Cassava mosaic

Potexvirus marmormanihotis is a viral pathogen that affects crops of cassava (Manihot esculenta). This disease belongs to the potexvirus group and is capable of significantly reducing the productivity of plantations in tropical regions. The virus affects all parts of the plant, including leaves, stems, and storage roots, posing a serious threat to food security in cultivation areas.

The primary host for this virus is cassava. The pathogen penetrates plant tissues, disrupting normal photosynthesis and carbohydrate metabolism. As a result of the infection, plants become more susceptible to other abiotic and biotic stressors, leading to a degradation in the quality of planting material during repeated vegetative propagation cycles.

Typical symptoms of infection include the development of a characteristic mosaic pattern on leaf blades, chlorotic spots, as well as deformation and curling of young leaves. In advanced cases, significant stunting of the entire plant, shortened internodes, and a reduction in the total assimilation surface area of the plant are commonly observed.

The spread of the virus within agricultural systems occurs mainly through infected planting material (cuttings), as well as mechanically through contaminated agricultural tools during routine maintenance. Vector transmission via insects also plays a role in the circulation of the virus, facilitating rapid outbreaks in local fields when environmental conditions favor pest multiplication.

• Utilization of virus-free planting material only.
• Thorough disinfection of farm tools after working with each plant.
• Prompt removal and destruction of symptomatic plants from the field.
• Monitoring and control of insect vector populations using insecticides.
• Adherence to crop rotation practices and spatial isolation for new plantings.

The economic impact of Potexvirus marmormanihotis is linked to substantial losses in tuberous root yields. Because the translocation of nutrients to the root system is impaired, cassava plants fail to reach standard sizes, and starch accumulation is significantly slowed. Severe infection can result in yield losses of up to 30–50%, making effective disease management a top priority for tropical crop agronomists.