Across the UK whitefly pressure is currently high and quickly increasing in the dry heat.
IPM manager, Selchuk Kurtev, advises growers to be alert to activity and prepare to implement actions for controlling the pest.
At all growth stages, glasshouse and the notifiable tobacco whitefly severely reduce protected ornamental crop quality and visual appearance.
Whereas macrobiologicals are struggling in the heat, these pests are thriving.
Now is a key period for planting imported poinsettia plugs from Europe, and this brings the added risk of introducing non-indigenous insects to existing crops.
Growers planting new crops into glasshouses, while preparing existing crops for autumn and winter dispatch, should implement a carefully planned IPM strategy to minimise the risk of a whitefly outbreak.
As whitefly is a sap-sucking pest, infested plants quickly lose vigour and leaves appear yellow. Honeydew produced by the pests can also lead to black sooty mould growth on leaves.
Certis recommends a step-by-step approach to effective whitefly control.
- Quarantine imported plants for at least two weeks
- Monitor pest levels by installing yellow sticky traps, and inspecting the crop twice a week with a hand lens
- Apply an insecticide, such as Applaud 25 SC, ensuring good crop coverage
- Introduce microbiological controls, such as parasitic wasps and predatory mites
- To reduce the risk of resistance, alternate actives with different modes of action and integrate biorationals, such as Botanigard and Majestik