Lesion nematodes

Lesion nematodes, belonging to the genus Pratylenchus, are microscopic, migratory endoparasitic roundworms within the phylum Nematoda. These pests gain their name from the characteristic lesions—or dead spots—they create on the root systems of host plants as they feed and burrow through root tissue.

They have an extremely wide host range, attacking major commercial crops such as corn, wheat, potatoes, and various fruits. Because they do not cause swellings or galls like some other nematode species, the damage they cause is often misidentified as nutrient deficiency or environmental stress, leading to substantial yield losses in agricultural sectors globally.

The biology of Pratylenchus is unique because both juveniles and adults are motile and infective throughout their lives. They move into the root cortex, destroying cells as they migrate, which weakens the plant's structural integrity. Their life cycle is relatively rapid, often completed within a few weeks, allowing populations to surge significantly under favorable agricultural conditions.

Development and spread are highly dependent on soil temperature and moisture. These nematodes thrive in well-aerated sandy soils where they can move freely between root systems. They are easily spread through contaminated soil transported by farm equipment, runoff water, or the movement of infected tubers and rootstocks across different field plots.

Control strategies for lesion nematodes require an integrated pest management (IPM) approach. This involves crop rotation with non-host or antagonistic species to starve the population, the use of certified nematode-free planting stock, and maintaining high soil organic matter to suppress pest activity. In high-pressure situations, targeted soil treatments and nematicides may be utilized to reduce population densities before planting.