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Control of blue mold of apples by preharvest application of Candida sake grown in media with different water activity

Author:
Teixido, N., Vinas, I., Usall, J., Magan, N.
Source:
Phytopathology 1998 v.88 no.9 pp. 960-964
ISSN:
0031-949X
Subject:
apples, Malus domestica, Candida, Penicillium expansum, water activity, biological control, biological control agents, acclimation, population dynamics, storage, harvest date, field experimentation, cold storage, fungal antagonists, application timing, postharvest diseases, Spain
Abstract:
Unmodified and low water activity (a(w))-tolerant cells of Candida sake CPA-1 applied before harvest were compared for ability to control blue mold of apples ('Golden Delicious') caused by Penicillium expansum under commercial storage conditions. The population dynamics of strain CPA-1 on apples were studied in the orchard and during storage following application of 3 x 10(6) CFU/ml of each treatment 2 days prior to harvest. In the field, the population size of the unmodified treatment remained relatively unchanged, while the population size of the-a(w)-modified CPA-1 cells increased. During cold storage, the populations in both treatments increased from 10(3) to 10(5) CFU/g of apple after 30 days, and then declined to about 2.5 x 10(4) CFU/g of apple. In laboratory studies, the low-a(w)-tolerant cells provided significantly better disease control as compared with the unmodified cells and reduced the number of infected wounds and lesion size by 75 and 90%, respectively, as compared with the nontreated controls. After 4 months in cold storage, both unmodified and low-a(w)-tolerant cells of C. sake were equally effective against P. expansum on apple (>50% reduction in size of infected wounds).
Agid:
1401313