Gray mold of tomato is one of the more common diseases of greenhouse-produced tomatoes. Although it is often a minor problem, if left unchecked, gray mold can cause yield loss. Gray mold, or more properly, Botrytis gray mold, often causes a light gray or brown necrotic lesion on leaves (Figure 1). The lesions on leaves are sometimes wedge shaped on the margin of the leaf. Stem lesions are a similar color and may encircle the stem, causing the death of the upper portion of the stem. Occasionally, gray mold may cause the rot of tomato fruit. Whether on leafs, stems or fruit, the gray fungal sporulation is often easily seen, thus the name. It is a rare symptom, but when fungal spores land on tomato fruit that is wet, the spores may germinate, causing a symptom known as a ghost spot (Figure 2). Botrytis gray mold can cause disease on many different host plants, enabling[Read More…]
