The use of brassica extracts and thermotherapy for the postharvest control of brown rot in peach

Abstract

Brown rot (Monilinia fructicola), one of the most important diseases of stone fruits, can lead to significant fruit losses in the field and postharvest. Canola and Indian mustard extracts acquired through different extraction methods, alone and in combination with thermotherapy, were tested against postharvest brown rot in peaches. Initially, canola and Indian mustard extracts collected through the methods of simple extraction (Sp), infusion (In) and maceration (Mc) were assessed for their capacity to control M. fructicola in vitro and in vivo. The Sp extracts of each species were selected to be tested under different treatment sequences, alone and in combination with thermotherapy (50°C for 30s) on peaches inoculated with M. fructicola. The most effective canola and Indian mustard treatment sequences were selected and compared with the chemical treatment (azoxystrobin®, 2gL−1) and a control (sterile distilled water). The Sp extractions of canola and Indian mustard were effective at postharvest control of brown rot in peaches. When these extracts were combined with thermotherapy in the sequence Sp extract+thermotherapy+Sp extract, the efficacy of postharvest brown rot control in peaches was improved. The canola Sp extract was more effective than the Sp of Indian mustard when combined with thermotherapy and it achieved a M. fructicola sporulation reduction level equal to that given by the fungicide solution when applied to “Eldorado” peaches.