Top Cross Assessment of Combining Ability for Extra Long Staple Trait in Upland Cotton.

Improvements in spinning technology and competition from man-made fibers require that plant breeders continue to improve the average length and strength of upland cotton, Gossypium hirsutum L., fibers. Improved length and strength, among other parameters, are needed in order for fibers to withstand ever increasing processing speeds and rigor. Such improvements in fiber quality could provide for greater flexibility in end products and help maintain the global competitiveness of U.S. cotton.  TAM B182-33 ELS (Extra Long Staple) germplasm line of upland cotton, Tamcot CAMD-E, a short staple obsolete cultivar, and Fibermax 832, a modern long staple cultivar, were crossed with 36 cultivars representing unique germplasm pools from China (12 cultivars), north Africa (12 cultivars), and southern Africa (12 cultivars), plus eight cultivars representing distinct germplasm pools within the United States. Parents and F₁s were grown in the Cotton Winter Nursery in a randomized completed block design during the winter 2009/10. Seedcotton was harvested by hand, returned to College Station, TX, ginned on a laboratory gin, and fiber properties determined by Cotton Incorporated. Fiber properties, especially length and strength parameters, will be presented and discussed.