Application of Candida saitoana and glycolchitosan for the control of postharvest diseases of apple and citrus fruit under semi-commercial conditions

The efficacy of the combination of Candida saitoana with 0.2% glycolchitosa n (the bioactive coating) as a biocontrol treatment of postharvest diseases of apple and citrus fruit was evaluated in tests with natural inoculations that simulated commercial packinghouse conditions. The growth of C. saitoa na in apple wounds and on fruit surfaces was not affected by glycolchitosan . The bioactive coating was more effective in controlling decay of several cultivars of apples (Red Delicious, Pome, Golden Delicious, and Empire) tha n either C. saitoana or 0.2% glycolchitosan alone. Depending on the apple c ultivar used, the bioactive coating was comparable or superior to thiabenda zole in reducing decay. The bioactive coating was also superior to C. saito ana in controlling decay of oranges (cvs. Washington navel, Valencia, Pinea pple, and Hamlin) and cv. Eureka lemons, and the control level was equivale nt to that with imazalil. The bioactive coating and imazalil treatments off ered consistent control of decay on Washington navel oranges and Eureka lem ons in early and late seasons, while C. saitoana or 0.2% glycolchitosan wer e most effective on early-season fruit. The combination of C. saitoana with 0.2% glycolchitosan also reduced the incidence of stem-end rot of cv. Vale ncia oranges, but control was less effective than treatment with imazalil.