Tag Archives: Cucumber

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.

 

2016 University of Guelph Cucumber Downy Mildew Results

In 2016, Cheryl Trueman compared several different cucumber downy mildew control programs in plots at the University of Guelph Ridgetown Campus. These studies indicated that the highest level of control was achieved using a three product rotation of Orondis Ultra A+B, Torrent and Zampro.

Several different product rotations were compared including:

  • Bravo-only applied 6 times.
  • a high input strategy that focused on optimal control and resistance management: Orondis Ultra A+B; Torrent; Zampro; Orondis Ultra A+B; Torrent; Zampro.
  • a low-input strategy that focused on early control and resistance management, switching to lower-cost fungicides in the final weeks of harvest: Orondis Ultra A + B (plus Bravo); Torrent; Zampro; Bravo; Bravo; Bravo.
  • a single application of Orondis Ultra, applied early followed by the other targeted downy mildew  fungicides (Orondis Ultra A + B; Torrent ; Zampro; Torrent; Zampro; Torrent).
  • Control – no fungicides applied
Product Rotation Leaf Area Infected Defoliation
Bravo Only
(6 applications)
45% 23%
High Input 3% 0%
Low Input 40% 20%
Single Orondis Ultra in rotation 28% 8%
Control 80% 80%

Final yields for both the high input and single Orondis Ultra (in rotation) were both significantly higher than the Bravo only programs. The yields for the high input program, were significantly higher than all other treatments.

See the 2017 Downy Mildew Control Strategy for Cucumber Crops for more information.