18 Jun Agronomy Update – June 18th

Good day,

It has definitely been a challenging spring this year across the Island. There are a number of growers still trying to get finished up on planting, as frequent rains and cooler temperatures in May have slowed down planting considerably. In addition, the slow spring combined with some compromised seed lots is already leading to some delayed and uneven emergence and reports of set rot. I am hoping that some more consistent warmth will pop a lot of potatoes out of the ground in the next week.

Christine and I were out and about in West Prince yesterday, and the significant rainfall from Saturday and Monday in the west was quite evident in places. Most fields left to plant are inland fields with heavier soils. We saw our first adult Colorado potato beetles yesterday, emerging from hedgerows in a winter wheat field on the march to find potatoes to munch on.  According to degree day model calculations provided by Dr. Suqi Liu from the PEI Dept of Ag, most of central PEI should hit the DD threshold for 5% emergence of adult beetles by the end of this week, with the ends of the Island lagging a little bit in degree days.

Weeds and Cover Crops:

• For those that don’t have pre-emerge herbicides on yet, that should be an immediate priority. The forecast rainfall for this weekend should be sufficient to ensure good activation of herbicides.  Remember:  pre-emerge herbicides are before weed emerge, not just potato emergence. For max efficacy, apply Sencor/Lorox plus tank-mix partners before weed emergence.
• A cool, wet spring with delays in herbicide application can be a recipe for weed development, especially perennial grasses like couchgrass/quackgrass. Sencor/Boundary is rated for “suppression” for couchgrass, and Loros is rated “Good” according to Dr. Andrew McKenzie-Gopsill at AAFC. Beyond glyphosate (which can be used before ground-crack), the best option is Venture L, a Group 1 grass herbicide.  Prism/Sencor post-emergence will have limited effect on couchgrass.
• A see a number of fields not yet worked/seeded that were potatoes in 2025, likely because the priority was getting potatoes in the ground.  For those planting sorghum sudangrass/forage pearl millet and waiting for soil to warm up, we’ve largely reached soil temps (18C) that should allow for fast establishment of those warm-season grasses.
• I see a big difference in some of our trial fields between forages/legumes that were direct-seeded last spring compared with underseeded forages. The drought last summer had a significant impact on many underseeded forage stands. If you need to re-seed some of those fields this year (the year before potatoes), something like sudangrass or pearl millet, possibly with a small amount of radish or mustard in the mix, would be a good option to ensure some quick biomass growth this year. Feel free to contact me if you have fields that you are trying to troubleshoot/manage along these lines.

Aphid Alert 2026:

 This week marks the first week of aphid collection under Aphid Alert, a collaboration between the PEI Department of Agriculture and the PEI Potato Board.

The number of samples is low because many seed fields have not yet emerged, so most growers won’t start collection until next week. However, we are already seeing non-colonizing aphids at numbers similar to early season last year. Seed growers with emerged plants are recommended to start mineral oil applications early to avoid early-season virus spread.

 Weather Info – AgIntel:

Last year, the Board and the PEI Agri-Watershed Partnership worked in partnership to re-activate 30 UPEI weather stations across the province.  Data from those stations has been available on the Agronomy Site on a station-by-station basis, but this hasn’t been very user-friendly.  This winter and spring, we started discussions with the East Prince Agri-Environment Assoc. and the PEI Federation of Agriculture to develop a weather information dashboard that includes all of our collective stations in an easy-to-use graphical dashboard.  That dashboard is now available to be accessed at https://agintel.co/weather.

The public, no login necessary page has current conditions, 24 hr rainfall, 7-day rainfall, and accumulated GDD and CHU for each weather station, displayed graphically on the map. In order to access historical data sets for each station, it will require a login, which will be launched in the near future.  We are also hoping to be able to build a number of pest and disease models (ie. Fusarium head blight, late blight, corn borer emergence) into this site as well, as development progresses.

The AgIntel Weather Dashboard is still a work in progress as the PEIFA team adds more stations, verifies data accuracy and builds additional tools. If you have comments to share related to the useability of the site or options/tools you’d like to see incorporated, please feel free to pass along to me and they will be communicated to the project team.  We hope to be able to add additional weather stations with publicly available data in the near future.

Potato Scouting Workshop – June 30^th

The PEI Department of Agriculture, PEI Potato Board and East Prince Agri-Environment Association are collaborating to host a Potato Scouting Workshop on Tuesday, June 30^th at the Emerald Community Center in Emerald, PE.  This workshop is targeted for anyone doing crop scouting or on-farm disease/pest surveillance.  Registration starts at 8:30 am, with sessions starting at 9:00 am.  Lunch is included, followed by in-field demo at 1:00 pm.

The morning will consist of short presentations by industry experts on foliar diseases, pests, weeds, nutrient deficiencies, and biosecurity practices. After lunch, there will be an in-field scouting demonstration, combining both traditional scouting methods as well as drone-assisted scouting techniques.

Cost is $40.00, which includes a noon meal.  To pre-register, please contact Rodrigo dos Santos at rsdsantos@gov.pe.ca or (902) 314-1607.