Root-lesion nematode

Systematic position: The root-lesion nematode (Pratylenchus penetrans) belongs to the order Tylenchida and the family Pratylenchidae. This microscopic nematode is considered a serious global threat to agriculture due to its polyphagous nature and ability to thrive in various soil types.

Host crops: This pest affects a wide array of crops, including potatoes, tomatoes, strawberries, apples, raspberries, and many forage grasses. It is a particular nuisance in greenhouses, fruit nurseries, and fields where the same crops are grown intensively.

Biology and life cycle: The life cycle comprises the egg stage, four larval stages, and adults. As a migratory endoparasite, Pratylenchus penetrans enters the root cortex, moves through the tissue causing mechanical damage, and may leave the roots to enter the soil depending on environmental conditions or food availability.

Damage and economic impact: Nematode feeding results in the destruction of root tissues, leading to brown lesions, stunted growth, and diminished nutrient uptake. The direct damage is often compounded by interactions with soil-borne fungi (e.g., Verticillium, Fusarium), which infect the plant through the lesions created by the nematodes.

Control measures: Integrated pest management is essential to control this pest. Key strategies include:

• Implementing crop rotation with non-host or antagonistic cover crops.
• Using certified nematode-free planting stock.
• Solarization of soil in greenhouse conditions.
• Chemical control via soil fumigation or granular nematicides when thresholds are exceeded.