Robert B. Wallace, 84, a former agribusiness executive, sustainable-development activist and son of former U.S. vice president Henry A. Wallace, died of cardiac arrest Oct. 10 at Georgetown University Hospital. He had a stroke in 1999.

Mr. Wallace, a Washington resident since 1973, was president of the Wallace Global Fund, a Washington-based charitable foundation he created in 1995 to support sustainable-development issues internationally, including population stabilization, environmental protection, energy consumption and economic and gender equity.

He had been active in women's rights and gender issues for three decades, predominantly as national co-chairman of what is now Population Action International, a Washington-based nonprofit organization that promotes family planning.

He began increasing volunteer activity with local and international family planning organizations in the early 1970s, raising awareness about the impact of unchecked population growth on the environment and food production. He worked with his first wife, Dr. Gordon G. Wallace, on education programs to combat the practice known as "female genital mutilation" common in parts of Africa and African communities throughout the world.

He was born in Des Moines. He was 14 years old when his family moved to Washington upon the appointment of his father, Henry A. Wallace, to serve as secretary of agriculture in 1933 under President Franklin D. Roosevelt.

His father went on to serve as vice president during Roosevelt's third term and as secretary of commerce under Roosevelt and President Harry S. Truman. He was the Progressive Party's candidate for president in 1948. Robert Wallace's paternal grandfather, Henry C. Wallace, had served as agriculture secretary under President Warren G. Harding.

Robert Wallace, who attended Sidwell Friends School, was a 1940 biology graduate of Iowa State University. His graduate studies at the University of Wisconsin were cut short by World War II, when he entered the Army and served as a major in Europe.

In 1946, he married Dr. Gordon Grosvenor, a sociologist and concert pianist. They settled near Philadelphia, where he was an animator, illustrator and producer of educational films.

From 1948 to 1973, he was chief executive of Hy-Cross Hatcheries Inc. in Doylestown, Pa., a subsidiary of Pioneer Hi-Bred International Inc., an agricultural genetics firm founded by his father. Pioneer grew to become among the largest producers of hybrid seed corn and other crops, merging with Dupont Corp. in 1999.

Mr. Wallace, who played tennis and squash, was an amateur ornithologist. A bird species discovered in 1999 in the Andes of Peru bears his name: Wallace's barbet.

He was a founder of the Council of Sponsors of the Worldwatch Institute and a member of the board of Planned Parenthood/World Population and the executive committee of the International Planned Parenthood Federation.

His first wife died in 1994. Their daughter, Allaire Wallace, died in 1992.

Survivors include his wife, Raisa Scriabine Wallace of Washington; three sons from his first marriage, Robert Bruce Wallace of Ottsville, Pa., Henry Scott Wallace of Bethesda and Randall Clark Wallace of New York; a brother, Henry B. Wallace of Scottsdale, Ariz.; a sister, Jean Wallace Douglas of Washington; and seven grandchildren.