| Eleven suitable cotton (Gossypium hiristurum) cultivars in Hexi area of Gansu, Longmian No.1, Longmian No.2, Longmian No.3, Jiumian No.11, Jiumian No.15, Jiumian No.17, Xinluzao No.39, Xinluzao No.48, Shuofeng No.2, Gengye No.6 and Jinkeng No.108 were used to study the effects of different irrigation volumes including 4800 m3·hm-2(Ⅰ1), 3600 m3·hm-2(Ⅰ2), 2400 m3·hm-2(Ⅰ3), 1200 m3·hm-2(Ⅰ4) during the entire growth period on growth and development of cotton under field conditions. The yield and irrigation water productivity of cotton were analyzed and the drought resistance of those cultivars were also evaluated by comprehensive evaluation by D method and resistance index method. The results showed that the plant height, number of fruiting branch, boll number per plant, single boll weight, fuzz length, dry mass and seed cotton yield of most cotton cultivars became increased with mild water stress, but went decreased significantly under severe water stress. The irrigation water productivity of all the cultivars was highest at the I3 level. I3 level was the best irrigation condition for Shuofeng No.2, Xinluzao No.48, Jiumian No.11,Longmian No.1, Longmian No.3, and Longmian No.2, resulting in the highest yield and productivity. I2 level was the best irrigation practice for Jiumian No.15, Xinluzao No.39, Gengye No.6, Jinkeng No.108, and Jiumian No.17, causing highest yield under sufficient irrigation conditions, but the irrigation water productivity was low. Jiumian No.17 and Longmian No.3 were highly resistant cultivars to drought; Shuofeng No.2 and Gengye No.6 were moderate resistant cultivars; Xinluzao No.48, Longmian No.1, Longmian No.2, Jinkeng No.108 were weak drought resistant cultivars; and Xinluzao No.39, Jiumian No.11 and Jiumian No.15 were sensitive to the drought. |