Importance of Cassava mosaic disease
Cassava mosaic disease is the very severe and widespread in sub-Saharan Africa. CMB infected crops produce several foliar symptoms including mottling, misshapen, mosaic and twisted leaflets and a reduction in the size of leaves and plants. This leads to the production of no tubers or few depending on the severity of the disease and the age of plant at the time of infection.
PREVENTION AND CONTROL
Use of Resistant Varieties
It is important to use cassava varieties resistant to the mosaic disease to ensure higher yields. The mosaic resistant varieties are developed for areas with high incidence of the disease.
Refer to Facts about improved cassava varieties in Ghana for mosaic resistant varieties.
However, improved varieties lose their resistance after a number of years of planting in areas of high mosaic disease pressures. Farmers, therefore need to monitor the performances of these varieties to detect loss in resistance and replace with new cultivars.
Use of Healthy Planting Materials
Planting materials distribution can also spread the cassava mosaic disease. To prevent the disease, farmers must look out for healthy planting materials. It is a very effective way of preventing mosaic, like other cassava diseases. Farmers must select plants with no symptom of the disease and use as planting materials.
To use a material from a branching susceptible variety, use cutting from the branches rather than the main stem. Main stem cutting may sprout with the disease.
If it is non-branching, avoid cutting from the basal portion of the stems which may give rise to diseased young plants after sprouting.
Roguing of Plants
Remove disease plants showing symptoms of the disease and destroy them. This will help reduce spread of diseases on farms. Farmers must inspect their cassava farms regularly to ensure effective disease control.
Replace young plants showing disease symptoms with healthy materials to ensure adequate plant population.