"Still a future for the banana"

The banana has suffered badly from fungal diseases that need more and more pesticides. Last century the Gros Michel banana disappeared due to the Panama disease. Now the replacement variety Cavendish is threatened. Yet Gert Kema, linked to Wageningen University & Research, sees a future for the banana. He was recently appointed a distinguished professor at a ceremony. During his speech he spoke about the future of the banana.

The export banana Cavendish does well in all kinds of soils and wasn't sensitive to the Panama disease for years. The Cavendish was therefore planted en masse on the old Gros Michel plantations. The 'agronomic miracle' Cavendish became dominant on the international market and has partially pushed out local varieties in India and East Africa, for instance," says professor Kema. "Retailers also keep the kilo price to a minimum, as bananas provide top turnover in supermarkets. They are money machines, comparable to cotton T-shirts. Like for other 'orphan crops' investments in the financially flourishing banana branch have been lacking. No money has been spent on basic scientific research. And this is now a problem."

Cavendish banana plant, affected by Panama disease, caused by Tropical Race 4 (TR4). The plant will soon die, as will the bananas. The fungus has contaminated the soil for years to come.

Revival of Panama disease
The cause of the Panama disease is a Fusarium fungus, which now has an extremely damaging variant, known as TR4 (Tropical Race 4), with disastrous consequences. And there are no seed banks with planting material for new varieties to replace the Cavendish. "We're back to the start," concludes the professor. Cavendish has one big disadvantage. There is no genetic variation. The bananas from the big brands or fair trade are genetically identical. They are clones grown in extreme mono cultures. As a result all copies are just as sensitive to fungal diseases," he says.

"At the same time you see the large producers staring themselves blind trying to keep the Cavendish and the practices around it," he criticises. "The Panama disease has been known in the Cavendish since 1960 in Taiwan, but it wasn't until we showed the TR4 fungal variant in Jordan, then later in Lebanon, Pakistan, Laos and Mozambique, that the sector woke up and called for action. Only 15% of the harvest is intended for the export, whilst the other production is sold on the local market. Millions of farmers are dependent on a good harvest. And it is threatened by the introduction of the TR4 fungal strain through new Cavendish plantations in 'clean' areas by conservative market parties."

Saving the banana
To control the fungal variant TR4 both genetic knowledge of the banana varieties and the fungus is needed. In Gert Kema's research group thousands of strains of Fusarium have now been mapped out and a genealogy has been created for the fungus. This way they can see from where the fungus originally spread and bring parallels with human migration into the picture.

The group also concentrates on breeding programmes from wild banana varieties. "Genetic variation is an absolute precondition to prevent most problems with bananas and it also gives the consumer more choice." Developing new varieties will take at least ten years. Besides this the Wageningen professor wants to work together with partners from businesses so that solutions can be applied in practice in the banana economy. The research group is also seeking contact with small banana farmers to research their questions, dilemmas, variety choices and access to the market. This should help them to end up being able to choose from various resistant banana varieties.

More information:
Wageningen University & Research
prof.dr. Gert Kema
Laboratorium voor Fytopathologie
tel. 0031 (0) 317 480 632
gert.kema@wur.nl