Maize streak virus

The causative agent of this disease is the Maize streak virus (MSV), a member of the Mastrevirus genus within the Geminiviridae family. It is a DNA virus that is transmitted by leafhoppers of the genus Cicadulina. The virus cannot be transmitted mechanically through sap or seed, making insect management critical.

Maize is the primary host for the virus, and it causes severe economic losses, especially in African regions where the disease is endemic. Other monocotyledonous crops such as sugarcane, wheat, and various species of millet can also serve as hosts, although the severity of symptoms may vary.

The disease is marked by narrow, broken, chlorotic streaks that develop parallel to the leaf veins. In susceptible varieties, these streaks may spread over the entire leaf surface, resulting in severe stunting. Plants infected at an early growth stage may fail to produce any grain or die prematurely.

The epidemic potential of the disease depends on the density of the vector population and the environmental conditions. Drought periods followed by rainfall often trigger migration of Cicadulina leafhoppers. The persistence of the virus in the leafhopper vector allows it to spread rapidly across fields during the growing season.

To mitigate the impact, farmers should prioritize the use of MSV-resistant maize cultivars, which is the most effective defense strategy. Integrated pest management, including the application of systemic insecticides at planting, can help reduce vector populations. Additionally, destroying volunteer crops and grassy weeds in and around fields minimizes the viral reservoir before the next planting cycle.