M. S. Swaminathan will turn 85 next year, but his mind remains scalpel-sharp. He calls up, without any effort, the date his father died: 12 October 1936. He remembers the name of the British district medical officer who had been summoned to the Tamil Nadu town of Kumbakonam to treat his father’s eventually fatal pancreatitis: “A tall man, named Kelly." And of course, he remembers Jawaharlal Nehru visiting his family in Kumbakonam three weeks later, offering his condolences. “I have a specific memory of him consoling my mother."

Turning point: Swaminathan cherishes the memory of an invitation to tea at Teen Murti Bhavan. Abhinandita Mathur / Mint

Swaminathan’s father M.K. Sambasivan, a doctor, was a disciplined Gandhian. Once, Sambasivan carried out to his yard heaps of clothing he’d acquired during his student days in Vienna and made a bonfire. Everybody in the family was required to spin the charkha for an hour or two a day.

Sambasivan had met Nehru twice in Allahabad, and his house had become a de facto destination for Congress leaders travelling through south India. “Mahatma Gandhi stayed with us once, and C. Rajagopalachari stayed a number of times," says Swaminathan. “In fact, my father came to call one room ‘Rajaji’s room’."

This was, however, Nehru’s first visit. “He patted all of us on the back but"—and here his memory uncharacteristically lets him down—“I don’t quite recall what he told us."

Shortly after independence, when riots were still roiling northern India, Swaminathan made an unsettling train journey from Chennai to New Delhi, to begin postgraduate studies at the Indian Agricultural Research Institute (IARI). The very next year, he met Nehru again. “He came to IARI, and there wasn’t all this security in those days, so a professor asked me to help out, give the guests water, and so on," Swaminathan says. “In that hall, Nehru made his famous statement: ‘Everything else can wait, but not agriculture’."

Later that day, Nehru sat the directors of various IARI divisions around a table and interrogated them; Swaminathan observed discreetly. “There is a food shortage of 10%, and I want to know how to solve that," Swaminathan remembers Nehru declaring. So, one by one, the directors offered their thoughts. “Get rid of rats, and we can get 10% more," a director said. “Figure out how to kill insects, and we can get 15%," an entomologist said. “Grow new varieties, and we can get 10%," a breeder said. At some point in this auction of ideas, Swaminathan says, Nehru started to laugh. “Gentlemen," he said, “I only wanted 10%. You’ve given me far more than that already."

Despite his much publicized love of industry, Nehru was keenly aware of the significance of the agricultural sector, which supplied the food to drive the men to drive their machines. When Swaminathan won the Shanti Swarup Bhatnagar Prize in 1961, and when Nehru couldn’t make it to the ceremony to give away the award, he invited the young scientist to Teen Murti Bhavan instead. “I think he must have felt bad that he wasn’t there," Swaminathan says. “One day, I just got a call from his office, asking me to come. I didn’t know what was what—I was still a young man then."

In the library of Teen Murti Bhavan, Nehru sat, accompanied by his daughter. “Young man, you have won the Bhatnagar prize, I understand?"

Swaminathan admitted that he had, in fact, won the Bhatnagar prize.

“Now tell me," Nehru said. “What did you do to get it?"

For the next 45 minutes, over tea and biscuits, Swaminathan lectured the prime minister about the architecture of the wheat and rice plants. Nehru rarely interrupted, and Indira Gandhi sat in silent absorption. “That was a turning point for me," Swaminathan says. “To have encouragement from the highest level, to have somebody like Nehru asking what I was doing."

But even beyond the strategic importance of agriculture, Nehru proved to be an inveterate lover of nature. Every year, when IARI organized its annual Rose Show, somebody would send a note to Nehru, inviting him to the gardens. “One year, he arrived slightly late, and as I was showing him around, he was joking and chatting. He asked for the latest variety of rose and slipped it into his buttonhole," Swaminathan says. “The next day, I read in the papers about (the Indian Army’s liberation of) Goa. He must have taken a lot of important decisions that day, but he was so relaxed." Swaminathan would recall the incident when, years later, he found himself beside a tense Indira Gandhi on a long car journey. “So I told her this story, and she smiled. The rest of the trip was very different."

It was his love of nature, in Swaminathan’s agronomist eyes, that made Nehru a compassionate man. “Even at the Rose Show, he’d spot a labourer’s child standing nearby, and he would immediately pick him up and play with him," Swaminathan says. “It wasn’t for a photo op, it wasn’t put on. That image of Chacha Nehru was born of completely genuine affection."