Рынок отказывается от зараженной афлатоксином кукурузы: фермеры теряют половину урожая

Amani Karwa, a maize farmer from Gatsibo District, recalls selling his harvest at giveaway prices after buyers rejected it because of aflatoxin contamination. Aflatoxin is a toxic substance produced by certain types of fungi, mainly Aspergillus, which can grow on crops such as maize, groundnuts, sorghum and other grains, particularly under warm and humid conditions. ALSO READ: Why agro-processing factories reject local maize produce Keep up with the latest headlines on WhatsApp | LinkedIn "We used to sell our maize harvest to informal markets because formal markets were rejecting maize contaminated with aflatoxin. The price per kilogramme of maize fell from Rwf400 to below Rwf200," he said. Karwa grows maize on five hectares and harvests about four tonnes per hectare. He said most farmers lack adequate drying and storage facilities, increasing the risk of aflatoxin contamination. An assessment by MINIMEX, a maize processing plant, showed that it was rejecting 50 per cent of the maize it received because of aflatoxin contamination. Farmers such as Karwa say efforts to reduce aflatoxin contamination are therefore welcome. Rwanda produces about 500,000 metric tonnes of maize annually. Against this backdrop, crop scientists are exploring aflatoxin-resistant maize varieties as a potential solution to one of the major food safety and agricultural challenges facing maize producers. At the Africa Food Systems Forum taking place in Kigali, scientists said they were considering the potential of such varieties to reduce aflatoxin contamination, improve food safety and strengthen maize production. Agnes Kalibata, a Rwandan board member of the International Maize and Wheat Improvement Center (CIMMYT), said advances in plant science could enable researchers to address traits that make crops vulnerable to certain threats. "There is a possibility of editing plant genes that have been problematic and giving plants the ability to deal with those problems," she said. ALSO READ: Investors appeal for more drying machines to save cereals from aflatoxin Kalibata said CIMMYT already has maize varieties with resistance to aflatoxin that are expected to be released soon. The centre says breeding maize resistant to mycotoxins, particularly aflatoxins and fumonisins, is important for ensuring a safer food supply. Mycotoxins are toxic chemical compounds naturally produced by certain moulds and fungi, while aflatoxins are one type of mycotoxin. Once grain is contaminated with mycotoxins, either in the field or during storage, the toxins can persist through digestion, cooking and freezing. They can also reach humans through milk or meat from livestock fed on contaminated grain. Mycotoxin exposure can cause serious health problems, including cancer, liver disorders and weakened immune systems. In children, exposure has also been associated with poor growth and underweight development. Aflatoxin is particularly difficult to detect because it is invisible and can be present in maize that appears clean. Researchers are therefore working to breed high-yielding maize varieties that can also resist infection by harmful fungi. New technologies to control aflatoxin could complement affordable grain-drying and storage technologies, helping to reduce contamination at different stages of production and handling. ALSO READ: Could DryCards be the solution to aflatoxins in grains? New research could also have implications for breeding approaches to combat aflatoxin contamination while addressing other nutritional challenges. A study titled "Provitamin A Carotenoids in Grain Reduce Aflatoxin Contamination of Maize While Combating Vitamin A Deficiency" documented how biofortification with provitamin A could help reduce aflatoxin contamination while improving the nutritional value of maize. Similarly, the Gene Editing for Reducing Aflatoxin in Groundnuts project seeks to develop safer and more nutritious groundnut varieties with durable genetic resistance to Aspergilli infection and aflatoxin contamination through gene editing. Climate-resilient crops Kalibata said decades of research had produced technologies that could help farmers cope with drought, pests and other stresses. She pointed to drought-tolerant crops, improved genetics and gene-editing research as important tools for the future of African agriculture. She also called for greater investment in crops that have traditionally received less attention but have helped African communities withstand recent shocks, including cassava, yams, millet and beans. "These crops grow and farmers know how to grow them," she said, arguing that they should become more commercially important rather than being treated primarily as subsistence crops. Finance remains key Innocent Musabyimana, Chief Agricultural Technologies Officer at the African Development Bank, highlighted the role of the African Emergency Food Production Facility in financing climate-resilient seeds. The $1.5 billion initiative was launched to support countries dealing with the food crisis. Musabyimana said the facility had supported 35 African countries through interventions including the distribution of quality seed and fertiliser, as well as technical assistance to strengthen national agricultural systems. He said the initiative had facilitated the availability of approximately 400,000 metric tonnes of quality seed and three million metric tonnes of fertiliser, while also supporting countries in improving seed policies, access to finance, digital systems and agricultural advisory services. He also emphasised the importance of partnerships among financial institutions, governments, research organisations and the private sector to move agricultural technologies from laboratories and research centres to farmers. "The bigger challenge is ensuring that technologies reach millions of farmers at the scale and speed required," he said. "That requires more than improved seed. Farmers also need access to finance, markets, insurance, information, digital services and reliable input distribution networks." Bram Govaerts, Director General of CIMMYT, said Africa must close the gap between scientific discovery and delivery if it is to avoid repeatedly falling back into emergency responses. "We have spent decades developing improved maize and wheat varieties and agricultural technologies able to withstand drought, heat, pests and diseases. The challenge is no longer simply one of scientific discovery," he said. Telesphore Ndabamenye, the Minister of Agriculture and Animal Resources, reiterated the need for financing for climate-resilient agriculture. He said Rwanda's Climate-Smart Agriculture Investment Plan, prepared with the International Finance Corporation, identifies $335.4 million in private investment potential by 2030. The plan aims to link 170,200 farmers and 375 companies to climate-smart finance while making 83,250 hectares more productive and resilient.