枣树缩果病空间分布格局和抽样技术研究

Spatial distribution pattern of jujube-fruit shrink disease and sampling technique

应用聚集指标法和Taylor幂指数及Iwaom*-m回归分析法测定了枣缩果病病株的空间分布型。结果表明:枣缩果病病株田间分布趋于聚集分布,其聚集原因主要是由风雨气候因素、病菌本身生物学特性和刺吸式昆虫吸食传毒扩散共同引起的。运用Iwaom*-m回归中的两个参数α、β值,建立了理论抽样数模型:N1.96=3.842/D(1.463/m+0.083),N1.64=2.69/D(1.463/m+0.083);序贯抽样模型:T0(n)=5n±6.0053n,确定了不同精度下的理论抽样数及序贯抽样数,提高了调查抽样的效率,可为枣缩果病林间抽样调查及防治提供依据。

Aggregated indices and power law of Taylor and Iwao＇s way （regressive relation by m^＊-m） were used to test the spatial distribution pattern of the jujube-fruit shrink disease on infected plants, The results showed that the infected plants was of aggregated type and the aggregation distribution was mainly caused by wind or rain, biological characteristics of the pathogen and spreading of jujube-fruit shrink disease transmitted by insects. According to the parameters of spatial distribution, the theoretical sampling number model N1. 96= 3. 842/D （1. 463/m＋ 0. 083）, N1.64 = 2.69/D （1. 463/m＋ 0. 083） and sequence sampling model To （n） = 5n± 6. 005 3√n were pro- posed. The optimal sampling number and sequence sampling table were determined for improving the efficiency of sampling, which provided a basis for the forest sampling survey and control.