Abstract:
Studies showed that enlarged planting acreage and delayed maturity of winter wheat in the sourth of Hebei increased the amount of F1 cotton bollworm and the harm to crops from F2 cotton bollworm, while enlarged acreage and delayed maturity of the summer-sowing corn, Summer-sowing cotton and plastic-sheet-covered cotton became important factors in bad attack of F2, F3 and F4 cotton bolloworm and increased the amount of overwintering of bollworm generation.It was, therefore, the determinantive factor of wide-ranging and serious harm from F1, F2, F3 and F4 cotton bollworm that the food condition of the bollworm was improved and optimum ecologic condition was continuous in late years.The integrated control of cotton bollworm was disccussed in the paper.
Key words:
Cotton bollworm,
Species group amount,
Crop ratio,
Crop growing stage,
Control of insects
CLC Number:
Ma Zhongshi, Li Baolan, Ding Jun. Effect of Crop Ratio on Species Group Amount of Cotton Bollworm in the Sourth of Hebei[J]. ACTA AGRICULTURAE BOREALI-SINICA, 1995, 10(S1): 120-124. doi: 10.3321/j.issn:1000-7091.1995.z1.026.