August 19th 2013. Banana researchers are on course to start confined field trials of a new banana variety that is genetically engineered to resist bacterial wilt disease. The disease is responsible for over 60 per cent of yield losses, which is unfortunate because bananas feed more than eight million households in East Africa.
It costs banana farmers about half a billion dollars in damage yearly across East Africa. More than 400,000 smallholder farmers in Kenya have grappled with the disease for the last decade.
The leaves of the affected plants turn yellow and then wilt, and the fruit ripens unevenly and before its time.
Eventually the entire plant withers and rots. There is currently no cure for the disease and once it strikes, farmers are left with no option but to uproot the entire plant and bury it to contain further spread.
Trials for the improved disease free variety have been successful in Uganda, which has given the scientists impetus to focus attention on Kenya. “We have proof of concept for bacteria wilt resistance and so another set of trials will be conducted in Kenya from 2014,” said International Institute of Tropical Agriculture (IITA) Plant Biotechnologist Dr Leena Tripathi during during an Open Forum for AgriculturalBiotechnology conference (OFAB).
Scientists however say that delays in passing a law regulating the commercial growing of genetically modified crops in Kenya means that even with the success of the research, farmers would have to wait a little longer to acquire the varieties.
According to the scientists, in Uganda 12 transgenic lines of the banana showed complete resistance to the wilt over three generations.
“So, we will begin transformation of five common varieties in Kenya and Uganda before rolling it out to cover all types,” Tripathi said. She said that the disease was first reported in Ethiopia over 40 years ago.
“The disease keeps spreading and it now covers Kenya, Uganda, Tanzania, Rwanda, Burundi as well as the Democratic Republic of Congo. If it is not controlled it will spread to the rest of the banana growing regions of Africa,” she said. Another set of scientists have also stepped up their fight against the disease in East Africa by transferring unique proteins from sweet green pepper into East African highland bananas.
The proteins work by quickly killing the cells that come into contact with the disease-spreading bacteria, blocking the disease from spreading any further.
Bananas are currently the fourth most important crop in Africa with a third of the world’s 130 million tonne annual production coming from the continent. In the past decade, the total global economic loss from the wilt was between $2 billion (Sh165 billion) and $8 billion (Sh696 billion) .
Althoug no resistant cultivars have been identified, some cultivars possess characteristics that make it harder for the bacteria to infect the plants under natural conditions.
By By HARRISON AGUNDO