• Response of the Tobacco Budworm to Permethrin and Methyl Parathion in Arizona, 1977-1990

      Watson, Theo F.; Kelly, Suzanne E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Field populations of tobacco budworm. Heliothis virescens (F.). have been monitored annually since 1977 with topical applications of synthetic pyrethroid insecticides (primarily permethrin) and methyl parathion to detect changes in insecticide susceptibility. These data showed that LD₅₀'s fluctuated somewhat from year to year with permethrin. but with one possible exception. the fluctuations were not sufficient to change levels of expected control in the field. Field populations continue to show susceptibility to permethrin even though one Maricopa County population showed an increase in the LD₅₀ to 12.4 in 1988. Field populations continue to show resistance to methyl parathion and susceptibility to permethrin.
    • Effect of Plant-Derived Oils on Sweetpotato Whitefly on Cotton

      Butler, G. D. Jr.; Coudriet, D. L.; Henneberry, T. J.; Silvertooth, Jeff; Bantlin, Marguerite; USDA-ARS-Western Cotton Research Laboratory, Phoenix AZ (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Cottonseed oil applied to cotton repelled sweetpotato whitefly (SPW) adults up to 8 days in greenhouse tests. Soybean oil (5 %) resulted in reduced numbers of adults and numbers of eggs laid. SPW egg hatch was reduced 84% after treatment with 10% crude cottonseed oil solutions as measured by the number of first instar larval emergence. Also, numbers of whitefly larvae were reduced 99, 91 and 83% on day 6 following treatment with 10% cottonseed oil, S and 1.5% soybean oil, respectively. Negligible plant leaf phytotoxicity occurred from the plant-derived oil treatments.
    • Cotton Response to Mutiple Applications of PIX, 1990

      Silvertooth, J. C.; Malcuit, J. E.; Husman, S. H.; Winans, W. S.; Hood, L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Three field experiments were conducted in 1990 in Arizona to evaluate cotton crop response to several treatment regimes of multiple applications of PIX (an anti-gibberellic acid plant growth regulator). Treatment regimes used in 1990 employed higher rates of PIX/acre/application and extended times of applications later into the fruiting cycle than earlier experiments in 1988 and 1989. Similar to earlier experiments, results in 1990 demonstrated the ability of some PIX treatments to significantly reduce plant height, relative to the untreated check treatments. The 1990 cotton production season in Arizona consisted of conditions which led to excessive rates of fruit loss and abortion, and somewhat vegetative plants. Final fruit retention levels of 30 to 50% were realized in the three 1990 experiments after a period of fruit loss through July and August. Lint yield results revealed significant differences (P ≤ 0.05) between several selected treatments at only one of the locations in 1990.
    • Photosynthetic Rate and Stomatal Conductance are Related to Heat Tolerance in Pima Cotton

      Cornish, Katrina; Lu, Phenmin; Radin, John W.; Turcotte, Edgar L.; Zeiger, Eduardo; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Breeding for high yield in hot environments (heat tolerance) has tripled the yield of Pirna cotton since 1949. We compared six strains (one primitive non-cultivated line, four cultivars representing advancing stages in the breeding process, and one unreleased advanced line) for their gas exchange properties in the greenhouse. Both photosynthetic rate and stomatal conductance increased with improving genetic yield potential. Photosynthetic rate was enhanced more in the morning than in the afternoon. Stomatal conductance did not limit photosynthesis; rather, the changes resulted from alterations of characteristics of the green mesophyll cells. There is no evidence that increased yield results from the enhanced photosynthetic rates of single leaves. However, the increased stomatal conductance in modem lines was also expressed in the field in 1990, allowing increased transpiration rate and evaporative cooling of leaves. Heat tolerance in Pima cotton may be related to the ability of plants to cool themselves by transpiration.
    • Residual Activity of Permethrin, Chlordimeform and Permethrin + Chlordimeform Against Susceptible and Resistant Budworm

