Pratylenchus sefaenis

Systematic position and pathogen type. Pratylenchus sefaenis belongs to the phylum Nematoda, class Chromadorea, order Rhabditida, and family Pratylenchidae. It is a microscopic, migratory endoparasite of plants. Unlike sedentary nematodes, this species actively migrates within the root cortex, feeding on parenchyma cells, which leads to tissue necrosis and the breakdown of the root system's integrity.

Diseases and affected crops. This pathogen causes a disease complex generally referred to as lesion nematode disease or pratylenchosis. It infects a wide range of host plants, including major cereal crops, legumes, and industrial crops. By damaging the vascular tissues, the nematode impairs the plant's ability to take up water and nutrients, resulting in stunted growth, chlorosis, and significantly reduced yield quality.

Biology and life cycle. The life cycle of Pratylenchus sefaenis consists of the egg stage, four larval stages, and the adult stage. All mobile stages are capable of infecting plant roots. The nematode can complete its life cycle within the host tissue or in the soil. Optimal development occurs in warm, moist soils, with reproduction rates peaking under favorable conditions of temperature (20–28°C) and sufficient soil organic matter.

Development and dispersal conditions. The primary modes of dispersal are infested propagation material, soil movement via farm machinery, and runoff from irrigation. While the nematode can survive in various soil textures, it thrives in light, sandy soils where its mobility is maximized, allowing it to easily colonize adjacent root systems across a field.

Economic impact and control. The economic damage is significant due to the reduction in root efficiency, making crops more susceptible to environmental stress and secondary infections. Control strategies focus on an integrated approach:

• Usage of certified pathogen-free planting material.
• Implementation of crop rotation using non-host or antagonistic crops.
• Application of targeted nematicides in high-pressure scenarios.
• Deep tillage and fallow management to reduce nematode populations in the topsoil.