Late blight alert – June 28

Late blight foliar lesionLate blight has been confirmed on tomatoes in Chatham-Kent.

Recent weather has been conducive to the development and spread of late blight.  Commercial growers should scout often and ensure they are using fungicides with good late blight activity in their fungicide program.  When late blight is in the area, spray intervals should be shortened. Continue reading Late blight alert – June 28

Cucurbit Downy Mildew Alert – June 27, 2017

ALERT

Cucurbit downy mildew has been reported on pickling cucumbers and cantaloupe in Essex County. This is the first field report for this disease in 2017.

All Ontario cucumber growers should now switch from a broadspectrum program to a 3-product rotation using targeted downy mildew fungicides.

The following products have shown the most consistent results in fungicides trials at the University of Guelph, Ridgetown and Simcoe campuses.  Under high downy mildew pressure, follow a spray interval that is no longer than 7-days.

  • Orondis Ultra A (mandipropamid) + Orondis Ultra B (oxathiapiprolin) + Bravo (chlorothalonil)
  • Torrent (cyazofamid)
  • Zampro (ametoctradin/dimethomorph)

For more information about the most effective spray rotations, see: 2016 University of Guelph Cucumber Downy Mildew Results.

Cucurbit Downy Mildew Report for the Week of June 26th, 2017

Elaine Roddy, OMAFRA and Cheryl Trueman, University of Guelph – Ridgetown Campus

There have been numerous new reports of cucurbit downy mildew in the Southern US last week.  Late June to early-July is typically when downy mildew arrives in the Great Lakes region. The on-going wet weather, and speed at which the tropical storm fronts pass through the region mean that disease conditions can change very quickly.

At this time, use a broadspectrum fungicide such as cholorthalonil or mancozeb. Fungicides are most effective when used preventatively.   Band spraying small plants helps to reduce the costs of the fungicide program.  For information of band spraying, see Sprayers 101.com.

Scouting for downy mildew in pickling cucumber fields in Norfolk County began on June 13 and in Kent County on June 19.

You can track sightings of downy mildew in North America on the IPMpipe Cucurbit Downy Mildew website.

More information:
2017 Downy Mildew Control Strategy for Cucumber Crops

2016 Fungicide efficacy and fungicide program results

The downy mildew scouting program is sponsored by the Ontario Cucumber Research Committee. Field scouting in Norfolk County is managed by Tania Keirsebilck-Martin at the Norfolk Fruit Growers’
Association. Field scouting in Kent County is managed by Cheryl  Trueman at the Ridgetown Campus, University of Guelph. We thank Elaine Roddy, OMAFRA vegetable specialist, for her guidance with
implementing this program.

2017 Growing Degree Days for European Corn Borer – June 24, 2017

Bivoltine: The first generation of European corn borer adults are just past peak flight levels.

Overlap: The overlap areas will experience sustained ECB pressure as the bivoltine moths are at peak flight and the univoltine moths are now emerging.  Pest pressure in both areas is expected to increase over the next week.

Univoltine: In the univoltine areas (Eastern Ontario) first flights of moths are beginning to emerge.

Scout all sweet corn fields regularly as soon as the tassel begins to emerge from the plant. For more information on European corn borer management in sweet corn, visit our Ontario CropIPM pages

Note: we are experimenting with this new format for communicating growing degree days for European corn borer. As we refine the techniques the quality of the charts below will improve. Thank you for your patience.

2017 Growing Degree Days for European Corn Borer – June 19, 2017

The first generation of European corn borer adults are at peak flight in the Bivoltine area. In the overlap areas, the emergence of the univoltine strains is beginning as well as the peak flight of the first generation bivoltine strains.  Pest pressure in both areas is expected to increase over the next week.  In the univoltine areas, first catch of adult ECB moths can be expected within the next week.

Note: we are experimenting with this new format for communicating growing degree days for European corn borer. As we refine the techniques the quality of the charts below will improve. Thank you for your patience.

Scouting for onion thrips

Onion thrips (Thrips tabaci) feed on more than just onions; they also feed on cabbage, leaf lettuce, a variety of other vegetables and fruits, field crops, and many weed species. Thrips are unique from other insects as they have rasping-sucking mouthparts that allow them to scratch the cell walls of leaves, suck up the cell contents including the chlorophyll, and leave behind a shiny, translucent trail on the leaf. A single female can produce Continue reading Scouting for onion thrips

Cucurbit Downy Mildew Report for the Week of June 19th, 2017

Cheryl Trueman, University of Guelph – Ridgetown Campus

Scouting for downy mildew in pickling cucumber fields in Norfolk County began on June 13 and in Kent County on June 19.

You can track sightings of downy mildew in North America on the IPMpipe Cucurbit Downy Mildew website.

More information:
2017 Downy Mildew Control Strategy for Cucumber Crops

2016 Fungicide efficacy and fungicide program results

The downy mildew scouting program is sponsored by the Ontario Cucumber Research Committee. Field scouting in Norfolk County is managed by Tania Keirsebilck-Martin at the Norfolk Fruit Growers’
Association. Field scouting in Kent County is managed by Cheryl  Trueman at the Ridgetown Campus, University of Guelph. We thank Elaine Roddy, OMAFRA vegetable specialist, for her guidance with
implementing this program.

Information for commercial vegetable production in Ontario