[Effects of girdling on growth, yield and water use efficiency of cotton]

An experiment with girdling applied on the main stem and fruit branch during the early or flourishing stage of flowering and boll-setting was conducted to investigate the effects of different girdling treatments on the growth, yield and water use efficiency (WUE) of cotton. The results showed that compared with the control (CK), leaf area index (LAI) of girdling treatments reduced significantly and the maximum LAI of girdled cotton occurred 5-15 days in advance. Girdling reduced the shedding rate of squares and bolls significantly, and the shedding rate of squares and bolls with girdling applied on the main stem at the flourishing stage was 15.8% lower than that of CK. In contrast with CK, the seed-cotton yield and WUE increased by 24.4% and 26.7% with girdling applied on the main stem at the flourishing stage, and increased by 13.9% and 16.7% with girdling applied on the fruit branch at the early stage, respectively. However, the girdling on the fruit branch at the flourishing stage improved the seed-cotton yield and WUE insignificantly. The seed-cotton yield with girdling on the main stem at the early stage had not significant difference and its WUE reduced slightly compared with CK. It has been concluded that the girdling applied on the main stem at the flourishing stage of flowering and boll-setting could effectively reduce the abscission rate of squares and bolls, improve yield and WUE significantly, and realize the effective unity of high production and water-saving.