Downy mildew is present in a pickling cucumber field in Kent County. A field scout, funded by the Ontario Cucumber Research Committee, collected the infected leaves. Downy mildew was confirmed by OMFARA staff. Sporulation is apparent on the underside of the leaf, indicating that the infection occurred within the last week.
All cucumber growers are advised to adopt an aggressive fungicide strategy immediately. Consider all cucumber crops to be at a high risk of infection. Apply downy mildew targeted fungicides at a 7-day spray interval. Use ample water volumes (ie: 30 gal/ac) to ensure adequate coverage. Where possible, apply fungicide prior to a rainfall or irrigation event.
The targeted downy mildew fungicides include Ranman 400SC, Tattoo C and Presidio.
For the full 2011 Downy Mildew Control Strategy see: http://www.omafra.gov.on.ca/english/crops/hort/2011-downy-cucurbits.htm Copies are also available from the OMAFRA contact centre, 1-877-424-1300.