieties were planted including FiberMax 989, which has been the highest yielding variety in the trial for two of the past three years. The highest yielding variety in the trial was FiberMax 989R, the Roundup Ready version of FM 989, with a yield over 950 pounds of lint per acre. 1517-95 and SureGrow 521RR followed in yield. Yields were considerably lower than seen in the previous year’s study (1). Several Roundup Ready varieties were included in this study. Plant mapping data and HVI data are also included in this report.
    • Short Staple Variety Trian in Virden, NM, 2001

      Clark, L. J.; Norton, E. R. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      Twelve varieties were tested including three New Mexico (NM) Acalas and one Acala from ButtonWillow Research in California, six Roundup Ready varieties, five of which also contained the Bt gene, along with a couple of other varieties were planted including FiberMax 989R, the Roundup Ready version of FM 989, which was the highest yielding variety in the trial for two of the past three years. The highest yielding variety in the trial was SureGrow 215BR, the stacked (Bt/Roundup Ready version of SG 125), with a yield near 925 pounds of lint per acre. FM 989R and DP 436BR followed SG 215BR in yield with yields not significantly different from the leader. Yields were slightly lower than seen in the previous year’s study (1). Plant mapping data and fiber quality (HVI) data are also included in this report along with lint value estimates and crop value per acre.
    • Upland Cotton Variety Evaluation in Graham County

      Norton, E. R.; Clark, L. J. (College of Agriculture, University of Arizona (Tucson, AZ), 2002-06)
      A field trial was established during the 2001 growing season as part of the statewide Upland Cotton Variety Testing Program. This trial was located in Thatcher with Dennis Layton Farms as the cooperator. The location was one of eleven around the state. Seven Upland cotton varieties to be evaluated at this location were entered by various cooperating seed companies. A new variety from FiberMax produced the highest yield and also possessed the highest quality fiber making it the variety that would have produced the highest gross income to the producer.