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May 18, 2008
The Magic of Seed Saving
Master Gardener Column 5/17/08
In ritual as old as civilization, indeed a ritual responsible for civilization itself, a tribal farmer planted seeds from a corn cob slightly larger than a fingernail. He took care at harvest to save the seeds from the largest and best ears, planting them again, and harvesting them anew each season, producing better ears of corn every year. After eons of this ritual, other farmers have harvested corn from their best seeds, resulting in its modern sizes, shapes and colors.
In this priceless ritual farmers throughout the years have practiced open-pollination which means an uncontrolled, natural pollination by bees, winds, insects, and birds, creating a variety of characteristics. In contrast, artificial, controlled pollination by cross-breeding different varieties creates a specified set of characteristics.
Nowadays, the danger of controlled pollination is the loss in one generation of an agricultural diversity 10,000 years in creation. As late as 1900, food for the planet's population was provided by at least 1,500 different plants, each one differentiated into thousands of cultivated varieties. In contrast, today over 90% of the world's nutrition is provided by 30 different plants with only four (wheat, rice, corn and soybeans) providing 75% of the calories consumed by human beings. Where once diverse strains strengthened each local botanical community, currently a handful of "green revolution", super-hybrid varieties are "mono-cropping" farms and gardens worldwide.
The danger inherent in “mono-cropping” is vulnerability because diseases or pests attack individual varieties. The strength of any botanical community is variety. If only one variety of potato is planted, as was done in Ireland in the early 1800's, the result is likely to be the loss of the entire potato crop in what is called the Irish potato famine.
In 1970, 50% of the genetically uniform corn crop in the southern United States worth more than a billion dollars was lost to a single disease. Without botanical diversity, the danger is the loss of an entire crop because diseases and pests are constantly emerging into new diverse forms. Each year newly emerging strains of influenza require new combinations of strains in the flu shots to immunize against emerging influenza viruses.
Today, potatoes are grown in Ireland and corn in the South because disease resistant varieties were found in other varieties. Botanists search for varieties resistant to new diseases in the "Vavilov centers," named after Nicolai Vavilov, the famous Russian botanist. Once these centers were banks for a variety of seeds, but now they are being planted with a handful of genetically narrow "green revolution" hybrids. The genetic center for wheat in Turkey is in danger of being planted completely with hybrids.
Thousands of native and heirloom wheat varieties are disappearing, becoming unavailable to botanists looking for varieties resistant to the future plant diseases. The threat is a genetically uniform agriculture with little or no diversity to protect it.
Individual gardeners and farmers have long created and sustained a rich genetic heritage. Now, they can continue by saving seeds from the best performers of their non-hybrid (open-pollinated) varieties, sustaining the diversity, remaining open to the future as was done in the past.
In Siberia, nearly everyone saves garden seeds, seed saving being an integral part of their gardening experience. As with gardeners everywhere, competition is intense, resulting in selective seed saving.
Without a background in genetics, Siberian gardeners select seeds only from plants with desirable characteristics. Creating new varieties, gardeners have designed simple selection system, planting the same variety in different environments or by planting different varieties in the same environment.
The story of Dima is a case in point. He lives Novosibirsk, