Managing Colletotrichum on Fruit Crops: A "Complex" Challenge.

The fungal genus Colletotrichum includes numerous important plant pathogenic species and species complexes that infect a wide variety of hosts. Its taxonomy is particularly complex because species' phenotypes and genotypes are difficult to differentiate. Two notable complexes, C. acutatum and C. gloeosporioides, are known for infecting temperate fruit crops worldwide. Even species within these complexes vary in traits such as tissue specificity, aggressiveness, geographic distribution, and fungicide sensitivity. With few effective chemicals available to control these pathogens, and the persistent threat of fungicide resistance, there is a need for greater understanding of this destructive genus and the methods that can be used for disease management. This review summarizes current research on diseases caused by Colletotrichum spp. on major fruit crops in the United States, focusing on the taxonomy of species involved, disease management strategies, and future management outlook.