Norman Borlaug, a modest, bespectacled scientist known as the "Father of the Green Revolution," held court in the Diplomatic Reception Rooms of the State Department last night in his quietly intense style. At the end of two days of talking about the world hunger and population problems, Borlaug, the recipient of the 1970 Nobel peace prize for his development of a new wheat strain, was steadfastly debating the ups and downs of food supply and needs.

"What we have here," said Peter McPherson, the administrator of the Agency for International Development, which invited Borlaug for consultations, "are three esteemed and senior scientists Borlaugh, Frank Press, the president of the National Academy of Science, and Nyle Brady, a rice expert at AID , who are helping us think through this policy."

But last night their hats were off to Borlaug. "There are very few people living who have done more for humanity than he has. There are countries that had famines every few years that are now self-sufficient, for example India and China," said Press.

As in the past, Borlaug is optimistic about the world's ability to balance the need for and supply of food. "In the future we have to train young people, encourage the governments to put their money into food production. We have 76 million more people a year to feed. There are 10,000 more people to be fed now than when we started this reception," said Borlaug. In recent months he has visited India and Pakistan, where he first tried a high-yielding, dwarf strain of wheat. "India became self-sufficient in 1978, and accumulated 22 million tons in the warehouse," said Borlaug.

After Washington, Borlaug, who lives in Mexico City, had planned to visit Kenya. "But while I was here I was persuaded to go to Poland, to find out what is the outlook on availability of food there."

Costas Michalopoulos, the chief economist for AID, said the two days of sessions had been stimulating. "Borlaug stressed that it is important to press on with research because the only way to increase food production is to increase the yield. There's little land." Secretary of State Alexander M. Haig and national security adviser William P. Clark didn't attend the reception, as had been anticipated. The guests included representatives from public interest and research groups on hunger and population issues. Davidson Gwatkin, a senior fellow of the Overseas Development Council, said Borlaug's public spirit as well as science should be admired. "I admire someone who doesn't stay in the lab."