Cotton grown in the United States comes from areas prone to periods of extremely high temperatures that can have a negative effect on cotton yield. Agricultural Research Service scientists Michael E. Salvucci and Steven J. Crafts-Brandner are developing technology to improve cotton yields in Arizona's extremely hot and dry summer environment.

The ideal daytime temperature for cotton production is 82 degrees. The plant also needs an adequate supply of water. In Arizona and other cotton-producing areas, daytime temperatures often exceed 100 degrees. Plant physiologists Salvucci and Crafts-Brandner have found that high temperatures can adversely affect the function of a plant enzyme called Rubisco activase, resulting in impaired photosynthesis and reduced yields.Read more about the research in the November 2004 issue of Agricultural Research magazine, available at: http://www.ars.usda.gov/is/AR/archive/nov04/cotton1104.htm.