Ontario Grain Farmer February 2021

Acuron Flexi, Callisto + atrazine and Shieldex + atrazine controlled Canada fleabane 91 to 95 per cent. The most efficacious herbicides were Acuron, Integrity, and Lumax at 98 per cent control. Callisto + atrazine, Pardner + atrazine and Shieldex + atrazine applied post-emergence in corn, controlled glyphosate-resistant Canada fleabane 90 to 94 per cent. The most effective herbicides were Distinct, dicamba (high labelled rate), and Lontrel at 96 to 99 per cent control. Glyphosate-resistant Canada fleabane was controlled 54 per cent with BlackHawk applied preplant in soybean. Control improved to 91 per cent with the addition of metribuzin. Elevore controlled glyphosate-resistant Canada fleabane 67 per cent; the addition of metribuzin or Eragon improved control to 93 to 94 per cent. Eragon, applied preplant in soybean, controlled glyphosate-resistant Canada fleabane 85 per cent; the addition of Elevore or metribuzin improved control to 94 per cent. For glyphosate-resistant Canada fleabane control in Roundup Ready Xtend soybean, dicamba, applied PP, at the low, medium, and high rate provided 78, 87, and 91 per cent, respectively. The addition of Elevore, BlackHawk, 2,4-D, or Eragon improved control to 94 to 98 per cent. Enlist Duo, applied preplant, controlled glyphosate-resistant Canada fleabane 57 per cent in Enlist soybean. Adding metribuzin or Eragon improved control to 93 to 96 per cent. For glyphosate-resistant Canada fleabane in wheat the most effective herbicides were Infinity, Pixxaro + MCPA, and Lontrel at 93 to 96 per cent control. For multiple-herbicide-resistant waterhemp in corn, these approaches were effective: • Acuron Flexi, Lumax, Primextra, Callisto + atrazine and Converge + atrazine, applied pre-emergence, in corn provided 82 to 89 per cent control; the most effective herbicides were Integrity and Acuron at 91 and 95 per cent, respectively. • Callisto + atrazine, Converge + atrazine, Shieldex + atrazine and Acuron Flexi, applied post-emergence in corn controlled multiple- herbicide-resistant waterhemp 91 to 92 per cent; Acuron controlled waterhemp the best, at 96 per cent. • In soybean, Bifecta, Boundary, Valtera and Authority Supreme, applied pre-emergence controlled waterhemp 81 to 84 per cent; the most effective herbicides were TriActor and Fierce at 90 to 92 per cent control. Sikkema recommends a planned two-pass waterhemp control program in soybean. He suggests that farmers use one of the aforementioned herbicides applied pre-emergence, then be prepared ONTARIO GRAIN FARMER 21 FEBRUARY 2021 This article features research funded by Grain Farmers of Ontario. to apply Blazer, Reflex, or Hurricane post-emergence in IP or RR soybean, Enlist Duo postemergence in Enlist soybean, and dicamba or Tavium in Xtend soybean. Sikkema urges applicators to use extreme caution when applying dicamba based herbicides post-emergence in Xtend soybean. “I’ve visited too many fields with injury to sensitive crops in adjacent fields due to off-target-movement of dicamba,” he says. The Herbicide Strategies project was funded in part by several industry partners. l This is Brad. He was so busy scanning the sky for rain, he didn’t see trouble on the ground and put a rock through his combine. Does Brad’s farm insurance cover the damage? Hahahaha - no. Sure thing. What’s Brads right answer? Talk to a Commonwell Broker or Agent today to find out how our coverage works for you. thecommonwell.ca/find-a-broker