Abstract
Mepanipyrim exhibited excellent disease control activity against Botrytis cinerea, but poor activity against Cochliobolus miyabeanus; however, the mycelial growth of C. miyabeanus was inhibited more strongly than that of B. cinerea. Therefore, disease control efficacy by mepanipyrim in vivo is not correlated with mycelial growth inhibition in vitro. While mepanipyrim prevented pectinase secretion in B. cinerea at 0.1–1 μg/ml, it did not interfere with secretion in C. miyabeanus, even at 100 μg/ml, indicating that its action is an important mechanism in disease control. Mepanipyrim affected the uptake of glucose and phenylalanine in the mycelia of both pathogens at higher doses. Thus, a secondary action of mepanipyrim may bring about mycelial growth inhibition in vitro.
