[1] His parents, James Robertson and Catherine Landles Brown were of Scottish Presbyterian background and returned to Scotland while Noel was still young.
He then studied Botany at Edinburgh University which at the time was partially taught in Inverleith at the Royal Botanical Gardens.
During his studies Robertson developed interests in plant pathology and fungal taxonomy, most probably inspired by the Reader in Mycology, Malcolm Wilson.
[2] Robertson won the Sir David Baxter Scholarship and the Turner Prize[1] and obtained a degree with first class honours in Botany in 1944.
He later described this time as one of the happiest in his life, as he was able to work on the land, getting his hands dirty, and gained pleasure and fulfilment from hard manual labour.
[2] The University of Edinburgh awarded Robertson their Gunning Victoria Jubilee Prize for his report on tree viruses.
Later he wrote this work up as a thesis, Virus diseases of trees in two continents,[3] for which the University of Edinburgh awarded him a PhD.
In conjunction with Eric Buxton he later undertook pioneering work,[2] unravelling of a deep understanding[1] of the parasexual recombination and variation of Fusarium oxysporum.
It embodied his breadth of vision and the then swiftly evolving disciplines of bio-chemistry, ecology, genetics, and plant pathology.
Robertson's 1962 article on botanic gardens published in Nature demonstrated that he "was in the vanguard of modern thinking on his subject".
John Friend, a distinguished plant pathologist and biochemist succeeded Robertson as Hull's Professor of Biology.
His proposers were James MacDonald, Harold Fletcher, Anthony Elliot Ritchie and Douglas Mackay Henderson.
His new posts allowed Robertson to create an institution that catered for teaching, research and provided an advisory service.
With Robertson at the helm, the Edinburgh School of Agriculture became a world leading centre for research and teaching.
[2] Prior to retirement Robertson lived in the Pentland Hills south of Edinburgh, where every day he walked his dog, a border collie.
[1] After retirement Robertson moved to Juniper Bank, near Walkerburn and the River Tweed in the Scottish Borders.
Although Robertson wrote the rest of the book, with characteristic modesty, he placed Blaxter's name first on the title page.
With David Ingram, Robertson wrote Plant Disease: A Natural History, which was published by HarperCollins in their New Naturalist series in 1999.