Chemical control of chocolate spot disease of field beans

Abstract

SummaryThe ability of two chemicals, Benlate and BAS352-04F, to control chocolate spot (Botrytis fabae) disease of field beans (Vicia faba) was examined in five small-plot or field experiments. The incidence of the fungus was never such as to reach the aggressive stage naturally, although severe infection was induced temporarily in certain experiments by enclosing the plots in plastic-covered boxes after inoculation with fungus. Increasing the recommended dose of BAS352-04F but not Benlate resulted in improved control and applying either chemical twice was preferable to a single application. Control by BAS352-04F was sometimes better than Benlate in the early days after infection whereas the reverse was true later. These results are in keeping with their roles as contact, and systemic and contact fungicides respectively. In these small experiments, with low levels of infection, the use of fungicides did not result in significant increases in yield or yield components.