Early maturing cotton varieties are more sensitive to potash deficiencies than late maturing varieties. Lint yields of the earliest maturing varieties were not maximized by yearly applications of 240 lb K₂O/A for 6 years. However, lint yield for the latest maturing variety was maximized with the 120 lb K₂O/A rate. Lint yield response to potassium generally increased with increasing earliness of varieties, as indicated by the reduced number of nodes above the uppermost first position cracked boll to the terminal for the earlier varieties.