Tag Archives: Downy Mildew

Downy mildew of brassica vegetables

Downy mildew of brassicas (Hyaloperonospora parasitica syn. Peronospora parasitica) is a fungal-like oomycete that can be devastating in cooler, wet weather. While the ideal temperature for downy mildew development is 8-16˚C it can infect in temperatures outside that range. Prolonged leaf wetness due to fog, dew, or evening irrigation can create ideal conditions for the pathogen to develop.

Downy mildew is most devastating on Continue reading Downy mildew of brassica vegetables

Cucurbit Downy Mildew Report for the Week of July 24th, 2017

Cheryl Trueman, University of Guelph – Ridgetown Campus

Risk of downy mildew to cucumbers and cantaloupe remains high, with new reports regularly occurring throughout the great lakes region.

Scouting for downy mildew in pickling cucumber fields in Norfolk County began on June 13 and in Kent County on June 19.  This is the final cucumber downy mildew scouting report for the 2017 season.

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

Cucurbit Downy Mildew Report for the Week of July 4th, 2017

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.

Cucurbit Downy Mildew Report for the Week of July 4th, 2017

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

Cucurbit downy mildew was confirmed on June 28th.  Additional reports now include the areas of Norfolk, Oxford and Kent. The risk of downy mildew infections remains high throughout Southern Ontario.

At this time all cucumber growers should use only targeted downy mildew fungicides.

Cantaloupe/muskmelon growers should alternate between broadspectrum fungicides and downy mildew fungicides.  In melon crops, broadspectrum fungicides are required to manage other foliar diseases including alternaria, anthracnose and powdery mildew.

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.

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.

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.

Downy Mildew Report for the week of June 12, 2017

By Cheryl Trueman, University of Guelph – Ridgetown Campus

Scouting for downy mildew in pickling cucumber fields in Norfolk County began on June 13 (3 of 5 sites) and will begin 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.