24 Aug Agronomy Update – Aug 24

Hi everyone,

Thanks for those that have come out to our AIM tours the yesterday up west and today in East Prince.  We had a great turnout at each of the first two tours, and we look forward to seeing lots of folks out in the Souris area tomorrow.  As a reminder, here our is schedule tomorrow:

Kings County Tour:  Google Map

• Stop 1:  paved laneway where New Harmony Road and Route 16 meet.  Mustard Trial (Living Labs)
• Stop 2:  field next to 200 Steeles Lane. Cover Crop before Potatoes (Living Labs)
• Stop 3:  MacAulay Farms, 590 Route 16, Chepstow for BBQ.

Each of the tours will start at 10:30 am at the first location.  We will have signs by the road to help you find us.  We should arrive at the final stop around 12:00 where a BBQ lunch will be served, as well as viewing some samples from a couple of other local trials.  In addition, reps from the PEI Federation of Agriculture will be on hand to discuss the On Farm Climate Action Fund, where farms can apply for funding to assist with cover cropping, improved nitrogen use, and rotational grazing.

Crop Update:

Over the past week, I’ve been into quite a few fields in Prince and Queens County getting ready for these tours, as well as checking fields for our Potato Early Dying project.  A few observations to share:

• Early-maturing varieties (Shepody, Prospect, etc) are starting to settle down and yellow up. A few seed fields will be killed by the end of this week, as they are pretty close to hitting their optimum size profile.
• For the mid to late season Russet varieties that I’ve pulled 10 foot strips on, they are generally ranging between 16 and 20 lbs per 10 foot strip, which is approx. 210-260 cwt/acre. Given that all of these fields are still quite green and have at least another month of growing to do…I think we are on track for some strong yields again this year in a lot of fields.
• Generally, I would comment that in the fields I’ve dug in, the average number of tubers per plant is above average.
• In general, fields look healthy. There is starting to be some Verticillium wilt setting in on “challenged fields” (ie. short rotation, high inoculum fields) but many fields show very few signs of early dying.
• I’m starting to see a fair bit of grey mould (Bortrytis) in the canopy in some fields. As you’ll see below, spore numbers for Bortrytis are quite high.  Keep an eye on your fields and consider grey mould as you plan your late season fungicide program.
• There are some reports of white mold around…I’ve come across it in one field. Again, keep and eye out and respond accordingly.

Here are some rainfall totals from the past 7 days: from weather.peiclimate.ca (UPEI weather stations)

West Prince got some rain late last week that most of the rest of the province didn’t get.  It is currently raining in Kensington as I write this, but it doesn’t look like it will amount to much.  The forecast is currently calling for ~10 mm between Friday night and Saturday, but who knows if that will come.  There are starting to be come fields in the eastern half of the province that could use a good drink in the near future.

Spore Trapping Update:

Spornado (10 sites):  No Late Blight Spores Detected

Airspore Spore Results:  No Late Blight Spores Detected in PEI.  Two weeks ago, late blight spores were detected in QC, NB and ME.

Spore Results from Aug 19/20:

Early blight (Alternaria solani) spore counts have levelled off quite a bit, and brown spot (Alternaria alternata) have generally stayed low all season.  Grey mould (Bortrytis) spores have started to spike quite high in several fields, including a field mid-week last week hitting 10,000 spores.  Numbers are lower in Kings County, where rainfall levels have generally been lower.

Looking Ahead at Cover Cropping:

 There are an increasing number of growers starting to terminate forage crops and working ground about now, with the intention of then planting a cover crop this fall ahead of potatoes next spring.  A few reminders why a fall cover ahead of potatoes is a great option:

1. Protects the soil from wind and water erosion.
2. Keeps something actively growing for 2-3 more months in your field, building soil organic matter and feeding the soil microbial community.
3. Scavenges nitrogen that might otherwise be lost to groundwater or the atmosphere, making it available for next year’s crop.
4. Two years of potato studies in PEI have shown a trend toward higher yields (+20-25 cwt/ac) following a cover crop compared with no cover crop.

In addition, you can get $75/acre from the PEIFA’s OFCAF program to establish cover crops this fall.  Visit www.peifa.ca/ofcaf for registration forms and more details.

A couple discussion points, based on questions I’ve been getting lately:

• If you’re using barley or oats: Yes, you can broadcast the cover as opposed to drilling it in.  However, I would recommend rolling it or giving the field a very light scuffle to ensure good seed to soil contact, especially if the soil is dry.
• For barley and oats, 75-80 lbs/acre is likely sufficient if you are going to drill or broadcast/roll the cover. If you aren’t doing anything to cover the seed, you may want to increase the rate by 25%.  If spreading the cover after mid-Sept, you may also want to up the rate a little bit as well.  In our trials, we have not seen any difference in percent green cover at much over 100 lbs/ac.  You’re just trying to cover the ground, not plant a crop to harvest.  This isn’t the same advice if you are using a winter cereal (winter wheat, fall rye).
• There is no need to fertilize fall cover crops.
• For oilseed radish/mustard, 8-10 lbs/acre is usually sufficient. Now is the best time to plant these brassica species.  After Sept 10^th, the level of growth won’t be the same.
• If looking at cover crops to follow potato harvest, the species and rate is highly dependent on harvest dates and method of establishment. For potatoes dug before October 1^st, barley and oats work fine. For later-dug potatoes, fall rye is usually the best option.  If you are spinning on the seed ahead of the harvester, you may need to up the rates a little bit to account for the amount of seed that will be buried by the digger.
• Winter wheat after potatoes harvested before October 10^th is a really great way of getting your ground covered and also having a crop to harvest next year.

If you have any other questions, feel free to give me a call.  I hope to see lots of you in Souris area tomorrow morning.

Ryan