25 Jun Agronomy Update – June 25th

Hi everyone,

Starting today, my goal is to have an Agronomy Update out on Wednesday afternoons that includes available data from various pest and disease monitoring programs as well as updates from my desk on crop progress and other tidbits to pass along.

After a somewhat slower planting season than last year, the crop is in and progressing relatively quickly. Most fields have emerged and growing rapidly. Early planted fields in Southern Kings are at row closure in many cases.  I haven’t heard many reports of emergence issues and in most cases, emergence seems to be relatively even.

Pest/Disease Update:

This past Monday was the start of collection under the Aphid Alert Program, managed by the PEI Department of Agriculture with some assistance from the Potato Board. We only had six traps with samples collected on Monday, with the expectation that numbers will climb starting with tomorrow’s collection.

Nonetheless, we are already seeing relatively high aphid numbers.  Average number of aphids per trap is 7.5, much higher than this time last year.  Numbers are quite variable by region due to the low number of samples collected so far. Potato aphids, buckthorn aphids, and other non-colonizing aphids have all been collected.  The University of Maine pest update reported finding green peach aphids in Aroostock County last week, as early as I’ve seen for GPA collection.

Recommendation:  all seed growers should have an oil spray on as soon after emergence as possible, and an aphicide spray is recommended given aphid numbers.

A breakdown in available in the table below. The total number of traps in the program this year has increased from last year, and we have also included 6 traps (2 in each county) that are being collected from non-seed fields, in an effort to better understand aphid populations.  Thank you to Rodrigo at the Dept of Ag for his help in getting the program going again this year.

Spore collection has not yet started in PEI.  I hope to have the first spore trapping results for you next week.  This year, we will only have spore trapping results from the Air Spore program, with an increase in the number of participating farms from last year.  Thank you to the farms that agree to share their spore trap data with the Board, which we will share in aggregate on a regional basis in these email updates.

After a hot and muggy day yesterday, the rest of this week looks a bit cooler and less humid. Also from the Maine pest report, late blight spores have been detected in Aroostock County, so they are recommending a tight protective fungicide spray schedule, especially for earlier planted fields with significant size of plants.

A few of other pest/disease points:

• There are a lot of volunteer potatoes around this year. For fields with volunteers that have not yet been planted, a full rate of glyphosate is recommended. A factsheet on volunteer management is located here.
• The Dept of Ag’s Pest Monitoring Program detected European corn borer (ECB) moths on June 20^th. This is earlier than last year (July 10^th) and 2023 (June 27^th). Keep an eye out for egg masses when scouting fields.
• Colorado potato beetles (CPB) are also making an early appearance in many fields. CPB are making quick work of volunteers in some fields. Stay vigilant for indications that CPB are hitting thresholds in fields in the coming weeks.
• We are now past the deadline for covering or disposing of potato cull piles. If you have cull piles that are not yet covered or disposed of, please do so immediately or contact the Department of Agriculture for the necessary permits.

Additional notes:

1. Presentations from the 2025 Scouting Workshop held last week in Emerald are now available on the Agronomy Site under Seminar/Workshop Presentations.
2. Our first Crop Update Meeting will be next Wednesday, July 2^nd at 2:30 pm at the PEI Potato Board or via Zoom.  Contact ryan@peipotato.org for Zoom details.  We had feedback from those who have attended these meetings in the past that having a hybrid option (attend in person or on Zoom) is preferred, and that we try having them in the afternoon instead of the morning so that we avoid times when scouts/field workers/growers are normally in the field. All growers, scouts, field workers, researchers, and agronomists are welcome to attend!

   Future meetings:
   Tues, July 15^th at Location TBA (2:30 pm)
   Tues, July 29^th at PEI Potato Board, Charlottetown (2:30 pm)
   Tues, Aug 12^th at Location TBA (2:30 pm)

Have a great rest of the week!

Ryan