Monitoring for problems in poinsettias during production

A recent eGro alert from Michigan State University experts Roberto Lopez and Heidi Lindberg highlights how 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. Recent reports of leaf abnormalities align with the traditional occurrence of these symptoms that often occur from mid-September to early October.

Poinsettia leaf distortions often occur on young or immature leaves and are believed to be caused by many factors. Leaf and meristem distortions can be caused by herbicide exposure, but if you can rule out an exposure, there are many environmental and cultural factors that can lead to leaf distortions. Physical damage during pinching, ruptured cells and latex residue can cause the expanding leaf to become distorted. Therefore, care should be taken to avoid latex from dripping onto the plant during pinching.

Sometimes growers wait too long to pinch their plants, resulting in poor and uneven branching. In such instances, plants become tall and lateral shoots emerge before pinch and break unevenly after pinch. Therefore, it is critical that plants are pinched before breaks form to promote uniform branching. For early branching cultivars, the maximum recommended time from planting to pinch is 12 to 14 days to minimize this disorder

Read the complete eGro alert here.

Source: Greenhouse Grower

Photo by Sharat Arackal on Unsplash

Source: Greenhouse Grower