Considered to be one of the superior forms of cotton for its strength, softness and durability, Pima cotton has been a focus of research at the West Side REC for over 20 years. Very little was grown in California until the early 1990's, but improved varieties and better information on production practices have resulted in large acreage increases since those early years, and California now produces over 90% of the Pima cotton grown in the United States.
American Pima used to be grown primarily in Arizona, where cultivars required high temperature tolerance as key characteristics to be successful. Since that time, however, researchers from the USDA-ARS, University of California, University of Arizona and private companies have expanded the number of available Pima cultivars to include varieties not only with high heat tolerance, but also with shorter growing season maturities more appropriate for the San Joaquin Valley production area. Well-adapted varieties, innovative growers, our dry Mediterranean summer weather, and fiber quality improvements make this export crop even more valuable and competitive in the marketplace. These types of Pimas have thrived in the conditions in the San Joaquin Valley. Although cotton in general is not as widely grown now as in the 1990's, the high quality Pima cotton in the past five years still has typically been grown on between 200,000 and 250,000 acres per year in the San Joaquin Valley production area.
University of California and USDA-ARS work at both Kearney and WSREC in cooperation with Steve Wright (UCCE-Tulare and Kings Countiess), Mike Davis (UCCE and UC Davis Plant Pathology), and Mauricio Ulloa of the USDA-ARS (Lubbock, TX) over the past ten years has been involved in developing and screening cotton cultivars, including Pimas, for resistance to a recently-identified serious fungal disease. Other Pima cotton research at the WSREC, headed up by REC Director Bob Hutmacher (pictured at left), has focused on evaluating differences in growth and yield responses of select Pima varieties to specific management approaches (irrigation water reductions, nitrogen fertilizer levels, plant growth regulator approaches), and determining fiber quality with these different management practices.