Burnoff cleavers with the one-litre rate

May 4, 2011 - Issue 6

Cleavers seeds are showing up in canola deliveries more often. Cleavers need to be hit hard and early for control

Fields with increasing populations of cleavers and other perennial and winter annual weeds will need a higher rate of pre-seed burnoff. The popular half-litre rate (180 grams of active per acre) is not likely enough. One litre (360 grams) per acre will control these weeds more effectively. And if cleavers and other winter annuals are larger, a 1.5-litre (540 gram) rate may be required.

The key is to determine weed staging. Dig up a few. Those with large established roots are probably winter annuals and will need a higher rate. If cleavers and other weeds are small and look like they germinated in the spring, a lower recommended rate may be enough.

Pre-seed burnoff is the most effective way to control these weeds. Under relatively normal moisture conditions, the earlier that burnoff is conducted the better for crop yield. Click here for more on the benefits of early weed removal. Click here for more tips to maximize glyphosate performance.

Remember that at this time of year, frost damage will impede herbicide uptake. After a hard frost, wait until daytime temperatures warm up and assess the amount of damage done to weed tissues. It may be necessary to wait for weeds to grow new leaves if they are heavily damaged. If weeds are not heavily damaged leave 48 hours after growing conditions improve to allow weeds to start actively growing again before spraying. Check product labels for post-frost instructions. Click your province for your guide to crop protection: Alberta Saskatchewan Manitoba

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