棉田棉铃虫卵估值抽样的研究

由于棉铃虫卵在棉株上的空间分布结构属负二项分布,并且它在棉株上的垂直分布特征系上部卵量明显较下部为多,这样,本文应用了二阶抽样技术代替当前国内采用的简单随机抽样法,在允许误差为10％时,每株抽取上部15个叶蕾,每块棉田共抽60株棉株。 抽样单位的大小对于抽样的时间消费与抽样精确度亦有直接的影响,因此,确定最适的抽样单位也是很重要的。本文根据棉铃虫卵在田间个体群平均占据的面积大小,提出一次调查6抹(2行×3株/行)棉株较单株为优。即在棉田中每次调查6株,共调查10次 新的抽样方法较当前国内应用抽样法,提高效率2.2—2.6倍。

SAMPLING TECHNIQUES ON THE EGG STAGE OF THE COTTON BOLLWORM IN COTTON FIELD

Since the spatial pattern for the cotton bollworm eggs in the cotton field is in agreement with the negative binomial series and the characteristics of the vertical distribution of the eggs on the cotton plant is more greater in the upper than in the lower, two-stage sampling technique based on the mean crowding (x*) - mean( x Relationship (Kuno, 1976) is used for allocating samplesThe number of sample cotton plant required to estimate the density of egg at a 10% level of precision is 60, and 15 leaves or s...