冬枣黑斑病空间格局及抽样技术研究

Pattern of spatial distribution and sampling technique of winter jujube black spot

冬枣黑斑病已成为威胁冬枣安全生产的主要病害。本文应用Taylor的幂法则、Iwaom*-m回归分析法及6个聚集指标,对冬枣黑斑病空间分布类型和抽样技术进行了研究,并进行了影响因素分析。结果表明:冬枣黑斑病在果实和叶片两个空间阶元都属于聚集分布,分布的基本成分是个体群,其聚集性随个体密度增大而增加。在果实和叶片两个空间阶元上,聚集都与致病菌本身习性和环境因素有关。运用Iwaom*-m回归中的两个参数α和β,确定了不同精度下的理论抽样数及序贯抽样数。

Black spots on winter jujube constitute the most significant threat to the safe production of winter jujube. In this paper, the pattern of spatial distribution, sampling technique and influencing factors of black spots in winter jujube were analyzed using Taylor＇s power law, Iwao＇s distribution function, and six aggregation indices. The results show that the pattern of spatial distribution of black spot in fruits and leaves of winter jujube is aggregative distribution. The basic component of the distribution is the individual colonies. The degree of aggregation increases with the increasing of individual density. The aggregation on fruits and leaves is due to the disease behavior and other environmental factors. Using the parameters α and β in Iwao＇s m＊-m regression equation, the optimal and sequential sampling numbers are determined.