Tea root-lesion nematode

The tea root-lesion nematode (Pratylenchus loosi) belongs to the order Tylenchida and the family Pratylenchidae. This microscopic plant-parasitic nematode is a major threat to agricultural productivity, specifically targeting the roots of perennial plants, which leads to significant yield losses in global tea-producing regions.

This nematode primarily infests tea plants (Camellia sinensis), causing extensive damage to their root systems. In addition to tea, the pest has been reported to affect various other hosts, including citrus trees and several ornamental plant species that share similar soil habitats or environmental conditions.

The biological cycle of this nematode is predominantly endoparasitic. The larvae and adults penetrate the cortical tissues of the roots, where they feed, migrate, and reproduce. High soil moisture content and moderate temperatures are ideal for their life cycle, allowing them to rapidly colonize and proliferate within the root tissues throughout the growing season.

The damage caused by Pratylenchus loosi is characterized by root lesions and necrosis, which impair the plant's ability to absorb essential water and nutrients. The above-ground symptoms include stunted growth, chlorosis, significant reduction in leaf production, and in severe cases, the eventual death of the affected bushes due to root system destruction.

Effective management and protection strategies include:

• Strict nursery management and the use of certified, nematode-free planting materials.
• Cultivation of nematode-resistant or tolerant tea varieties.
• Implementation of soil management practices, including the use of green manures and organic amendments that suppress nematode populations.
• Periodic monitoring of soil and root samples to detect infestation levels early.
• Judicious use of chemical nematicides following local agricultural regulations to manage high-density populations.