Abhijit Ghosal, D. Manna and R. Adhikary
Abstract
Leaf hopper infestation was recorded during first and second week of July but its population build-up starts from third week of July (2.51 leaf hoppers/3 leaves), the first peak population was recorded during second week of august (12.78 leaf hoppers/3 leaves) and it reached its highest peak during first week of September and recorded maximum leaf hoppers population (16.45 leaf hoppers/3 leaves) respectively. Maximum temperature was positively correlated (r=+0.129) and rainfall was negatively correlated (r= - 0.095) with leaf hopper population. In respect of comparing the efficacy of neonicotinoid insecticides against leaf hopper population; acetamiprid 20% SP @ 40 g. a.i./ha was recorded as the most effective insecticidal treatment which recorded lowest leaf hopper population/plant (3.01 leaf hopper/3 leaves) along with 81.27 % protection over control which was followed by thiamethoxam and imidacloprid, dimethoate and acephate 77.71%, 76.43%, 69.56% and 67.10% protection over control respectively. Acetamiprid also recorded highest marketable yield (113.35 q/ha), followed by imidacloprid (110.54 q/ha), thiamethoxam (109.02 q/ha).