Seasonal development
and life cycle—Gray mold
The fungus that causes gray mold and blossom blight, Botrytis cinerea, is widespread, infecting dead
or dying plant parts and causing decay on many crops. In the absence of hosts, the fungus can survive
as small black resting structures called sclerotia or in infected plant debris.
When it is humid and cool, spores are produced on moldy fruit, other hosts, plant debris, or sclerotia.
They are spread by wind and splashing water. During flowering, germinating spores may infect flowers,
causing blossom blight or invading developing fruit. Young fruit may decay soon after infection or
the fungus may remain dormant until later. Spores produced continue to infect other fruit throughout
the
season. The incidence of fruit infection increases with the length of time fruit remains wet.
Gray mold is favored by cool, damp conditions, especially
rainy weather. Botrytis is most active at
temperatures of about 65° to 75° F. |
Blossom
infection |
Early
infection |
Fungus
over fruit |
Velvety
gray spores |
|
