In 1947, he took up genetics and plant breeding at Indian Agricultural Research Institute (IARI), New Delhi, and obtained a post-graduate degree with high distinction in cytogenetics in 1949. With the UNESCO Fellowship opportunity, he pursued genetics in Wageningen University in the Netherlands, and later moved to study at the Plant Breeding Institute in the University of Cambridge School of Agriculture in 1950, earning his Doctor of Philosophy degree in 1952.

Swaminathan returned to India in early 1954, and took up an opportunity as an assistant botanist at Central Rice Research Institute in Cuttack. He then joined the Indian Agricultural Research Institute (IARI) in New Delhi in October 1954 as an assistant cytogeneticist.

Food insecurity and recurrent famines were a regular feature in India. Swaminathan had learned of Dr Norman Borlaug’s newly developed Mexican dwarf wheat variety and invited him to India. They collaborated to develop dwarf wheat varieties that would have higher grain yields and stronger stalk structures to support the biomass. In 1964, Borlaug sent supplies for a range of Mexican dwarf varieties of wheat that were to be bred with Japanese varieties. A total of 150 demonstration plots on one hectare were planted. With initial testing showing high yield and disease-free results, Swaminathan made more modifications to adapt the grain for Indian environmental conditions and presented small-holder farmers with the new, genetically superior grain that would thrive in their fields. The new wheat varieties were sown, and in 1968 production reached to 17 million tonnes (five million tonnes more than the previous harvest). Similar changes were achieved with rice.

In 1970, before he received the Nobel Peace Prize, Norman Borlaug wrote to Swaminathan:

“The Green Revolution has been a team effort and much of the credit for its spectacular development must go to the Indian officials, organizations, scientists, and farmers. However, to you, Dr Swaminathan, a great deal of the credit must go for first recognizing the potential value of the Mexican dwarfs. Had this not occurred, it is quite possible that there would not have been a Green Revolution in Asia.”

Following the success of the Green Revolution, Swaminathan worked with the then Prime Minister of India, Mrs Indira Gandhi, to establish agricultural policies and programmes that would maintain long-term self-sufficiency across the country. The Government of India declared the country as self-sufficient in food production in 1971. Swaminathan was appointed as director-general of the Indian Council of Agricultural Research (ICAR) and a secretary to the Government of India in 1972. He later joined the Planning Commission of India, and left for the Philippines to serve as director-general, International Rice Research Institite (IRRI) between 1982-88. He was the first Asian to lead the institute.