There are numerous types, of which two are sometimes associated with poinsettia. "B-biotype" is an effective vector of more than 110 viruses from several families. "Q-biotype" is more invasive and has shown more resistance to insecticides currently used for whitefly control.
HDC project PO 003 was undertaken after a Bemisia outbreak at a nursery in 2009. The Q-biotype population proved extremely difficult to eradicate and. Subsequent work tested the efficacy of chemical and biological products. Control programmes developed for this type should be equally suitable for use against the B-biotype.
To complement the efficacy work in the quarantine facility at the Food & Environment Research Agency, the same sequential spray programmes were tested on a nursery so that any phytotoxic effects could then be quantified. The aim was to determine spray programmes for B. tabaci control that were effective against the pest and safe for use on poinsettia crops.
The work found that early eradication is essential and growers should apply a control programme within the first four weeks after potting. Sprays are also more likely to be effective when applied while plants are small.
Dates for your diary
HDC Field Vegetables Panel Meeting 15 September, Stoneleigh.
HDC Soft Fruit Panel Meeting 21-22 September, East Malling.
Horticultural Development Company
For details on all HDC activity, visit www.hdc.org.uk