Assessment of losses inflicted by the aphid, Myzus persicae (Sulzer) to sweet pepper under protected environment in north western Indian Himalayan region

Damage potential of green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), on sweet pepper, Capsicum annuum Linnaeus, under protected environment was assessed by artificially releasing different aphid densities (1, 2, 4 and 8 aphids/ plant) at 30 and 60-days after transplanting coinciding with vegetative and flowering/ fruiting crop growth stage. Aphids were restricted to feed for 30 days (limited exposure duration) as well as throughout crop growth stage (unlimited exposure duration). Myzus persicae infestation exhibited varying levels of stunting effects on plant growth. Aphid infestation also reduced marketable yield, being more pronounced at higher infestation levels of 4 and 8 aphids. Infestation initiated in vegetative stage resulted in lower yield as compared to the infestation initiated in later growth stages. Loss in marketable yield varied from 31.49 to 76.20 and 30.63 to 100 per cent in summer and autumn season crops, respectively. Relationship deduced between reduction in yield and cumulative aphid days (CADs) under unlimited exposure duration depicted per unit increase in CADs to reduce marketable fruit yield to the extent of 0.01 and 0.027 g for the infestation initiated in vegetative and later growth stages, respectively. Corresponding reduction in fruit yield on the basis of initial aphid infestation levels (AILs) was 165.3 and 129.9 g/ plant/ aphid level. Economic injury level of M. persicae worked out for the infestation initiated in vegetative and flowering/ fruiting stage to be 3862 and 1464 CADs whereas on the basis of AILs it was 0.25 and 0.31 aphids/ plant for the infestation initiated in corresponding crop stages.

Automated summary

Green peach aphid can have a significant impact on sweet pepper plants, causing stunted growth and reduced marketable yield, particularly at higher infestation levels. The relationship between cumulative aphid days and reduction in yield was analyzed, with economic injury levels calculated for different infestation levels and growth stages.