• Controlling Purple and Yellow Nutsedge with Postemergence Applications of EPTC

      Chernicky, J. P.; Heathman, E. S.; Rodgers, C.; Hamilton, K. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • Defolation Research on Pima Cotton at the Maricopa Agricultural Center in 1989

      Nelson, J. M.; Briggs, R. E.; Hart, G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A field study was conducted at the Maricopa Agricultural Center to evaluate the effectiveness of selected defoliation treatments on Pima cotton under warm and cool weather conditions. Dropp and other defoliants caused desiccation and freezing of leaves when applied at air temperatures above 100° F. Dropp was an effective defoliant when maximum air temperatures were in the low 90s. The experimental defoliant SN 597 NA218 appears to be a promising defoliant for Pima cotton when temperatures are cool.
    • Short Staple Variety Demonstrations, Pinal County, 1989

      Malcuit, J.; Stedman, S.; Silvertooth, J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Short staple variety demonstrations were conducted in Pinal County in 1989 at the Prechel and Benedict Farms near Coolidge Az. Twelve varieties were included in the demonstration at Prechel Farms. Results from the analysis showed significant differences among varieties. Seedcotton yields in this test ranged from 4826 to 2844 lbs. acre⁻¹ for STV BR-110 and S-55 respectively. Seven varieties were included in the demonstration at Benedict Farms. Results from the analysis showed significant differences among varieties. Seedcotton yields in this test ranged from 4127 to 3530 lbs. acre⁻¹ for STV BR-110 and DP-50 respectively.
    • Short Staple Variety Demonstration, Maricopa Agricultural Center, 1989

      Malcuit, J.; Silvertooth, J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A short staple variety trial was conducted on the demonstration farm, at the Maricopa Agricultural Center in 1989. Twenty varieties, received from various seed companies, were entered into the test. Results from the analysis showed significant differences among varieties with no observable performance trend in terms of maturity types (long or short season). The lint yields in this test ranged from 4679 to 3353 lbs. acre⁻¹ for DPL90, and S55 respectively.
    • Pima Cotton Genetics

      Percy, R. G.; Turcotte, E. L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      In an investigation of the genetic diversity and structure of Gossvpium barbadense L. it was determined that northwestern South America was the species' center of variability and probably the species' center of origin. Cultivars of the species were found to possess as much genetic variability as the center of variability. Cultivar variability was due in large part to introgression with G. hirsutum. Studies of interspecific hybrid performance revealed that development of G. barbadense parents could significantly affect the plant height, earliness, and yield of the resulting hybrids. Environment significantly affected hybrid performance and could enhance or obscure any beneficial effects of hybrid parent selection. A conversion program to convert photoperiodic short-day flowering tropical accessions to day neutrality continues. Preliminary results from inheritance and linkage studies of a male sterility factor and a foliar mutant indicate that both are single gene, recessive traits. No linkages between the male sterility factor and 21 marker traits were found.
    • Insecticide Efficacy on Beet Armyworm Infestations in Open and Closed Cotton Flowers and Effects of Flower Infestation on Boll Abcission

      Akey, D. H.; Henneberry, T. J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      In 1988 severe beet armywonn (BAW) infestations resulted in damaged cotton flowers and foliage. Some insecticide applications failed to eliminate larvae in the flowers because applications were applied before the flowers opened. Applications made after flowers were open were more effective. In 1989, tests were conducted to define further these results. Karate™ applied when cotton flowers were open achieved 90% control compared to 9% when flowers were closed in one test, and 97% compared to 13 %, respectively, in a second test (P\0.01). A higher percentage (18 %) of cotton bolls was shed on day 7 following flower infestations than were shed (6 %) when flowers were not infested.
    • Influence of Multiple Applications of PIX on Long and Short Staple Cotton, Safford 1989

