• Pima Cotton Genetics

      Percy, R. G.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1995-03)
      A short season feasibility study, using early maturing Pinta genotypes was conducted for a second season. Four early maturing genotypes, a short season check (P62) and a full season check variety (PS-7) were evaluated in replicated tests under short season and full season regimes. In both 1993 and 1994, most genotypes reached cutout around August 4, with 2759 accumulated heat units. All genotypes were earlier maturing than PS-7, as indicated by plant growth measurements and by sequential harvests. In 1994, the four early maturing experimental genotypes produced yields equal to or slightly better than the longer season cultivar PS-7. No differences in yield occurred between the short season and standard practice management systems in either year. A fiber improvement project was initiated in 1989 with the primary goals of increasing the fiber length and strength potential of Pima cotton. In 1989 the early maturing, short statured Pima strain P62 was crossed to Giza 45 and Giza 70 to transfer the fiber strength of those varieties into a heat tolerant, earlier maturing, productive Pima background. Likewise, P62 was crossed to the Sea Island cultivar St. Vincent V-135 with the objective of transferring the latter cultivar's long fiber length into an agronomic Pima background. Two resulting lines, one possessing high fiber strength and the other possessing high fiber length are planned for release in 1995-96.
    • Pima Cotton Improvement

      Moser, H. S.; Percy, R. G.; Ray, I. M.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1995-03)
      The objective of this study was to evaluate the performance of five experimental lines (P73, P75, P76, P80, and P81) with two commercial varieties ('Pima S-6' and 'Pima S-79 of Pima cotton. All seven strains were grown in replicated strip tests at four locations across the Pima belt in 1994. While none of the experimental lines produced significantly more lint than the best Pima variety at any site, some of them possess traits that are valuable to Pima cotton breeders. P73 has long and strong fiber. P76 is a high yielding, early maturing line that produces long and strong fiber. P80's lint yields are similar to Pima S-7, but it is significantly earlier.