Effect of adjuvants and oils on bioformulation of entomopathogenic fungus, Metarhizium anisopliae

摘要

There is growing interest towards biological approaches for management of pests and diseases. Use of entomopathogenic fungi is one of the potential components of integrated pest management (IPM) systems against insect pests. They are being developed worldwide for the control of many pests of agricultural importance. Among different potential biocontrol agents, Metarhizium anisopliae (Metschnikoff) Sorokin is one of the highly promising frontline fungal bioagents. Metarhizium species are currently being used as a biological insecticide to control a number of pests such as termites, thrips, aphids etc. Very recently, Dutta et al., (2013) reported that the pathogenicity test of M. anisopliae against target pest like termite and aphids, showed their potentiality to use as an alternative to chemical pesticides.Efforts were made to develop suitable formulations of the entomopathogen for management of cow pea aphid and subsequently the cow pea mosaic disease. But level of infection of insect by the fungus through direct contact with spores from sprays or sprayedleaves may be very low. Epizootics usually results from insects being infected directly by aerial conidia from sporulating cadavers (Hall, 1980; Hall and Burges, 1979) or mycelial conidia of foliage (Hall, 1982). Most of the biocontrol agents are formulated in solid form (contain only conidia) with shelf life of 6 months at 5°C and 3 months at 25-35°C. No information on addition of adjuvants and oils in the spore solution of M. anisopliae are available. Therefore the present study was conducted to see the effect of adjuvants and oils in suspension concentrate and liquid formulation of M. anisopliae. The experiment was carried out at Mycology Research Section, Assam Agricultural University (AAU), Jorhat, Assam, India during 2012-13.