Cotton Report 1991
ABOUT THE COLLECTION
The Cotton Report is one of several commodity-based agricultural research reports published by the University of Arizona.
This report, along with the Forage and Grain Report, was established by Hank Brubaker, Extension Agronomist, after seeing a similar report published by Texas A&M University in the mid-1970’s.
The purpose of the report is to provide an annual research update to farmers, researchers, and those in the agricultural industry. The research is conducted by University of Arizona and USDA-ARS scientists.
Both historical and current Cotton Reports have been made available in the UA Campus Repository as part of a collaboration between the College of Agriculture and Life Sciences and the University Libraries.
Contents for Cotton Report 1991
- Evaluation of Date of Planting and Irrigation Termination on the Yield of Upland and Pima Cotton
- Effects of 3 Irrigation Termination Dates on a Full Season Type of Upland Cotton in Mohave Valley, Arizona
- Defoliation of Pima Cotton, 1990
- Defoliation Research on Pima Cotton at the Maricopa Agricultural Center in 1990
- Defoliation Research on Pima Cotton at the Marana Agricultural Center in 1990
- Effect of Plant Nitrogen Status on Effectiveness of Defoliants for Short Season Cotton Production
- Basic Cotton Crop Development Patterns
- Photosynthetic Rate and Stomatal Conductance are Related to Heat Tolerance in Pima Cotton
- Uptake and Reside of 3, 4-Dichloro-5-Isothiazole Carboxylic Acid in Cotton Plants and Soils Under Field Conditions
- Cotton Response to Mutiple Applications of PIX, 1990
- Short Staple Variety Demonstration, Maricopa Agricultural Center, 1990
- Short Staple Variety Demonstration, Pinal County, 1990
- Cotton Variety Trial, Safford Agricultural Center, 1990
- Short Staple Variety Demonstrations, Graham County, 1990
- Short Staple Variety Trial, Cochise County, 1990
- Short Staple Variety Trials, Greenlee County, 1990
- Cotton Lint Qualities of Varieties Grown in Southeastern Arizona, 1989
- Pima Cotton Improvement
- Pima Cotton Genetics
- Comparison of Three Irrigation Scheduling Methods and Evaluation of Irrigation Leaching Characteristics
- Irrigation Scheduling on Long and Short Staple Cotton Safford Agricultural Center, 1990
- Water Stress Effects on Upland Cotton Lint Yields Using Infrared Thermometry to Schedule Irrigations
- Aflatoxin Contamination: Variability and Management
- Comparative Development and Reproduction of Pink Bollworm on Upland and Pima Cotton Cultivars
- Planting Date and Susceptibility to Pink Bollworm
- Cotton Yields as Affected by Pheromone Treatments for Pink Bollworm
- Pink Bollworm Management in Pima and Upland Cottons: Planting Date and Termination Date Effects
- Pink Bollworms in 'Detapine 90' and 'Pima S-6' Cottons in Arizona
- Effect of Plant Growth Regulators Under Short-Season Conditions on Pink Bollworm Populations, Cotton Yields and Defoliation
- Status of Pink Bollworm Resistance to Insecticides in Arizona
- Susceptibility of Field Populations of Pink Bollworm (Lepidoptera: Gelechiidae) to Azinphosmethyl and Permethrin
- Reversion of Permethrin Resistance in Field Strains and Selection for Azinphosmethyl and Permethrin Resistance in Pink Bollworm (Lepidoptera: Gelechiidae)
- Inheritance of Resistance to Permethrin by the Tobacco Budworm, Heliothis Virescens (F): Implications for Resistance Management
- Response of the Tobacco Budworm to Permethrin and Methyl Parathion in Arizona, 1977-1990
- Residual Activity of Permethrin, Chlordimeform and Permethrin + Chlordimeform Against Susceptible and Resistant Budworm
- Field Performance of Cotton Genetically Modified to Express Insecticidal Protein from Bacillus thuringiensis
- Microplitis sp. From Australia (Hymenoptera: Braconidae): Development in the Beet Armyworm and Adult Longevity in Relation to Temperature
- Effect of Plant-Derived Oils on Sweetpotato Whitefly on Cotton
- Control of the Sweetpotato Whitefly by Insect Growth Regulators
- Trap Crop Effectiveness in Community Boll Weevil Control Programs
- Fat Content and Reproductive Condition of Migrating and Dispausing Boll Weevils in South Carolina and Arizona
- Nitrogen Management Experiments for Upland and Pima Cotton, 1990
- Upland and Pima Cotton Response to Banded Fertilizer Applications, 1990
- A Comparison of Three Cotton Tillage Systems
- Cottonseed Treatment Evaluations in Arizona, 1990
- Laboratory Tests Designed to Improve Cotton Planting Seed Quality
Laboratory Tests Designed to Improve Cotton Planting Seed QualityA number of representative seed lots of both upland and Pima cotton cultivars and experimental strains have been evaluated utilizing two instruments which measure relative seed coat strength. Seed coat strength was found to have a strong genetic component of determination, with relatively minor influence of environment and year of production being observed Greater seed coat strengths should contribute to the relative resistance to seed damage and cracking during picking ginning and conditioning operations. It may be possible to incorporate this trait into cotton cultivars by mass selection techniques.
