When combating blackgrass and other problematic weeds, it is always important to reduce the seed potential. Therefore, try to prevent the blackgrass from reaching maturity and producing seeds.
If in the coming weeks you find that chemical weed control, or harrowing and hoeing, were not entirely successful on your fields, it may be useful to mechanically prevent the weeds from forming seeds.
If only small areas or patches are affected, Andreas Hommertgen from the DLR Rheinhessen-Nahe-Hunsrück recommends timely mulching as a solution.
It should be noted that often one pass of mulching is not enough, and two or three passes may be necessary. Therefore, the mulcher should be operated as shallow as necessary and as high as possible to prevent the weeds from producing ears close to the ground.
If necessary, consider using GPS technology.
If blackgrass is more widespread, consider early use of GPS technology or forage. It is essential to act in a timely manner - ideally before the weeds bloom. In the long run, this measure is more cost-effective than having a seed input of 200 to 600 seeds per blackgrass ear into the soil reserve, provided that a utilization possibility (biogas) is available.
Harvest the most severely affected areas last.
If the seed stock in the soil is already very high, then the post-harvest management should focus on bringing as many seeds as possible to germinate before the next sowing. This means that after harvest, no soil cultivation should take place initially, and the straw should remain on the field. "Through seeds adhering to the straw, there can otherwise be further spread of partially multi-resistant seeds," according to Hommertgen.
To further reduce the risk of spread, work from "clean" to "dirty" during threshing. The areas most heavily infested should be harvested last. This way, there is an opportunity to thoroughly clean all threshing parts in the evening or the following morning where weed seeds are still present.