Bacterial and fungal pathogens that decay high carbohydrate plant tissue often target fleshy fruit. Fruit spots reflect a delimiting margin of pathogen development into a restricted zone. When many pinpoint infections coalesce, the area may become blighted or, with advancing growth, may decay and rot either on the plant or after it has dropped to the ground. Some of the greatest economic losses are from this group of diseases. The fungal pathogen, Botrytis, is a major fruit spot and rot producer of such crops as strawberry, onion, peach, cherry, plum, pear, grape, pepper, tomato, eggplant, celery, lettuce, and carrot. Brown rot of stone fruit affects cherry, nectarine, peach, apricot, and almond, causing enormous annual dollar losses on these crops. Likewise, Penicillium blue mold, which we otherwise recognize on stored breads, causes fruit rot on apple, pear, avocado, persimmon, quince, and other soft fruits.

Specific diseases



Other images

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Fly speck (clusters of tiny black dots) on apple fruit (Malus) is a fungal disease that is only skin deep
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Apple ring rot on Fuji apple fruit (Malus) caused by Botryosphaeria sp.