Farm Ireland

Thursday 27 October 2016

Banana disease is a symptom of greater ills

Joe Barry

Published 24/02/2016 | 02:30

A new disease is spreading through the world's largest banana plantations.
A new disease is spreading through the world's largest banana plantations.

Bananas are one of the most popular snack foods available. They are tasty, full of healthy vitamins and minerals and arrive conveniently self-packed in their own bio degradable wrapping.

  • Go To

Their benefits are numerous and we are told they are good for our blood pressure, heart health and eyesight; they speed up brain function and are reputed to help prevent diabetes and cancer.

Athletes such as cyclists love them as they are easy to carry and deliver an energy boost during competition. It is even claimed that it was the banana, not the apple that was the "forbidden fruit" that Eve offered Adam which perhaps proves the seductive powers of Eve or the banana or both!

Whatever your thoughts are about the Garden of Eden, the banana seems an excellent addition to any diet but like so many other plants, it is now under threat from yet another fungal disease.

Hardly a day seems to pass without reading about some new plague or other. We have had scares about the future of many of our common tree species with the most recent, Chalara fraxinea, threatening our native ash.

The movement of plants worldwide has meant that it scarcely matters where a fungal mutation that can kill a particular plant species appears. The globalisation of trade has ensured that disease will spread rapidly, despite the best efforts of port authorities and others.

We only have to look back at the infamous Irish potato famine of the 1840s to see the catastrophes that can occur when we rely on one single species as a food.

There are of course plenty of alternatives to the banana but few are as popular and as affordable. Until the 1960s the most widely grown variety was the 'Gros Michel' which was wiped out by what was known as the PanamaDisease. The banana industry was then in deep crisis and a new alternative had to be found. They began growing a cultivar called 'Cavendish' which was considered to produce a slightly inferior fruit but was immune to the disease.

The problem with Cavendish is that it is at greater risk from any new disease than the majority of other banana varieties because it is a sterile, seedless mutant.

New plants are created from cuttings of existing ones, making them little more than clones of one another. Without the natural diversity resulting from natural sexual reproduction, these bananas continue, generation after generation, with the identical genetic makeup.

Being unable to mutate and adapt makes them vulnerable to species-wide disaster. What affects one of them can prove the undoing of every plant within that particular variety.

The new disease is similar to the one that wiped out the Gros Michel and is called Tropical Race 4. It started out in Malaysia around 1990, and is caused by the relatively common Fusarium fungus. Like sudden ash death, there is no known cure and with the majority of the world's banana plantations currently using Cavendish, it would appear that they will now have to start all over again.

This is not meant to be some kind of scare article, but there is no doubt that food security worldwide is threatened by many modern agricultural practices.

Organic matter

We continually tamper with the complex natural relationship between plants and the soil and have managed to grow huge crops of carefully bred strains of wheat for example, in soil that contained little organic matter.

At least we are now required to return organic matter back to the soil , but it took many years to arrive at this decision.

We need to adopt further "close to nature" alternatives and not just grow crops for short term profits. Fungal diseases that affect our food crops keep mutating and the chemists are in a constant battle to counter these changes.

We are over reliant on monocultures and too much of what we do on our more intensive farms is simply not sustainable. I find it really annoying that whenever anyone questions modern farming practice, they are immediately targeted as loonies.

Why do cattle, sheep and horses prefer the old grasses and herbs growing on the untouched margins of reseeded pastures to the lush but less palatable new strains of ryegrass? Perhaps they know more than we do.

Indo Farming