EVALUATION OF <I>DRECHSLERELLA DACTYLOIDES, DRECHSLERELLA BROCHOPAGA,</I> AND <I>PAECILOMYCES LILACINUS</I> FOR BIOCONTROL OF <I>ROTYLENCHULUS RENIFORMIS</I>

Abstract

Castillo, J. D., K. S. Lawrence, J. W. Kloepper, and E. van Santen. 2010. Evaluation of Drechslerella dactyloides, Drechslerella brochopaga, and Paecilomyces lilacinus for the biocontrol of Rotylenchulus reniformis. Nematropica 40:71-85. Experiments were conducted to evaluate the biological control potential of Drechslerella dactyloides, Drechslerella brochopaga, and Paecilomyces lilacinus against the reniform nematode, Rotylenchulus reniformis under in vitro, and in greenhouse conditions. Pathogenicity tests in vitro with Drechslerella dactyloides and D. brochopaga revealed conidial germination at 14 hours and at 72 hours trapping-rings had formed and ensnared reniform nematodes. Paecilomyces lilacinus conidia germinated in 12 hours and parasitized nematode eggs within 24 hours after the initial exposure. Pathogenicity of the fungi was examined in the greenhouse in autoclaved and non-autoclaved soil. In autoclaved soil, all three fungi reduced (P ≤ 0.05) the number of vermiform R. reniformis nematodes in soil 60 days after planting. Paecilomyces lilacinus also reduced (P ≤ 0.05) numbers of eggs extracted from the cotton roots. In non-autoclaved soil, D. dactyloides reduced R. reniformis vermiform life stages, but none of the fungal isolates affected the number of R. reniformis eggs extracted from the roots. Drechslerella dactyloides, D. brochopaga, and P. lilacinus parasitize R. reniformis in vitro and in the greenhouse using autoclaved soil. However, the fungi did not reduce numbers of R. reniformis in non-autoclaved soil. These results illustrate these fungi are parasites of R. reniformis; however they need to have an advantage to compete with native soil microorganisms.