EFFECTS OF MOISTURE-CONTENT AND TEMPERATURE ON STORAGE OF METARHIZIUMFLAVOVIRIDE CONIDIA

The effects of moisture content and temperature on the medium-term (3- 4 months) storage of conidia of Metarhizium flavoviride were investiga ted. Conidia harvested after 24 days of culturing on rice showed great er tolerance to long storage than conidia from 12-day cultures. es. Th e moisture content of the conidia was of greatest importance; at harve st from the culture, conidial moisture contents could be > 40%, while the optimal moisture content for storage was found to be 4-5%. Dried c onidia stored in oil benefited from the addition of dl ted silica gel, as did conidia stored as powder. A range of mineral oils proved satis factory,ibr storage, and when dried silica gel was added to suspension s, germination levels were 79.8% after 105 days at 28-32 degrees C. Dr ied conidia stored in oil maintained germination levels of up to 96 an d 85% after 80 days at 10-14 degrees C and 28-32 degrees C respectivel y. Dried conidia stored as powder retained germination levels of 95% a t 10-14 degrees C, but only up to 27% at 28-32 degrees C. In another e xperiment, dried conidia maintained greater than 90% germination over 128 days, with or without silica gel at 10-14 degrees C or - 15- - 18 degrees C.