Thomas Wallace

Thomas Wallace (1891 to 1965) was a British professor of horticultural chemistry and one of the world's leading experts on mineral deficiencies in plants. The son of a blacksmith and agricultural mechanic, he won a scholarship to Rutherford College in Newcastle and graduated in chemistry from Armstrong College, University of Durham, in 1913. He won a Military Cross at Gallipoli and was severely wounded in 1916. From 1919 he was a research chemist at the Long Ashton Research Station of the University of Bristol, deputy director from 1923 to 1943 and director from 1943 to 1957, and Professor of Horticultural Chemistry at Bristol from 1943. In 1921 he showed that leaf scorch in fruit trees could be due to a soil deficiency of potassium. During the Second World War he recommended indicator plots to find mineral deficiencies when pasture was ploughed for crops, and his colour atlas The Diagnosis of Mineral Deficiencies in Plants by Visual Symptoms, first published in 1943, became a standard reference. He was joint editor of the Journal of Horticultural Science from 1943 to 1958.