气象因素对陕西省苹果褐斑病流行的影响及预测模型

基于对1999—2008年陕西省气温、相对湿度以及陕西省苹果主产区苹果褐斑病发生、流行的监测，对苹果褐斑病发生时间、发病规律及流行程度进行了分析，并构建了旬平均气温(T)和旬平均相对湿度(Hm)影响下苹果褐斑病一维和三维动态预测模型.结果表明：研究区苹果褐斑病受环境因素影响严重，7、8月在田间扩展迅速并引起大量落叶，危害可持续至9月，初霜后不再有新病斑扩展；构建模型所用的T和Hm与田间实际条件基本一致，苹果褐斑病三维动态预测模型为：f(T,Hm)=-0.0172T³+0.9497T²-16.2209T+88.9923-0.00001Hm³+0.00354Hm²-0.15554Hm+2.36578［f(T,Hm)为病情指数］.模型结果表明，田间引起苹果褐斑病发生的T为15 ℃，大流行条件为7、8月T为 23 ℃、Hm在90%以上.

Effects of climate factors on the epidemic of apple Marssonina blotch in Shaanxi Province and related prediction models

Based on the long term (1999-2008) monitoring of air temperature and relative humidity and of the occurrence and epidemiological trend of Marssonina blotch in the main apple-production area of Shaanxi Province, this paper analyzed the occurrence time, pathogenesis regularity, and epidemiological level of Marssonina blotch, with the 1- and 3-dimensional models for predicting Marssonina blotch under effects of ten-day mean air temperature (T) and relative humidity (Hm) constructed. In study area, the development of Marssonina blotch was mainly affected by environment factors. This disease spread rapidly in field in July and August, causing orchard defoliation, and the harm persisted until September. After the first frost, new disease spots no longer developed. The data of T and Hm in the models showed a good fitting with field condition. The 3-dimensional dynamic prediction model of Marssonina blotch was f(T,Hm)=-0.0172T³+0.9497T²-16.2209T+88.9923-0.00001Hm³+0.00354Hm²-0.15554Hm+2.36578, where f(T,Hm) was disease index. The modeling results showed that the T  for the occurrence of Marssonina blotch in field was 15 ℃, and the disease would have an epidemic peak when the T and Hm in July and August reached 23 ℃ and ≥90%, respectively.