Botrytis Blues

The cool, late spring experienced by much of the mid-Atlantic region has provided excellent conditions for Botrytis grey mold to appear in some retail greenhouses.

by Lee Stivers

Not only has the weather favored disease development, but slower early sales mean that plants can get backed up in the greenhouse. The resulting crowded conditions further restrict airflow, so petal and leaf surfaces stay moist longer. This increases the opportunity for the fungal pathogen to spread.

I observed Botrytis symptoms on geranium, petunia, and leucanthemum plants last week at a large retail operation in Pennsylvania. At this point in the season, control options are somewhat limited, but retail managers should keep a careful eye on displays, and pull plants with obvious disease symptoms. Botrytis can be managed effectively, but this requires a proactive approach to prevent the disease from creating significant problems.

An earlier eGRO Alert, by Paul Thomas and Jean Woodward, provides a thorough discussion of Botrytis prevention and control.

Source: eGRO Blog