Stem borer is one of the most damaging pests of maize in India. It attacks the crop from the early seedling stage to maturity. Farmers often notice holes on leaves, dead hearts in young plants, and damaged stems when the infestation is severe. If the pest is not controlled in time, it can significantly reduce maize yield. Understanding how stem borers behave and taking the right steps at the right time can help farmers protect their crop effectively.
The first signs of stem borer attack usually appear as small, window-like holes on the young leaves. These holes are formed when the larvae feed inside the stem, and the damage becomes visible only when the leaves unfold. In young plants, the pest can cause “dead heart,” where the central shoot dries and breaks off easily. In older plants, stem tunnelling reduces nutrient flow, weakens the plant, and results in poorly filled cobs.
The first step in managing stem borer is timely sowing. Early sowing, especially at the beginning of the season, reduces the chances of pest attack because stem borer population is usually low at that time. Late-sown maize often suffers more damage. Therefore, farmers should try to complete sowing at the recommended time for their region.
Crop rotation is another helpful practice. Growing maize on the same land continuously increases stem borer infestation. Rotating maize with pulses, oilseeds, or vegetables breaks the pest cycle and reduces the next season’s infestation.
Maintaining a clean field is equally important. Removing and destroying crop residues after harvest prevents the stem borer larvae from surviving in the leftover stems. Deep ploughing in summer exposes and kills larvae hiding in the soil. These simple steps significantly lower pest pressure in the next crop.
Using resistant or tolerant maize varieties can also help reduce damage. Many improved hybrid maize varieties show better tolerance to stem borer. Consulting local agriculture departments or seed companies helps farmers choose suitable varieties for their region.
Biological control is an eco-friendly option. Releasing Trichogramma egg parasitoids at the recommended dose can help control stem borer naturally. These tiny beneficial insects attack stem borer eggs and prevent the larvae from hatching. Farmers can purchase Trichogramma cards and place them in their fields at regular intervals during the early stages of crop growth.
Chemical control becomes necessary when the infestation is high, especially during the early growth stages. Spraying recommended insecticides at the correct time can protect the crop. The best time to spray is when the first window-like holes appear on the leaves. Farmers should ensure that the spray reaches the whorl region where the larvae hide. Granular insecticides can also be applied in the whorl for better control. It is important to avoid unnecessary spraying and always follow the prescribed dose to prevent resistance development.
Healthy crops are less affected by pests. Providing balanced nutrition, especially nitrogen and potash, strengthens maize plants and helps them tolerate pest stress better. Adequate irrigation during critical stages also supports strong plant growth.
In simple words, managing stem borer in maize requires a combination of practices—timely sowing, crop rotation, field sanitation, biological control, and timely insecticide application. With these practical steps, farmers can effectively control stem borers and ensure a healthy and high-yielding maize crop.
