African peanut nematode

The African peanut nematode (Ditylenchus africanus) belongs to the order Tylenchida and the family Anguinidae. It is a highly significant quarantine pest primarily affecting groundnuts (peanuts). As an endoparasite, it causes substantial economic losses by invading the subterranean parts of the plants and compromising the entire yield.

While the primary host is Arachis hypogaea (peanut), research indicates that the nematode can also infest various other crops, including potatoes and certain leguminous plants. Its ability to survive on alternative hosts and weed species makes it a persistent threat in agricultural lands where diverse crop rotations are not strictly managed.

The biological cycle of this nematode is heavily dependent on soil moisture and root exudates. The pest completes its life cycle by feeding on plant tissues, where it destroys cells and disrupts nutrient transport. The dispersal of Ditylenchus africanus often occurs through infested soil, infected seeds, and agricultural machinery moving between fields.

Symptoms of infestation are typically observed on the pods, which show characteristic dark lesions, browning, and structural degradation. Affected seeds often appear shriveled or discolored. The damage is severe because the nematode not only feeds directly on the crop but also facilitates the entry of secondary pathogens that cause decay during storage and in the field.

Management strategies focus on preventing the spread of the nematode. Essential practices include the use of nematode-free, certified seeds and strictly controlled irrigation to prevent movement through water runoff. Crop rotation with non-host plants and deep tillage are recommended to reduce the population density of the nematode in the soil profile.