Climate change will hit crops very hard
THE IMPACT of climate change on key food crops in Africa and South Asia may be much worse than previously estimated — with reductions of up to 40 per cent by the 2080s — according to a study, which synthesised results from related studies published over the last 20 years. It also identified “major gaps in climate change impact knowledge” for certain crops and regions, such as central Africa. Such lack of knowledge could hamper effective adaptation policy decisions, it warns. The study projects an eight per cent average decrease for all crop yields — and this figure increases to 40 per cent in worst-case scenarios. In Africa, the most significant yield reductions are predicted for maize, millet, sorghum and wheat, while in South Asia, maize and sorghum will be hardest hit. The study looked at more than 1,140 publications that have projected the impact of climate change on eight key food and commodity crops (rice, wheat, maize, sorghum, millet, cassava, yam, and sugarcane) that together account for more than 80 per cent of total crop production in the two regions, and then analysed 52 of those studies in depth. The strength of evidence on how severe the impact will be differed for different crops and regions. In Africa, just six out of 162 observations from the scientific publications analysed were about rice, yam and sugarcane, despite these accounting for almost a third of Africa’s cropped area. The study says that that the development of new crop varieties and uptake of new technologies — the most costly adaptation options — are likely to bring the most benefits. But since these will require substantial investment from farmers, governments and development agencies, “it is vital that any policy decisions to support their implementation, particularly aid investments, are informed by a synthesis of best available evidence” and not distorted by single studies. “We need to ensure as much evidence as possible is gathered on the impact of climate change before making decisions on how to move forward,” said Jerry Knox, lead author of the study and a researcher at Cranfield University, United Kingdom. The findings have led some Indian researchers to question whether India’s National Mission on Sustainable Agriculture (NMSA) will be sufficient to cope with the predicted impacts of climate change. “The whole agenda [of NMSA] is dictated by production enhancement for national food security which is likely to push agriculture practices against the environment and create more complex problems,” said Rajeshwari Raina, a scientist at the National Institute of Science Technology and Developmental Studies. She added that greater priority should be given to help small farmers adjust to such conditions and to neglected areas like coastal agriculture. But Pramod Aggarwal, regional programme leader for the CGIAR research programme on Climate Change, Agriculture and Food Security, said that most climate impact projections do not account for the steps scientists and governments are taking to combat the effects of climate change, such as breeding new crop breeds. He added that projections which do not account for interventions will always project incorrect scenarios. (SciDev)
Asian farmers failing to use pest-resistant rice
RICE FARMERS in China and South-East Asia are neglecting to adopt new pest-resistant cultivars, preferring to rely on excessive use of insecticide to combat pests, according to a leading rice scientist. This has led to outbreaks of pests and disease in rice, affecting thousands of farmers, mainly in China, Indonesia and Thailand, said KL Heong, a senior scientist at the International Rice Research Institute (IRRI), in the Philippines. Heong was speaking following his presentation at the Forum for Agricultural Risk Management in Development’s (FARMD) annual conference, held last month in Ho Chi Minh City, Vietnam. The most serious of these pests is the brown planthopper, an insect which damages rice at every stage of its development, by feeding directly upon the plant, and by transmitting viruses that destroy the plant. A farmer can easily lose an entire crop, Heong said. According to his estimates, Thai farmers have lost about 12 per cent of their yields to planthoppers over the past eight harvest seasons. In Java, Indonesia, infestations have completely destroyed crops on some 22,000 hectares of farmland, with an estimated economic loss of US$27.5 million. While there are many varieties of pest-resistant cultivars to choose from, farmers’ decisions over what to plant are usually dependent on yield, quality, and the demands of rice millers, Heong explained. “On the other hand, researchers are focused on finding new things such as new genes, but pay little attention to how these genes are actually being adopted by farmers,” he added. Heong said that language had a strong role to play in fostering the low pest-resistant cultivar uptake: people fail to grasp that “a resistant variety [is] one that will have no insects on it”. In many Asian languages there is no concept of ‘resistance’, so the word is often translated as “immunity”. He added that because of weak communication with experts, local farmers rely on shopkeepers or pesticide salesmen for advice instead, often resulting in farmers falling victim to uncontrolled pesticide advertising and incentives. “Researchers, scientists and extension officers need to understand farmers well. To appreciate the constraints farmers live under, these groups will have to spend time in the villages, hold focus group discussions, carry out interviews, and experience the farmers’ lives directly,” Heong said. Participatory experiments are needed to show farmers products and best practice, make scientific concepts easier to understand, and make learning more pleasurable. Raul Montemayor, national manager for the Philippines at the Federation of Free Farmers Cooperatives, Inc., agreed that researchers should listen to other players in the value chain, particularly traders and processors, because they may be able to introduce cost-reduction or value-improvement technologies that will eventually benefit the farmers. Montemayor said another approach is to develop new remedies for diseases and pests that will involve minimal costs and risks to farmers, such as bio-pesticides, proper timing and application of insecticides and pesticides, and synchronised plantings. (SciDev)