水稻纹枯病空间参数特征及应用

Spatial Parameter Characteristics and its Application in Pellicularia sasakii

用各种聚集度指标及Ｉｗａｏ平均拥挤度ｍ＝α＋βｘ和Ｔａｙｌｏｒ幂法则Ｓ２＝ａｘｂ等方法，对水稻纹枯病空间参数特征进行了测定。结果表明：水稻纹枯病在田间呈聚集分布，分布的基本成分为个体群，个体间相互吸引。聚集原因由病害本身习性或环境因子引起。在此基础上利用Ｉｗａｏ法和Ｔａｙｌｏｒ法得出了其理论抽样数，并利用Ｉｗａｏ法和Ｔａｙｌｏｒ幂法建立了序贯抽样模型。

Seven aggregation indices, Iwao's and Taylor's method were used to test the spatial distribution patterns of Pellicularia sasakii, The results showed that the disease presented aggregation distribution. The basic component of the distribution is colonies and it attracted each other. The reason of the aggregation seems to be due to the disease activity or the environmental factors. The theoretical sampling number of Pellicularia sasakii in the field, and sequential sampling model has been established by use of Iwao's and Taylor's method.