The researchers studied how different planting techniques affect weed growth in crops. They compared growing maize alone to growing maize with peanuts or cowpeas. They found that planting maize with cowpeas reduced weed growth the most. The more diverse the weed species in a field, the more equal their numbers were. Intercropping with cowpeas also reduced the weight of weeds in the field. Overall, planting maize with cowpeas can help control weeds better than other methods.