Vol. 11, Special Issue 4 (2022)

Author(s):
R Emaiya, E Sumathi, VG Mathirajan, SV Krishnamoorthy, N Sathiah and K Venkatesan

Abstract:
Coconut (Cocos nucifera) is an important plantation crop and cultivated in all agro ecological conditions in Tamil Nadu. Rhinoceros beetle (Oryctes rhinoceros L.) is an important pest that causes damage and reduce the yield. During 2018, Gaja cyclone affected the coconut plantations in delta regions of Thanjavur, Thiruvarur and Nagapattinam Districts. Rhinoceros beetle cause severe damage in replanted young coconut seedlings. In this context, the present study was carried out to assess the damage due to rhinoceros beetle in juvenile and established coconut gardens of Thanjavur, Thiruvarur and Nagapattinam Districts. Rhinoceros beetle incidence was high in hybrid (VHC3) compared to variety (ECT). Low shoot damage of 19.28 per cent and 25.18 per cent was recorded in variety and hybrid respectively in Okkanadu Keelaiyur village in Thanjavur District. However, maximum shoot damage was recorded in Kovilpathu village in both variety (48.57%) and hybrid (55.53%) in juvenile gardens of Nagapattinam District. In established gardens, low leaf damage of 13.74 per cent was recorded in variety at Kulamangalam village and 21.82 per cent in hybrid at Okkanadu Keelaiyur village. However, maximum leaf damage in variety (35.00%) and hybrid (41.23%) was recorded in Kovilpathu village. Low tree damage of 23.39 and 32.14 per cent was recorded in variety at Veppankulam and in hybrid at Okkanadu Keelaiyur village respectively. However maximum tree damage was recorded in variety (42.32%) at Idumbavanam and hybrid (45.89%) at Thillaivilagam village of Thiruvarur District.