Peanut seed nematode

The peanut seed nematode (Aphelenchoides arachidis) is a microscopic plant-parasitic nematode belonging to the Aphelenchoididae family. Unlike many soil-borne nematodes, this species is specifically adapted to inhabit and feed within the pods and seeds of the peanut plant (Arachis hypogaea). It is recognized as a significant threat to peanut production due to its seed-borne nature and potential for long-distance dissemination.

The primary symptom of infestation is the development of necrotic lesions on the pod shells and the internal shriveling of the peanut kernels. Heavily infected seeds often exhibit reduced size, discolored seed coats, and significantly compromised germination rates. Because the parasite thrives inside the fruit, the damage is frequently internal, making early visual diagnosis challenging for farmers during the growing season.

The biology of Aphelenchoides arachidis revolves around the development of the host plant. The nematodes invade the developing pods, feeding on the parenchyma and developing seed tissues. They are capable of entering an anhydrobiotic state, which allows them to survive for extended periods within dried seeds. This adaptation ensures the parasite's survival between cropping seasons and facilitates its spread through global seed trade.

The spread of the pathogen is primarily driven by the movement of contaminated peanut seeds. Once planted, the nematodes emerge from the dormant state, move into the soil moisture, and re-infest the developing pods of the new crop. While survival in the soil is possible in residual plant tissues, the infected seed is the most critical factor in the dispersal of this nematode to previously uninfested agricultural areas.

• Strict quarantine and inspection of imported peanut seeds.
• Use of certified, nematode-free seed stocks for planting.
• Implementation of crop rotation cycles to disrupt the parasite's life cycle.
• Deep plowing of post-harvest crop residues to promote decomposition.
• Chemical treatment of seeds with appropriate nematicides if contamination is suspected.