Efficacy of fungicide treatments on gray mold of poinsettia, 2025

Botrytis blight, caused by Botrytis cinerea, is one of the most destructive diseases of poinsettia in greenhouse production. On bracts, leaves, and stems, Botrytis blight typically develops as rapidly expanding water-soaked lesions that become necrotic with characteristic gray sporulation. This PDMR reports on the evaluation of the efficacy of spray programs with conventional fungicides for the management of Botrytis blight. The trial was conducted in 2025 in Storrs, CT on greenhouse grown ‘Christmas Eve Red’ poinsettias. Results from this trial will aid in developing management programs for this disease.