The borer is a very damaging pest. It attacks maize before and at the start of flowering and reduces the size of cobs. Stems collapse and the plant produces little grain.
The borers are caterpillars. They are usually pink and between 5 or 10 millimetres long.
The caterpillars dig brown or black tunnels inside the maize stem. The caterpillars make large holes where they leave the stems.
The borers eat and grow for about 3 or 5 weeks. Caterpillars also tunnel into maize cobs and damage the grains.
The caterpillars survive in dead stalks and stubble. From there they get into the next year’s crop.
There are several ways to control the borer.
- Remove and burn stalks that remain after harvest.
- Plant different crops in the same field at different times. Mix maize with groundnut or cowpea.
- Do not grow maize year after year in the same plot. After harvesting maize, plant groundnut or some other crop for at least one year.
- Plant resistant varieties such as DMR-ESR yellow and Suwan. These are available at the IAR Njala and other stations.
- Flood plot and leave water standing for two days before planting, to drown the maize borers.