Investigations on brown rot of apricots caused by Sclerotinia fructicola (Wint.) Rehm. I. The occurrence of latent infection in fruit

Abstract

Evidence is presented that infection of apricot fruit with Sclerotinia fructicola may occur early in the fruit's development but remain latent until ripening commences. Evidence from culturing from green fruit is supported by the results of spraying experiments with fungicides and by inoculation experiments. Latent infection is confined to the epidermis and is not associated with any particular position on the fruit surface. Histological studies indicate that infection takes place through the stomata. It is tentatively suggested that an inhibitory substance is present in green fruit, and maintains infections in a latent condition. The presence of a substance inhibitory towards a species of Histoplasma is demonstrated. This substance begins to disappear as ripening commences.