Postharvest pathogens affecting South African pomegranates

South Africa is a developing pomegranate producer and exporter to various Northern Hemisphere markets from February to May. Almost 80% of commercial plantings are found in the Western Cape province; the most prominent cultivar is ‘Wonderful’ (78%), followed by ‘Acco’ (8%) and ‘Herskawitz’ (8%). Despite following a standard postharvest treatment protocol which includes chlorine and fludioxonil submersion of fruit, significant losses occur in the market every season due to postharvest fungal diseases. A survey was conducted on commercially handled fruit to determine the key fungal pathogens responsible for postharvest rot in stored fruit of ‘Wonderful’, ‘Herskawitz’ and ‘Acco’. The effect of the current industry postharvest treatment on the control of specific pathogens was also determined. Various Penicillium spp. were frequently isolated from cold-stored (6°C) fruit, while Aspergillus niger, Coniella granati, Cytospora punicae, Alternaria sp. and Colletotrichum gloeosporioides were also isolated. Differences in the prevalence of the fungal spp. occurred between treated and non-treated fruit. Research outcomes from this work contribute to a better understanding of the suitability of current postharvest practices and will contribute to the development of alternative or additional postharvest management protocols for the pomegranate industry.