Current weather patterns of cloudy, overcast days can lead to an increase in disease problems such as Botrytis blight, Pythium root rot, powdery mildew, and downy mildew. Scout plants for early symptoms and signs of the pathogens. Quick action is needed to reduce crop losses. See these e-GRO Alerts for more information on Botrytis blight (http://www.e-gro.org/pdf/2019_810.pdf), Pythium root rot in propagation (http://www.e-gro.org/pdf/2019_804.pdf), powdery mildew (http://www.e-gro.org/pdf/EGRO_3_10.pdf), and downy mildew on coleus (http://www.e-gro.org/pdf/2016_514.pdf) and on rose (http://www.e-gro.org/pdf/2017_719.pdf).
Always remember to follow good sanitation practices to minimize pathogen survival and disease spread within greenhouses. When using fungicides, the best control is achieved when applying products preventively. Applying products after symptoms are present will not effectively manage plant diseases.