Supermarkets would have us believe that we eat a huge variety of fruit and veg. In reality 90 per cent of the human population survives on only 30 crop varieties. In Britain alone we have lost 97 per cent of our fruit and veg varieties since 1900.
If any one of the remaining 3 per cent were to succumb to disease the consequences could be devastating.
Why does it matter
When people rely on just a few varieties of a single crop, disease can have disastrous effects.
From 1845 to 1846 Ireland's potato crop consisted of one or two closely related varieties. Both were wiped out by blight. In the ensuing famine, nearly a million people died and more than a million others were forced to emigrate. By 1851 Ireland’s population had diminished by 23 per cent. If Irish farmers had been growing many varieties of potatoes with different genetic backgrounds the disaster would never have happened. And had a gene for blight resistance not been found among the thousands of potato types in
South America it is unlikely that any potatoes would be grown in Europe today.
In the 1940s a French cauliflower variety was introduced to cauliflower growers in Cornwall. With its denser white curds, the French plant was much more popular. Soon the old Cornish varieties, which were resistant to fungal ringspot, were no longer produced. Ringspot is a recurring problem to this day, but the old Cornish variety has long been extinct.
In 1972 several varieties of corn in the US, all with similar genetic backgrounds, were killed off by blight. The country lost 15 per cent of its corn crop; in some southern states the loss was as high as 50 per cent.
Since crops today are so vulnerable, they are treated as disposable commodities. If one variety succumbs to disease, we simply move on to the next. A barley bred in East Germany was introduced to Ireland in 1982. Its resistance to disease was eroded within a couple of years, so it was replaced by the English-bred variety Blenheim. By 1994 this new variety also needed replacing.
Instead of working with nature by maintaining crop variety so as to counteract disease, we have increased the use of pesticides by 210 per cent since the 1970s.
But disease can become resistant to pesticides. Mosquitoes’ resistance to DDT, for example, began to emerge just six years after the pesticide’s introduction.
1 domestic tall pea still exists in Britain; 119 other varieties have disappeared
3 of the 550 varieties of pear available 100 years ago are still grown commercially
9 varieties of apple are available in the UK today; in the 19th century there were 2,000 varieties
50 traditional rice varieties were grown in China in 1970; 21 years earlier the
figure was 8,000
75 per cent of the genetic diversity of crop plants was lost in the last century
80 per cent of the varieties of Mexican maize have been lost
97 per cent of the crop varieties once listed by the US Department of Agriculture have been lost in the last 80 years
Under the Plant Varieties and Seeds Act of 1964 it is illegal to sell seeds that are not included on the UK national list. The costs of listing seed is prohibitively high. Annual application fees are £300, and the supplementary costs of entering and testing seed varieties can reach £2,100. The legislation has had two effects.
1 Unusual seed varieties were lost as small seed companies went bust. Unable to compete, companies sold out to larger rivals. For example, Rank Hovis bought 83 small companies in just one week when the legislation came into effect in 1980. Unfortunately, no incentives exist for the larger companies to supply the seed varieties that only small-scale farmers and gardeners demand.
2 Valuable genetic resources were lost. Restrictions demanded that only one strain of a traditional variety be entered on the national list. In the 1970s the onion varieties Hurst Reselected, Golden Globe, Nuttings Golden Ball, Cambridge Number 10, Sutton Globe and Up-to-Date were all listed as Bedfordshire Champion.
What's the solution?
Since agriculture began farmers have used the selective sowing of seed to encourage and develop a variety of traits in crops. Differing conditions between one farming community and another resulted in the development of locally adapted varieties. Eventually hundreds of thousands of distinct varieties of widely cultivated crops evolved. These varieties are known as landraces.
If disease struck there was enough variation within the crop to ensure at least some varieties were resistant and would survive. However, most crops today are genetically homogeneous and extremely vulnerable to being wiped out entirely if hit by an unknown disease.
One response to this loss of biodiversity has been the setting up of seed banks (frequently known as gene banks). Worldwide, there are now 1,300 banks containing around 6 million acquisitions.
In the UK, the Henry Doubleday Research Association (HDRA) recognised the problem as long ago as the 1970s. Dedicated to researching and promoting organic agriculture, the HDRA set up the Heritage Seed Library (HSL) in 1975 so as to conserve the seeds of endangered European vegetable varieties.
However, there are drawbacks to the seed bank approach to conserving biodiversity. Varieties stored in seed banks adapt to the conditions of storage and have to be replanted on a regular basis in order to regenerate viable seed.
Varieties you can buy in Sainsbury's:
Cherry, Flavia, Plum, Pomodarino, Romalia, San Marzano, Sungold, Vittoria, Sainsbury’s Tomatoes
Sugar-snap, Mange-tout, Garden, Little-big Sweet Peas, Sainsbury’s peas
Sainsbury’s French Green Bean, Continental Choice,Sainsbury’s Green Beans, French
Varieties you can adopt from the HDRA seed library:
Auntie Madge’s, Brandywine, Broad Ripple Yellow Currant, Cheetham’s Potato Leaf, Cherokee Purple, Cyril’s Choice, Czar, Egyptian, Essex Wonder, Golden Queen, Grandma Oliver’s Green, Green Zebra, Iraqi Heart-shaped, Ivory Egg, Jersey Sunrise, Kenilworth, Madame Jardel’s Black, Maltese Plum, Market King, Mrs Taylor’s Yellow Pear, My Girl, Peacevine Cherry, Plum Fryer, Potato Leaf White, Ryder’s Midday Sun, Salt Spring Sunrise, Scotland Yellow, Spanish Big Globe, Sub-Arctic Plenty, Sundrop, Thompson’s Seedless Grape, Tiger Tom, Whippersnapper, White Princess, Yellow Oxheart
Carlin, Carruther’s Purple Podded, Champion of England, Commander, Duke of Albany, Epicure, Gladstone, Glory of Devon, Gravedigger, Kent Blue, Lancashire Lad, Laxton’s Exquisite, Magnum Bonum, Mr Bound’s Bean Pea, Poppet, Prince of Prussia, Purple Podded, Simpson’s Special, Table Talk, Telephone, Time
Out of Mind, Veitch’s Western Express, Victorian Purple Podded
Bird’s Egg, Black Canterbury, Black Valentine, Blue and
White, Brighstone, Caseknife, Cherokee
Trail of Tears, Coco Bicolour, District Nurse, Early Warwick, Emperor
of Russia, Ernie's
Big Eye, Hutterite
Soup, Jacob’s Cattle,
Kew Blue, Lazy
Housewife, Parfree’s Dragon Tongue, Pea
Bean, Red Robin, Ryders Top O’Pole, Soldier
The HDRA’s seed library includes more than 800 different fruit and veg varieties. The organisation is continually increasing its collection by rescuing seeds as they are discontinued by seedsmen. What can you do?
1 Adopt a Veg. With a donation of £10 to the HDRA’s ‘Adopt a Veg’ scheme, you can help pay for the HSL’s seed handling, storage and propagation facilities.
2 Become a member of the HDRA. As a member you can choose six free seed packets a year from the HSL bank to grow yourself.
To find out more, write to Adopt A Veg, HDRA, Ryton Organic Gardens, Coventry CV8 3LG, or email email@example.com
This article first appeared in the Ecologist October 2003