Eco Friendly Management of Arecanut Root Grub (Leucopholis lepidophora Blanchard) in Hilly Tracts of Uttar Kannada, Karnataka

Amongst the several factors attributed for lower productivity of Arecanut, damage by root grubs is substantially important in Malnad belt of Uttar Kannada district. The root grubs cause damage to the arecanut tree by directly feeding on roots resulting in symptoms like yellowing of leaves, stem tapering at the crown region, reduced inter-node length, nut fall and ultimately leads to reduced vigour, yield and death of plant. To manage this insect, usually insecticides are recommended but farmers of this district are reluctant to use chemical pesticides due to the deleterious effects on soil health, fauna and flora. Indigenous technical knowledge followed by the farmers were documented in 15 villages of three taluks viz., Sirsi, Siddapur and Yellapur and based on scientific validation, an on farm trial was conducted to evaluate the feasibility and economic viability of aqueous extract of soap nut and neem oil 5% mixture and entomopathodenic fungi, Metarrihizium anisopliae 2 X 10 8 conidia/g @ 20 g per palm tree against root grubs in arecanut during 2009–12 at farmers'fields. The results revealed that the recommended practice i.e. drenching with chlorpyrifos 20 EC @ 10 ml/l of water (3-4l of solution per palm tree) recorded highest grub mortality of 86.83 per cent as against 64.88 per cent in aqueous extract of soap nut and neem oil 5% mixture treated palms. Appearance of new healthy green frond and improvement in the growth of the palms are the visual indicators. Neem oil and soap nut extract was the best alternative to chemical insecticides, locally available and is ecofriendly.