Effect of storage conditions on the survival of two potential biocontrol agents of nematodes,the fungi Paecilomyces lilacinus and Pochonia chlamydosporia

The nematophagous fungi Paecilomyces lilacinus and Pochonia chlamydosporia have been extensively studied as biological control agents for plant-parasitic nematodes. This study describes the formulation of alginate pellets containing mycelia of these fungi and also describes the effect of storage conditions on shelf-life of the pellets. The shelf-lives of P. lilacinus and P. chlamydosporia, which were measured monthly for 6 months, were significantly improved at low temperatures and low water activity (a _w) values (<0.33). Vacuum did not affect the viability of the formulated P. lilacinus but increased the viability of P. chlamydosporia. Carbon dioxide reduced the activity of P. lilacinus as compared to ambient air but increased the activity of P. chlamydosporia. Nitrogen, however, significantly improved the viability of both fungi. The optimal parameters of each factor for our formulation of P. lilacinus and P. chlamydosporia included a temperature range of 4 to ?20°C, a _w=0.12, and a nitrogen-filled atmosphere.