There are currently various possible sowing procedures that can be used at different time points and with different mixtures. The aim of the individual mixtures is not to weaken the competitiveness of the maize at the respective sowing times. Thus, early undersown crop mixtures can already be applied shortly before or after the seed using a conventional drill or grass drill. The later mixtures can be applied with the aid of a pneumatic spreader or even with the slurry tanker. To do this, the grass seeds are introduced using a hose attached to the intake sack at the same time as the slurry is fed into the tanker.
Ideally, the aim should be to split herbicide treatments for crop protection. By doing so, it is possible to perform a treatment with a soil active ingredient relatively early at the 2-3 leaf stage, and then a second treatment at the 5-6 leaf stage. Here, specific herbicides that work via the foliage can then be selected according to the type of weed. A number of the current substances are generally compatible with undersown crops and can be applied in a targeted manner to eliminate problem weeds such as sorghum. However, care should be taken that the undersown crop is sown at least two weeks after the first herbicide treatment so that the soil-applied herbicide does not cause severe damage to the young seedlings. You can request precise herbicide recommendations from the Chamber of Agriculture and your local DSV advisor.
Strategies for using crop protection:
A deciding factor for the success of the undersown crop is the adapted maize plant protection. Meanwhile there are a number of strategies available which make weed control possible. There are numerous herbicides (see table) that are compatible with undersown crops. However, a period of two weeks should be allowed after each spraying before sowing the grasses. A crop protection strategy is even possible against problem weeds like sorghum. At very high weed pressure, the undersown crop is however only possible with compromises in the herbicide effect. Your consultant can provide you with the current recommendations.