      Clark, Lee J.; Carpenter, Eddie W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A four-by-four factorial experiment was performed on the Safford Agricultural Center to determine if CaZn, Foliar Triggrr or Soil Triggrr would cause increases in lint yields on short or long staple cotton. Four levels of PIX were used to see if there would be any interaction between PIX and the other materials. The results in 1989 showed that CaZn and the Trier products did not increase yields, the levels of PIX did not increase yields and there was no interaction between them. Very favorable weather conditions and good crop management kept plants from growing vegetative and prevented crop stress, thus reducing the opportunity for the plant growth regulators to increase yields. Yields were excellent with over 1700 and 1600 pounds of lint per acre for short and long staple cotton, respectively.
    • Cotton Variety Trial, Safford Agricultural Center, 1989

      Clark, Lee J.; Carpenter, E. W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Forty-nine, short- staple varieties and Pima S -6 were grown in a replicated trial on the Safford Agricultural Center in Graham County. Most of the varieties were commercially available in the Cotton Belt, however, a few experimental varieties from the New Mexico acalas and from Delta Pines were included. Weather conditions were favorable through most of the year and the cotton produced well. Fifteen varieties produced more than 4000 pounds of seed cotton per acre, with the highest yielding variety producing 4759 pounds per acre. Delta Pine 77 was the highest yielding commercial variety but it was topped by an experimental New Mexico acala.
    • Pima Cotton Irrigation Scheduling Using Infrared Thermometers and the Crop Water Stress Index

      Garrot, D. J. Jr.; Stedman, S.; Fangmeier, D. D.; Husman, S. H.; Benedict, B.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The Crop Water Stress Index (CWSI) was used to schedule irrigations on Pima S-6 cotton on 12 four-acre furrow-irrigated test plots in Coolidge and 20 drip- irrigated test plots at the Campus Agricultural Center in Tucson. Scheduling irrigations between 0.30 and 0.50 CWSI units resulted in highest lint production and plant water use efficiency at both locations.
    • Short Staple Variety Trial, Cochise County, 1989

      Clark, Lee J.; Schwennesen, Eric; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The old standar4 1517-75, was the best yielding variety in 1989, yielding over three bales of lintper acre. 1517-77BR, which yielded well in 1987 and then dropped off a bit in 1988, carne in second and an experimental, 6658 came in third. The touted New Mexico star, 1517-88 came in fourth followed closely by California's Prema. Eight of the 10 varieties tested yielded over 2.5 bales per acre. More than normal heat units coupled with good management practices brought the highest yields yet recorded in a University cotton variety trial in Cochise County.
    • Effect of Harvest Date on Aflatoxin Contamination in the Yuma Valley

      Cotty, P. J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Experiments were performed at the Yuma Valley Agricultural Center to determine how timely harvest of cotton may affect aflatoxin contamination of cottonseed As the cotton was held in the field between the final irrigation and harvest, the quantity of aflataxin in the crop increased. Significant reductions in aflatoxin contents of seed were realized by harvesting in early September.
    • Cotton Variety Trial, Mohave Valley, 1989

      Grumbles, R.; Malcuit, J.; Green, L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Seven cotton varieties including Pima S -6 were demonstrated in Mohave Valley, Mohave County in 1989. Of the six upland varieties two were new varieties not previously demonstrated in this area. Trial results indicated DP77 at 1697 lbs. led other varieties by 109 lbs. of lint over DP90, 1590 lbs. and 287 lbs. over bottom variety STV115 at 1412 lbs. STV110 yielded 1482 lbs., DES 119 at 1429 lbs., DP50 at 1414 lbs. Pima S-6 yielded 950 lbs. The two new varieties STV110 and STV115 placed last and third on yield but when economic values were calculated based on grade and price they ranked third and fourth. The second attempt on Pima saw an increase in yield from 447 lbs., the previous year to 950 lbs. in current trial.
    • Nitrogen Management in Irrigated Cotton

      Silvertooth, J. C.; Clark, L. J.; Carpenter, E. W.; Malcuit, J. E.; Else, P. T.; Doerge, T. A.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two field experiments were conducted in 1989 in Arizona to compare several methods of nitrogen (N) management in Upland and Pima cotton. Standard preplant, preplant plus sidedress, and use of soil and petiole analysis for NO₃⁻-N were the basic methods of N fertilization management compared. A nonfertilized check treatment also was included with the N management treatments, which were arranged in a randomized complete block design in each experiment. Preseason soil samples and a series of in- season petiole samples were taken for all treatments and analyzed for NO₃⁻-N. The concentrations of NO₃⁻-N in the petioles reflected the boll load obtained and the crop fruiting patterns as well as the N fertilization patterns in the respective treatments. Final lint yield analysis revealed distinct differences among the treatments imposed at the Maricopa location but no statistically significant differences at the Safford location.
    • Response of Texas Root Rot to a Soil Sterilant the Second Year After Application in Marana, 1989

