Agronomy Update – June 1

Hi everyone,

It’s the start of a new month as well as Phase 3 of the province’s Renew PEI plan.  Due to the warm and dry conditions, the majority of growers are finishing up potato planting as well as planting other cash crops.  I think we all agree that we could use some rain now…fortunately, it looks like there is some rain in the forecast this week.  Hopefully it manifests itself in order to help get crops emerged and healthily established!

Just a few things to think about as potato planting gets finished up and attention moves to other things:

Planting Soil-Building Crops:

I’ve had a few questions in recent days on whether it’s too early to start planting crops like sorghum sudangrass or pearl millet, given the warmer weather we’ve had recently.  While the ground has warmed up considerably, it is going to be a little cooler the first part of this week.  It may still be prudent to wait another week or so to plant these warm season grasses.  The same goes for a crop like buckwheat or multi-species mixtures that include these grasses.  You are better to delay planting a little bit and plant in warm, moist soil rather than plant into cooler soil, as these grasses don’t seem to “catch up” the same way that traditional grasses or legumes do.

Here is an except from SARE on establishment of sorghum sudangrass:

“Plant sorghum-sudangrass when soils are warm and moist, usually at least two weeks after the prime corn-planting date for your area. It will tolerate low-fertility, moderate acidity and high alkalinity, but prefers good fertility and near-neutral pH. Standard biomass production usually requires 75 to 100 lb. N per acre.

With sufficient surface moisture, broadcast 40 to 50 lb./acre, or drill 35 to 40 lb./acre as deep as 2 inches to reach moist soil. These rates provide a quicker canopy to smother weeds than lower rates used for forage production, but they require mowing or grazing to prevent lodging. Herbicide treatment or a pass with a mechanical weeder may be necessary if germination is spotty or perennial weeds are a problem.”

Full management profile on sorghum sudangrass from SARE available at  Management for forage pearl millet is very similar to sorghum sudangrass.

Full management profile on buckwheat from SARE at:

A couple of things to remember with these crops:

  • These crops can be effective at helping to control weeds, but to do so, you should be starting with a field that is as weed-free as possible, either by herbicide or mechanical control.
  • All soil building crops will require adequate fertilizer to make the amount of biomass (both above and below ground) that you desire to help build organic matter, fight disease, and improve your soil. You are using these crops to invest in your soil and your future potato yields, so don’t skimp too much on the fertilizer.  If you are not removing much biomass from the field, you’ll be returning the majority of these nutrients to the soil to be used for future crops.
  • Likewise, make sure you use the right seeding rate. Too low of a seeding rate and you might get into weed issues and low biomass.  Too high of a seeding rate is expensive and might create other issues.  Calibrate your planters/drills and use the recommended rate.
  • Like all crops, plant into soil with adequate moisture for quick germination and emergence. This goes for all grasses, legumes, and brassicas.  The forecast rain this week should help with that.

In my travels so far this spring, I’ve seen a lot of good looking forage crops that overwintered much better this year.  In fact, there is a bunch of Italian ryegrass that survived the winter in a number of fields, and alfalfa stands look generally quite good.

Some Notes on Mustard:

This year, AIM is starting a new study on the use of biofumigant mustard with a higher rate of beneficial glucosinalates to assess what yield/economic impact a true biofumigation program will have under field conditions in PEI.  We are also working with ECODA to assess the yield/economic return of Centennial brown mustard as either a green manure or harvested cash crop alongside a check crop (ie. barley).  We won’t have yield data on these trials until next year, but we are working hard to generate this data for you to consider.

In the meantime, if you are growing mustard for wireworm control or to help with Potato Early Dying (PED), make sure you have your planting dates timed with when you plan to incorporate that mustard with available soil moisture.  Mustard only takes about 50-55 days to reach early flowering, which is when it should be incorporated (if you’re planning to do green manuring/biofumigation).  Make sure your mustard crop is adequately fertilized, paying specific attention to Nitrogen and Sulfur.

Looking Ahead at Disease Management/Scouting:

The warm, dry conditions during planting this spring, as well as the forecast for the next couple of weeks, looks to be favourable when it comes to reduced incidence of bacterial soft-rot, fusarium, or Rhizoctonia affecting potato seed pieces after planting.  However, do keep any eye on your fields as plants start to emerge and watch for any significant issues with delayed emergence or lack of emergence.  If you think you have an issue with emergence or seed piece decay, be sure to send samples to the Provincial Pathology Lab for testing.

Lorraine MacKinnon and the PEI Department of Agriculture & Land are putting together a Scouting Clinic to be held online on Tuesday, June 23rd.  Please feel free to contact Lorraine for more information.  We’ll be sharing login details a little closer to the date, but please mark on your calendar.  This will be particularly useful for any new field staff that you have this year, as well as a good refresher for everyone.

Cull Pile Deadline – June 15th

Just a reminder that the deadline to get cull piles covered is coming up on June 15th.  It is very important to have cull piles covered to prevent the spread of seed-borne diseases such as late blight, early blight, and PVY.  This is particularly important this year, as the improved spring weather should accelerate seed germination and there is a greater volume of unused seed/cull potatoes around the countryside.  Do your part to minimize the spread of disease!

Morgan and I have been busy getting required sampling for a number of projects done over the last few weeks.  A big thank you to all of the growers who have provided fields for trials…you are essential to our collective success!

If you have any questions about anything agronomy related, please feel free to reach out.  My cell number is listed below.  I am able to come out to farms to visit if you want to discuss something in-person, as long as we maintain proper physical distancing.

All the best with the rest of planting season!