Biology and Epidemiology

- Survival and sources of inoculum

The Pratylenchus spp. may overwinter in the soil on roots (figure 1). They have a wide host range, ensuring their survival and multiplication at any time of the year. P. penetrans and P. crenatus attack namely potatoes, sorghum, sunflower, corn and fruit species ...


- Penetration into the plant and invasion

The nematodes enter the roots by drilling holes with their stylets (figure 2). They gradually invade the cortex, destroy cells and dig holes during their feeding activities. In these nematodes all stages are mobile, that is why they are called "migratory endoparasitic” nematodes.


- Dissemination

Many eggs or larvae from the diseased plants can be transported passively by water runoff, drainage and irrigation. The larvae move actively over short distances in wet soils. Disseminations may occur through contaminated dust, which is carried by strong wind to neighboring fields. Also this nematode can be spread by contaminated plants, tools, and vehicles.


- Favourable conditions for the nematode development

Their thermal requirements vary depending on the species of Pratylenchus. With regard to P. crenatus and P. penetrans, the more the temperatures rise in the soil, the more they are active, in a range between 18 and 30 ° C. As for P. crenatus, it prefers rather heavy, loamy soils, while P. Penetrans is more active in sandy soils.