麦套棉受棉蚜为害卷叶株的空间分布和序贯取样技术研究

SPATIAL DISTRIBUTION OF LEAF-CURLED COTTON PLANTS INTERPLANTED IN WHEAT FIELDS INFESTED BY COTTON APHIDS AND SEQUENTIAL SAMPLING TECHNIQUE

棉蚜(Aphis gossypii Glover)的苗蚜和伏蚜为害春套棉、夏套棉和夏直播棉形成的卷叶株的空间分布,经4种频次比较法测定,属负二项式分布或核心分布;经6种聚集指标公式测定,属聚集分布。求得了它们的理论抽样次数。分析提出以双对角线10点取样,苗蚜期每点20株、伏蚜期每点10株取样调查方法。组建了它们的序贯抽样调查表,为实施防治指标调查等提供了科学依据。

The cotton aphid (Aphis gossypii Glover) is one of the important pests of cotton interplanted in wheat feilds. The spatial distribution pattern of leaf-curled cotton plants (interplanted in wheat fields in spring or summer and monocultured in summer) infested by the cotton aphid explored at seedling stage or in summer does not fit random, negative-binomial or contagious distributions but belongs to aggregated pattern. The theoretical frequency Of distribution and sequential sampling table of leaf-curled plants are obtained. Based on the distribution pattern of leaf-curled cotton plants, a suitable bidiagonal sampling method with ten sampling points each including twenty plants is proposed and discussed.