Development of Extra‐Long Staple Upland Cotton

Abstract

An objective of U.S. cotton breeding programs is to provide raw material that processes efficiently and produces better textile products without compromising yield. Annual domestic consumption dropped from 10.4 million bales in 1998 to 5.5 million bales in 2007. Exports increased from 4.3 to 16.2 million bales. Increased reliance on export markets will require the United States to compete more effectively in price and quality. The desired minimum upper half mean (UHM) fiber length in international markets is 28 mm, while the traditional U.S. minimum is 27 mm. To compete at this higher UHM length expectation, breeding programs should target minimums well above the international base. Extra‐long staple (ELS) upland cotton (Gossypium hirsutum L.) germplasm lines were developed by the Cotton Improvement Lab, Dep. of Soil and Crop Sciences, Texas A&M AgriLife Research, as part of an effort to create germplasm with combinations of improved fiber quality, especially UHM length and fiber bundle strength. These ELS upland lines exhibit high volume instrument UHM length >32.0 mm, and several strains exceed 34.8 mm, which is the minimum UHM length for pima (G. barbadense L.). These ELS strains range in agronomic performance from less than to equal to that of ‘Fiber Max 832’ (PI 603955). TAM 94L‐25 (PI 631440), or its full sib 94L‐2 (unreleased), is the common parent in these ELS strains and is proposed as the major contributor of favorable allelic combinations for this exceptional UHM length.