Wheat Pete's Word, June 17: Nitrogen needs, herbicide injury, hitting the target, and insect invasions


Some years are disease years and some are insect years. 2020 is shaping up to be an insect year, which is perhaps not surprising given the dry bias to the weather.

In this mid-June edition of Wheat Pete’s Word, host Peter Johnson answers so many of your agronomic questions, including what to do about armyworm in wheat, why we’re seeing plenty of herbicide injury, what the analysis difference is between dry and liquid dairy manure and so much more. Listen or download below, and check out the summary below the player!


  • We’re all tired of social distancing, but we have to see this through, even though it’s exhausting
  • Build that community, keep reaching out!
  • The crops look incredible. The dry hay looks great, but make sure it’s dry. We don’t need to push it, we’ve had good haying weather.
  • Forage yields have also been good — many of the cereals/grasses did very well in the cool spring. So let’s hope that is an indication of the wheat crop…
  • Fertility is the name of the game with forage, too
  • Knee-high corn on the 12th of June? Wow! Planted early May
  • Wind and spraying: c’mon guys, that fungicide must hit the head in order to actually protect the plant. Don’t spray the neighbour’s field.
  • On that note, all the dicamba should have already been sprayed. We don’t want to lose it. If you need to rescue something, or have to use it late, take ALL precautions. We cannot have off-target movement. Full stop
  •  Alert! Alert! Alert! We have insect pressure for sure. Leafhopper in alfalfa, well above threshold. Measure the number against the stage of the crop — little plants are really susceptible. Scout, scout, scout. Control when the alfalfa is under four inches. They CAN move into an edible bean crop
  •  Alert! Alert! Alert! Armyworm reports in the wheat crop from all sorts of areas. If you’re scouting at dusk or just before and see birds swooping into the canopy…you have armyworm. Threshold is four to five larvae per sq ft IF under an inch in size (larger and they’ve already done the damage). There are natural enemies that can help, and you’ll notice if they’ve been parasitized. And how far are we into the grain fill period. When was Day 0 to Day 2? If there’s only 3 weeks to go, is it worth control? Look in your best fields.
  • Also swede midge. Last two years were easy, so this year is shaping up to be a bad one for the pest
  • It’s dry! The wheat is burning up on the sand knolls. But corn and soybean crops are OK so far as their water demand is low at this time of year. Winter annuals, winter crops will suffer the most
  • Herbicide injury showing up on crops. Because of the cold nights, Dr. Peter Sikkema says. The plant had reduced ability to metabolize herbicides.
  • Edible bean crop is showing damage from pre-plant Duel or Frontier (which is an off-label use)
  • Do low night temps stop the corn crop at this time of year? Good question. Likely not like it does late in the year.
  • Nitrate rate for the Ontario corn crop: 14 ppm! 12 is average. Low release, but to the good, low loss. So there is N there
  • Don’t roll beans after the 3rd trifoliate. Do every other pass and then come back and fill in to protect the headland beans, too
  • Fusarium in wheat after corn. Yup, it happens, even in a non-fusarium year. Wheat after corn is risky and why we spray.
  • Lontrel in corn is smoking the sow thistle! If it stays dry we can have rotation concerns for soybeans the next year. Watch the weather and keep track.
  • Control of volunteer corn in IP beans? Best option is Assure, always has been. We do have Group 1 resistant crab grass because of it. Select (or equivalent) is the only one that will control it
  • Sow manure on pasture — won’t hurt it. But if the pasture is for sheep, watch copper levels (Editor’s note: Thanks, Pete! – LS)
  • Difference between liquid and dry dairy manure? Approximate N-P-K is 16-11-24 for liquid and 5-7-13 PLUS lots of organic matter of dry dairy manure



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