Agronomy Update – Aug 3

Hi everyone,

Another sunny and warm week in PEI this week.  Some folks in Prince County were fortunate to get between 5 and 15 mm of rain over the weekend in thundershowers, but they were very spotty and Eastern PEI did not receive much rain at all.  The forecast looks favourable for some rain early next week…let’s hope it arrives.  Most growers I’ve talked to this week report that the crop is not suffering due to lack of moisture just yet, but soil moisture levels are starting to hit wilting point levels and will require immediate top up with either irrigation or rainfall (or both).  ET rates are pretty high, as the crop is at full canopy and temperatures are high and staying warm overnight.

I haven’t pulled many tops yet, but I’m hearing reports from growers of a good number of tubers per plant overall.  I think that we still have the potential for a very good crop, provided that some moisture arrives soon.


Rainfall/GDD Report:

Thank you to Morgan, who does up a weather report at the start of every month during the growing season.  Here are some highlights from that report.

  • July 2022 rainfall was pretty close to the historical average across the province. West Prince had about 10-15 mm more rain than Eastern/Central PEI.
  • Below is a table which shows how we are tracking for rainfall across the province this growing season:



Rainfall Amounts (mm)

Location May 2022 June 2022 July 2022 Current Season Total (mm) Historical Accumulative Total (mm) Difference (mm)
O’Leary 58.8 89.4 104.4 252.6 283.7 -31.1
Fox Island 51.6 110.2 99.6 261.4 261.1 +0.3
Graham’s Road 48.0 117.6 81.0 246.6 272.1 -25.5
Lower Freetown 52.0 96.6 89.4 238.0 260.3 -22.3
Victoria 35.4 99.6 163.2 298.2 269.7 +28.5
Charlottetown 25.8 97.8 88.8 212.4 -57.3
York 38.2 118.8 96.0 253.0 -16.7
Montague/Brudenell 16.8 125.4 34.8 177.0 272.3 -95.3
New Zealand 35.4 101.4 52.8 189.6 280.6 -91.0
East Baltic 40.2 113.4 76.8 230.4 -50.2


  • Morgan has highlighted in yellow the areas with a 50 mm or greater deficit in rainfall from the historical average. All of these are in Kings County.
  • When looking at growing degree days (GDD, base 5C), July saw us running between 35-57 GDD ahead of average. Looking at the province for the season:



Growing Degree Days (GDD)

Area May 2022 June 2022 July 2022 Current Season Total Historical Accumulative Total Difference
West Prince- O’Leary 169 271 479 919 860.7 +58.3
Summerside- Kensington 170 292 465 927 842.1 +84.9
Charlottetown- Harrington 121 275 466 862 848.9 +13.1
St. Peters- Souris 141 260 442 843 778.7 +64.3


These advanced number of GDD may help to explain the advanced flowering and row closure for most varieties, as well as the earlier insect pressure that many have seen, especially in Prince County.


Crop Update:

Thanks to those that attended the Crop Update Meeting in O’Leary yesterday morning.  Some key points from that meeting as well as from my own observations this week:

  • Growers in West Prince are reporting higher than normal levels of Colorado potato beetles, with many growers going in with foliar sprays to help control populations.
  • There is evidence of European corn borers that survived pesticide applications and are making their way into stems, but the level of infestation is not considered to be terrible.
  • There are very few reports of fungal disease (early blight, brown spot). There are a few reports of white mold (Schlerotinia) in West Prince.
  • Aphid numbers have declined significantly in the last couple of weeks.
  • While most acres look good, there is the occasional field (usually planted in June) where emergence rate is not great. But majority of the crop looks very good.


Spore Trapping Update:

Spornado (10 sites):  Submission delayed by a day due to August long weekend.  Watch for results tomorrow.

Airspore Spore Results:  No Late Blight Spores Detected.


Early Blight Brown Spot Grey Mould
Jul 29/30 Aug 1 Jul 29/30 Aug 1 Jul 29/30 Aug 1
West Prince 41 24 14 11 7 12
East Prince 6 113 2 10 26 51
Queens 0 27 0 28 9 38
Kings 11 7 0 1 15 20


Early blight spore counts in Prince County are higher in the last 5 days than last week, particularly in East Prince.  Bortrytis (grey mould) spore counts are also trending higher; however, the numbers are still much lower than we saw late last year when there was lots of rain in late summer.  Brown spot spore counts continue to be generally low, except for a couple of individual collection sites.


AIM Grower Tours and BBQs in August:

 Save the date for AIM Grower Tours and BBQs to be held between August 23-25.

Our tentative schedule:

Tues, Aug 23rd:  West Prince Tour finishing at Dock Corner Farms (10:30 am to 1:00 pm)

Wed, Aug 24th:  East Prince Tour (Freetown/Bedeque/Kinkora), finishing at Hilltop Acres, Shamrock (10:30 am to 1:00 pm)
Thurs, Aug 25th:  Eastern Kings Tour (Rollo Bay/Souris area), finishing at MacAulay Farms (10:30 am to 1:00 pm)

Each tour will be comprised of 2-3 field visits to view field trials that are part of AIM, Living Labs, or PEIDAL research programs.  We will also have 10-foot yield samples from additional field trials at each of our end locations, followed by a free BBQ.  All growers and industry partners are welcome to attend!  Stay tuned for the final program and field locations later in August.

There will not be an agronomy update next week, as I’ll be away on vacation.  However, stay tuned for Lorraine MacKinnon’s pest update for any pertinent updates.  Talk soon!