Banana diseases threaten African crop

Reuters 26 Aug 09;

DAR ES SALAAM (Reuters) - Two banana diseases spreading in Africa could hurt food supply for 30 million people on the continent who largely rely on the crop, an international agricultural research body said on Wednesday.

The Consultative Group on International Agricultural Research (CGIAR) said the banana bunchy top viral disease has infected 45,000 hectares of bananas in Malawi alone and a survey done last year found it in 11 other countries.

"We found the disease to be well-established in Gabon, DRC (Democratic Republic of Congo), Northern Angola and central Malawi," CGIAR quoted Lava Kumar, a researcher at the International Institute of Tropical Agriculture and the survey's leader, saying in a statement.

A serious attack of banana bunchy top causes all leaves to sprout from a plant's top, stunting its growth. The affected countries are in eastern, central and southern Africa.

CGIAR said another study earlier this year found banana bacterial wilt disease in Ethiopia, Uganda, Rwanda, western Kenya, northwest Tanzania and north and South Kivu in the Democratic Republic of Congo.

Scientists fear it could spread to Burundi.

Uganda, the continent's leading banana grower and consumer, has experienced bacterial wilt since 2001 and it causes losses of between $70 million and $200 million annually, according to CGIAR.

"All but the traditional varieties of bananas in sub-Saharan Africa lack tolerance to the two diseases, which necessitates more research into the continent's local ... varieties," it said.

"The diseases require drastic and expensive control measures such as completely excavating entire banana fields and treating them with pesticides, or burning the plants in order to complete the disease."

Scientists from the affected countries are meeting this week in Arusha, northern Tanzania, to discuss how to counter the diseases.

(Reporting by George Obulutsa; editing by Giles Elgood)

Banana diseases hit African crops
BBC News 27 Aug 09;

Food supplies in several African countries are under threat because two diseases are attacking bananas, food scientists have told the BBC.

Crops are being damaged from Angola through to Uganda - including many areas where bananas are a staple food.

Experts are urging farmers to use pesticides or change to a resistant variety of banana where possible.

Scientists have been meeting in Tanzania to decide how to tackle the diseases, which are spread by insects.

'Big danger'

The scientists, from the Consultative Group on International Agricultural Research (CGIAR), issued a statement saying "drastic and expensive control measures" were needed.

They recommended "completely excavating entire banana fields and treating them with pesticides, or burning the plants".

Experts say the two diseases - bunchy top viral disease and bacterial wilt - are both spread by insects and very few varieties of banana have resistance to them.

While bunchy top stunts the growth of plants by causing leaves to sprout from the top, bacterial wilt kills off plants and makes their fruit inedible.

Christopher Chemirehreh, of the Kawanda Agricultural Research Institute in Uganda, said people were particularly vulnerable in the areas where the diseases were found.

"It's a big danger because the affected areas have the banana as their staple crop," he told the BBC's Focus on Africa programme.

"So if they fail to control the bacterial wilt, their incomes are affected and their food is affected, so it's a very big problem."

Crop Disease: In Africa Where Bananas Are a Staple, Two Diseases Are Destroying Plants
Donald G. McNeil Jr., The New York Times 31 Aug 09;
By DONALD G. MCNEIL Jr.

Two diseases are attacking banana crops across central Africa, putting about 30 million people at risk in regions where it is a staple.

At a meeting in Tanzania last week on the crisis, agricultural experts urged farmers to use pesticides or switch to resistant varieties, according to reports from the meeting by BBC News and Reuters.

The Consultative Group on International Agricultural Research, the world’s leading network of agricultural research centers, recommended “excavating entire banana fields and treating them with pesticides, or burning the plants.”

Such measures are hard for poor farmers to afford and can devastate ecosystems. Bananas sprout from “mother plants,” and killing them ruins a crop. Huge banana trees are costly to spray, and they hold soil in place.

One disease, banana bunchy top virus, stunts and kills plants. Spread by aphids and infected suckers from older plants, it can be impossible to eradicate from a crop once it is established. It has been found in Angola, the Democratic Republic of Congo, Ethiopia, Gabon, Kenya, Malawi, Rwanda, Tanzania and Uganda.

The other, bacterial wilt, causes fruit to ripen prematurely, which can wipe out up to 90 percent of a crop. It survives in soil and plant debris and is spread by insects and contaminated hoes.

The wilt has been found in eastern Congo, Ethiopia, western Kenya, Rwanda, northern Tanzania and Uganda.

In central Uganda, many farmers have abandoned bananas and switched to cassava and corn, which are less nutritious.