It s important that PGR s are mixed and applied at appropriate rates and dates to avoid distortion of bract size or color development. See Technical Information Bulletin on Using Chemical Growth Regulator s for more specific information and guidance. Monitor plants and their root systems through plant inspection and yellow sticky cards throughout the crop. It is possible to maintain a clean and healthy crop to market. This pest is readily found in decaying organic matter in greenhouses and moist growing media.
Whiteflies cause damage to the crop by feeding on plant tissues.
An additional problem, known as sooty mold results from whiteflies feeding on the undersides of the leaves. A sugar-rich liquid, known as honeydew, is produced by whiteflies and cover leaves directly below the feeding insect. This honeydew is an ideal food source for the dark, sooty mold. Although the fungus itself is not pathogenic, it does cover leaves, blocks light and limits photosynthesis. Thrips, although not a major pest of poinsettias, have been known to cause damage to the leaves and bracts.