STUDIES TO CALCULATE THE LOSS IN YIELD IN MUSTARD CROP DUE TO INFESTATION OF MUSTARD APHID, LIPAPHIS ERYSIMI (KALT.)

摘要

The study was conducted to calculate the loss in yield in mustard crop due to infestation of mustard aphid Lipaphis erysimi (Kalt.) in Muzaffarnagar. Loss in yield of mustard crop calculated from two sets often healthy plant grown in caged area. The loss in yield of there sets calculate seperately. The experiments were repeated in year 2002-03,2003-04 and 2004-05 respectively. During year 2002-03 yield loss was 84.96 percent, in year 2003-04 was 89.53 percent and 74.57 percent was during the year 2004-05.