Cassava is a crop that likes a challenge. It can tolerate drought, heat or infertile soils as agriculture intensifies and populations grow. It is a carbohydrate source for 500 million people globally and a staple in Africa, Asia and South America, accounting for 53, 33 and 14 percent of global production respectively.
Yet during the week-long World Congress on Root and Tuber Crops in Nanning, China this week, Dr. Claude Fauquet, Director of the Global Cassava Partnership for 21st Century leading the Congress, said more investment is needed if relatively resilient crops like cassava are to stay ahead of climate challenges.
A shift from responding to crisis to anticipating it is needed, he said. “Nigeria is the perfect place for cassava today. But that doesn’t mean it will be the perfect place for cassava tomorrow. We need more resources for research, to help people living in these areas prepare for what’s going to happen.”
Dr. Graham Thiele, Director of the CGIAR Research Program on Roots, Tubers and Bananas, added that research can provide valuable insight into the dynamics of climatic change and foresight which can be translated into climate models, to guide breeding programs as well as investment into new technology.
“We know temperatures will increase,” he said. “However, we need to think outside of the box about what this means, for example how will changes affect processing technology? If it rains more, what does that mean for sun drying technology?” These are the kinds of tricky questions smallholder farmers in the poorest places, relying on root and tuber crops for food security, need answered.
When disaster strikes
Farmer Huyen Thi Phuc, a smallholder in Southern Vietnam, has grown the root crop cassava with cashew nut for 15 years. It brings in more than half her income. She grows it because it doesn’t require heavy labor or fertilizer investments, and it’s one of the few crops that grow in the poor soil on her farm.
But strong winds, worse in recent years, have blown down the tall-growing cassava varieties which she usually plants. So, she tried planting new cassava varieties, developed at the local Hung Loc Research Center, in Dong Nai Province.
“I recently grew two new varieties and my yield doubled,” she said. “Also, the stems do not fall down when it’s windy,” she said. Huyen Thi Phuc is one of millions of farmers who today can find better, higher-yielding, disease or climate-resilient cassava varieties as a result of decades of agricultural research.
Since the 1990s, dedicated agricultural researchers in the region and globally have collaborated to develop highly successful cassava varieties. Take for example cassava variety KU 50, released in 1992. Tapping the diversity of germplasm in Latin America – CIAT’s genebank where the world’s largest cassava collection is kept – researchers evaluated, made many crosses and exchanged germplasm with local breeding programs across the region.
Climate change: opportunity or threat?
They improved varieties with potential to meet demands in Asia: higher fresh root yields and starch content; improved disease resistance and environmental adaptability. By 2002, Asian breeders had released more than 50 improved varieties including KU 50 – the world’s most cultivated cassava variety.
Widespread adoption of these varieties was also a result of new soil and crop management practices explored together with farmers, which led to rapid yield increases in Asia in the last 15 years. Thailand and Vietnam are now today’s leading cassava exporters.
With rapid population growth and urban expansion, cassava is now used in a range of niche markets, for example in low fat and gluten-free products – a huge opportunity for smallholder cassava farmers, who are the majority suppliers. But new threats, such as emerging pests and diseases in Asia exacerbated by more intense weather patterns, need to be tackled if full benefits of improved varieties are to be realized.