Email: pk.singh@cgiar.org

Wheat blast is an emerging disease caused by the fungus Magnaporthe oryzae pathotype Triticum (MoT) and has shown growing threat to global wheat production. Its epidemics had been confined to the Southern Cone region of South America before 2016, the year when a major outbreak occurred in Bangladesh, marking its movement from South America to South Asia. In 2018, the detection of wheat blast in Zambia signaled its initial appearance in Africa.

Predictive models, which consider agro-climatic factors, have identified vast areas with warm and humid conditions as vulnerable, a risk that could increase with climate change and the pathogen's potential to adapt to cooler and drier environments. Since mid-2010s, CIMMYT has worked closely with international partners on germplasm screening, resistance breeding, as well as integrated blast management.

Sources of resistance have been limited, and genetic studies have indicated the importance of the 2NS/2AS translocation, with minor effects contributed by other loci. Breeding efforts are challenged by lack of resistant sources and the rapid mutation of MoT populations threatening the fungicide and host resistance management strategies. Seed treatments effectively prevent seedling infections but do not protect against infections in the spikes.

Although fungicides provide some preventive advantages, their effectiveness is reducing as MoT rapidly develops resistance. Altering planting times is the most frequently adopted cultural method in regions impacted by wheat blast, but the use of bio-control agents remains minimal and is not yet a standard practice in agriculture. Overall, addressing wheat blast requires a complex, multi-disciplinary strategy and international collaboration to mitigate its harmful effects.