Quantitative structure-activity relationships (QSAR) analyses of fungicidal activity of Fluazinam impurity 1 against
Sphaerotheca fuliginea
,
Pyricularia oryzae
and
Rhizoctonia solani
are carried out and the results are compared. In the case of
S. fuliginea
, a usual QSAR equation with Hammett's electronic parameter (sigma-m) and hydrophobicity (pi) is obtained, suggesting that the uncoupling mechanism might be involved in the mode of action. In the cases of
P. oryzae
and
R. solani
, QSAR equations are consisted of sigma-m, pi and the activity rank against Botrytis cinerea as independent variables,indicating both of uncoupling and SH-inhibition are working in the action mechanism.