Cottonseed Treatment Evaluations in Arizona, 1990Field experiments were conducted at four locations in Arizona (Yuma, Maricopa, Marana, Safford) to evaluate 16 cottonseed treatments on cotton that included 12 on Upland (Q. hirsutum L.) and 4 on Pima (Gossvpium barbadense L.). Stand counts were taken to evaluate the effectiveness of each treatment. Statistical analysis showed no significant differences among the treatments used for the Upland cottonseed. Significant differences were found among the treatments used for the Pima cotton seed at the Marana and Safford locations only.
A Comparison of Three Cotton Tillage SystemsOver 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.
Upland and Pima Cotton Response to Banded Fertilizer Applications, 1990Two 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.
Nitrogen Management Experiments for Upland and Pima Cotton, 1990Two 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.
Fat Content and Reproductive Condition of Migrating and Dispausing Boll Weevils in South Carolina and ArizonaOverwintered 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.
Trap Crop Effectiveness in Community Boll Weevil Control ProgramsTrap 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.
Control of the Sweetpotato Whitefly by Insect Growth RegulatorsTwo 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.
Effect of Plant-Derived Oils on Sweetpotato Whitefly on CottonCottonseed 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.
Microplitis sp. From Australia (Hymenoptera: Braconidae): Development in the Beet Armyworm and Adult Longevity in Relation to TemperatureThe effects of temperature on development and longevity of a Microplitis sp. from Australia on the beet armyworm, Spodoptera erigua (Hübner) was studied in the laboratory. Time of development ranged from 25 days at 15°C to 6.2 days at 27.5 °C. The parasite developed twice as fast as its beet armyworm host. Average longevities of male and female parasites were not significantly different.
Field Performance of Cotton Genetically Modified to Express Insecticidal Protein from Bacillus thuringiensisFive transgenic lines of cotton, Gossypium hirsutum L., carrying the delta-endotoxin gene from Bacillus thuringiensis Berl., and two control cultivars, Coker 312 (the parent stock) and MDS1N (an adapted nectoriless line) were evaluated at the Maricopa Agricultural Centerfor resistance to attack by several insect pests and for agronomic properties. The transgenic lines were highly resistant to pink bollworm (PBW), Pectinophora gossypiella (Saunders), as shown by 90% fewer rosetted blooms, 96% fewer PBW recovered from incubated bolls, and 92% less seed damage than in the control cultivars. The transgenic lines were highly resistant to saltmarsh caterpillar, Estigmene acres (Drury), and beet annyworm, Spodoptera exigua (Hbn.), as shown by minimal damage to transgenic leaves and almost complete defoliation of control leaves. The transgenic lines were virtually immune to cotton leafperforator, Bucculatrix thurberiella Busch as shown by no apparent damage to transgenic leaves, and many mines, "horseshoes", and feeding areas on the control leaves. Compared to Coker 312, one transgenic line yielded more lint, and one yielded less. Four transgenic lines had higher lint percentages and all five had smaller bolls and were later maturing than Coker 312. Compared to MD51N, no transgenic line yielded more lint and one yielded less. All five transgenic lines had lower lint percentages, three had smaller bolls, and three were earlier maturing than MDS1N (USDA, ARS, Western Cotton Research Laboratory in cooperation with Monsanto Co. and Arizona Agricultural Experiment Station).
