• 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.
    • ABA and Auxin Contents of Squared and Flowers in Relation to Water Deficit Stress and Subsequent Young Boll Shedding

      Guinn, G.; Brummett, D. L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Water deficit increases boll shedding. Large squares, however, are much less likely to shed, possibly because they contain high concentrations of free and total auxin (indole-3-acetic acid or IAA). Our previous research indicated that much of this IAA disappears by the time the squares open as flowers and the IAA content remains low for about four days after anthesis. If water deficit decreases the IAA content, or increases the ABA conten4 of squares and flowers, then water deficit before flowering could have a carry-over effect and increase the shedding rate of young bolls that subsequently develop from them. In field plots, water deficit increased the ABA content of flowers as much as 66 %. Water deficit first decreased and later increased the concentrations of free and total IAA in squares that were analyzed about three days before anthesis. Flowers contained much less IAA than squares. Despite pronounced effects of water deficit on the IAA content of squares it is unlikely that it had any carry-over effect on the free IAA content of young bolls that subsequently developed from them. Water deficit slightly increased the total IAA content of flowers, but had no effect on their free IAA. Because water deficit increased the ABA content but did not decrease the IAAA content of flowers, any carry-over effect of water deficit on young boll shedding might have been from changes in ABA but not from changes in IAA before the young-boll stage.
    • Short Staple Demonstrations, Graham County, 1989

      Clark, Lee. J.; Cluff, Ronald E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Short- staple variety trials were grown in two locations in Graham County in 1989. Exceptional weather conditions, coupled with good management practices, provided record cotton yields in the Safford valley. Delta Pine 77 was the highest yielding variety in the Thatcher location with a yield of 1740 pounds of lint per acre. An experimental acala from New Mexico came in second in this triad ahead of Delta Pine 90. Delta Pine 90 was the highest yielding variety in the Eden area with a yield of 1196 pounds per acre. Data on percent first pick plant height and plant populations are presented for each variety in each location. Graphs of heat units received each day throughout the growing season at the AZMET station on the Safford Agricultural Center are presented for 1988 and 1989.
    • A Study of PIX Rates across CaZa and Triggrr on Long and Short Staple Cotton, Safford Agricultural Center, 1989

      Clark, L. J.; Carpenter, E. W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      An experiment was designed to test seven treatments of PIX on both short and long staple cotton. The treatments included single applications of 1/2- and 1-pint rates and multiple applications of 1/8- and 1/4-pint rates. Because of the exceptionally good growing season with lots of early heat units, both short- and long-staple plants set fruit early, which limited their vegetative growth naturally without the need for FIX. Yields were high with lint production over 1800 and 1400 pounds of lint for short and long staple, respectively. Plant mapping also was performed on each treatment.
    • 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.
    • Effect of Plant Nitrogen Status on Effectiveness of Pix and Defoliants for Short-Season Cotton Production

      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 determine the effect of nitrogen fertility level on the effectiveness of PIX and defoliants for short- season - cotton production. Increasing the nitrogen fertility level from 90 lbs N/A to 240 lbs N/A increased lint yields from 2.23 to 3.14 bales/A, respectively, in a 157-day growing season. FIX treatments did not promote earliness, and resulted in yield reductions. Increasing the application rates of Dropp from 0.1 to 0.2 lbs a.i./A and Def-6 from 0.75 to 1.13 lbs a.i./A resulted in increases in leaf drop. There was a significant linear decrease in the effectiveness of defoliants as the petiole NO3 N content increased from 850 to 2450 ppm.
    • 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.
    • 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.
    • Effects of Date of Planting on the Yield of Four Cotton Varieties at Yuma, Arizona

      Malcuit, J. E.; Howell, D. R.; Silvertooth, J. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A field experiment was conducted in Yuma, Arizona, to evaluate the effects of planting date on cotton yields. One Pima and the Upland cotton varieties were planted on four dates from 23 February to 5 April. DPL-90 produced the highest yield (1760 lbs lint acre⁻¹) at the second planting date (9 March). The lowest yields, for all varieties, resulted from the latest planting date (5 April). The greatest reductions in yield when comparing an early planting date to the latest planting date, were observed for DPL-90 and Pima S-6. However, in spite of the reduction in yield, DPL-90 was the highest yielding variety at the latest planting date.
    • 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. .
    • Accumulation of Proline in Germinating Cotton (Gossypium hisutum L.) Seeds During NaCl Stress

      Lehle, F. R.; Zegeer, A. M.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The accumulation of proline (Pro) in plants during NaCl stress may have adaptive significance and the study of this response could reveal a genetic strategy for enhancing NaCl tolerance. Our objective was to determine if the Pro content of germinating cotton seeds is altered by exposure to exogenous NaCl. Seeds were imbibed for 24 h at 32°C before transfer to agar media containing NaCl. After 24 h of NaCl exposure, the Pro contents of radicles and cotyledons were measured using a colorimetric assay. Results showed that Pro contents of both radicles and cotyledons increased as the level of NaCl increased. The bulk of Pro content increases were restricted to the radicle and occurred in the range of NaC1 concentrations from 200 to 400 mM NaCl.
    • Short and Long Staple Variety Trials, Greenlee County, 1989

      Clark, Lee. J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two short staple and one long staple variety trials were implemented in Greenlee County in 1989, with new varieties topping each trial. The most exciting new discovery was HS 46, which topped the competition in the short-staple trial by nearly 200 pounds of lint per acre. In the acala trial, the top four entries were composed of three New Mexico experimentals and Prema from the San Joaquin Valley. Any one of these acalas could become the new standard for the valley. P-69 in the long staple cotton trial yielded over 850 pounds of lint per acre and topped the S-6 yield by 25%. The testing program in Greenlee County is not only of benefit to the cotton producers and related agri-businesses in southeastern Arizona, but also to southwestern New Mexico.
    • Pima Gotton 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.
    • 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.
    • 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.
    • 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.
    • 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.