Deadly cassava disease hits Uganda

CASSAVA brown streak, a new strain of disease that affects the edible part of the crop, has hit several parts of the country.

According to the agriculture ministry, the disease has affected 50% of the country.

“It is spreading fast and we are faced with a more serious situation than we witnessed with the cassava mosaic disease,” Ephram Tumubweine, the commissioner of crop protection, said.

Tumubweine said almost all varieties, bred or selected for resistance to cassava mosaic disease, are susceptible to the brown streak. Only three varieties, 29, 51 and Akena, were resistant.

The disease has been registered in the central region, with Mukono being the worst hit district. It has also affected the north and north-eastern part of the country.

Tumubweine said the disease is spread through distribution, sub-planting and by white flies. He cited the example of the stalks distributed by the World Food Programme in the north and north-east.
The only solution is to destroy the crop, officials said.

The cassava brown steak is a viral infection that affects the tuberous roots, leading to loss of yields.

Unlike the cassava mosaic disease, which affects the whole plant, with brown streak, the plants look healthy, but the tubes are affected.

The symptoms include root constriction and a dry hard rot when the root is cut. It also cracks and discolours the tubers, while the harvested roots have corky, yellow-brown spots.

The disease also causes yellow and green patches on the leaves, a phenomenon commonly called chlorosis.

Dr. Fred Mukulu, the Mukono production officer, said the disease was first reported eight months ago and has spread to four sub-counties, including Kasawo, Ntunda and Nabbale.

Farmers are being sensitised about the disease and how to curb its spread.

Mukulu said they were trying to introduce another variety of the plant in collaboration with National Agricultural Research organisation (NARO).
NARO is in charge of developing disease-resistant and high yielding crops.

In the early 90s, Uganda incurred a loss of $60m per year due to cassava mosaic disease.