Roberts S. Pickens, 78, a former author and newspaperman and a farmer in Loudoun County, Va., for more than 40 years, died Sunday at his home, Janelia Farm, near Ashburn, Va. He had suffered from emphysema and related ailments for the past 10 years.

Mr. Pickens was born in Lenoir, N.C. He attended Emory and Henry College in Southwest Virginia and the University of North Carolina. He began his newspaper career with the Bristol, Va., Herald Courier. He later worked for several other papers in North Carolina and Virginia.

In 1927, he went to China as a correspondent for The Atlanta Constitution and The Chicago Tribune. He returned to the United States after about a year and joined the Associated Press in Washington. He covered the White House during the Hoover administration and then resigned to return to Asia on his own.

Out of this second trip, which also included travels to Japan, the Philippines and Indochina as well as China, grew a book entitled "Storm Clouds Over Asia," published in 1934.In it Mr. Pickens said that war between the United States and Japan was likely.

He moved to Janelia Farm in Loudoun County in the mild-1930s and had made his home there since. During World War II, he was an officer in the Army in Washington and in Europe and Africa.

Mr. Pickens was a noted grower of lilies at his farm. He was a member of the North American Lily Society and a winner of the Society's Alida Livingston Trophy. He also was an honorary member of the Leesburg Garden Club.

He was a former chairman of the Loudoun County Red Cross Chapter and of the Loudoun County Council of the Boy Scouts of America. He was a trustee of the Thomas Balch Library in Leesburg and a member of St. James Episcopal Church in Leesburgh.

Survivors include his wife, the former Vinton Liddell, of the home in Ashburn; two daughters, Jane P. Church, of Sonoita, Ariz., and Cornelia P. Suhler, of McLean; two brothers, Wiley M., of Raleigh, N.C., and Marshall L., of Charlotte, N.C., and five grandchildren.