Climate change may trigger pest attacks on cassava

Researchers say cassava in South-East Asia may be hit by more pests in the future

Flickr/CIAT by Neil Palmer

[MANILA] The multi-billion dollar cassava industry of South–East Asia may already be suffering from multiple pest and disease outbreaks triggered by climate change, cassava researchers have told a conference in Bangkok.

Although the crop can thrive in hotter and dryer conditions in the region, an increase in pests and diseases could easily wipe out recent productivity gains, researchers said at the Climate Smart Agriculture in Asia: Research and Development Priorities Conference this month (11–12 April).

Scientists from the International Centre for Tropical Agriculture (CIAT) and the Climate Change, Agriculture and Food Security (CCAFS) programme noted that the pest situation in the region is already serious, and could get much worse as temperatures rise.

"Many of the current pest-disease problems could already be due to climate change," said CCAFS programme director Bruce Campbell. He added  that the growing pest problem coincides with the warming conditions and changing rainfall pattern in the region.

Cassava is a major staple food in many developing countries. In South–East Asia, about five million small-scale farmers depend on the crop. Although it is not a major consumer of cassava, Thailand is the world's biggest exporter of the crop, accounting for 60 per cent, followed by Vietnam with over 12 per cent, according to data from CIAT and the FAO.

In recent years, cassava farms in the region have seen outbreaks of green mite and mealy bugs which are believed to have originated from South America. They are more dangerous than endemic species as they lack natural enemies, said CIAT's agricultural geographer Glenn Graham Hyman.

Hyman called on government and industry to support pest monitoring systems.

Hanoi-based Rod Lefroy, CIAT coordinator for Asia, told SciDev.Net that while complete elimination of pests is very difficult, infestation can be reduced through removal and destruction of disease-infested plants, cultivation of varieties tolerant or resistant to certain pests or diseases, use of clean planting materials, and a reduction of transfer of planting materials from infested areas.

Lefroy said scientists should understand pests and diseases so they can assist in monitoring them, and in identifying traits of tolerance or resistance.

Governments could develop advisory services for farmers, Campbell said.

In India, for example, three million farmers get weather alerts that could be used to predict pests and disease outbreaks and advise farmers on what can be done to counter the outbreaks, said Campbell.