Horticultural Experiment and Training Centre, Chaubattia-263 651, Ranikhet, Almora, Uttaranchal, (India).
Six insecticides viz., methyl demeton 25 EC, koranda 28 EC (fenvalerate 3% + acephate 25% EC), Carbosulfan 25 EC, profenofos 50 EC, polytrin C44 (Profenofos + Cypermethrin) and thiamethoxam 25 WG applied at 0.05% concentration in two spray schedules against San Jose scale, Quadraspidiotus perniciosus (Comstock) infesting apple significantly reduced the scale population. All the insecticides caused maximum reduction of scales over control at 14 days after the 2nd Spray. Among these, koranda was the most effective, the reduction in scale population being 97.33% followed by methyl demeton and carbosulfan which caused 94.66% and 83.33% reduction, respectively. However, profenofos and polytrin exhibited moderate reduction i.e. 53.66% and 51.66% over control, respectively. The thiamethoxam was the least effective.