      Watson, Theo F.; Kelly, Suzanne E.; Estesen, Betty J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Cotton was sprayed with permethrin, chiordimeform and the permethrin-chlordimeform combination to determine residual efficacy against resistant (R) and susceptible (S) populations of tobacco budworm (TBW) and reciprocal crosses of the two populations. Permethrin alone gave excellent results against susceptible tobacco budworm for the entire 7-day test period. However, against the resistant strain the highest level of mortality achieved was 40% on the 1-day post -treatment residue; results with the S:R and R: S (♂:♀) crosses were generally intermediate. Chlordimeform gave poor and erratic kill unrelated to the residue period regardless of the strain of TBW. The combination resulted in mortality similar to that of permethrin alone with the susceptible strain hut generally greater than that with permethrin alone against the resistant strain. The combination resulted in high mortality in the crosses, particularly the R. S (♂:♀) cross.
    • Short Staple Variety Demonstrations, Graham County, 1990

      Clark, Lee J.; Cluff, Ronald E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Short staple variety trials were grown in two locations in Graham county in 1990, Thatcher in the central part of the valley and Eden on the west end Acala Prema from the San Joaquin Valley in California had the top seed cotton yield in both locations with yield of 3789 and 3162 pounds per acre, at the two locations, respectively. The average lint yield in the Thatcher site was down more than 200 pounds per acre from 1989, whereas the average at the Eden site was about the same as in 1989. 1990 is characterized by its record setting heat spell in the end of June, even though fewer heat units were received in 1990 than in 1989. HS 46, a variety first seen in Graham county in 1989, performed well in both sites and in fact, topped both trials with lint yield Data on yields, percent first pick, plant height and plant populations are presented for each variety in each location.
    • Cotton Lint Qualities of Varieties Grown in Southeastern Arizona, 1989

      Clark, Lee J.; Carpenter, Eddie W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      High Volume Instrument (HVI) classing of eighteen cotton varieties grown at several elevations in southeastern Arizona are compared by location in this paper. Data presented herein would indicate that elevation does not affect fiber length nor strength, these factors are more a function of variety and management. Micronaire values were seen to be lower at the higher elevations and this was felt to be a function of lower maturity level because of reduced growing season coupled with production of fine fibered New Mexico acalas. This report also contains HVI values on lint from 47 varieties of short staple cotton grown on the Safford Agricultural Center during the 1989 season.
    • Short Staple Variety Trials, Greenlee County, 1990

      Clark, Lee J.; Schneider, Mike; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Fourteen short staple varieties were evaluated in Greenlee county in 1990 in two separate trials. Average yields were higher in 1990 than in 1989 in both locations. The highest yielding variety in the acala trial was a new variety from California, C-37, with a yield of 1271 pounds of lint per acre. The highest yielding delta variety in the trials was DP 20 with a yield of 1116 pounds of lint per acre.
    • Effect of Plant Growth Regulators Under Short-Season Conditions on Pink Bollworm Populations, Cotton Yields and Defoliation

      Chu, Chang-chi; Henneberry, Thomas J.; Bariola, Louis A.; Deeter, Brian; Silvertooth, Jeff; Bantlin, Marguerite; USDA-ARS, Western Cotton Research Laboratory, Phoenix, AZ; Rhone Poulenc Ag Co., Wickenburg AZ (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Plant growth regulators (PGR's) [thidiazuron (Dropp®) N-phenyl-N' -1,2,3-thiadiazol -5 ylurea, 50% wettable powder, Nor-Am Agricultural Products, Inc., Naperville, IL, and ethephon (Prep®) a- chloroethyl phosphonic acid Rhone - Poulenc Ag Co., Research Triangle Park NC] were applied to reduce late- season fruiting forms as a source of host material for developing overwintering PBW populations. Combinations of ethephon and thidiazuron or thidiazuron alone were more effective than ethephon alone for reducing late -season immature green bolls. None of the PGR's alone or in combination affected yields. Highest rates of defoliation occurred after applications of thidiazuron. The data suggest that temperature thresholds for highest plant growth regulator activity occur.
    • Defoliation Research on Pima Cotton at the Marana Agricultural Center in 1990

      Nelson, J. M.; Silvertooth, J. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      A field study was conducted at the Marana Agicultural Center to evaluate the effectiveness of selected defoliation treatments on Pima cotton under cool weather conditions. Defoliants were slow acting at this location, probably due to cool night temperatures and dry field conditions. The combination Dropp + Def 6 + Accelerate gave good defoliation results 18 days after application. The experimental defoliant SN 597 NA 243 shows promise as a defoliant for Pima when temperatures are cool.
    • 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), 1991)
      Four flea experiments were conducted in 1990 in Arizona to evaluate the response of Upland and Pima cotton to dates of planting and dates of irrigation termination. Planting dates ranged from as early as 27 February in the Yuma Valley (150 ft. elevation) to 8 May at Marana (2,000 ft. elevation). Dates of irrigation termination ranged from 18 July in the Yuma Valley to 8 September at Maricopa and Marana.
    • Fat Content and Reproductive Condition of Migrating and Dispausing Boll Weevils in South Carolina and Arizona

