Ralph Warren Marsh OBE (27 December 1899 in Crewkerne, Somerset – 29 February 1992) was a British mycologist and phytopathologist, known for his research on the control of apple scab.
After briefly working at the Royal Botanic Gardens, Kew, Marsh spent three years from 1923 to 1926 as a mycological research assistant at the University of Manchester.
[3] In 1965 he retired from the Long Ashton Research Station and the University of Bristol and was appointed OBE (Officer of the Most Excellent Order of the British Empire).
Based on his spore collection records, he conducted in 1930 large-scale field trials that demonstrated a greatly improved method of control of apple scab.
[3] With Hubert Martin, he demonstrated a simple way to control potato blight by spraying with a water can fitted with a round nozzle — this was useful for the Dig for Victory campaign.