Herbicide carryover risk will not be as great as the past few years due to good spring rainfall.
However, the risk is greater for in-season crop applications due to a sharp reduction in rainfall from July and on.
The Saskatchewan Ministry of Agriculture has released the herbicide carryover maps for pre-seed, early in crop and late season crop applications.
The Risk Maps are based on rainfall in 2024. Because soils remained warm until late September, end dates on all maps for 2025 risk are taken until Sept. 30.
Cory Jacob is the Provincial Oilseed specialist with the Saskatchewan Ministry of Agriculture.
There is a low risk across the province for the pre-seed application with some medium to higher risk zone for the early in-crop herbicide applications.
“We do see some isolated areas again and I’m going to say South Central to southwest Saskatchewan; Leader, Swift Current, Maple Creek, Assiniboia, Coronach areas,” he said. “We’re seeing moderate to high risk towards Lloydminster as well as we have a bit of a little pocket where they reported not having a lot of moisture up to June 1 in that area.”
The risk areas are more extensive for later season crop applications, according to Jacob.
“Up towards Lloydminster and Meadow Lake where we have moderate to high risk. Areas around Prince Albert, Nipawin, Melfort, and Hudson Bay,” Jacob said. “RM’s 313 and 333 and Kelvington and Wynyard and isolated areas as well where there could be some potential carryover based on our crop reporter data.”
Jacob said, again, South Central to Southwest Saskatchewan, there’s areas in there that are moderate to high to very high for carryover.
The maps are based on rainfall data gathered in the weekly Saskatchewan Agriculture crop reports. Jacob suggested using local rainfall data for more accurate results.
“I would go to local rainfall records and local data if you want to be 100 per cent sure. If you had less than 50 millimetres in an area, collect rainfall data to really be accurate at a very local level,” he said.
Not only do producers need to be aware of persistent herbicide they applied in 2024, but also those they may have applied in 2023 or earlier, particularly for those products that have multi-year plant-back restrictions. Much of the west side of the province was in very high to severe and even extreme deficiencies for herbicide breakdown going into 2024.