Rolling breaking herbicide seal

[Laggard]

If you’ve applied a herbicide for example to stop blackgrass emergence, how much does rolling “break the seal”? I suppose timing comes into it , if you do it just before the crop covers over then is it so bad?

 

[Brisel]

What crop? How long ago was the herbicide applied? If it was September then there won't be much left. Anything that disturbs the surface risks breaking the layer and stimulating another flush of any weed. Don't roll when the cereal is in stem extension as you will damage the ear as it comes up from the base of the stem.

 

[Laggard]

Wheat December drilled behind sugar beet (rough), also some spring barley that got rained on post drilling so couldn’t roll which has had a preemergence for blackgrass.

 

[Brisel]

Oh. Yes, you’ll write off about half of the remaining residual depending on how rough it was. It’s a trade off between weed/WBF control and the benefit to the crop itself.