• Nematocide Use for Control of Rootknot Nematodes

      Farr, Charles (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Injection of Telone II in sandy loams containing more than 60 percent sand increased Pima S-6 yield 493 pounds of lint but failed to give economic response with DP 77 in second year cotton. Treatment with Vapam at two rates at the same locations did not increase yield significantly in 1987.
    • Pima Cotton Improvement

      Turcotte, E. L.; Percy, R. G. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Five experimental strains and Pima S-6 were grown in nine Regional Tests across the Pima belt in 1987. Experimental strain P70 averaged highest in yield both below and above 2,500 foot elevation. The difference in yield between Pima S-6 and P70 across all locations was 48 pounds of lint per acre. Sequential harvests at Phoenix and Safford, AZ, indicated that P70 was the earliest and Pima S-6 the latest entry in the 1987 Regional Test.
    • Natural Resistance of Cotton to Cotton Leaf Crumple Virus

      Wilson, F. Douglas; Brown, Judith K.; Butler, G. D. Jr. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Cultivars and germplasm lines of cotton, Gossvpium hirsutum L., differed in response to infection by the cotton leaf crumple virus (CLCV). The most widely grown cultivars in Arizona and southern California, 'Deltapine 90' and 'Deltapine 61', are susceptible, while ' Cedix', developed in El Salvador, and 'Coral', developed in Nicaragua, are highly resistant or immune. Nineteen other lines from a resistance breeding project in Nicaragua showed highly variable responses.
    • Resistance to Verticillium Wilt by Eight Varieties of Short Staple Cotton, Safford Agricultural Center, 1987

      Clark, Lee J.; Hine, Richard B.; Carpenter, Eddie W. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Eight short staple varieties were evaluated for severity of symptoms, percent of plants infected and yield while being grown in a Verticillium nursery on the Safford Agricultural Center. Delta Pine 90 showed the least severe symptoms, had the least number of infected plants and also yielded the highest. Another Delta Pine variety, DP 77, showed moderate symptoms and a 96% infection rate, but it still managed to come in third in yield, only 49 pounds per acre behind DP 90. Yield potential and varietal adaptability must be considered along with Verticillium wilt resistance in deciding what variety to plant, even in a field infested with Verticillium.
    • The Effect of Soil Temperature and Inoculum Levels of Thielaviopsis basicola on Black Root Rot of Cotton

      Hine, R. B.; Mauk, P. A.; Tedla, Tesfaye (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Two planting dates, March 28, and April 28 were used to study the effect of soil temperature during planting on black root rot of cotton. Also, several cotton varieties were evaluated for response to the disease under varying soil temperatures and inoculum levels.
    • Weather Conditions Associated with the Development of Southwestern Rust on Cotton

      Young, Deborah; Brown, Paul (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Weather conditions leading to the development of southwestern rust on cotton were evaluated at 3 locations in southeastern Arizona. Rust appeared following an extended period of wet, humid weather. In excess of 16 hours of wet canopy/high humidity conditions were observed on two consecutive days between 5 and 7 days prior to the appearance of rust. Temperatures during the wet canopy/high humidity periods were moderate, ranging from 65 F to 76 F. Afternoon rain showers initiated these extended periods of wet canopy /high humidity conditions.
    • Response of Texas Root Rot to a Soil Sterilant in Marana in 1987

      Thacker, Gary; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Methyl bromidelchloropicrin, a soil sterilant, was deep-injected into cotton beds ten days before planting. Within the kill areas of the Texas Root Rot, the soil sterilant had some significant effects on the mortality and yield of the cotton.
    • Response of Texas Root Rot to a Soil Sterilant in Graham County, Part II, 1987

      Clark, Lee J.; Cluff, Ronald E. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Residual effects from methyl bromide applied in 1986 showed increased yields in 1987. Increases from 115 to 281 pounds of lint per acre were observed, depending on the rate applied in 1986. This residual effect increases the possibility that this soil sterilant will be a useful tool to combat Texas root rot. Differences were also noted between 1986 and 1987 applications.
    • Irrigated Cotton, Safford Agricultural Center, 1986

      Biggs, E. Niel; Clark, Lee J. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Cotton was grown using a computer model to schedule irrigation; yields of 2.5 bales per acre were produced. Even though some discrepancies were seen between calculated and measured soil moistures, the model was considered successful. No yield differences were seen between cotton grown with small, frequent irrigations and large, infrequent irrigations. The plant heights, however, were significantly altered.
    • The Use of Drip Irrigation in Maricopa County

      Farr, Charles (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Drip irrigation of cotton in Maricopa County decreased from 13,335 acres in 1984 to approximately 600 acres in 1987 at five locations. The most common reason was that drip was not cost effective.
    • Pima Cotton Genetics

