Viability of Stored Conidia of Metarhizium flavoviride Gams and Rozsypal, Produced under Differing Culture Regimes and Stored with Clays

Abstract

Conidia of Metarhizium flavoviride were cultured under a range of conditions and stored , with or without clays and silica gel , as powder or in oil . Fungal biomass was produced in shake flasks in liquid media containing nutrients before being added to sterilized rice for conidial production . Conidia pre - cultured under a low C:N ratio , or dried over a 9 - day period compared with 2 days before being placed in storage , showed greatest loss of viability . Conidia stored at 10 o C survived better than those stored at + 30 o C . A range of clays had no significant effect on storage of dried conidia but montmorillonite K10 clay was often harmful in terms of conidial viability . Conidia survived better when stored as dry powder than when stored in a mixture of mineral and vegetable oils . The addition of silica gel proved beneficial even when dried conidia were being stored .