Floriculture Greenhouse Update

Biocontrol on Poinsettia

Friday, 25 June 2010 14:05

If you are a wholesale propagator of poinsettias, be sure to use IPM practices and pesticides that are compatible with biological control agents (BCA) or use BCA’s  during propagation. This will help customers who are planning to use BCA’s  during production. It would also be helpful to provide a list of pesticides used on the crop. To find out if a pesticide is compatible, use one of the on-line searchable side effect data bases available from suppliers. Click on "Side Effects" Enter product and natural enemy to search.
Biobest
Koppert

If you are buying in cuttings and plan to grow poinsettias using biological control for pest management, know the pesticide history of your cuttings. Last year, some growers had problems with biocontrol for whitefly due to pesticide residue on their cuttings. Pesticide residues negatively affect BCA's for the first 3-4 weeks of the crop after arrival at the finishing growers operations. BCA’s are then not able to establish on the first generation of whitefly.

For the past few years, Sanmite (pyridaben) IRAC Group 21 has worked well for whiteflies on poinsettia, without causing phytotoxicity. It was being used by breeders, rooting stations and growers. As a result of overuse, reports are coming in that resistance seems to be occurring.

Tina Smith, University of Massachusetts and Leanne Pundt, University of Connecticut