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通过1983年——1985年的田间小区接菌试验及电算统计分析表明:棉花生长中期黄萎病的病情指数对棉花产量损失的影响最大,是造成产量损失的主要因素。田间种植密度愈高,棉株群体间的补偿作用愈显著。说明适宜密植是弥补损失的措施之一。分析还表明:病害主要通过减少单株结铃数使产量降低,而对单个铃重的影响次之。作者还用多因素回归法求得了棉花产量损失的预测式为:L%=1-exp[-exp(1.028LnX_2-0.000157X_4+0.9967)]决定系数 R~2=0.7470在田间种植密度为每亩5000株左右情况下,产量损失的预测式为:
Through the field experiments of 1983-1985 in field and the statistical analysis of the computerized statistics, it was shown that the disease index of Verticillium wilt affected the cotton yield loss the most, which was the main factor of yield loss. The higher the planting density in field, the more significant the compensation effect among cotton plant groups. Explain the appropriate density planting is one of the measures to make up for the loss. The analysis also showed that the disease mainly affected the yield of single boll weigher by reducing the number of bolls per plant. The author also used multivariate regression to get the prediction formula of cotton yield loss: L% = 1-exp [-exp (1.028LnX_2-0.000157X_4 + 0.9967)] The coefficient of determination R ~ 2 = 0.7470 The planting density in the field was Under the condition of about 5000 strains, the prediction formula of yield loss is: