Effect Of Different Density On Cotton

Two field experiments were conducted from 2008-2010 to study the effect of different planting density on cotton's growing characters, yield, quality and physiological and biochemical index, with Xiangzamian No8 and Huazamian H318 as experiment materials, in two places. The main results were showed:1. Cotton plants were growed under different density in Huazhong agricultural university.The experiment took Xiangzamian No8 as the variety, through six treatments of different density, as follows:800 plants per 667m2,1400 plants per 667m2,2000 plants per 667m2,2600 plants per 667m2,3200 plants per 667m2,3800 plants per 667m2. Application of fertilization was based on 20 kg per 667m2 with pure nitrogenous fertilizer in each treatment, fertilizer proportion of N:P2O5:K2O within 1:0.4:0.8. The results indicated that there were definite infection in growth etc of cotton under different density.Plant height, fruit branches, caulis leaves, the dry material accumulation per plant, the content of chlorophyll,temperature, boll weight,fruit bolls per plant and cotton boll setting ratio were all gradually decreased but cast setting ratio, total dry material accumulation per unit area added by the growing density added from 800 plants per 667m2 to 3800 plants per 667m2 for different treatments in the same growth period. Soluble sugar content and soluble protein content of planting leaves under different density increased at first and declined later over time. The quality and lint percentage of cotton were no significant differences under different density. The yield of cotton increased to reduce as the density increased.The cotton yield of 2000 plants per 667m2 was the highest. In conclusion,2000 plants per 667m2 was the suitable density for cotton in Huazhong agricultural university.2. This test studied density effect of cotton on Lukou farm in Ezhou city. Huazamian H318 was used as experiment material.The experiment was based on four treatments of different density (1200 plants per 667m2,1500 plants per 667m2,1800 plants per 667m2,2100 plants per 667m2) in 2008, through five treatments of different density (900 plants per 667m2,1200 plants per 667m2,1500 plants per 667m2,1800 plants per 667m2,2100 plants per 667m2) in 2009. The experiment was the coupling test of nitrogenous fertilizer and density but we mostly discussed the effect of different planting density on cotton's growing characters and yield etc at the same fertilization application as the test of Huazhong agricultural university. The results indicated that plant height, fruit branches, caulis leaves, the content of chlorophyll, boll weight, fruit bolls per plant and cotton boll setting ratio were all gradually decreased by the growing density increased for different treatments in the same growth period. The treatment data showed that there were increments on the cast setting ratio as the density added. The yield of cotton was significantly influenced by the different density. There were gradual increments on the the yield of cotton by the density added and yield of 281.78kg per 667m2 under 2100 plants per 667m2 was the highest in 2008. The yield of 1500 plants per 667m2 was the highest, and 2100 plants per 667m2 was the second in 2009. Therefore, the density within1500-2000 plants per 667m2 is recommended be used in the scheduling density programs in similar conditions for cotton.