Water management of short-season high-density cotton

Abstract

Water management of short-season, high-density cotton was studied for three seasons (1972, 1973 and 1974). Various irrigation schedules and nitrogen fertilizer application rates were examined. Data on amounts of water applied, yield, boll and fiber properties, soil nitrate levels and cotton petiole nitrate levels were collected. Cotton was planted on 40-inch beds with two plant rows per bed 12 inches apart. For 1972, two varieties were planted, Anderson- Clayton 1764 and Deltapine 16; the plant population was 60,000 plants per acre. Deltapine 16 was the only variety planted in 1973 and 1974 with plant populations of 50,000 and 60,000 plants per acre, respectively. The 1972 experiment showed that Deltapine 16 was better suited to the short-season, high-density cotton production system than Anderson-Clayton 1764. In 1973 and 1974, experiments indicated that available soil moisture depletion should not exceed 50-55 percent. Also, criteria (based on available soil moisture) of when to irrigate should not be varied throughout the season. Results suggest that yields can be maintained with early irrigation termination if soil moisture, before irrigation, is kept at a higher level than is the normal practice. Application of 100 pounds of N per acre seemed to adequately meet the crop's needs for the season.