Weeds are unwanted plants that affect the growth of cassava and reduce the crop yield. Weeds compete with cassava for nutrients, water, space, light and soil moisture. They give protection and food for crop pests, which makes the number of pests increase.
Weeds need light to be able to grow. They will grow on bare soil and where there is a lot of light. If there are already other plants growing and shading the ground, then weeds will not grow as well. They can develop from seeds or other parts of the plant that remain in the soil. Therefore it is important to prepare the ground properly before planting.
The best way to control weeds in cassava farms is to combine different practices especially at land clearing, ridge preparation, planting and post planting stages of growing the cassava.
- Prepare the land properly by slashing the bush before planting. This will reduce the frequency and labour of weeding the crop. Pull any weed from the land and near the land before planting.
- Grow cassava varieties that suppress weeds. Early branching varieties form a thick canopy that shades the ground before too many weeds can grow.
- Mulch cassava seed beds with dead plants. Use leaves from alley crops, leguminous plants and rice husks to cover the soil surface. This will block out light to the soil and make it difficult for weeds to grow.
- Crop rotation reduces weeds.
- Between the cassava plants grow other crops like grain legumes and vegetables to reduce the amount of bare soil.