India allowed imports of 100,000 tonnes of corn at the concessional tax rate in June.

The additional 400,000 tonnes of imports were permitted at the same rate following a request from the poultry industry, the government said in a statement.

India, the world's seventh-biggest corn producer, normally imposes a 60pc import tax on the grain, but an infestation of the fall armyworm, which devastated African crops in 2017, and dry weather in some areas have cut the country's corn output.

Amit Saraogi, managing director of Anmol Feeds Pvt. Ltd., said the shortage of corn had been hurting the cattle feed industry since last year and the additional imports would help to bring down prices.

India was a major exporter of corn to southeast Asia until falling output and increasing demand from poultry producers and corn starch manufacturers turned it into an importer a few years ago.

The switch in India's position cheered rival suppliers such as Brazil, Argentina and the United States, which have now replaced New Delhi in the southeast Asian market.

India, which does not allow the cultivation of any genetically modified food crops, has rules designed to ensure that imports contain no trace of genetically modified organisms.