Paratrichodorus hispanus

Systematic position: Paratrichodorus hispanus belongs to the phylum Nematoda, class Enoplea, order Triplonchida, and the family Trichodoridae. These nematodes are known as ectoparasites that spend their entire life cycle in the soil, affecting the root systems of a wide range of host plants.

Host range: The nematode is considered a polyphagous pest, capable of damaging a broad variety of crops. Key targets include potatoes, sugar beets, tomatoes, and various legumes. Furthermore, they are frequently found in association with cereal crops, allowing them to persist in agricultural fields even when rotation crops are changed.

Biology and life cycle: The life cycle involves an egg stage, four juvenile stages, and an adult stage. They thrive in light-textured, sandy soils with adequate moisture content. Being ectoparasites, they move through the pore spaces in the soil. Their population dynamics are highly dependent on soil temperature and moisture levels, typically peaking during the spring and early summer growing seasons.

Nature of damage: Feeding by Paratrichodorus hispanus causes the classic 'stubby root' symptom. The nematode uses its onchiostyle to puncture and feed on the root cells, primarily at the root tips. This feeding disrupts the cell division process, resulting in stunted, thickened, and stunted root systems.

• Stunted top growth
• Reduced uptake of water and nutrients
• Increased susceptibility to secondary pathogens

Control measures: Management of this pest requires an integrated approach. Cultural practices include long-term crop rotation, control of weed hosts that act as reservoirs, and the use of resistant varieties where available. Soil fumigation or the application of registered nematicides at planting time is often necessary for fields with high infestation levels to protect the seedling root development.