      Leggett, J. E.; Silvertooth, Jeff; Bantlin, Marguerite; USDA-ARS-Western Cotton Research Laboratory (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Overwintered female boll weevils, Anthonomus grandis Boheman, collected in grandlure- baited traps were significantly leaner than weevils taken from winter habitat. Weevils that emerged from naturally infested cotton bolls tended to be fat as adults regardless of subsequent adult diet, but adult diet can affect gonadal development. Weevils that emerged from bolls in 1975 in South Carolina had a higher winter survival rate and emerged from winter habitat earlier than the total population. Migrant weevils appear to be mainly colonizers that have some body fat and medium size gonads. The physiological condition of migrants was fairly consistent over time and location in South Carolina but not in Arizona. The time of migratory flight was related mainly to plant maturity and population levels in South Carolina. Weevils collected from cotton plants in South Carolina and Arizona had significantly more body fat than weevils trapped at the cotton field but oogenesis was variable between the two locations.
    • Pink Bollworms in 'Detapine 90' and 'Pima S-6' Cottons in Arizona

      Henneberry, T. J.; Chu, C. C.; Forlow Jech, L.; Silvertooth, Jeff; Bantlin, Marguerite; Western Cotton Research Laboratory, USDA ARS (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Pink bollworm (PBW), Pectinophora gossypiella (Saunders) infestations in Deltapine 90, Gossypium hirsutum L., and Pirna S-6, G. barbadense L., cotton bolls were initiated at about the same time during the cotton growing season. Male moth trap catches in gossyplure-baited Delta traps followed similar trends in both cottons throughout the season, but tended to be higher in Pima S-6 cotton than in Deltapine 90 cotton late in the season. Late crop termination (last irrigation 26 September) as practiced in Pima cotton production vs. earlier crop termination (last irrigation I September) as practiced in upland cotton production resulted in higher numbers of late- season immature green bolls, higher numbers of PBW larvae per boll and higher populations of diapause larvae at harvest time in Pima than occurred in the upland cotton cultivar. PBW seed damage was lower in the Deltapine 90 cultivar than in the Pima S-6 cotton cultivar. Deltapine 90 lint yield was higher than Pima S-6 lint yield.
    • Control of the Sweetpotato Whitefly by Insect Growth Regulators

      Bartlett, A. C.; Lewis, L. J.; Hunter, B. A.; Silvertooth, Jeff; Bantlin, Marguerite; USDA-ARS-Western Cotton Research Laboratory (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Two newly developed insect growth regulators were tested at two dose levels for control of the sweetpotato whitefly on cotton. The two chemicals showed some promise for control although the dose rate and application schedules were not optimal and plot sizes were too small to show a decrease in cotton stickiness or sugar content due to the treatments. In these tests a chitin synthesis inhibitor was more effective in controlling immature stages than a juvenile hormone mimic.
    • Upland and Pima Cotton Response to Banded Fertilizer Applications, 1990

      Silvertooth, J. C.; Thacker, G. W.; Malcuit, J. E.; Doerge, T. A.; Husman, S. H.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Two field experiments were established in Arizona in 1990 to evaluate the effects of banded phosphorus (P) fertilizer on cotton. Experiments involved both Upland (Gossvpium ltirsutum, L.) and American Pima (Q. barbadense L.). Banded applications of P fertilizerwere made with placement of the concentrated band of fertilizer 6 in. below and 3-6 in. to the side of the zone of seed placement. The P₂O₅ was supplied from 10-34-0. Rates of applied P ranged from 0 to 160 lb P₂O₅ /acre. In one experiment, treatments consisting of 5 to 10 lbs. Zn/acre were included in all possible combinations with the P₂O₅ treatments. In all cases, treatments in the field were arranged in a randomized complete block design with four replications. Plant measurements for plant height, flower numbers per unit area, number of mainstem nodes, and nodes to the first fruiting branch were initiated by the fifth true leaf stage to evaluate plant response in terms of growth and development. Plant tissue samples were also taken at several stages of growth from each experiment throughout the growing season. Tissue samples consisted of petioles from the uppermost fully - developed leaves. Petioles were analyzed for extractable PO₄-P. Lint yield measurements also were taken. No statistically significant differences (P ≤ 0.05) were found among any treatments for any of the plant growth parameters. The same was true with regard to petiole PO₄-P levels measured. No significant differences were detected among Upland or Pima cotton lint yields in response to the applications of P fertilizers.
    • Effects of 3 Irrigation Termination Dates on a Full Season Type of Upland Cotton in Mohave Valley, Arizona

