渭北旱塬苹果黑星病流行因子分析

利用渭北旱塬7年(1997～2003年)的温度、相对湿度、降水量和苹果黑星病流行程度资料,采用逐步回归法分析了影响渭北旱塬苹果黑星病流行的因子,求得最优回归子集,包括4月和8月份的降水量、前1年12月份的平均相对湿度、1月和7月份的平均温度,建立苹果黑星病多元线性回归预测模型,以残差绝对值<0．5为统计标准,对1997～2003年苹果黑星病的流行程度进行回测。结果表明,预测模型回测准确率高,可用于指导渭北旱塬苹果黑星病的防治工作。

Analysis on factors affecting apple scab prevalence in Weibei semi-arid plateau of Shaanxi Province

Factors effecting apple scab caused by Venturia inaequalis (Cooke) Wint. ]prevalence were studied on the basis of temperature,relative humidity,rainfall and prevalent levels of diseases from 1997 to 2003 through stepwise regression. Results show that the key factors affecting the prevalence of apple scab are rainfall in April and August,average daily relative humidity of last December and average daily temperature in January and July. A predictive model was set up through collecting meteorological data and disease prevalent data in 1997 to 2003. Apple scab occurrence from 1997 to 2003 was proof-tested respectively with the statistic standard of residue value less than 0.5. Results indicate that predictive model has a highly acurate ratio and can be used to guide the control of apple scab in semi-arid plateau of Weibei in Shaanxi Province.