Outbreaks of green apple aphid, Aphis pomi (De Geer) in apple orchards of Kashmir, India: Grower-Adopted management tactics and their implications for cultivation costs

Abstract

Green apple aphid (GAA), Aphis pomi has assumed the status of a major pest in the last few years in Jammu and Kashmir (India) with continuous seasonal outbreaks. Based on a grower perception survey conducted in ten major apple-growing districts, we assessed the reported incidence of GAA, the management practices adopted by growers, and the perceived economic losses incurred. We found that the high incidence of GAA is widespread in all apple growing districts and on all the major commercial varieties under cultivation (Delicious group) including newly introduced varieties in the Gala group. Up to four additional insecticide sprays are needed for the management of GAA. The type of insecticides sprayed is dominated by the old chemistry insecticides like dimethoate, chlorpyriphos and cypermethrin. Higher number of sprays is needed if these insecticides are included in the spray regimes, and these insecticides are responsible for control failures. The cost of insecticide treatments can lead to 13.13 % increase in cost of cultivation in case of traditional orchards, and up to 18.58 % in case of high-density orchards, and 4.37 %–11.67 % increase in cost of post-harvest operations owing to incidence of sooty mold on harvested fruit. It is concluded that GAA has a significant economic impact on the apple production system in India. The probability of insecticide resistance development seems to be the major reason for GAA outbreaks in the recent years. Therefore, the use of new chemistry insecticides, and laying off the traditional insecticides is necessary and efforts at educating the growers about the best management practices are imperative.