• Evaluation of Cotton for Resistance to Pink Bollworm

      Wilson, F. D.; Flint, H. M.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Cotton cultivars and germ plasm lines were screened for resistance to pink bollworm. Sixteen advanced strains were selected for resistance to pink bollworm and/or high yield potential. In a regional early maturing germ plasm lines test, only the short- season check had less seed damage caused by pink bollworm than did the long-season check. Five lines yielded more lint than both checks. In a Pima test, Pima S-6 nectariless had 14% less seed damage than Pima S-6. Seven pink-bollworm-resistant germ plasm lines will be released in the near future.
    • Evaluation of Date of Planting and Irrigation Termination on the Yield of Upland and Pima Cotton

      Silvertooth, J. C.; Watson, T. F.; Terry, L. I.; Malcuit, J. E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Three field experiments were conducted in 1989 in Arizona to evaluate the response of Upland and Pima cotton to two dates of planting and two dates of irrigation termination. Planting dates ranged from as early as 22 February in the Yuma Valley (150 ft. elevation) to 4 May at Marana (2,000 ft. elevation). Dates of irrigation termination ranged from 27 July in the Yuma Valley to 8 September at Maricopa and Marana. Based upon the final lint yield, planting date provided a significant main effect within two of the three experimental locations (Yuma Valley and Marana). At the Maricopa location, there was a significant effect on yield due to date of irrigation termination with both 30-inch- and 40-inch-row Upland cotton experiments, resulting in differences of 167 and 157 lbs. lint /acre, respectively, by extending two irrigations (approximately 12 acre inches) past 10 August to 8 September. The Pima experiment at Maricopa was similar with a significant (P <0.05) response to two additional irrigations (approximately 12 acre-inches) of 184 lbs. lint /acre. Return from additional lint yield must be considered against additional costs (water, insect control, etc.), as well as possible quality losses from insect infestations.
    • Exogenous L- and D-Proline Does Not Reduce NaCl Inhibition of Radidle Growth of Germinating Cotton (Gossypium hirsutum L.) Seeds

      Lehle, F. R.; Zegeer, A. M.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The adaptive significance of proline (Pm) accumulation in cotton seeds can be assessed by determining if NaCl tolerance is influenced by changes in the Pm level of the seed. The objective of this study was to determine if exogenous L-Pro and D-Pro reduce NaCl inhibition of radicle growth of germinating cotton seeds. Seeds were imbibed for 24 h at 32°C before transfer to agar medium containing either Pro, NaCl or mixtures of both. Results indicate that exogenous Pro increases the Pro contents of cotton seed radicles and cotyledons to a similar extent. Such increases are independent of whether L- or D-Pro is fed exogenously. Results also show that exogenous Pro does not significantly reduce NaCl inhibition of radicle growth in germinating cotton seeds. .
    • 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.
    • 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.
    • The Influence of ULV Malathion, Applied for Boll Weevil Control, on Other Pest and Beneficial Species in Arizona Cotton Fields

      Leggett, J. E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • 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.
    • Interaction of Pima Cotton Defoliation and Crop Water Stress Index

      Silvertooth, J. C.; Stedman, S. W.; Tollefson, J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A single field experiment was conducted in 1989 to evaluate the relationship of crop water status on Pima cotton defoliation by use of a crop water stress index (CWSI) as estimated by infrared thermometry. The entire study area was given the last irrigation uniformly on 24 August, and 20 row plots were outlined for the arrangement of three treatments in a randomized complete block design with three replications. Treatments consisted of making defoliant chemical application at three different targeted CWSI levels (0.40, 0.60, and 0.85). All defoliant treatments consisted of Dropp plus Accelerate (0.4 lb. and 1.5 pt. of material/acre, respectively) applied with a ground rig applicator. Results indicated no distinct advantage in terms of percent defoliation as a function of lower CWSI levels at which defoliants were applied. The defoliations made at 0.40 CWSI did result in more regrowth after 14 and 21 days. It appears from this test that Pima plants will defoliate satisfactorily with proper chemical treatments up to CWSI levels of 0.80. Further desiccation of the crop results in very erratic CWSI readings, resulting in difficulties in applying this technique to defoliation management. It does appear, though, that Pima cotton defoliation can be accomplished when CWSI readings are between 0.5 and 0.8 without substantial regrowth problems, providing precipitation or irrigation events do not occur.
    • 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.
    • 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.
    • 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.
    • Pima Cotton Improvement

      Turcotte, E. L.; Percy, R. G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Five experimental strains, P67, P69, P71, P72, P73, and Pima S -6 were grown in Regional tests at eight locations in 1989. P69 averaged highest in mean yield across locations followed by P73, Pima S-6, P71, P67 and P72. The difference in mean yield between P69, the highest yielding entry, and Pima S-6 was 35 pounds of lint per acre. Pima S-6 was the latest maturing and tallest entry in the Regional test at Maricopa. Pima S-6 also showed less tolerance to heat stress than the experimental strains. The experimental strains had longer, stronger, finer, and more whitish fiber than Pima S-6.
    • 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.
    • PIX Multiple Application Evaluations in Arizona on Upland and Pima Cotton, 1989

      Silvertooth, J. C.; Malcuit, J. E.; Howell, D. R.; Farr, C. R.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • Plant Growth Regulator Research on Upland Cotton at the Maricopa and Marana Agricultural Centers in 1989

      Briggs, R. E.; Nelson, J. M.; Hart, G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Field tests were conducted at the Maricopa and Marana Agricultural Centers to evaluate the effectiveness of growth regulators on Deltapine 90 cotton. With full season management, the check treatment yielded as well as any of the growth regulator treatments at both locations.
    • Planting Date and Susceptibility to Pink Bollworm

      Brown, P.; Huber, R.; Moore, L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The susceptibility of cotton to spring emergence of pink bollworm (PBW) was evaluated for a variety of planting dates in Pinal Maricopa, LaPaz and Yuma counties using historical climate records and heat-unit-based models that predict PBW emergence and cotton development. Early planted cotton proved most susceptible to the PBW emergence, however, cotton type (shoe vs. long staple) and springtime weather conditions both played an important role in overall susceptibility.
    • 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)
    • Regional Variety Tests

      Pegelow, E. J. Jr.; McAlister, A. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Regional variety tests were conducted at Maricopa, and Marana Agricultural Centers in continuing cooperation with the beltwide testing program. The national standards included in this test were Coker 139, Deltapine 50, and Paymaster 145. Lint yields for each variety, at both locations, are given in Table 1.
    • 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.
    • A Sensor System for Monitoring Cotton Water Status

      Fangmeier, D. D.; Husman, S. H.; Garrot, D. J. Jr.; Yitajew, M.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)