摘要
本文应用10个聚集度指标分析了不同时期稻瘿蚊为害株的空间格局,用Fuzzy聚类分析法测定空间格局的时序状态,并对田间抽样技术进行了探讨.结果表明:田间受害株密度不超过3株/丛时,受害株的空间格局是聚集型的;超过3株/丛时,则为均匀型的;受害株分布的基本成分是个体群,基本成分的分布是聚集型的;不同时期的为害株的空间格局可归纳为低密度前期和高密度后期两大类;田间的最适抽样部位是水稻的分蘖株;为害株的Iwao和改进的Iwao序贯抽样模型分别是: T′_0(n)=0.15n+t·(0.18n)^(1/2);T″_0(n)=0.15n-t·(0.18n)^(1/2) 和T′_0(n)=0.15n+t·(0.1342n)^(1/2);T″_0(n)=0.15n-t·(0.1342n)^(1/2)式中,T′_0(n),T″_0(n)分别为序贯抽样过程中累计标葱数的上限和下限;n为序贯抽样数;t为在给定的显著性水平下的t分布值.
Eleven aggregation indices were used to analyze the spatial pattern of rice infested by the rice gall midge Orscolia oryzae (Wood -Mason)in paddy field in different Mages from July to August, 1990 in Debao county. The pat-lern dynamics were tested by Fuzzy clustering method. At the same time,the sampling techniques were also studied. The results showed that the distribution patterns were aggregated as the infested plant density was not more than 3 plants per hill .and became uniform distribution as the plant density was more than 3 plants per hill. The basic components of distribution were colonies and the distribution of the basic components was aggregate. It could be divided into mo kinds of spatial patterns:the low density is in early stages,and the high density is in late stages. The optimum sampling position is the tillering plants of rice. The Iwao's sequential sampling model and improved Iwao's sequential sampling model of the infested plants are:Where.T'0(n) ,T''0(n) is upper limit and lower limit of accumulated sillvershool numbers in the process of sequential sampling respectively ;n is sequential sampling n umber ;t is t-value for certain significant level.
出处
《华南农业大学学报》
CAS
CSCD
1993年第3期48-54,共7页
Journal of South China Agricultural University
关键词
稻瘿坟
水稻
危害
空间格局
The infested plants
Aggregation indica
Spatial pattern dynamics
lwao's and improved Iwao's sequential sampling
