What is 'wheat blast', that might threaten the world's food security?

Scientists believe that a fungus named ‘Magnaporthe oryzae’ can spread from South America to the whole world.

By Shishir Agrawal 06 May 2023

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Read in Hindi | The whole world including India is overcoming the consequences of the Coronavirus pandemic. The world is coming back to normalcy. But, recently scientists have expressed the possibility of the 'Wheat Blast' epidemic spreading across the world. Unlike the coronavirus pandemic, its victims can be wheat and other grain crops. The epidemic of these crops has put the world’s food security in danger once again.

What is Wheat Blast?

Scientists believe that a fungus named ‘Magnaporthe oryzae’ can spread from South America to the whole world. Due to this fungus, crops like wheat and rice are damaged, which is known as wheat or rice blast. Due to this disease, crops grown in the form of grass like wheat or rice plants dry up along with the leaves.

This disease was first noticed in Brazil in 1985. In the early 1990s, the disease was widespread in South America. During this period, it affected about 3 million hectares of land. In the year 2016, the wheat blast affected 15,000 hectares of agricultural land in 8 districts of Bangladesh. The damage caused by this can be gauged from the fact that during that time the production of wheat in Bangladesh was halved.

Effects of ‘Wheat Blast’ on Humans

Wheat is an important part of the human diet all over the world. Due to having up to 20% protein in it, it is 50% part of the diet of developing countries. If this disease spreads in the fields of South Asia, it will have a very bad effect on the people here and on food security.

About 300 million malnourished people live in this part of the world, which consumes about 100 million tons of wheat.

How is this disease spreading?

In 2018, the disease was again found in Zambia, Africa. This was the first case of this disease in Africa. But since then, scientists started searching that how did this disease reach different parts of the world? To find out the origin of this fungus, 500 samples of fungus were tested by the scientists. Apart from this, genome sequencing of 71 samples was done. This revealed that two different lineages of this fungus spread from South America were responsible for the disease spread in Bangladesh in 2016 and Zambia in 2018.

Experts believe that this disease is spreading from one country to another through infected seeds. After studying the disease spread in Bangladesh, the facts revealed that before the spread Bangladesh had imported wheat seeds from Brazil on a large scale.

Conclusion

This disease has the ability to destroy the crop within just a week. Due to the short time, it becomes difficult for the farmers to deal with it. So far no clear instructions have been found regarding the method of its rescue. Crop rotation means sowing different types of crops is being considered as a solution. However, even this can be partially controlled. Scientists say that its spores can travel long distances in the air, so it can affect other crops as well. Hence this fungus can persist in the fields. In such a situation, avoiding the use of infected seeds and spraying fungicide before symptoms appear can be a way to avoid it.