Pima cotton has been grown in the southwestern USA since the early 20^th century. It originated from extra-long staple introductions from Egypt. The introductions had long, strong and fine fiber, and were very tall, late maturing and unproductive. In the early 1900's, Pima cultivar development was either by direct selection from the introductions or through hybridization followed by selection. Cultivar improvements up through the release of ‘P32' in 1949 by R. H. Peebles at the USDA Field Station at Sacaton, AZ, were minimal because of the narrow genetic base of the germplasm.