Influence of Pesticides, Plant Oils and Antagonist on Entomopathogenic Fungus, Metarhizium anisopliae

Compatibility of the entomopathogenic fungus, Metarhizium anisopliae with representative pesticides, plant oils and a fungal antagonist were studied in vitro. The pesticides tested were: endosulfan, acephate, abamectin, ethion, chlorothalonil, iprodion + carbendazim, thiophanate methyl and dinocap, an antagonist, Trichoderma harzianum and the plant oils: coconut oil, groundnut oil, gingili oil, sunflower oil, neem oil, pongamia oil, and castor oil. Each product was tested in the laboratory at 27 ± 1 C and 65% RH, based on the recommended rates for application in the field. The products were added to PDA culture medium for growth of the entomofungal pathogen and the dual culture technique was followed in the case of T. harzianum. Reproductive and vegetative growth was evaluated for M. anisopliae. Results showed that the action of the pesticides on the vegetative growth and conidial spore formation of M. anisopliae varied as a function of the chemical nature of the products. Thiophanate methyl recorded maximum vegetative growth of 2.46 cm diameter, whereas the maximum conidial spore formation of 2.45 × 10 spores/ml was observed in chlorothalonil. Iprodion + carbendazim suppressed M. anisopliae completely. In the case of plant oils, sunflower oil yielded 5.77 × 10 spores/ml with a vegetative growth of 4.40 cm diameter indicating a synergistic effect when compared to all other treatments. However, 3.38 cm diameter and 3.4 × 10 spores/ml were recorded in the untreated control. _____________________________________________________________________________________________________________