Category Archives: Disease

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.

 

Making Lemonade Out of Lemons – A Tomato Fungicide Stewardship Tip Amidst Changing Regulations

Cheryl Trueman (Ridgetown Campus, University of Guelph) & Janice LeBoeuf (OMAFRA)

It seems like recently there have been a rash of proposed or pending pesticide regulation changes that affect field growers, and tomato growers are no exception. There are re-evaluations ongoing for a number of products used in tomatoes, including mancozeb, neonicotinoids, and Lannate, as well as Ethrel, but the big one that comes to mind for field tomato growers is the proposed changes to the use of chlorothalonil (Bravo, Echo). The final outcome of this review is not yet known, but it’s likely that significant changes to the chlorothalonil labels are coming.

Chlorothalonil is a go-to fungicide for tomato growers. Data from trials at Ridgetown Campus demonstrate its value. Chlorothalonil is often just as good at controlling early blight, Septoria leaf spot, and anthracnose fruit rot as alternative fungicides, and it also provides protection from late blight, which many targeted fungicides do not. It’s a good value active ingredient for tomato disease management and has a low risk of resistance development. But, if proposed changes go through, the number of chlorothalonil applications you can use will be drastically cut.

So, have you thought about how you are going to adapt? Continue reading Making Lemonade Out of Lemons – A Tomato Fungicide Stewardship Tip Amidst Changing Regulations

2017 Downy Mildew Control Strategy for Cucumber Crops

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.

IPM Scout Training Workshops Begin This Week

ONfruit

The free OMAFRA IPM scout training workshops are available for those who will be scouting horticultural crops this year. Be sure to register if you or your scout are planning to attend!

To register, please contact OMAFRA’s Agricultural Information Contact Centre at 1-877-424-1300 or ag.info.omafra@ontario.ca.

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