| This research employed Xinhai24 and Xinhai36 as the materials to study the effects on yield of island cotton at flowering and boll forming stages under different drip levels. The results showed that the LAI, leaf Pn, SPAD value, and dry matter accumulation were highest with drip level of 3 900 m3·hm-2, followed by that of 3 150 m3·hm-2, and then that of 2 400 m3·hm-2. However, cotton boll shedding rate assumed the opposite trend. Lint yield with drip level of 3 900 m3·hm-2 was 2 228.49 kg·hm-2, 36.68% and 49.38% higher than those of 3 150 m3·hm-2 and 2 400 m3·hm-2, respectively. In addition, the responses to different drip levels varied from varieties. For LAI, dry matter accumulation and cotton boll shedding rate of Xinhai24 were smaller than those of Xinhai36, but leaf Pn, SPAD value, and lint yield were higher than those of Xinhai36. Therefore, combined with the corresponding irrigation system, and also based on the difference in responses from varieties to different drip levels, a drip level at 3 900 m3·hm-2 would be beneficial to achieve high yield. |