      Percy, R. G.; Turcotte, E. L. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Maintenance and evaluation of a collection of primitive Gossypium barbadense L. cottons progressed in 1987. Conversion of the non flowering tropical cottons to a flowering, day- neutral habit progressed. So did efforts to incorporate potentially useful biological and environmental stress tolerant traits into agronomic Pima backgrounds. Six cottons of the primitive cotton collection were found to potentially possess bacterial blight resistance. Genetic populations were developed to investigate the inheritance and distribution of two mutant marker traits in cotton. Interspecific Fl hybrid populations were developed for evaluation in 1988.
    • Cotton Variety Observation, Safford Agricultural Center, 1986

      Clark, Lee J.; Carpenter, Eddie W. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      The check variety, Delta Pine 90, produced more than any of the new varieties in this unreplicated strip test. However, three new varieties produced yields within 10 % of the Delta Pine 90 yields; they were BR 110, Northrup King 111 and Germains GC 365.
    • Cotton Variety Trials, Greenlee County, 1987

      Clark, Lee J.; DeRosa, Edith (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Four short staple variety trials were harvested in Greenlee county in 1987, covering long season varieties, early maturing varieties, acala varieties and a regional variety trial which was duplicated in Cochise county. Germains GC 510 and Delta Pine 90 yielded equally with acala 1517-75 in the long season trial. Delta Pine 20 out-yielded acala 1517-SR1 in the trial of earlier maturing varieties. An experimental acala, B 510, out-yielded the other acalas in the trial, but required more time to produce the yield. Wider experience with this new acala and others in the trials will be necessary before recommendations can be made. The better yielding varieties produced more than two bales of lint this season.
    • Short Staple Variety Trial, Cochise County, 1987

      Clark, Lee J.; Schwennesen, Eric (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Eleven varieties of short staple cotton, containing four varieties of Acala 1517 (including two new releases from New Mexico State University) were grown near the town of Cochise, which is at an elevation of 4,180 feet and has an average growing season of 232 days. Northrup King's KC 380 (the same as the experimental variety 2019) was the high yielder for the second year in a row, with 954.6 pounds of lint per acre. One of the new Acala' s, 1517-77BR was second in yield, with 936.5 pounds per acre. With the current premium structure, 1517-77BR would produce about $50 more gross farm income per acre than KC 380.
    • Short Staple Variety Demonstration, Graham County

      Clark, Lee J.; Cluff, Ronald E. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Two short staple variety trials were held in Graham county, one toward the west end of the valley (Eden), and one in the center of the valley (Thatcher), both with 15 varieties. Delta Pine 90 was the highest yielding variety at both locations, with yields of 1,386 pounds of lint per acre at Thatcher and 1,123 pounds at Eden. Two new varieties, Northrup King 111 and BR 110, show some promise in the area, with yields close to that of Delta Pine 90. Lint quality and grade are listed for each variety.
    • Regional Variety Test

      Pegelow, E. J. Jr.; McAlister, A. C. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
    • Effect of Pix on Three Tall Statured Short Staple Cotton Varieties and One Short Statured Cotton Variety, in Graham County, 1987

      Clark, Lee J.; Cluff, Ronald E. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Four short staple cotton varieties were grown with and without an application of PIX to see its affect on their growth, maturity and yield. PIX is a plant growth regulator thatmodifies plant architecture, Two of the tall -statured varieties, Delta Pine 90 and Acala 1517-75, showed increases in lint yield of 5.8 and 13.7%, respectively, coupled with a hastening of their maturity. Stoneville 506, a short- statured, medium- maturing variety was unaffected by the plant growth regulator. A tall, gangly variety, Germains GC 365, was shortened in height and in maturity, but exhibited a small decrease in yield.
    • Effect of Spray Dilution and Rate of Pix Application on Long and Short Staple Cotton, Safford Agricultural Center, 1987

      Clark, Lee J.; Carpenter, Eddie W.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      PIX was applied to long and short staple cotton in 5, 10 and 20 gallons of water in an incomplete factorial design involving 0.5, 1 and 2 pints of the product per acre. Plant heights were significantly shortened and the percent of lint obtained in the first picking was significantly increased when Piz was applied on the short staple cotton. No statistically significant yield differences were observed between the volumes of dilution or the rates of application for either long or short staple cotton. A factor underlying the experiment was that the monsoon rains. They kept the surface of the ground moist and the plants looking good; however, the subsurface moisture had apparently been depleted, and the plants were under some stress. This stressed condition offset what good the FIX might have done for yield.
    • Effect of Ethphon (PREP™) on Short Staple Cotton in Marana, 1987

      Thacker, Gary; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Ethephon was applied to Deltapine 55 cotton with 35% of the bolls open. Ethephon significantly increased the percent first pick yield of the cotton. There was no significant difference in the total yield.
    • Defoliation of Pima Cotton

      Silvertooth, Jeff; Howell, Don R. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Afield study was conducted in Yuma County to evaluate the relative effects of a plant growth regulator application and several defoliation treatments on Pima cotton. There were no statistically significant effects recorded with regard to the plant growth regulator application. There was a significant difference among defoliation treatments by analysis of percent leaf drop estimates. Promising results were recorded for DROPP as a defoliant material for Pima cotton under the given test conditions.