Susceptibility of Peach Tree Pruning Wounds to Fungal Gummosis as Affected by Time of Pruning

Four-year-old trees of ‘Redglobe’ peach [ Prunus persica (L.) Batsch] were pruned on 1 Mar. and again on 15 Aug. 1982 and the pruning wounds inoculated with spore suspensions of Botryosphaeria dothidea [(Moug. ex. Fr.) Ces & de Not. ( B. ribis Gross & Dugg.)]. Spring-pruned trees were susceptible to invasion for only the first week after pruning as determined by visual gum ratings and reisolation rates. Summer-pruned trees were susceptible for a similar period, but fungal isolation frequency was much lower than for the spring-pruned trees. A benomyl-captan spray immediately after summer pruning reduced both gumming and isolation frequency.