There are many more varieties of coffee bean than is widely understood and they could be used to produce strains with drought and pest resistance, according to a study.
Research published in Science Advances said there were 124 different varieties and wild coffee species could be “a resource for the sustainability of the coffee sector”.
The report, High extinction risk for wild coffee species and implications for coffee sector sustainability, said Arabica and robusta were the most widely used strains, with robusta making up around 40% of global trade.
There are an estimated 100m coffee farmers worldwide, said the report. Arabica has been farmed for “at least several hundred years and may have been wild harvested for millennia” while farming of robusta was “first recorded in Africa in the early to mid 1800s but probably predates records by hundreds of years”.
The research said a third strain, liberica, was first recorded in the early 1870s “but despite great hopes its cup qualities failed to meet the taste requirements of the consumer, and thus the aspirations of growers and coffee merchants, particularly in Sri Lanka”. Liberica is still cultivated but is “insignificant in terms of global trade”.
The report said wild species occurred naturally in tropical Africa, Asia, Australasia and the Indian Ocean islands of Madagascar, Comoros and Mascarene.
“These species have useful traits for coffee development, such as climatic tolerance and especially drought tolerance, pest and disease resistance, low or zero caffeine content and sensory (taste) amelioration,” said the report.
The report said at least 60% of coffee species are threatened with extinction, compared with a global figure of 22% for all plants.
The researchers called for efforts to preserve wild coffee species, including protected areas and storage of seeds.
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