When’s the best time of day to spray herbicides? Morning, noon, or night? University of Guelph weed scientist Dr. Peter Sikkema says that every herbicide has a time-of-day effect but generally speaking, growers get the best weed control at 3:00 pm in the afternoon. That’s Sikkema’s conclusion based on time-of-day efficacy trials he conducted using… Read More

It’s time for Day 3 of the virtual Ontario Diagnostic Days! This week, we’re joined by Dr. Peter Sikkema with the University of Guelph, and Mike Cowbrough, weed specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs. This episode focuses on weed management, specifically on glyphosate resistant Canada fleabane and waterhemp, and the… Read More

As of 2019, glyphosate resistant waterhemp has been confirmed in 13 counties in Ontario. Christian Willemse, a master of science student at the University of Guelph, under the supervision of Dr. Peter Sikkema, will continue a survey on glyphosate resistant waterhemp this fall as part of his master’s project. Farmers and agronomists are encouraged to… Read More

Crop researchers and agronomists are encouraging Ontario farmers to continue to follow established stewardship recommendations when using dicamba herbicides. Last week, a U.S. court decision to cancel the registration of in-crop use of dicamba herbicides left regulators, product manufacturers, herbicide applicators and farmers scrambling to understand the ramifications of the ruling and the implications for… Read More

What effect will extreme cold temperatures have on early-season weed control? That’s a question University of Guelph, Ridgetown College weed scientist Dr. Peter Sikkema has been hearing a lot lately. With farm fields across Ontario being punished by extreme cold temperatures that have dropped to nighttime lows of minus 5 degrees C, many growers are… Read More

Herbicide resistance is nothing new to Ontario farmers. It all started in 1973 when triazine-resistant lamb’s-quarters were found on a farm near Ripley, Ontario. Group 2 herbicide-resistant weeds were first documented in 1996. Fast forward to 2018, and we find that the province is now home to a host of glyphosate-resistant weeds including Canada fleabane, giant… Read More

It’s not necessarily the happiest of discoveries, but it’s a first-of-its-kind discovery, nonetheless. Work out of the University of Guelph has confirmed Group 14 resistance in waterhemp at multiple locations in Ontario. What’s more, Dr. Peter Sikkema’s research team, including graduate student Lauren Benoit, has also confirmed waterhemp with cross-resistance to Groups 2, 5, and… Read More