1929 and 1946 at Long Ashton Research Station. He wrote the government's official national Diseases of Vegetables practical guide for trade growers: the six editions from 1941 to 1969 (in 1969, retired and aged 71) were full of photos of wilting crops. Ogilvie was influential in the World War II and post-war challenge of feeding Britain: he was the leading British expert on the diseases of cereal crops and vegetables. By the 1940s, wheat varieties had not been sufficiently bred to resist the rust and other diseases in the damp climate prevalent in Britain and particularly in the south west where he was responsible for advising farmers. Before the war, Britain imported half its food, but by 1941 relied on home-grown crops because German submarines were sinking about 60 merchant ships per month, and the priority for shipping was to carry matériel to resist the impending invasion. The 1940s varieties of wheat were still unable to resist disease, with long stalks prone to lodging in the heavy rains of the west of England. Ogilvie was also consulted about willow diseases during World War II. Surprisingly, willows were a strategic material throughout the war. Everything dropped by parachute was dropped in a basket – light and strong, they bounced on impact and could be made to any shape. Home production of willows was about 2000 tonnes per year. There were 630 manufacturers employing 7000 basket makers. He was the international authority on the diseases of wheat that flourished in these British damp, warm conditions – particularly Black Stem Rust<ref>2nd European Colloquium on Black Rust of Cereals, Madrid April 1961 Studies of Black Rust Epidemiology in England L Ogilvie and I G Thorpe</ref> and Take All.Sciencedirect.com Ogilvie and his team of scientists advised growers and farmers in the south-west of England through the war years and until his retirement age 65 in 1963.Sciencedirect.com This was particularly important to Britain during the war and the continued food rationing period to 1954Plant Pathology Volume 2, number 4, December 1954 New or uncommon plant diseases and pests in England and Wales: "Net blotch" of field and broad beans Moira C D Justham and L Ogilvie – bread for instance was rationed from 1946 to 1948, even though it was not rationed during the war. Ogilvie was elected a vice president of the British Mycological Society in December 1956. Personal life On 10 January 1931 in