      Grumbles, R. L.; Hood, L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      A single field experiment was conducted in 1990 on a grower cooperator field to evaluate the response of a full season maturity type of Upland Cotton (DPL 90) to three dates of irrigationtermination. The crop was planted 26 and 27 of March, managed uniformly in all respects until August 1 when earliest irrigation termination wsa imposedThe dates for the second and final irrigationtermination treatments were 15August and 15 September. Each irrigationtermination treatments were given an additional 8 acre inches of water (approximate). Harvest results revealed no significant differences in lint yield on the first two dates but the last date yielded 110 pounds more. All plots received a 2 inch rain 18 August.
    • A Comparison of Three Cotton Tillage Systems

      Coates, Wayne E.; Thacker, Gary W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Over a three year study, two reduced tillage systems used significantly less energy than conventional tillage. The Sundance system averaged 46% of the energy used by the conventional system, and the Uprooter-Shredder-Mulcher (USM) averaged 65% of the energy used by the conventional system. These energy savings translate directly into cost savings of about the same proportions. Additionally, the Sundance and USM systems can plow down and prepare the next seedbed in about one-half the time that conventional tillage requires. In three years of testing we have not detected any significant differences in soil compaction, and we have not measured any yield reductions from these reduced tillage systems.
    • Susceptibility of Field Populations of Pink Bollworm (Lepidoptera: Gelechiidae) to Azinphosmethyl and Permethrin

      Osman, Abdelgadir A.; Watson, Theo F.; Sivasupramaniam, Sakunlala; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Responses of five field -collected populations of the pink bollworm. Pectinophora gossypiella (Saunders). from Arizona and southern California. were compared with those of a standard. susceptible -laboratory strain. Field strains showed less than twofold difference in response to azinphosmethyl at LD₅₀ but had variable levels (1.3- to 18.3-fold) of response to permethrin. Strains from Yuma and Phoenix (Arizona) and Westmoreland (California) had highest levels of resistance to permethrin.
    • Trap Crop Effectiveness in Community Boll Weevil Control Programs

      Moore, Leon; Watson, Theo F.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Trap crops, along with delayed uniform planting and pinhead square treatments, greatly reduced spring populations of overwintered boll weevils, Anthonomus grandis Boheman, in a Laveen. Arizona community -wide 1PM program in 1987. Thirty four trap crops. planted fifteen days ahead of the regular crop. had as many as 39536 damaged plants/ha before insecticide treatments were initiated. Five insecticide applications at 3 day intervals beginning at square initiation were used to destroy weevils before the trap crops were plowed under at the time pinhead square treatments were initiated in regular planted fields. Damaged square infestations were 2 to II times lower throughout the season in 1987 compared to 1986 while average lint yields per ha increased from a low of 941 kg in 1985 to 1345 kg in 1986 and 1506 kg in 1987.
    • Nitrogen Management Experiments for Upland and Pima Cotton, 1990

      Silvertooth, J. C.; Clark, L. J.; Malcuit, J. E.; Carpenter, E. W.; Doerge, T. A.; Watson, J. E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Two field experiments were conducted in Arizona in 1990 at two locations ( Maricopa and Safford). The purposes of the experiments were to validate and refine nitrogen (N) fertilization recommendations for both Upland and Pima cotton. The experiments each utilized N management tools such as pre - season soil tests for NO₃⁻-N, in-season plant tissue testing (petioles) for N fertilirystatus, and crop monitoring to ascertain crop fruiting patterns and crop N needs. Results at both locations 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 in response to the N fertilization regimes used. At Maricopa, fruit retention levels were low, petiole NO₃⁻-N concentrations relatively high, and yield responses to higher and later applications of fertilizerN were negative. At Safford, fruit retention levels were higher, petiole concentrations of NO₃⁻-N reflected strong crop demand, and a positive response to rates of fertilizer N up to 170 lbs. N/acre was measured.