Tom La Dell reviews Where Our Food Comes From by Gary Paul Nabhan

The man who did more than anyone to reveal where our food crops come from was Nikolay Vavilov, a Russian geneticist who pioneered the understanding of genetic diversity in food crops and its importance in plant breeding. He travelled the world to find varieties grown in traditional agriculture and brought thousands of them back to his Institute (now named after him) in Leningrad (St Petersburg). He developed the idea that some parts of the world have unusually large numbers of crop plant varieties and he called these 'centres of diversity'. They have many subtle variations of climate and soils and the inventive local people have developed a wide range of varieties that crop well in these varying conditions and provide food throughout the year - some to eat fresh and some to store for winter and spring.

Vavilov was born in 1887 and died of starvation during the second world war in one of Stalin's jails - for telling scientific truths. His arch enemy Trofim Lysenko said that organisms could inherit characteristics that they acquired in their lifetime and this was music to Stalin's ears. This was despite the fact that Vavilov's travels searching out the origin of food crops across five continents had begun to provide varieties that were adapted to the great variety of Russian climate and soils through his huge plant breeding and trialling programmes.

 Vavilov led the way in discovering the origins of crop plants and this is even more relevant now to the future of food supplies and food security. As climate, soils and the environment change and pests and diseases adapt even faster we have to use the widest range of genetic resources of our food crops to keep ahead. The National Fruit Collection at Brogdale Farm, Faversham, Kent is the most comprehensive and best documented collection of temperate fruits in the world and one of many collections that conserve the genes of the world's major food crops. There are collections of all the world's major food crops held in different countries under the International Convention for the Conservation of Plant Genetics Resources within the Global Food Security Programme of the United Nation's Food and Agriculture Organisation. Wheat, barley, potatoes, maize, rice and may more are available to the world's plant breeders.

In his book on Vavilov, Gary Paul Nabhan not only tells the story of Vavilov's travels collecting seeds of crop plants but he also travels to many of the same places and reports on current cultivation and the inevitable loss of crop variety in these centres of diversity. These include the Pamir Mountains north of Afghanistan, Italy's Po Valley, the Levant, the Maghreb oases, Ethiopia, Kazakhstan, the southern United States and the Amazon. They are all centres of food crop diversity, where the crops originated and were first cultivated, and there is great genetic variation and adaptation to a wide range of growing conditions and pest and disease resistance. Nabhan tells the story well and evokes the spirit of the places where Vavilov learnt about local cultivation and collected seeds. His institute in Leningrad housed well over 100,000 collections of seeds.

The trip became personal for Nabhan when he visited his farming cousins in the Bekaa Valley of  Lebanon and this brings it closer to home. One lesson of the book is that no food supplies in human history have been safe unless crops and cultivation can adapt to changing conditions. This has played its part in, for example, the decline of the Roman Empire, elimination of the Nabateans of Petra and collapse of civilisation on Easter Island. If we get it wrong this time it will affect not just an empire or a civilisation, it will be the whole world.

Tom La Dell

Where Our Food Comes From by Gary Paul Nabhan, published 2009 by Island Press, Sherewater Books; pp 223, illustrated b&w and colour photographs; £15.99.