Assessment of Cashew Varieties against Apple and Nut Borer, Thylocoptila paurosema (Phycitidae: Lepidoptera)

Abstract

Cashew is influenced by many of the pest out of which cashew apple and nut borer is one of the most important pest which causes economic losses, by considering the importance of this pest a field experiment was conducted at college of Horticulture, Mudigere during the year 2022. Field screening was assessed with cashew varieties to find out the less preferred variety with possible biochemical constituent against incidence of apple and nut borer in a complete randomised block design. Results revealed that, the mean incidence of apple and nut borer showed the least per cent damage in cultivar Priyanka (20.00 %), followed by VRI 3 (20.75 %) and Dhanashree (21.52 %) and highest infestation was recorded in cultivar Sulabha with 43.05 per cent damage during fruiting stage of cashew which was found highly susceptible. Relationship between cashew apple and nut borer with biochemical constituents showed negatively correlated with vitamin C (0.39) and tannin (0.23) with significant impact on pest damage. The Cashew apple and nut borer pest confined to the fruit and nut bearing stage of the crop with a peak incidence during summer season. None of the varieties screened were found resistant to apple and nut borer damage to some extent variety Priyanka is less preferred, while vitamin c and tannin content in fruits showed tolerance to some extent of damage.