种植密度、氮施用量及打顶时间对棉花产量及产量因子影响的研究

Study on Cotton Yield and Yield Components Affected by Planting Density,Nitrogen Fertilizer Mount and Topping Time

获得高产是棉花育种家最重要的目标之一。棉花产量因子较多且受多种因素影响。本研究以转基因抗虫杂交棉品种慈抗杂3号为实验材料,研究种植密度(A)、氮肥施用量(B)及打顶时间(C)三因素对棉花产量及产量因子的影响。通过三因素四水平的正交实验设计,考察7个性状指标:小区籽棉产量(SY)、50铃籽棉重(50SCW),50铃皮棉重(50LW),衣份(LP),单株铃数(BN),单株节数(NN)和株高(PH),对所获数据分别用直观分析法和方差分析法两种方法分析,以期确定打顶时间、种植密度及氮肥施用量三因素对棉花产量及产量构成因素影响的主次关系及最优组合。结果表明,(1)氮肥施用量对SY产量影响最大,其次是种植密度,最后是打顶时间,即B>A>C;获得高产的最优因素组合为氮肥施用37.5 kg/667m^2,种植密度1 400株/667 m^2,打顶时间比正常延迟10 d;(2)产量构成因素不同,对应最优因素组合亦不同,影响因素的主次顺序亦不同。对于50SCW,B>C>A;对于50LW,B>A>C;对于LP,A>B>C;对于BN,A>B>C;对于NN,B>A>C;对于PH,B>C>A。(3)SY、50SCW、50LW、BN、NN和PH性状表现与氮肥施用量正相关;BN和NN性状表现与种植密度负相关;SY、NN、PH和BN性状表现和打顶时间正相关。本研究所获结果不仅为指导棉花高产种植提供参考材料,同时对长江流域棉区及相似生态棉区提高棉花经济收益奠定基础。

High yield is one of the most important goals in cotton breeding. There are many yield components of cotton and all of these yield components are affected by many factors like planting density, fertilization application, water irrigation and topping time etc.. In this study, take Cikangza No.3 which is a B. thuringiensis transgenic cotton cultivar as experimental material, three factors of nitrogen fertilizer amount（A）, planting density（B） and topping time（C） with four levels respectively were used for further orthogonal design analysis. A totalseven traits i.e. Seed yield per plot（SY）, 50 boll seed cotton weight（50SCW）, 50 boll lint weight（50LW）, Lint percentage（LP）, boll number per plant（BN）, node number per plant（NN） and plant height（PH） were investigated.The obtained data were analyzed by two methods i.e. direct analysis method and variance analysis method in order to find the primary and secondary relationship of the three factors and confirm the optimum scheme. The results showed that（1） The most important factor that influence SY was nitrogen fertilizer amount, followed by planting density, and the last was topping time. Major and minor relationship of SY affected by different factors was B〉A〉C. The optimum scheme of obtaining the highest SY was to apply 37.5 kg/667 m2 nitrogen fertilizer, control planting density of 1 400 plants/667 m2 and delay topping time 10 days than normal.（2） The optimum orders of factors affecting traits performances varied for different traits and the optimum schemes of yield components were not the same. Major and minor relationship of different factors were BCA for 50 SCW trait, B〉A〉C for 50 LW trait, A〉B〉C for LP trait, A〉B〉C for BN trait, B〉A〉C for NN trait and BCA for PH trait.（3） Performances of traits SY, 50 SCW, 50 LW, BN, NN and PH were all positively correlated with nitrogen fertilizer amount.Performances of traits BN and NN were both negatively correlated with planting density. Performances of traits SY, NN, PH and BN were all positively correlated with topping time. Methods designed and results obtained in this study will not only provide reference for guiding high yield scheme, but also make suggestions to enhance economic performance for cotton production in Yangtze River Valley and other areas with similar ecologies.