Cassava mosaic Zanzibar virus

The causal agent of this disease is Begomovirus manihotiszanzibarense, a viral pathogen that significantly impacts cassava cultivation in East Africa. As a member of the geminivirus family, it disrupts the physiological processes of the host plant, leading to substantial yield losses.

The primary host for this virus is cassava (Manihot esculenta). Given the importance of cassava as a staple crop in tropical regions, the prevalence of this virus poses a serious threat to food security, particularly in subsistence farming systems.

Symptoms of the infection include chlorotic mosaic patterns on the leaves, curling, and leaf size reduction. Infected plants typically show stunted growth, shortened internodes, and a bushy appearance. The accumulation of the virus affects the tuberization process, leading to thin and poorly developed roots.

The virus is primarily transmitted by the whitefly Bemisia tabaci, which acquires the virus while feeding on infected plant sap and transmits it to healthy plants. Additionally, the virus spreads through the use of infected cuttings during vegetative propagation, which is the most common method of establishing new cassava fields.

Management strategies focus on the integration of several preventive measures. These include the implementation of rigorous phytosanitary practices, such as rogueing infected plants and ensuring the use of virus-free stem cuttings. Breeding programs are also crucial for developing resistant varieties that can withstand the pressure of this begomovirus in areas where it is endemic.