· Bean · Pigeonpea · Chickpea · Wheat · Maize
An infestation with lesion nematodes initially shows no apparent manifestation because they attack the root system. As they become more numerous and colonize the roots, aerial parts of the plants show nutrient or water deficiency symptoms. Plants may become chlorotic and wilted, resulting in stunted growth or death. When pulled out of the soil, the roots exhibit small reddish-brown spots. Later on, these spots can coalesce to become large necrotic black areas that eventually girdle the root.
Lesion nematodes have a life cycle of 4-8 weeks, depending on the environmental conditions. High soil moisture and warm temperatures (above 20°C) favor their development. They penetrate plant roots completely and migrate throughout the root tissue, mainly the cortex, as they feed. The destruction of the root hairs and the internal tissues of the root hinders the transport of water and nutrients, resulting in nutrient deficiency symptoms and wilting.
Immerse infested plant material in hot water at 54°C for 30 minutes.This will kill the nematodes but won’t harm the plant. Microbial antagonists of lesion nematodes such as soil fungi can also reduce population levels
Always consider an integrated approach with preventive measures together with biological treatment if available. Nematicide metham-sodium or 1,3-dichloropropene as part of pre-planting soil fumigation can provide good lesion nematode control in some cases. Post-planting options include nematicides based on aldicarb, oxamyl, fenamiphos, and carbofuran.