New Africa maize disease threatens food security

A new maize disease, never reported anywhere in Africa, has emerged in Uganda threatening the food security of millions of people and the future of an important cash crop for farmers in Africa.

The rough dwarf maize disease, spotted early this year in the areas of Masindi district and Namulonge in the western and central parts of Uganda respectively, is causing panic among farmers of the major staple food crop in Africa.

Maize is at the core of Kenya, Uganda and Tanzania’s agriculture, which is the backbone of these countries economies contributing 20-30 percent of the GDP and providing 70 percent of rural employment.

Maize is also a major food crop with over 80 percent of rural and urban populations depending on it as their major source of calories in Kenya, Tanzania and lesser in Uganda, and researchers have no immediate solution to the devastating disease.

“The only line of defense we have so far is to sensitize farmers on how to control spread of the disease. We shall advise them to keep uprooting and burning the infected crop,” said Dr. Godfrey Osea, head plant breeder of the Cereals research programme, National Crops Resources Research Institute (NaCRRI).

Researchers dumbfounded and farmers scared

The devastating nature of the dwarf maize disease causes total loss of the crop it attacks – the crop has no yields at all – and has left researchers dumbfounded and farmers scared.

“We do not know what causes it but I know it is a major threat to maize production and the experts say they do not know much about it,” said John Kityo, a maize farmer in Namulonge.

Unfortunately, the disease has not yet been fully diagnosed and characterized to understand its causative pathogen, strain and rate or scope of infection around Uganda or the east African region.

“Being a new disease, we have not started developing resistant varieties but we are yet to understand how the vector thrives, characterize it in the laboratories and all this comes in stages,” Dr. Osea told New Science.

Initial indications show that the infected maize crop appears with wrinkled leaves, no cobs at all and generally has stunted growth. It is thought that the vector, a leaf hopper, transmits the infection through eggs.

The highly dangerous dwarf disease is also known, from observation by specialized maize plant breeders, to have an incidence rate of 20-30 percent infection of a whole maize garden.

Uganda the basket of erupting crop diseases in Africa

It is little wonder that the disease has erupted in Uganda, as experts believe it has not been reported anywhere in Africa yet, but historically the country seems to be the basket of erupting crop diseases.

“Compared to our neighboring countries, disease erupt here and survive because of the high humidity, temperatures and wet conditions which are conducive,” said Dr. Osea.

But experts believe they would develop a maize resistant variety with time as they have done with the maize steak virus, graleaf spot, leaf bright and ear rots. The maize streak virus was diagnosed in 1991-92 by one of Uganda’s leading maize researchers and current Director General of NARO, Dr. Denis Kyetere.

So far 11 varieties of maize have been developed by the NaCRRI team in Namulonge in partnership with the Kenya Agricultural Research Institute (KARI) and international partners like CIMMYT.

The current average yield in Uganda is 1.74 metric tons per hectare per annum, having risen by over 24 percent from 1.2 metric tons per hectare due to improved varieties that are faster and higher-yielding, early-maturing, more drought-tolerant farmer-preferred improved varieties (the Longe varieties). 

The timing of the disease could not come at a worse time than now when prices of maize have nose dived throughout Uganda, after a bumper harvest enabled by the heavy rains in the first quarter of the year.

Prices of maize on the market are stuck at Ushs 120 ($ 0.05 cents) per kilogram for the second season running, from Ushs 1000 ($ 0.50 cents) so farmers are stuck with the bumper harvest some waiting for the prices to raise for those who have storage facilities.

But for farmer Kityo he has to sell at the current prices which is really demotivating in spite of the new maize dwarf disease.