Abstract
The present investigation was undertaken to evaluate the controlling effect on rice blast in relation to the structural modifications of chlorophenylhydrazine and β-acylchlorophenylhydrazine derivatives.
Chlorophenylhydrazine-oxalate, -hydrochloride, -sulfate and -nitrate showed high protective effect upon rice blast in the pot tests in greenhouse.
A series of β-acylchlorophenylhydrazines was tested against rice blast. Results showed that highest controlling effect among 29 β-acylchlorophenylhydrazine derivativea was obtained at a chain length of 1-2 carbon atoms of acyl radical. β-formyl- and β-acetylchlorophenylhydrazines showed marked protective and therapeutic effects on rice blast in the pot tests in greenhouse. They also gave good controlling effect equally or more or less inferior to the organic mercury, phenylmercuric iodide, in protective spray and blasticidin-S in therapeutic spray in the seedling bed tests in field.
