The Global Diversity of Taro: ethnobotany and conservation

Six months ago, an outbreak of Taro Leaf Blight in Cameroon, West Africa, decimated fields cultivated with taro, causing a 90% loss of the taro harvest. The disease spread rapidly to other countries in West Africa, creating a devastating cascade effect: reduction in food, reduction in household incomes, increased poverty and disease.

A new publication from Bioversity, ‘The global diversity of Taro’ highlights ways to address new epidemics of diseases like taro leaf blight and to cope with other threats.

Taro (Colocasia esculenta) is an important staple crop for several hundred million small-scale farmers and is widely grown throughout Asia and the Pacific, the Americas and Africa. It is a good source of vitamins, especially folic acid, and can grow in varied and often harsh conditions so it can be a valuable security net in times of food shortage. It is widely used for its medicinal properties – in Ghana, uncooked taro root (botanically a corm) is applied to cuts to stop the bleeding of wounds, while mashed fresh leaves are used to treat toothache.

Yet in spite of its many attributes, taro continues to receive relatively little attention from the international agricultural research community.

Outside Southeast Asia, only a narrow selection of taro diversity has been cultivated. This lack of diversity is what makes it increasingly vulnerable to a range of pests and diseases such as taro beetles (Papuana spp.), taro viruses such as the Alomae-Bobone virus complex (ABVC), and, most importantly, taro leaf blight (TLB), caused by the fungus Phytophthora colocasiae. It is Taro Leaf Blight that has had the greatest impact on taro production.

‘The global diversity of Taro’ explores the genetic diversity of different varieties of taro and their uses. Further, the book details breakthroughs in taro breeding and evaluation for resistance with specific information about TLB-resistant varieties that have been released in Papua New Guinea and evaluated in Samoa. Accurate methods to detect TLB and other diseases are now in place, which means that resistant varieties could now safely be moved to other countries without the risk of spreading other diseases.

Information in the book, which includes the status of taro genetic resources in all the major geographic regions where it is grown and collects farmers' hard-won knowledge about the crop, enables the authors to highlight ways to address new challenges to taro. Diseases such as Taro Leaf Blight, and the problems of climate change, can be tackled by combining genetic diversity science and farmer knowledge.

Download: The Global Diversity of Taro  [2]

For more information: contact:  Teresa Borelli  [3]