Effects of Fungicides on Penetration by Pyricularia oryzae as Evaluated by an Improved Cellophane Method

Abstract

Effects of several fungicides, active against rice blast, on the penetration by Pyricularia oryzae were studied in vitro by using cellophane film as a model of plant cell walls. The fungus penetrated the film by infection pegs emerging from appressoria (appressorial penetration) and partly by hyphal tips (hyphal penetration). Some fungicides known to be nontoxic against spore germination, appressorium formation, and mycelial growth affected selectively the appressorial penetration but not hyphal one. Effects of fungicides on appressorial penetration seem to be useful to explain the disease-control activity of fungicides. © 1977, Pesticide Science Society of Japan. All rights reserved.