Field evaluation of benomyl to control cylindrocladium fruit spot of custard apple

Abstract

Cylindrocladium leaf and fruit spot caused by Cylindrocladium colhounli is a recently reported disease of custard apple (Annona cherimola x A, squamosa). The fungus defoliates leaves and renders fruit unsaleable. A field spray trial showed that seven fortnightly applications of benomyl at 0.25 g, 0.5 g and 1.0 g a.i./L significantly reduced the incidence of disease compared to unsprayed trees. There were no significant differences in control achieved by different rates of benomyl. The levels of benomyl residue in fruit sprayed with the two higher rates were below 2 ppm, 7 days after the last application. The lower rate (benomyl 0.25 g a.i./L) should be recommended to control disease under orchard conditions.