Denis Garrett
Stephen Denis Garrett[a] FRS (1 November 1906 – 26 December 1989) was a British plant pathologist and mycologist who did pioneering work on soil-borne pathogens, root pathology and soil ecology.
Garrett spent most of his career at Rothamsted Experimental Station (1936–48) and the University of Cambridge's school of botany (1949–73), where he was professor of mycology and acting head of department, and also held a fellowship at Magdalene College.
[1] His father was killed in action at the Battle of Neuve Chapelle during the First World War when he was eight, and his mother moved the family to Oxford, where her sister lived, and later to Eastbourne.
[1][3] He read natural sciences at Magdalene College, University of Cambridge in 1926–29, gaining a second-class degree in botany and also studying chemistry and geology.
[1][3][4] On the recommendation of Brooks, Garrett took up a post as an assistant plant pathologist at the Waite Research Institute in Adelaide, South Australia (1929–33), under Geoffrey Samuel.
"[2] Recognising that root pathology is complex and multifactorial,[2] and describing then-current methodology as "crude and inadequate",[4] he used an experimental approach that changed one factor against a constant background.
[2] Most of his experiments were simple and eschewed technology to use only basic equipment; for example, he preferred jam jars and glass tumblers to specialist soil containers because they were less expensive,[1][2][3][4] and even once purchased rejected plastic lavatory cisterns for his laboratory to use.
[1][2][5] His early papers on soil conditions and G. graminis, based on work at Rothamsted before the Second World War, are described by the Indian mycologist C. V. Subramanian as "very original in approach, content and technique, and are classic.
He showed that the fungus was unable to spread through soil, requiring direct hyphal contact with a root; this was later shown by Garrett's laboratory and others to be the result of limited oxygen.
He examined how the fungus could nevertheless persist in soil, finding that in the presence of sufficient nitrogen it was able to grow using cellulose from cereal stubble as a carbon source.
[1][2] In 1973, he published an essay on how pathogenic fungi infect and reproduce in the face of plant disease resistance, focusing on nutritional requirements, and later extended his ideas to include competition or antagonism.
[1] He was described by Peter J. Grubb, E. Anne Stow and S. Max Walters as having "an ability to extract from complex systems simple concepts that could be approached experimentally.
"[5] Garrett is described by J. W. Deacon as a "naturally gifted writer" whose "flair" and "flowing but precise style" render "even the most difficult concept easy to understand",[2] while R. C. Cooke criticises his "quaint and old-fashioned" writing.
[11] Deacon later describes it as "a tour de force in assembling and synthesizing all the then known information on effects of environmental factors on soilborne plant pathogens".
[12] Cooke, writing in 1971, calls the earlier book highly influential, with "new and exciting ideas" that stimulated research by many other scientists in the field, and praises the follow-up for maintaining the focus on fungal activity and interactions in the natural environment, rather than in the laboratory.
