Progress in the Management of Peach Fungal Gummosis ( Botryosphaeria Dothidea) in the Southeastern US Peach Industry

Abstract

Peach fungal gummosis, incited by Botryosphaeria dothidea[(Moug.:Fr.) Ces. & De Not.] has been shown to be capable of reducing growth and yield by up to 40% on susceptible peach [ Prunus persica(L.) Batsch] cultivars. At this time there is no management program for this disease other than practices to reduce inoculum in the orchard. In field tests under high inoculum pressure no fungicide tested appeared to provide effective control and in one test not only did all of the trial fungicides fail to provide control but even a proven (though no longer registered) fungicide failed as well. However, several paint treatments appeared promising. Field screens under high inoculum pressure have demonstrated that some important peach cultivars utilized in the southeastern US peach industry are highly susceptible to this disease. The relative susceptibility of additional peach cultivars, including many recently introduced, was determined, the majority of which were either moderately or highly susceptible to gummosis. However, several varieties appear to have high levels of resistance to fungal gummosis and may prove suitable as founding parents for resistance breeding. The large proportion of recent releases that appear to be highly susceptible makes this approach all the more urgent.