Assessment of economic threshold level for onion thrips

The present experiment was carried out the to determine the economic threshold level of onion thrips. The economic threshold level of T. tabaci is determined using the pesticide application technique. So the Economic Injury Level (EIL) of T. tabaci on onion plants can be determined as the number of thrips follows the value of ET levels for the detected peaks ranging between 4-5 individuals/leaf during the study. As the results of the pesticide application technique, the thrips mean numbers and mean yield of onion plants were correlated significantly during the two years. Results of chi-square analysis (R2) indicated that the values of the economic damage threshold of T. tabaci infested onion plants were 7 thrips/plant, while the economic injury level was 9.6 thrips/ plant during the study.