Study On Population Quality Index Of Super High-yield Cotton In Xinjiang

Study on relations of population quality index of super high-yield cotton(lint yield over 3 000 kg·hm^-2)of zhong mian-suo No.49 and number of zhao feng No.1 in south Xinjiang in 2008 and 2009, the comparison of high yield (lint yield 2 250 kg·hm^-2～3 000 kg·hm^-2) and middle-low yield (lint yield under 2 250 kg·hm^-2), revealed population quality index and buildup yield elements of super high-yield cotton, in order to providing theory for planting super high-yield cotton in Xinjiang. The main results were as follows:1. The course of growth took on fast before flower forming stage and firmed after flower forming stage of super high-yield cotton, the height of plant increased fast before flower forming stage, and attained 55 cm, and retained 65 cm～75 cm after tip pruning times. The leaf expansion rate remained a high level, formed 2.5～3 bud while expended a leaf. For horizontal distribution of boll, the inside of boll occupied over 70% of super high yield cotton, so high yield and middle-low yield cotton occupied 65%. For vertical distribution of boll, the middle and upside boll occupied 60% of super high yield, especially middle boll occupied 35%, obviously exceeding high yield and middle-low yield. The underside boll occupied 40%, under high yield and middle-low yield cotton.2. Compared with high yield and middle-low yield cotton, super high-yield cotton pre-reproductive LAI growth faster and bigger than high yield cotton and middle-low yield cotton, and largest peak value in boll forming stage. The peak value of LAI were 4.44,4.39 in boll peaking stage, more than 10.83%,26.42% and 2.57%,15.83% of high yield and middle-low yield,respectively. MTA achieved peak value along with generation stage development of super high yield, and above 60°, so reduced DIFN of population, increased photosynthesis efficiency.The correlation between the leaf SPAD values and cotton leaf Pn. The leaf SPAD values grew faster before flowering stage of super high-yield cotton. In this stage, the leaf SPAD values grew slowly and kept high levels after boll forming stage, so Pn declined slowly. The accumulation speed of bud and boll dry matter was fast, and dry matter accumulated very large.3. The photosynthatesis distributed to shoot and leaf before flowering stage of super high-yield cotton, and step by step decreased, and more and more photosynthatesis distributed to bud and boll, and much photosynthatesis still distributed to shoot,leaf after flowering stage of high yield and middle-low yield cotton, which influenced yield of cotton.The boll load of unit leaf area of super high yield cotton , higher than high yield and middle-low yield cotton, were 26.87 per·m^-2,31.70 per·m^-2. Effect of variety biggish, total fruit node unit leaf area firmed about 90 per·m^-2, it reduced cotton yield that total fruit node unit leaf area were higher or lower. In production of cotton, it improved cotton yield that changed total fruit node unit leaf area, and regulated LAI.4. The shoot and leaf accumulated N,P₂O₅,K₂O of super high yield before flowering peak stage, attained peak value in flower forming stage and flower peaking stage, so bud and boll accumulated peak value in boll peaking stage, and peak value was remarkable higher than high yield and middle-low yield. Nutrient absorption attained t1 in turn N> K₂O >P₂O₅, and long timeâ–³t, and great GT, and reduced along with yield levels.