Cleavers that emerge in the fall can survive a cold winter if they’re under a nice blanket of snow. With all the snow this winter, any fields that had cleavers and other winter annuals emerge last fall may have significant early growth this spring. Early control is essential — otherwise winter annuals will quickly grow to a size where herbicide control is much less effective.
Some elevators in Eastern Saskatchewan have reported higher than usual cleaver counts in canola samples. These elevators say they may have to start downgrading more canola unless cleaver counts start to come down. With all the cleavers, some elevators are losing their ability to blend canola to nullify the downgrading effect of weed seeds. No.1 canola must have less than 1.0% of other seeds that are conspicuous and that are not readily separable from canola. This includes cleavers. The cut off is 1.5% for No.2 and 2.0% for No.3. The Canadian Grain Commission says that most of the canola samples downgraded because of “conspicuous admixture” did contain cleavers, but overall, the number of canola sample downgraded for this reason has not been unusually high this year. Click here to see the grading guide.
Increase the preseed glyphosate rate for cleavers. With cost-effective glyphosates on the market, increasing the rate of glyphosate in the preseed window is a good option and will result in increased control of both annual and winter annual cleavers.
Published on February 7, 2011