Farmers return to nuts as cure boosts crop’s immunity

At a time when Kenyan farmers are grappling with old and emerging macadamia diseases which have seen more farmers dump the once lucrative plant, a scientist is breathing new hope with a cure that once administered not only heals but boosts the crop’s immunity.

Farmers who had initially planted coffee in the 90’s got disappointed due to its erratic market places and opted to go for macadamia farming due to its high demand which saw prices hit unprecedented highs. But emerging diseases have made farmers a worrying lot. Joseph Ndirangu Muriithi one such farmer from Gatanga in Central Kenya  is a worried man. He has already lost three of his 45 trees and he is worried that more might dry off in the near future.

But Muriithi has little to fear because research scientist Jesca Mbaka has the interests of macadamia farmers at heart. “With support from other scientists and organisations, we hope to bring the disease into total control as soon as possible. Farmers must never lose hope on this big cash crop,” said Mbaka, who is based at the Kenya Agricultural Research Institute (KARI).

A study conducted in Kenya and published in the Journal of Applied Sciences in August 2009, where Mbaka was the lead researcher, found two major fungal diseases to be the cause of anguish among macadamia farmers in Kenya.

“There is a growing prevalence of two main diseases namely root rot, and stem canker – both caused by the fungus Phytophthora cinnamomi,” said Mbaka. Though the pathogen is not new in Kenya, it is the first time it has been seen to have an extensive effect on macadamia. It is a disease that causes root decay mostly in eucalyptus trees and avocado trees. It also dries the bark of a tree, hence killing it after a few months. According to KARI, Mbaka is the first scientist to conduct extensive research on this particular fungus and how it affects macadamia in Kenya.

The study recommended a range of fungicides that could be used against the diseases, but pointed out that there was a need to carry out sensitivity tests with different active ingredient concentrations of the chosen fungicides. Based on her research, the African Women in Agricultural Research and Development program offered Mbaka a two-year fellowship in 2009, to develop skills on how to implement her findings. The fellowship program is hosted under the Gender and Diversity program at the Consultative Group on International Agricultural Research.

Mbaka’s goal is to find out what types of pathogens exist in order to identify the best antifungal chemicals that would be appropriate. She has completed the study at the University of Stellenbosch in South Africa, where she discovered that there is only one type of the pathogen affecting macadamia and other trees in Kenya. “This means that we can easily tackle it based on the existing knowledge,” she said.

South Africa, a country also affected by the fungal disease is considered the third-largest producer of macadamia in the world. However, other African countries including Kenya are beginning to consider commercial farming of the crop as an option.

Mbaka is now looking at ways on how her studies on the fungal diseases can be implemented for the benefit of smallholder farmers in Africa. She said for her study to be implemented accurately, there is need for collaboration between KARI, the Kenyan Ministry of Agriculture, selected Agro-chemical input suppliers and selected macadamia farmers, among others, to develop and disseminate the technology to all farmers in the country.

It is estimated that over 10,000 Kenyan farmers have ventured into farming macadamia as a cash crop mainly for the export market. It has certainly provided a steady income for Muriithi over the years. “When I planted my trees of the crop 26 years ago, I did not know that it was a potential cash crop that would see my children through their education,” he said.

By selling the nuts mainly to companies that export them, the farmer has paid for his three children to complete secondary school. He is currently paying the school fees for three more children in his extended family.

Though he said that the prices of macadamia nuts are still low due to limited competition between exporting and processing companies, Muriithi makes on average 1,300 dollars every time he has a harvest.
Like many other farmers, Muriithi is optimistic that in the near future, macadamia is likely to emerge as a perfect cash crop as coffee was. “All we need is for the scientists to offer a remedy for the prevailing diseases, and some of us can promise never to die poor,” he said.