Control of Rhizopus barn rot of flue-cured tobacco using dicloran

Abstract

The severity of barn rot (Rhizopus arrhizus Fischer) of flue-cured tobacco was reduced by soaking tying twine, or by spraying butts of leaves, with 0.05, 0.1 or 0.2 per cent dicloran suspensions. In preliminary experiments, where leaves were sprayed individually, twine treatment was less effective than leaf treatment, and no added benefit resulted from treating both twine and leaves. In large scale experiments twine treatment tended to be more effective than spraying the butts of bundles of leaves and better control of barn rot was obtained when both twine and leaves were treated. Spraying sticks of tied tobacco proved less effective than other treatments. Barn rot was more destructive on leaves cured on higher tiers of the kiln than on leaves on lower tiers. A relationship was established between weight of tobacco lost and disease index.