Abstract
Organophosphorus compounds, N-methylcarbamates, amide compounds, alcohols, phenols and other compounds were tested for joint action with phosphorothiolate (PTL) fungicides by crossing the paper strips impregnated with the test chemicals on agar plate uniformly seeded with rice blast fungus.
Antagonism was found for phosphoramidothionate herbicide (amiprophos) and phosphorothiolothionate having carboxy ester structure (malathion and phenthoate). While synergism was found for some amide compounds, including propanil (3', 4'-dichloropropinanilide) and its derivatives. There would be specificity of chemical structure in these amide compounds for synergism with PTL fungicide. The synergism was not observed when the PTL-resistant lines of the fungus was used as a test organism.
Mchanism of the synergism was discussed in connection with resistance of the fungus to PTL fungicides.
