By Tom Dudek, Michigan State University Extension
The forecast for the next five days indicates cloudy, cool and rainy weather conditions. These low light, humid conditions combined with many of our greenhouse floral crops being at or near full flower in area greenhouses can lead to Botrytis blight outbreaks. Crops like geraniums, Gerbera daisy, petunias, fuschia and calibrachoa, to name a few, can be especially vulnerable to this disease now since they have a full flower canopy and most greenhouses are soon to be filled to the maximum allowable space.
Remember that Botrytis is a fungal disease that can cause leaf spots, petiole blighting and stem cankers on many different annuals and perennials. It will produce large masses of “fuzzy looking” spores that are most often called “gray mold.” These spores or conidia will be spread on wind currents and can readily travel from infected to uninfected plants in that manner. The spores can survive for upwards of 21 to 24 days before they germinate on a plant.
Click here to read more.
Latest from Nursery Management
- Meet the 2026 Leading Women of Horticulture
- [SNEAK PEEK] Leading Women of Horticulture: Louise Schaefer and Susan Tantsits
- The Growth Industry podcast Episode 10: State of the Horticulture Industry
- Tennessee Green Industry Field Day scheduled for June 11
- UTIA and UT Knoxville research teams will develop automated compost monitoring system
- Ken and Deena Altman receive American Floral Endowment Ambassador Award
- [SNEAK PEEK] Leading Women of Horticulture: Becky Thomas
- [WATCH] Taking root: The green industry’s guide to successful internships