S. KRISHNA VENI, K. MANJULA* AND T. MURALI KRISHNA
Department of Entomology, S.V. Agricultural College, Tirupati-517 502, Andhra Pradesh, India
Grain formulations of N. rileyi were prepared by mass producing the fungus on six different grain media viz., rice, wheat, jowar, bajra, maize and ragi for evaluating the viability of N. rileyi conidia during 2013-14. After observing full sporulation on grain media (20 days after inoculation), the spore mass along with media were dried, pulverized, sieved and packed in polythene bags. These formulations were stored at two different conditions i.e., refrigeration (at 4ºC) and incubation (at 25ºC). The viability of N. rileyi conidia were recorded at monthly intervals upto 90 days. The results indicated that viability of spores decreased gradually with increase in storage period. Among the grain formulations tested, maize grain formulation has shown higher viability upto 90 days of storage (86.67 to 83.33 per cent germination). The lowest of 63.33-60 per cent germination of conidia was recorded with ragi grain formulation due to its low nutrient status. In rice, jowar, wheat grain formulations 66.67 to 76.67 per cent germination was noticed. Under the storage condition of refrigeration, slightly higher germination percentage was noticed in all the formulations.
Conidial germination, Days after storage, Grain formulations, Viability.