Study of the Major Pathogens That Lead to Apple Fruit Decay During Storage

Different pathogenic fungi (e.g. Penicillium spp., Monilinia fructigena, Venturia inaequalis, Glomerella cingulata, Diaporthe eres etc.) can cause apple rot by producing pectic enzymes that break down apple pectin to expose the nutrients of the cells to the fungi. This study aimed to identify the pathogens that lead to the degradation of apples from five different varieties (‘Granny Smith’, ‘Topaz’, ‘Imperial Gala’, ‘Jonagold’ and ‘Golden Reinders’) and also the incidence of those pathogens under different treatment conditions. The results reveal different frequent attacks on distinct varieties ranging from 5 to over 50%. Of the pathogens that infect and occur in vegetation and deposit it can be seen that Venturia inaequalis has been identified in all varieties in most test variants. The highest frequency was recorded in the variant where during the vegetation period no treatments with fungicides against apple diseases were applied. Of the pathogens that infected and appeared during storage, isolated on the fruits, only Fusarium spp. and Penicillium spp. had a higher frequency. Applying treatments during the growing season reduced the rotting attack degree of apple fruits during storage. The best response to rot attack in the warehouse was ‘Topaz’ and ‘Jonagold’, the attack degree ranged between 0.3 and 10% on treated variants. By applying chemical treatments, the spectrum and the share of pathogens that lead to fruit degradation is different. This means that chemical treatments must be chosen depending on the nature of the pathogens and the apple variety.