Economic threshold level of cutworm, Agrotis segetum (Schiffer), on potato crop grown in north-western higher hills of Himachal Pradesh (India)

Abstract

The impact/effect of different population levels of cutworm, Agrotis segetum (Schiffer) larvae on tuber damage for determining the economic threshold level (ETL) was studied for two years during summer crop season (March to September) on both the table and seed crops of potatoes at Shimla. In general, a positive correlation was observed between the number of cutworm larvae released and damage caused by them to potatoes (tubers) on all the recorded parameters, viz., plant showing tuber damage (%), tubers damaged by no. (%), damaged yeild (%), and damaged yield (q/ha). Besides, the population level of 40 larvae/plot containing 16 plants (2.5 larvae/plant) was responsible for highest damage and yield losses. The economic threshold levels (ETLs) on table and seed crops were worked out, respectively, as 2.88 and 1.20 larvae of A. segetum per 10 m² crop area. Hence, judicious and need-based control programmes may be decided accordingly.