EFFECT OF HEAT TREATMENT AND THREE PESTICIDES UPON THE GROWTH AND REPRODUCTION OF THE MYCORRHIZAL FUNGUS GLOMUS FASCICULATUS

Abstract

The effects of several heat treatments, a nematicide (DBCP) and two fungicides (ethazole and PCNB) on survival, infection, and sporulation by the mycorrhizal fungus Glomus fasciculatus, were examined. Inocula of G. fasciculatus were killed when exposed for 10 min at 52·5 °C, but not when exposed to 51·5 °C. Although inocula of G. fasciculatus survived a 10 min soaking in PCNB at several concentrations, infection and sporulation on Sudan grass were consistently inhibited by soil drenches with this fungicide. Soil drenches of DBCP (20μg ml−1 H2O) or ethazole (50 μg ml−1 H2O) applied at the time of inoculation with G. fasciculatus did not significantly affect infection and sporulation by the fungus on Sudan grass. However, soil drenches with DBCP (15 to 20 μg ml−1 H2O) and ethazole (10 to 40 μg ml−1 H2O) applied 30 to 60 days after inoculation significantly increased infection and sporulation by G. fasciculatus. All data indicate that the pesticides DBCP and ethazole could be used to reduce contamination and to increase the quantity of inoculum of G. fasciculatus. Copyright © 1979, Wiley Blackwell. All rights reserved