Full-Text Search:
Home|Journal Papers|About CNKI|User Service|FAQ|Contact Us|中文
《Journal of Plant Protection》 1981-04
Add to Favorite Get Latest Update

STUDIES ON THE ECONOMIC THRESHOLD OF THE ASIATIC CORN BORER[OST RINI A FU RN AC ALIS(GUENCE)]IN THE COTTON FIELD

Liu Dejun Yuan Quanchang (Institute of Plant Protection, Shanghai Academy of  
In the vicinity of shanghai, the damage to cotton caused by the Asiatic Corn Barer has been increasing during recent years and in many places has surpassed that of the pink boll worm, the major pest of cotton in Shanghai area. For the efficient use of chemical control, it is necessary to estimate the yield loss due to it's damage and establish it's economic threshold.These experiments were conducted during 1977~1979, including establishing the relationship between the number of egg masses per 100 plats and the number of damaged plants per 100 plants, determining the yield loss of damaged plants and the compensatory effect of the normal plants immediately surrounding the damaged plant.According to the experimental data, the economic thresholds for the 1st, 2nd and 3rd generations were calculated to be 2.2-2.8, 0.9-1.1 and 3.1 egg masses per 100 plants respectively.The suggested economic thresholds were verified during the growing season at six diffrent places in 1979 by field experiments and the results showed that these economic thresholds were acceptable.
Download(CAJ format) Download(PDF format)
CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.
©2006 Tsinghua Tongfang Knowledge Network Technology Co., Ltd.(Beijing)(TTKN) All rights reserved