Thorvaldur Johnson, plant pathologist (b at Arnes, Man 23 Oct 1897; d at Winnipeg 15 Sept 1979). Johnson became Margaret NEWTON's assistant at the Winnipeg Rust Research Laboratory in 1925 and was its head from 1953 until his retirement in 1962. His chief work was the plant-disease survey, especially for wheat. Following the discoveries of J.H. CRAIGIE, a constant watch was kept for new varieties of crop-plant diseases, and genetic material was collected for C.H. GOULDEN to breed into new disease-resistant wheats. Johnson later wrote the standard history, Rust Research in Canada (1961), and an informal memoir of the rust laboratory and its staff 1925-67.