Fungicidal Effect and Effective Duration Period of Sterol Demethylation Inhibitor (DMI) Fungicides in Japanese Pear Scab Control

Abstract

The degree of efficacy and duration period of sterol demethylation inhibiter (DMI) fungicides among many kinds of fungicides against the Japanese pear scab, Venturia nashicola, were investigated through artificial inoculation to Japanese pear (Pyruspyrifolia var. culta) cultivar Kosui grafted seedlings of conidial suspension. Each of the four kinds of DMI fungicides performed with high efficacy, with protective values of 86.7 to 100. A long efficacy duration period was also confirmed, based on the result that there was very little if any occurrence of scab disease as long as 20 days after fungicide application.