Studies on the Statistical Standards for Forecasting Data of Cotton Bollworm in Quanzhong Cotton-producing Areas
Wang Yaowen Mong Weixiao Liu Junsheng(.Plant Protection Station of Shoanxi Province)Qin Zhenglin (.Plant Protection Station of Weinan Prefecture')Zhang Shuaalao (.Plant Protection Station of Dali County')
Based on the systematic observations on the cotton bollworms from the first class of cotton fields in the main cotton-producing counties ofGuanzhong (the central part of Shaanxi Province) during 1971-1987, this\ paper analyses the principal meteorological factors affecting cotton bollworm'semergence, suggesting that the statistical standards for the date of the pest-outbreak be divided into two types, the lower reaches of Weihe and Luohe rivers are earlier emergence region,and the Jinghe,Weihe and Fenghe valleys are later emergence region. It also presents the statistical standards for pest-outbreak date, grade and yield loss caused by the pest-outbreak. Examination of all the data from the forecasting stations of Dali and Jingyang counties shows that the conformity with historical reality is as high as 97.6%.