FACTORS AFFECTING POSTHARVEST FUNGAL FRUIT DECAY IN SWEET CHERRY IN A COOL, WET CLIMATE

Abstract

The growing season in Norway is characterized by a relatively cool and wet climate, and all commercial sweet cherry production takes place under plastic roofs or in plastic tunnels for protection against rain and thus reduction of fruit cracking and fungal fruit decay. Fungal pathogens found to cause postharvest decay in Norway include Monilinia sp., Botrytis cinerea, Mucor piriformis, Colletotrichum acutatum, Penicillium sp. and Cladosporium sp. The following experiment with postharvest fruit decay took place over two seasons: Samples of 5A—100 fruit of ‘Lapins’ and ‘Van’ from orchards delivering fruit to three packing houses, were stored for 10 days in Life Span® bags at 2°C followed by 2-3 days at 20°C. Averaged over all fruit assessed, 55% developed fungal decay after storage in the first season and 4% in the following season. However, the amount of decay differed greatly between packing houses and orchards. In the season with high incidence, fruit decay varied from 12 to 100% and 1.6 to 95% on ‘Van’ and ‘Lapins’, respectively. Respective data for the successive season were 0 to 38% on ‘Van’ and 0 to 41% on ‘Lapins’. Mucor rot was the dominant cause of fruit decay in both years. Factors affecting postharvest decay are discussed.