Nematicidal activity of Pochonia chlamydosporia blastospores and attempts to improve dehydration tolerance and storage stability with additives.

Abstract

For the large-scale use of Pochonia chlamydosporia as a bionematicide, cost-effective production coupled with robust stabilization processes is essential. Submerged liquid fermentation yields large amounts of infective blastospores in a short period. This study aimed to evaluate the nematicidal activity of P. chlamydosporia blastospores from two fungal strains against the eggs of two plant-pathogenic nematodes, as well as to assess the use of various additives to enhance their dehydration tolerance and storage stability. For the more promising strain, submerged culture yielded 1 × 109 blastospores mL-1 after 96 h. Juvenile hatch inhibition was more pronounced with blastospores (64.8%-86.7%) than conidia (48.2%-65.3%) on Meloidogyne javanica and M. enterolobii eggs, respectively. Skim milk added to the liquid medium prior to inoculation or 72 h after fermentation protected fungal cells from dehydration. Following dehydration, storage stability after 10 days was significantly greater at 4°C compared to 25°C. Stabilization processes to prevent cell mortality during dehydration are crucial for the development of blastospores as active ingredients in bionematicides.