摘要
测得菜青虫幼虫空间分布型为负二项分布，根据该分布型求理论抽样数的公式及甘蓝莲座期菜青虫防治阈值为０．６９头／株，建立了可变强度抽样法的抽样数图及具体操作方法．模拟抽样结果表明，该法能反映总体实际情况。
The distribution of larval population of Pieris rapae in the cabbage field was represented to a negative binomial distribution.With the spetial pattern obtained,a formula used to estimate theoretical sampling numbers was derived.The economic threshold of Pieris rapae on cabbage at rosette stage was 0.69 larva / plant varied from 0.39 to 0.99 larva per plant.A sampling chart according to a variable intensity sampling procedure was developed,and performance of the procedure using the chart was described in details.The simulated results showed that the estimation of population density of Pieris rapae was according with the practical data in the field,and the sampling numbers were less than the numbers obtained compared with fixed sampling size procedure.
出处
《湖南农业大学学报（自然科学版）》
CAS
CSCD
1997年第4期341-346,共6页
Journal of Hunan Agricultural University(Natural Sciences)
基金
中澳合作ACIAR9213项目
关键词
甘蓝
菜粉蝶
可变性
抽样法
brassica oleracea pieria rapae changeability sampling method