Residual Activity of Permethrin, Chlordimeform and Permethrin + Chlordimeform Against Susceptible and Resistant BudwormCotton 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.
Response of the Tobacco Budworm to Permethrin and Methyl Parathion in Arizona, 1977-1990Field 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.
Inheritance of Resistance to Permethrin by the Tobacco Budworm, Heliothis Virescens (F): Implications for Resistance ManagementA laboratory selected permethrin resistant strain of tobacco budworm. Heliothis virescens (F), was crossed with a susceptible strain to determine the nature of inheritance of the resistance. Crossing of these highly resistant and highly susceptible strains showed susceptibility to permethrin to be auto trial and incompletely dominant. Backcrosses of F₁ progeny with resistant males indicated either that more than one gene is responsible for the resistance in this strain, or that the strain was not homozygous for resistance. It is likely that more than one locus is influencing permethrin resistance. The crosses and backcrosses performed provided relevant information for resistance management in the field.
Reversion of Permethrin Resistance in Field Strains and Selection for Azinphosmethyl and Permethrin Resistance in Pink Bollworm (Lepidoptera: Gelechiidae)Rearing of two field strains (Maratha, Yuma) of pink bollworm. Pectinophora gossypiella (Saunders). from Arizona under conditions free of insecticides resulted in reversion of resistance (in adults) in four and five generations. respectively. to levels close to that found in the susceptible laboratory strain. Permethrin resistance in these field strains is unstable and is apparently in its early phase of development. Results suggest that monitoring of pink bollworm resistance in field strains reared in the laboratory should be performed in the F₁ generation. Subsequent selection studies were performed on both larval and adult stages to investigate the capacity of the pink bollworm to develop resistance in both life stages. Fourteen generations of selection of larvae and adults with azinphosmethyl produced 1.9- and 1.6-fold tolerance. respectively. in the adult stage. Sixteen generations of larval selection with permethrin generated 9.7-fold resistance in adults. while 14 generations of adult selection produced 8.8-fold resistance in adults. Azinphosmethyl evidently possesses a low degree of selectivity for development of resistance in pink bollworm adults. Selection of larvae with both azinphosmethyl and permethrin seemed to generate higher levels of tolerance in larvae than in adults.
Susceptibility of Field Populations of Pink Bollworm (Lepidoptera: Gelechiidae) to Azinphosmethyl and PermethrinResponses 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.
Status of Pink Bollworm Resistance to Insecticides in ArizonaPopulations of pink bollworm. Pectinophora gossypiella (Saunders), from Yuma, Casa Grande, Marana and Safford were compared with that of a susceptible laboratory (USDA) strain relative to their susceptibility to permethrin. A limited comparison was made with azinphosmethyl. All field strains were significantly more tolerant to permethrin than was the USDA susceptible strain. A comparison of the USDA and Yuma strains using azinphosmethyl indicated no difference in susceptibility between the laboratory and field strains.
Effect of Plant Growth Regulators Under Short-Season Conditions on Pink Bollworm Populations, Cotton Yields and DefoliationPlant 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.
Pink Bollworms in 'Detapine 90' and 'Pima S-6' Cottons in ArizonaPink 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.
Pink Bollworm Management in Pima and Upland Cottons: Planting Date and Termination Date EffectsDifferent planting and termination dates of Pima S-6 and Upland (Deltapine 90) cotton (Gossypium barbadense L. and hirsutum L. respectively) were tested for their effects on pink bollworm (Pectinophora gossypiella) infestations. Tests were conducted during 1989 and 1990 cotton seasons at the University of Arizona Yuma Valley Agricultural Experiment Station. Planting dates indicated little effect on early season infestations of pink bollworm for either cotton. However. irrigation termination had the greatest effect on late season infestations. In 1989. heat unit (degree day 12.8/30° C. lower and upper thresholds) accumulations were several days earlier than 1990, due to a very warm year. Pheromone trap counts indicated higher populations in 1989 than 1990; however. infestations in the field were similar between the years. Infestations dramatically increased during July through September, indicating that a longer cotton season with actively growing fruit, results in a continued population increase. The termination dates affected the amount of fruiting structures left in the field and thereby affected infestations of overwintering larvae in the field. Termination date had a dramatic effect on the % bolls infested with overwintering larvae and the density of overwintering larvae /m.