Stemborers remain a persistent threat to cereal crops like maize, sorghum, and millet across many regions of Africa. If left unchecked, these pests—particularly the African maize stemborer (Busseola fusca) and the spotted stemborer (Chilo partellus)—can lead to major yield losses. In search of sustainable solutions, farmers who are using Push Pull Technology have turned to the practice of planting Napier grass around their maize fields. In the blog, explore how Napier grass (also known as elephant grass) fights the stemborers and keeps it at bay and how to incorporate Push-Pull Technology (PPT).
Understanding the Stemborer Menace and Benefits of Napier Grass
Stemborers are moth larvae that bore into the stems of cereal crops, hindering the flow of nutrients and causing plants to weaken or die. Symptoms of infestation typically include withered central leaves (“dead heart”) and lower grain production. In severe cases, stemborers can decimate entire fields, threatening both household food security and commercial production.
Napier grass is more attractive to stemborer moths than maize. This characteristic makes it a highly effective “trap crop.” When planted around a maize field, it lures stemborer moths to lay their eggs on its leaves instead of on the maize. Once the larvae hatch, the Napier grass releases a sticky substance that traps or kills them, preventing major infestations within the maize. With one or two rows of Napier grass forming a living fence around the field, stemborer moths are drawn to the tall grass at the perimeter rather than the maize in the centre.
By diverting pests away from maize, Napier grass significantly helps cut stemborer populations. When combined with the PPT, farmers see even more benefits. The “push” aspect involves planting a stemborer-repellent crop like Desmodium among the maize rows. Desmodium emits chemicals that deter stemborer moths, pushing them away from maize. Meanwhile, the “pull” aspect features Napier grass at the borders, attracting (pulling) those moths away, ensuring that most larvae fail to thrive once they land on the grass.
The benefits of Napier grass extend far beyond pest control. It doubles as a nutritious forage for cattle, goats, and sheep, helping farmers meet their livestock feed needs while protecting their maize from stemborers. Because the strategy reduces or eliminates the need for chemical pesticides, it is cost-effective and better for soil health. Ultimately, the combination of increased maize yield and extra livestock fodder can bolster food security and income for households
Practical Tips for Success
Farmers adopting Napier grass as part of their PPT should also practice good field hygiene. After harvest, it is vital to remove and destroy crop residues, since stemborer larvae often hide in stalks left in the field. Keeping the area weed-free minimizes competition for nutrients and helps spot early signs of pest activity. Also, harvesting Napier grass regularly for livestock feed removes any eggs or larvae before they can mature. Proper disposal of infested stalks prevents surviving larvae from returning to the soil and attacking the next crop.
Farmers are also obliged to monitor fields regularly for pest levels since this is important for adjusting strategies as needed. This might include introducing beneficial insects, such as parasitic wasps (e.g., Cotesia flavipes), to further reduce stemborer populations. Planting various crops and conserving other beneficial insects also fosters a balanced ecosystem where stemborers struggle to gain a foothold.
As documented in the Daily Monitor’s article and through numerous field studies, using Napier grass as a trap crop exemplifies a win-win solution that benefits both the farmer and the environment. If you’re looking to reduce stemborer damage and maximize yields, consider giving this sustainable, low-cost technology a try in your next planting season!
