Agronomy Update – August 18th

Good morning everyone,

Incredibly spotty rainfall over the past 3-4 days.  Some places have gotten big rainfalls, others have gotten next to nothing.

A taste of that variability from stations around the province.  The majority of locations have gotten approximately 5 mm of rain from Aug 1 to 18th.  Some outliers to that (combination of Weather Underground and Ukko Agro stations)

Foxley River/Tyne Valley area:  14 mm
Miscouche:  102 mm
Mont Carmel :  57 mm
Lower Bedeque :  52 mm
Augustine Cove :  61 mm
Hampton:  19 mm
South Lake:  10 mm

The rain on Saturday fell heavy close to the south shore but did not penetrate far inland.  Some places missed rainfall completely.  For example, Lot 16 has had only 0.8 mm in August.  St. Peters area was similar (1 mm).

Farmers are undoubtedly feeling the stress of the drought more acutely than anyone.  I sincerely hope that your potato fields are able to hang on just a little bit longer to hopefully catch some rain later this week.  For those that did get some rainfall on the weekend, I hope that the fields are still in a position to use that moisture.  As noted last week, please feel free to reach out to me if you just want to chat, but take advantage of the Farmer Assistance Program if you feel like you need to talk to a mental health professional.

Weed Seed Management:

It’s a bad year for weeds all over the Island.  The dry weather at and after planting meant that many of the pre-emerge herbicides were not very effective.  This has resulted in a particularly large number of broadleaf weeds surviving and thriving this growing season.

While there isn’t much that you can do to control weeds in your potato crop at this point, it does make sense to try and prevent as many weeds from setting seed as possible in your rotation.  Some management options to consider:

  • Mow or till headlands that are particularly weedy.  This might just seem like a chore, but reducing the seed bank of weed seeds is worth the effort, particularly for lamb’s quarters.
  • Mow forage fields where weeds are well established.  There was a lot of ryegrass planted this year that is full of weeds.  Likewise for sudangrass/pearl millet fields.  It’s important to keep weeds from reaching the reproductive stage where possible, either by mowing or herbicide.
  • Use a broad spectrum herbicide like glyphosate (Round-Up) on weedy forage fields before any fall tillage, and give enough time for that herbicide to work before performing tillage.
  • If performing tillage in August/September, plant a fast establishing cover crop to out-compete weeds.  Fall rye, oats, and oilseed radish/winter rapeseed are all good at suppressing weeds.  Fall rye is particularly good at keeping weeds down both this fall and next spring, as it has a strong allelopathic effect.

Spore Trapping Update:

We continue to detect no late blight spores in PEI from the growers participating in the Air Spore program.  Likewise, no spores have been detected in NB or Maine either.  The weather has not been conducive to late blight infection for most of this summer and the forecast looks to be dry until the weekend.

Early blight spore counts have also fallen noticeably in the last week or so.  Test results from yesterday (Monday, Aug 17) showed zero early blight spores at all but two sites (both in West Prince), and those were at the lowest detectable number (4 spores).  Growers have been doing a great job managing their fungicide programs for Alternaria, and I’ve seen very little early blight or brown spot when walking fields the last few weeks.  Particularly given the hot, dry weather, kudos to growers for keeping their canopies as healthy as possible.

There are a few grey mold (Bortrytis) spore counts this week, as there has been all season.  However, I don’t get a sense from any growers that they are having particular worries about grey mold.  Again…this weather is not prime conditions for the spread of Bortrytis and contact fungicides should keep it in check.

I am seeing more evidence of blackleg symptoms in some fields.  Keep an eye out for blackleg symptoms as we get closer to harvest.  If you see significant blackleg in areas of a field where plants have set tubers, you may want to dig those acres last, putting them on the front of the pile to make sure they don’t cause storage losses.  We are seeing changes in the strains/species that are causing blackleg, and some of these strains are causing infection later in the growing season, after the plants have been able to set viable tubers.  This requires a change in approach and a reason to keep up full-season scouting.

Looking for Trial Partners:

  • For an AIM trial, I am looking for growers who would have planted a commercial field of a processing variety with seed between 1.5 and 3.0% PVY at planting. We are doing a small trial looking at the potential for mechanical PVY spread in wheel tracks.  If you have a field that might fit these criteria, please give me a call or send me an email.  I would like to inspect fields next week for this trial.
  • For a Living Labs/AIM trial, I am looking for growers in Kensington North/Dunk-Wilmot/Souris watershed areas that would be interested in planting some winter barley as a cover crop following potatoes to compare against planting spring barley next April/May.  I have a line on getting some winter barley seed and the project has some funding to help cover some of your seeding costs.  Again, please give me a call if interested and want to know more.  I need to get growers lined up for this project soon so that I can get enough seed ordered.
  • Any growers interested in doing Fall Hilling this August/September in advance of potatoes next year…I’m looking for some more fields to continue our AIM research into use of Fall Hilling.  If you’d like to know more and want to discuss how we can cooperate, please give me a shout!

I’d like to take this opportunity to thank the large number of growers that have been working with Morgan and I this year on a variety of different trials.  We really appreciate your willingness to work with us and your efforts to keep us in the loop on your fields throughout the season.  I know that incorporating these trials into your management practices requires some time and extra costs at times, so I really do appreciate your efforts.  My hope is that by working together we’ll be able to generate valuable data that will help you and all Island growers make beneficial changes to production practices that improve yields, improve profitability, and improve sustainability.