The saying “prevention is better than cure” is no more true than when applied to agriculture. Taking precautionary measures against common pests can increase farmer income by investing a small amount of money into minimising crop losses, ensuring a high yield. Preventative measures can include correct land preparation, physical barriers, field hygiene and cultivation of tolerant varieties. Unlike resistant varieties, tolerant varieties can host the pest, but are not seriously affected by it. Different varieties have different levels of tolerance to different pests. It is therefore important for farmers to select a variety with tolerance to the pests known to occur in their area. This month’s Factsheet of the month ‘Tolerant bean varieties against stem maggots’ provides information about the use of bean varieties tolerant to stem maggots, also known as bean flies. Stem maggots are an important pest of legumes found mainly in Asia and East Africa. They feed by tunnelling into leaves, stems and roots, weakening the plant and increasing the chance of death in younger plants.
This factsheet was written last year by staff from the Zambia Agriculture Research Institute (ZARI).