Glyphosate: minimum tillage
- Pre-emergence/ early post-emergence chemical application. Identify suitable herbicides.
- Postemergence with activity on broad-leaf weeds e.g. 2,4-D amine
This is a cumbersome activity, time-consuming, and expensive than where agrochemicals are used to control weeds. With chemical, one needs to only weeds once. Where manual weeding is practiced, one needs to weed twice i.e. 1 month after germination (depending on weed pressure) and at knee-high in preparation to top-dress.
Competition is critical between V3 and V8 stages of maize crop. Weed competition in maize depends on these factors:
- The crop growth stage
- The amounts of weeds present
- The degree of water and nutrient stress
- Weed species
High weed competition is as a result of:
- Poor manual weed control.
- Weeding too late Ineffective herbicide application.
- Planting delayed after land preparation
- If the land has been used for continuous maize cropping for many years, the load of weed seeds may be very high.