Abstract

This study was conducted to determine suppression rates on various crop pathogens in response to ethanol and glycerol. Pyricularia oryzae, Phytophthora capsici, Colletotrichum acutatum, Rhizoctonia solani and Botrytis cinera were completely controlled by ethanol at 5 or 10%. The suppression rates of the above five pathogens by commercial alcohol (Soju) at 5% were similar to results of high purity ethanol at 5%. Suppression rates of P. oryzae by glycerol at 5 and 10% showed 43 and 73%, respectively, compared with untreated control. Suppression rates of P. oryzae by ethanol at 5%+glycerol at 3% or ethanol at 5%+glycerol at 5% showed over 90%. Rice injury due to P. oryzae infection was reduced (45–80%) by ethanol at 3, 5, and 10%, glycerol at 3%, or ethanol at 5%+ glycerol at 3%, respectively, compared with untreated control at 20 days after treatment. Symptom reduction rates of powdery mildew in cucumber plants showed 73% by glycerol at 3% and 68% by ethanol at 5% + glycerol at 3% compared with untreated control, but not by ethanol treatments. Leaf injuries, reduction of plant height and shoot fresh weight in squash, cucumber, tomato, red pepper, watermelon, and rice plants did not appear in ethanol and glycerol treatments at 3, 5, 10, and 20%. Thus, ethanol and glycerol can be used in organic crop cultivation because they showed higher controlling effect on rice blast and powdery mildew without inhibition of crop growth.