Simple steps help Colombian farmers on the road to recovery

12 August 2013

David Guest in Colombia
David Guest in Colombia

Colombia's progress towards social and economic recovery has been assisted by Sydney scientist David Guest, whose intervention is helping to control a devastating outbreak of disease in one of the county's most important crops.

The oil palm tree has been hailed by the Colombian government for its role in promoting peaceful and sustainable development across Colombia. As the South American country comes out of a long period of social turmoil, the production of oil palms offers farmers a safe and legal alternative to coca as a source of employment and income.

Oil produced from the red berries of oil palm trees is used in cosmetics, cooking and manufacturing. But the industry was threatened when a mysterious epidemic of bud rot wiped out plantations across the country, costing farmers almost $370 million annually in lost income.

Then Colombian scientists discovered in 2010 that the epidemic was caused by a fungal-like pathogen called Phytophthora - derived from the name of hammer-wielding god Thor - which literally means "plant destroyer". The disease was being spread by minute fungal spores, invisible to the naked eye.

To combat the problem - known locally as PudriciĆ³n de Cogollo - the research institute of the Colombian Palm Oil Growers Association (CENIPALMA) teamed up with Professor David Guest, an agricultural scientist at the University of Sydney. A world expert in Phytophthora diseases in tropical countries, Professor Guest has designed a research program that trains oil palm farmers to manage bud rot.

"The greatest benefits come from implementing simple solutions," says Professor Guest. "Farmers everywhere seem to know the importance of, but tend to forget about, maintaining sanitation on plantations. The Phytophthora spores originate from infected palms, so we train farmers to improve sanitation by, for example, removing diseased trees promptly to prevent the pathogen from spreading."

Colombia's bud rot epidemic is particularly severe compared to other countries, and Professor Guest's research suggests that there is also a social dimension to the problem. "During the worst days of kidnappings in Colombia, many oil palm farmers abandoned their plantations out of fear for their lives," he says. "As a result, diseased trees were left to rot and helped to propagate the disease.

"As a scientist, I investigate how plants defend themselves against disease, but it has been interesting to discover the human aspect to this problem. In Colombia, the farmers I work with say that they now prefer growing oil palms to rearing cattle, because the relatively inconspicuous value of the trees compared to cows offers them a greater degree of safety from kidnappers."

By planting on former cattle farms, Colombia's oil palm growers have also avoided the need to clear rainforests to plant oil palms, a serious problem encountered in other countries.

Through his work with CENIPALMA, Professor Guest hopes to strengthen the relationship between Australia and Colombia. He also hopes to attract more Colombian students to Sydney to complete their PhDs. He says: "I particularly enjoy working with PhD students because it gives me the opportunity to work with very enthusiastic people and guide them through an apprenticeship that often results in lifelong relationships and more research collaborations."

Contact: Richard North

Phone: 02 9351 3191

Email: 205c293f253931742740353b21041f4c500f29305e1c1104762030