Resistance Risk of Plant Pathogenous Fungi to Tolclofos methyl

Resistance risk of the plant pathogenous fungi to tolclofos methyl was studied in lab. depending on testing resistant degree, growth ratio on PSA medium, infectivity to rice, sensitivity to other fungicides of the fungi, sclerotia examination, and analyzing condition of application of the tested fungicides; using resistant strains from lab.. Result showed that resistance risk to tolclofos methyl differed between different species of plant pathogenous fungi. High resistance and resistance risk to tolclofos methyl appeared in Rhizoctonia solani (rice sheath blight), but low in Rhizoctonia cerealis (wheat sheath blight ) and Sclerotinia sclerotiorum (rapeseeds sclertinia blight). Resistant strains of R. solani to tolclofos methyl showed relatively strong positive cross resistance to dimethachlon and high resistance risk. While that of R.cerealis to dimethachlon and iprodione is medium. Posifive cross resistance of both germ is low to quintozene. There was no any cross resistance between tolclofos methyl and diniconazole and IBP . Inhibiting activity of tolclofos methyl, dicarboximides and hydrocarbon aromatic is alike.