Fertilizer trials and field studies in 1957, 1958, and 1959 indicated that the soil in some cotton fields in the San Joaquin Valley was deficient in available potassium, and the application of potassium fertilizers significantly increased cotton yields. Where available soil potassium is in low supply, cotton plants show distinctive visible deficiency symptoms.

Forrest Fullmer of the American Potash Institute assisted in the above studies.