Last season many nurseries were severely hit by the disease Plasmopara obducens and, once established, infections were very difficult to control.
A Certis representative said: "Impatiens downy mildew has the ability to survive in soil and plant debris, so a preventative fungicide programme using products such as Triptam (thiram) and Aliette (fosetyl aluminium) should be adopted as early as possible to have any hope of effectively controlling it."
The company also recommends disinfecting surfaces, tools and other equipment with Jet 5 (peroxyacetic acid) before new bedding plants arrive. Imported stock should be inspected and kept quarantined for a short period.
Other products that can be used against the disease are Bravo 500, Filex, Subdue and products under SOLA/LTAEU: Amistar, Fubol Gold WG, Karamate Dry Flo Newtec, Stroby WG and Previcur Energy.
ADAS consultant Wayne Brough is revising the code of practice on how growers should prevent and manage the disease. It will be completed this month and then published by the HDC.