Breakthrough science and innovation

S. Kilungu (CCAFS)

Breakthrough in improving climate-risk simulations for rice in arid environments

West Africa

Rice does not produce grain under very hot or very cold conditions; it becomes sterile. Even now, very hot and very cold temperatures limit where rice grows; this problem will be exacerbated as the climate changes. The areas where rice will be productive may alter. CCAFS scientists at AfricaRice are working on models that will show where Africa’s present rice-growing area can expand and where farmers can continue to grow rice in areas that become hotter or colder.

The ORYZA2000 rice crop growth simulation model helps predict where rice will grow as temperatures change

The ORYZA2000 rice crop growth simulation model helps predict where rice will grow as temperatures change. F. Fiondella (IRI)

The scientists found that existing models overestimated heat stress and underestimated cold stress. Scientists have made vast improvements to the models using new data on the temperatures at which leaves, flowers and grain form, transpiration rates at different temperatures and temperatures that make plants sterile. To better assess heat stress, they took account of early morning flowering and the cooling effect of transpiration. To assess cold stress, scientists used daily minimum temperatures, rather than daily average temperatures, in the model.

Assessing the impact of climate change on rice production in arid regions such as West Africa is critical for advising smallholders on cropping calendars—when to sow, plant out, fertilize and irrigate. Innovative models that assess the impacts of variable weather and a changing climate are critical tools that provide a basis for framing practical advice for farmers to manage their crops.

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