Monitoring leaf and stem disorders in poinsettias

Added on 23 August 2023

Tags

Monitoring leaf and stem disorders in poinsettias

Earlier this month, we reported on a blog post from OnFloriculture.com on monitoring for pests and diseases in poinsettias. This week, we turn to the identification of physiological disorders and leaf abnormalities in poinsettias. Given that poinsettias are propagated during the hottest months of the year and have a very long production time, they are prone to such disorders. Occasionally, greenhouse growers observe irregularities on the leaves or stems of their crop that are not caused by insects or diseases.

In a recent eGRO alert, Michigan State University’s Roberto Lopez and Heidi Lindberg note that environmental factors during both propagation and production, such as drought stress, exposure to high light or temperatures, or changes in relative humidity, can all cause poinsettia leaf abnormalities, distortion, crippling, or puckering. These issues are often the most difficult to diagnose, as you cannot isolate the problem in a petri dish or visually observe an insect or pathogen. Reports of leaf abnormalities align with the traditional occurrence of these symptoms that often occur from mid-September to early October.