03 Sep Agronomy Update – Sept 3

Hi everyone,

One would be tempted to say that it’s another lovely late summer day in PEI, except for the fact that every day without rain is another day of frustration and heartache.  We are undoubtedly looking at a significantly reduced potato yield this year, but the dry weather is also taking its toll on other crops and on plans for fall tillage and cover cropping.

I’ve been getting lots of calls and texts about tillage and cover cropping. In many fields, the ground is too dry and hard to get equipment in the soil. We will need significant rainfall to change that and to allow for sufficient germination of cover crops. I think that cereals (barley, oats, wheat, rye) will be more successful as cover crops this year than radish, mustard, buckwheat, etc.

I want to take a second to thank everyone who came out to one of our three AIM BBQs last week.  We had terrific attendance, with over 170 people across the three events.  It means a lot to have a great turnout at a time when we know that everyone has a lot on their minds. Particularly, I’d like to thank the following people:

• Our hosts:  Mooney Farms, Wallace Properties, and Cavendish Farms Discovery Farm
• PEIPB staff for their help with setup and barbequing, particularly Scott, Humna, Krista, Rebecca, Holly, Greg and Amanda
• Emily Belliveau and Andrea McKenna with the East Prince Agri-Environment Assoc. for helping us promote the BBQs
• Folks with AAFC and PEI Dept of Ag who helped me dig some potato samples for the BBQs.

Aphid Alert:

• A number of seed fields have already been top-killed, while others have delayed killing to try and get a little more yield.
• Aphid numbers remained high last week, with numbers increasing as you move east.
• Very few colonizing aphids (green peach, potato, buckthorn) are being found.  Most aphids are non-colonizing.
• Growers leaving seed to bulk should be diligent to continue oil applications and aphicides where warranted.

Air Spore:

No late blight spores have been detected in PEI or NB again in the past week.

We are down to only 8 farms with spore samples this week, as a number of farms start to wind down collections. Early blight spore numbers are increasing as the dry weather drags on. However, we are long past the effective window to control Alternaria effectively, particularly as most fields lose lower leaves due to the lack of moisture.  Bortrytis spore counts remain relatively low in most fields, reflective of the dry and warm weather.

August Weather Totals:

Table 1: Rainfall amounts for the month of August (current year 2025 vs historical records 1981-2010)

Table 2: Cumulative rainfall totals for 2025 growing season compared with historical cumulative rainfall

As you can see, the whole Island is in a significant moisture deficit, with that deficit being the most acute East Prince and Queens County.  Summerside has only had about 5 inches of rainfall since June 1^st.

Table 3: Cumulative GDD for 2025 growing season compared with historical cumulative GDD

Somewhat surprisingly, growing degree day (GDD) accumulation for the growing season hasn’t been as high as one would think.  Cooler nights in August has helped to mitigate the effect of record high afternoon temperatures somewhat. West Prince has been the hot spot for the majority of the growing season, once again.

Looking for Trial Fields:

I am looking for growers who would be interested in participating in the following trials this fall:

1. Legume Nitrogen:  I’m looking for a field currently in red clover that will be terminated this fall in preparation for potatoes in 2026. In next year’s potato crop, we would look at 4 nitrogen rates, with most of the field at grower standard practice.  A grower participation fee will be offered.
2. Winter vs Spring Cereal Cover Crops:  I’m looking for one or two fields to compare a winter cereal (winter wheat ideally) compared with a spring cereal (barley, oats) after potato harvest. Ideally looking for fields due to be harvested before Oct 5^th.
3. Use of Reglone to reduce bruising:  I’m looking for a couple of Cavendish growers interested in comparing top-kill with Reglone compared with digging green for newer varieties such as Mountain Gem and Targhee Russet.

If you have interest in any of these trials and would like to know more, please give me a call at (902) 439-9386 or email me for more details.

Fingers crossed for some rain to show up soon. Please feel free to reach out to me or anyone with the Board if you have questions or need our assistance this fall as we face this challenging harvest. Also be sure to make use of the Farmers Talk Help Line (1-800-736-8006) if you need someone else to talk to.

Ryan