Wheat Pete's Word, June 7: Increased resistance, smoke and smog, drift concerns, and an alert on cereal leaf beetle


Pop quiz: do dry conditions automatically mean a dialling back of nitrogen rates on corn?

This is a tricky question to answer as very dry conditions for prolonged periods can impact yield potential, but dry conditions also mean nitrogen is less available to the plant, so it’s a tough call. For the answer to why that is, as well as discussions on cereal leaf beetle, smog and smoke and sulphur rates, killing ragweed and more, tune in to this early-June edition of Wheat Pete’s Word.

Have a question you’d like Wheat Pete to address or some field results to send in? Agree/disagree with something he’s said? Leave him a message at 1-888-746-3311, send him a tweet (@wheatpete), or email him at [email protected]


  • Be safe, please. Don’t try to save a second, save a life. Think twice, act once
  • It is dry in Ontario
  • Do not give up on the wheat crop!
  • Management does change in dry conditions
  • The other thing is the smoke — really hazy in a huge area
  • It is cooler
  • One of the questions that I got asked on Twitter was does the smoke have sulphur in it?
  • The wheat crop, winter canola crop, and winter barley crop, they should be flat out filling, but reduced sunlight will slow it down
  • In severe drought, shade is better, but without that, less sun is bad
  • Frost damaged wheat is out there
  • What’s interesting is the winter canola crop was in flower during those cold temps, but it’s looking good for podset
  • Talking about short, wow, we just didn’t get stem elongation
  • 4 to 6 inches of shortening, regardless of plant growth regulators on wheat
  • If you are in typical cereal leaf beetle area, this is an Alert, Alert, Alert, get out there and scout
  • The threshold is one per stem, you have to include the adults as well as the larvae
  • We can’t use lambda-cy products (Matador, for example) on wheat this year
  • So there are some potential options if you also have armyworm out there with that cereal leaf beetle
  • The ragweed that is now Group 14 resistant, some of those populations are also resistant to Group 9, which is glyphosate
  • It is getting tough to control ragweed in soybeans without traits, i.e. Enlist or Xtend
  • Plenty of corn pre-emerge herbicides are working very, very well. But for fields where it was put on/worked after May 19th, there just wasn’t enough rain to activate
  • A fair bit of lamb’s-quarters is breaking through in IP soybeans and edible beans, they are the two tough weeds to control
  • Target these weeds when small and also spray in the heat of the day. Don’t forget water volume and the right surfactant
  • More on post-emerge in IP beans, here
  • Pete is hearing of some drift concerns
  • Yes, even in Ontario we need to think about herbicide carryover
  • Does a dry year mean cutting back on nitrogen? Keep your rates the same! Because of reduced root growth and reduced N movement
  • Side-dress: if you can, get the N as close to the row as possible. Try it, but don’t cut roots
  • Get it to moisture, three to four inches down. Surface apps need rain
  • No nitrogen on corn, yet? Eep! You need 50 ppm right now in a nitrate test. Get the N to the crop, please
  • The corn planted tough, came up fine, and  it looked okay. But now it’s starting to grow its secondary roots; those roots are hitting the sidewall. And it’s just like brick because it’s dry and they are stalling and they’re falling behind. Rootless corn syndrome could be an issue without a timely rain


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