Breeding and Deploying Multiple Stress-Tolerant Maize Varieties in the Tropics

Maize is the key crop for food, feed, and nutritional security of millions of smallholder farmers and consumers in the developing world, especially in sub-Saharan Africa (SSA), Asia, and Latin America. CIMMYT and partners have adopted innovative approaches over the last one decade to develop, evaluate, and deliver elite stress-resilient and nutritionally enriched maize varieties with relevant client-preferred traits, especially in the stress-prone tropics. Effective integration of modern breeding tools and strategies, including high-throughput and precision phenotyping, doubled haploid (DH) technology, and genomics-assisted breeding, are integral part of these efforts leading to impressive genetic gains, while enhancing the pace, precision, and efficiency of breeding pipelines. Through extensive public-private partnerships, CGIAR-derived climate-resilient and multiple stress-tolerant improved maize varieties are being deployed in over 13 countries in SSA, four countries in South Asia, and several countries across Latin America. Certified seed production of CGIAR-derived improved stress-tolerant maize varieties was estimated to cover approximately 7.2 million hectares in SSA in 2022, reaching an estimated 7.2 million households, and benefitting 44 million people. In the past five years, a total 20 high-yielding drought and heat stress-tolerant maize hybrids were released in South Asia, including four new hybrids in 2022 – BWMRI-2 in Bangladesh; Rampur Hybrid-12 in Nepal; and IMH-222 and IMH-223 in India. In collaboration with seed company partners, certified seed production of climate-resilient maize hybrids scaled-up from a baseline of just 70 MT in 2018-19 to 1026 MT in 2021-22, and deployed in about 50,000 hectares in various stress-vulnerable targeted ecologies in Bangladesh, India, Nepal and Pakistan, reaching 128,200 farm families. Experiences of CIMMYT strongly indicate that besides strengthening the seed sector, adoption of progressive seed laws and regulations, are vital for improving smallholder farmers’ access to climate-resilient improved seed. Policy support and institutional innovations are also required for overcoming key bottlenecks affecting maize seed value chain.