02 Jul Agronomy Update – July 2nd

Hi everyone,

We’re in the middle of warm, muggy week in PEI.  The forecast looks unsettled for the next few days, with chance of afternoon and evening thundershowers.  Today’s update is slightly delayed due to the Canada Day holiday, and we don’t have all of our pest collection data back yet, but I will have a short update out on Friday with hopefully more data to share.

June Weather Summary:

June rainfall was close to normal in the eastern half of the Island in June; however, most of that rainfall came in one rainfall event. East Prince/Summerside is the area with the least rainfall in June, with West Prince being only slightly below normal.

The western half of the province accumulated more GDD in June compared to the eastern half of the province. O’Leary is about 120 GDD (or 30%) ahead of historical averages, with Summerside about 15% ahead of normal.

Aphid Alert Report:

• The number of traps submitting samples is increasing with each collection date.  Samples from last week see an average of close to 4 aphids per trap. This is significantly higher than at this time last year.
• About one-third of aphids collected last week were colonizing aphids (potato or buckthorn aphids). The remainer were “other” non-colonizing aphids.
• All seed producers should be diligent about frequent application of mineral oils, especially during this time of rapid foliar growth. Use of aphicides is also recommended.
• Results from this week should be available to share on Friday.

Other Insect Pests:

• Scouts/growers in West Prince and East Prince are reporting significant numbers of European corn borer moths being trapped or observed. Scouts are finding corn borer egg masses at blackhead stage now in parts of West Prince. This is the key stage for insecticide control of ECB.
• Colorado potato beetle (CPB) incidence is variable across the province. Many growers/scouts report larvae at 3^rd or 4^th instar that are feeding but are starting to be controlled by in-furrow insecticides. There have been a few reports of CPB that are multiplying even with use of in-furrow neonic products, indicating increased resistance.
• For foliar control of CPB, there are four groups of chemistry that have shown to be effective in PEI as foliar products (according to recent AAFC population surveys):
  • Group 5 (Delegate, Entrust, Success)
  • Group 6 (Minecto Pro which includes Group 28)
  • Group 28 (Verimark, Harvanta, Coragen, Vayego, Exirel, Minecto Pro)
  • Group 30 (Cimegra)
• Be sure to not use the same group of chemistry back-to-back in the same season to slow the rate of insecticide resistance.
• If you note any particularly resistant populations of CPB in your fields, please let me know and I can see if we can collect samples for resistance monitoring.

Fungal Diseases:

• Spore trapping is just getting going in PEI, with just a few samples collected and analysed so far.
• Spore trapping in Maine detected late blight spores at multiple collection locations. Results from this week have not yet been shared. No late blight spores have been detected in New Brunswick yet.
• For varieties susceptible to early blight/brown spot (ie. Targhee, Dakota, Ranger), it is advised to get at least one targeted fungicide application on prior to row closure, to ensure good coverage on lower leaves.
• Growers/scouts seeing potential symptoms of early blight, brown spot, and black dot are encouraged to contact me for sample collection as part of disease surveys that we are undertaking this season.  You can also submit samples to the provincial Plant Pathology Lab if desired.

Additional Notes:

• The Potato Sustainability Alliance (PSA) Symposium is taking place in Charlottetown on July 16-17^th. If you are interested in attendance the conference portion of the Symposium, there is a “grower rate” of $150 USD.  To register:  https://potatosustainabilityalliance.regfox.com/psa-summer-symposium
• UPEI is hosting a Sustainable Agriculture Conference on August 5^th and 6^th in Charlottetown. More on this event is available at https://atlanticsustainableag.ca/. Registration is now open, with a fee of $125.
• We had a limited attendance for our first Crop Update Meeting today. We will reassess format ahead of our next planned meeting on July 15^th.  If you have a preference for time (8 am or afternoon) please let me know. We would like to pick a time that works for the most people. These meetings are a good opportunity to hear what people are seeing around the province.

Have a great rest of the week, everyone!

Ryan