15 Aug Agronomy Update – Aug 15th

Hi everyone,

Getting back into the swing of things after a week away in Ontario.  Despite being away just over a week, I’ve noticed a considerable change in the potato crop in many areas.  Shorter season varieties that were planted early are noticeably starting to yellow, with evidence of flagging from Verticillium wilt.  Longer season varieties are also suffering with the dry weather in the western half of the province.  While 10 foot strips have been ahead of normal for most varieties, we need some rain for most of the province in the immediate future for the crop to bulk up.

Spore Trapping:

• Late Blight has not been detected in PEI this week in either Spornado or Airspore programs.
• Late blight spores were detected in multiple locations in Aroostock Co, Maine early this week.  In addition, foliar late blight was discovered in Presque Isle, ME late last week.  No late blight has been detected in NB so far.
• The forecast for the next several days doesn’t look favourable to late blight development, but if we transition to a wetter/muggier trend early next week, that is liable to change.

• Early blight spore counts have increased significantly in the western half of the Island in the past week.  As the western half of the province has been drier, it makes sense that we are seeing more secondary infection on lower leaves.  Brown spot counts are generally lower and consistent for the time of year.

Spornado Bortrytis count averages:

 West Prince:  2,952,367/trap

East Prince:  1,454/trap

Queens:  164/trap

Kings:  5,473,450/trap

• Bortrytis (grey mold) counts are increasing in both the Spornado and Airspore programs. Counts appear to be highest in the Spornado program at the two ends of the Island, with some spore counts in the millions!  The Spornado tests will naturally capture more spores as they are in the environment for 7 days, but these numbers are very high, indicating that there is lots of inoculum.
• Grey mold is most worrisome when we start getting daytime temperatures consistently below 23 C (with cooler nights) and lots of free moisture.  As the forecast transitions to cooler and wetter weather, switching up your fungicide program to include chlorothanonil (Bravo/Echo) or a product like Miravis Duo or Scala would be advised.
• If you have observed early blight or brown spot in any fields and would like to submit a sample for resistance testing, please contact me!  You can either drop off samples at the office, or we can arrange to collect samples.  I need a few more samples for this survey!

Pest/Disease Update:

• Second generation Colorado potato beetles adults are being observed in multiple areas.  In some fields, foliar sprays did a good job of killing larva on the plants, but adults emerged afterward that largely escaped pesticide application.
• Flea beetle damage has been reported by multiple growers/scouts as neonic efficacy wears off.
• Aphid numbers have been generally low for the last couple of weeks.  A number of seed growers have already started to top-kill, as early-planted seed has already reached target size profile.  Only 8 aphids were detected from 20 trap locations so far this week, with all of them being non-colonizing aphids (“other aphids”).
• Getting reports of significant ECB damage in a few fields, some that resembles blackleg but where upon closer inspection you can see entry holes and larvae in the stems.  So far no reports of a second generation of moths this year.
• If you have fields with noticeable corn borer damage and you would be open to having insect samples collected for resistance testing, please contact me at your earliest convenience.

AIM BBQs:  Aug 27-29^th

All are welcome to AIM BBQs the week after next.  Each event will start at 11:00 am with viewing of some samples from AIM trials in each region and a chat about ongoing AIM research projects.  This will be followed by a BBQ at 12 pm.  Dates and locations:

Tues, Aug 27:  Triple S Farms, 25 Smallman Rd, Knutsford (https://maps.app.goo.gl/NpdDjFYgV39JMiey5)

Wed, Aug 28:  Island Holdings, 987 Campbellton Rd, New London (https://maps.app.goo.gl/LG2vwUfrNBH7Xq7z6)

Thurs, Aug 29:  Mo Dhacaidh Farms, 7173 St. Peters Rd, Morell (https://maps.app.goo.gl/9JMAPoXigCwA8Xim7)

Advanced Grazing Pasture Walk – Aug 28^th

The PEI Dept of Ag is hosting a pasture walk at Oyster Cove Farms on Aug 28^th from 6 to 8 pm to showcase advanced grazing practices in rotation with potatoes.  Oyster Cove Farms are a participant in a Living Labs research project with grazing ahead of potatoes.

Matt Ramsay of Oyster Cove Farms is a potato farmer with a focus on building soil health.  As part of this effort, he is now custom grazing cow calf pairs, aiming to develop mutually beneficial collaborations between neighbors.  Oyster Cove Farms benefits from additional manure and cover crop management to improve soil health, and their neighbor benefits from reducing costs of stored feed.  Matt will discuss practical realities when integrating grazing ruminants onto a cropping operation, and forage/grazing management strategies.

Have a great rest of the week, and hoping that some rainfall arrives soon for those that need it.

Ryan