Compatibility of Trichoderma asperellum (Tr-9) with Carbofuran and Cassava-based Biopesticide, Nanma under In-vitro Conditions

Root-knot nematodes (Meloidogyne spp.) pose a major threat to tuber crops, challenging the development of effective and environmentally sustainable management strategies. Although chemical nematicides have been effective in controlling nematodes, but their adverse environmental impact has urged to explore eco-friendly alternatives such as bioformulations. Trichoderma asperellum (Tr-9), an indigenous fungal bioagent isolated from elephant foot yam was effective against root-knot nematode under in-vitro conditions. Additionally, Nanma, a cassava-based biopesticide developed by ICAR-CTCRI, is commonly used to treat elephant foot yam tubers before planting to control diseases and nematode infestation. They can be combined with nematicides for effective nematode management while minimizing environmental risks. However, evaluating the compatibility of Trichoderma with nematicides is crucial before integrating both strategies for nematode management in tuber crops. In this context, the present study evaluated the compatibility of T. asperellum (Tr-9) with different concentrations of Carbofuran 3G (50, 100, 200, 400, 800 and 1000 ppm) and the Cassava-based biopesticide, Nanma (5, 10, 25, 50, 75 and 100 ppm) using the poisoned food technique after a five-day incubation period under in-vitro conditions. Results revealed that Carbofuran 3G exhibited cent percent compatibility at 50 ppm, and with minimal inhibition (6.98%) observed at 100-200 ppm. Even at higher concentrations (400-800 ppm), only slight mycelial growth inhibition (15.25%-19.75%) was recorded, while at 1000 ppm, inhibition percentage increased to 36.30%. These findings indicate that all concentrations up to 800 ppm are highly compatible, while 1000 ppm remains moderately compatible with Carbofuran. In contrast, Nanma exhibited high incompatibility, inhibiting Trichoderma growth completely at concentrations ranging from 50 to 100 ppm. At even lower concentrations, inhibition percentage still remained high (70.32% - 78.55%). These findings indicated that Carbofuran 3G can be effectively integrated with T. asperellum (Tr-9) for nematode management in tuber crops, offering a balanced approach that combines chemical and biological methods while reducing environmental impact. Further research is required to evaluate the compatibility of novel nematicides such as Fluopyram, Fluensulfone, and Fluazaindolizine with Trichoderma, along with pot and field studies, to develop an effective integrated nematode management module for tuber crops.