Heat tolerant maize hybrids: a pursuit to strengthen food security in South Asia

After a decade of rigorous effort, CIMMYT, along with public-sector maize research institutes and private-sector seed companies in South Asia, have successfully developed and released 20 high-yielding heat-tolerant (HT) maize hybrids across Bangladesh, Bhutan, India, Nepal, and Pakistan. CIMMYT researchers used a combination of unique breeding tools and methods including genomics-assisted breeding, doubled haploidy (a speed-breeding approach where genotype is developed by chromosome doubling), field-based precision phenotyping, and trait-based selection to develop new maize germplasm that are high-yielding and also tolerant to heat and drought stresses.

While the first batch of five HT maize hybrids were released in 2017, by 2022 another 20 elite HT hybrids were released and eight varieties are deployed over 50,000 ha in the above countries.

In South Asia, maize is mainly grown as a rainfed crop and provides livelihoods for millions of smallholder farmers. Climate change-induced variability in weather conditions is one of the major reasons for year-to-year variation in global crop yields, including maize in Asia. It places at risk the food security and livelihood of farm families living in the stress-vulnerable lowland tropics. “South Asia is highly vulnerable to the detrimental effects of climate change, with its high population density, poverty, and low capacity to adapt. The region has been identified as one of the hotspots for climate change fueled by extreme events such as heat waves and intermittent droughts,” said Pervez H. Zaidi, principal scientist at CIMMYT.