      Thacker, G. W.; Silvertooth, J. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two years after sterilizing a sandy loam soil in Marana, we measured significant yield responses of short staple cotton. The yield response was significant in the first year as well, but was not enough to pay the cost of sterilization. This second year of yield response made the treatment economically feasible.
    • Defoliation Research on Upland Cotton at the Maricopa Agricultural Center in 1989

      Nelson, J. M.; Briggs, R. E.; Hart, G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A field study was conducted at the Maricopa Agricultural Center to evaluate the effectiveness of experimental defoliants and adjuvants on DPL 90cotton. None of the defoliation treatments tested were effective in September when air temperatures were above 100° F. Several chemicals gave 80% or higher defoliation in early October when temperatures were in the low 90s. The experimental defoliant SN 597 NA218 appears to have promise as a late-season defoliant for DPL 90 cotton.
    • Gossyplure-baited Pink Bollworm Male Moth Trap Studies

      Chu, C. C.; Henneberry, T. J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Gossyplure, the pink bollworm, Pectinophora gossvpiella (Saunders), sex pheromone is an excellent tool as a bait in traps for detection, survey, research and monitoring male moth populations. We studied the within - and between-seasonal changes of pink bollworm male moth catches in gossyplure-baited live traps installed in cotton fields each year from 1981 to 1988. Seasonal average number of male moths caught varied from 14/trap/night in 1982 to 148 /trap /night in 1981. Male moths caught/trap/night were highly correlated with the minimum air temperatures. The number of male moths caught from March to June were significantly correlated with those caught from July to August, indicating that early spring trapping can be used to identify potential problem fields.
    • Sweetpotato Whitefly Populations in Cotton Genotypes at Poston, Arizona in 1988

      Butler, G. D. Jr.; Henneberry, T. J.; Perkins, H. H. Jr.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Studies were conducted to identify potential sources of cotton germ plasm resistant to sweetpotato whitefly (SPW), Bemisia tabaci (Gennadius). Numbers of adult SPW sampled using black pan and vacuum methods showed reduced numbers of SPW on GC-EXP-7007 experimental variety vs. all other entries. However, numbers of SPW pupae on leaf samples in most cases were not different. Pima P-62 had the high numbers of SPW adults per blackpan sample, and highest number of pupae/leaf sample.
    • Irrigation Scheduling on Long and Short Staple Cotton, Safford Agricultural Center, 1989

      Clark, L. J.; Carpenter, E. W.; Scherer, T.; Slack, D.; Fox, F.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two irrigation scheduling trials were performed in 1989, one for short staple and one for long staple. Yields in the trials were very good with the best treatments yielding over 1700 and 1600 pounds of lint per acre for DP 90 and S-4 respectively. The treatment using Infrared thermometry was the best overall treatment in the short - staple trial, with the highest yield, the highest percent first pick, the shortest plants, the lowest water use and the highest water use efficiency. The two computer methods were very close to the IR treatment in yield and percent first pick, but grew taller plants with more water and were not as efficient with their water use. The trial on long staple cotton was encouraging in that reasonable yields were obtained using short-staple parameters. The computer model using AZMET data yielded significantly lower than the other treatments, indicating that we need to refine the evapotranspiration crop coefficients.
    • Short Staple Variety Demonstration, Yuma County, 1989

      Howell, D. R.; Silvertooth, J.; Malcuit, J.; Sharp, D.; Sharp, C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The standard variety DPL 61 yielded higher in this trial. M-5, a California acala type was tested for the first time.
    • Potential Injury to Rotational Crops Following Single or Multiple Applications of Bladex to Cotton 3

      Chernicky, J. P.; Rodgers, C. A.; Heathman, E. S.; Hamilton, K. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)