Management of Burrowing Nematode, Radopholus similis (Cobb, 1893), Thorne, 1949 in Black Pepper Nurseries

Burrowing nematode, Radopholus similis is a severe threat to black pepper cultivation, which cause slow decline disease. Carbofuran or phorate is being widely advocated for the management of the nematodes. Because of the ban on these nematicides in mostly black pepper growing area in India, there is a need to identify suitable alternative pesticide for managing this nematode. Hence, the nematicidal activity of eight pesticides viz., fipronil (Regent) 0.3 GR, thiamethexan (Actara) 25 WG, acephate (Lucid) 75 SP, cartap hydrochloride (Padan) 4 GR, quinalphos (Vazra) 25 EC, flubendamide (Takuni) 20 WG, carbosulfan (Marshal) 25 EC and chloropyriphos (Classic) 20 EC were evaluated in vitro and in planta against the burrowing nematode, R. similis infesting black pepper. Phytotoxicity of the promising pesricides were also evaluated. Out of tested eight, five chemicals viz., fipronil, thiamethexan, cartap hydrochloride, flubendamide, and carbosulfan were found promising under in vitro conditions. These five promising pesticides were further evaluated under pot conditions. Among the tested pesticides, carbosulfan was found to be more effective and caused 100% mortality of nematodes, followed by fipronil (96%). The effective dosage of carbosulfan was not phytotoxic to black pepper plants as evident from the height of plants, the number of leaves, fresh weight of the plant, and root biomass after three months of exposure. It is concluded that the application of carbosulfan is given cent percent control of the nematode population without any toxic effect on the plant. Therefore, the drenching of 0.1% carbosulfan (Marshal) 25 EC @ 50 ml/polybag containing 1.5 kg potting mixture is recommended for the management of plant-parasitic nematodes in black pepper nurseries.