University of Florida

Gray Mold

Fungus

Botrytis cinerea

Infects

Foliar plant parts and fruit.

Symptoms

Wedge-shaped grayish-brown lesions develop on older leaves; large elliptical, water-soaked lesions occur on stems, becoming grayish-tan in color; fruit are often infected at the stem end or shoulder; water-soaked spots appear with a light brown to tan central region, decaying rapidly; a gray fungal growth is evident from infected tissue during cool moist weather. If there is a rapid weather change (not favorable to the fungus), fruit infections may abort. Ghost rings (Ghost spot symptoms) develop on fruit in this situation.

Pathogen Spread

Rain or wind borne from crop debris or volunteer hosts; colonizing dead or dying tissue, cold damaged tissue, wounds, growth cracks or insect injuries in foliage or fruit.

Favorable Conditions

Cool, wet, humid weather and a low calcium to phosphorus level. More commons in areas 3 and 4 (Appendix 9).

Gray mold (and ghost spot) Pictures

gray mold lesions on leaf
Image # 121.
Gray Mold
-
typical lesions on leaves.

Gray mold on fruit
Image # 122.

a soft fruit rot often starting at the stem end where the gray fungal growth often emerges from ruptured tissue.

ghost spotImage # 122.
Ghost spot-
note light colored rings on fruit surface.