Because one-variety and one-quality have been designated by law for the San Joaquin Valley, Acala cotton has been the predominant variety grown since the first field was planted in 1917. In 1988 Pima was introduced in the San Joaquin Valley. S-6 was the first variety of Pima grown in California. Then S-7 was introduced and became the variety predominantly grown in the San Joaquin Valley and set the standard. In 1998 DP-HTO and Phytogen 57 were introduced. Growers now have more choices in Pima varieties and have a higher quality of Pima to choose from. HTO provides Acala type turn out of about 35% to 36% with excellent grades. Over the past couple of years, Pima has occupied about 25 to 35% of the cotton acres grown in the San Joaquin Valley.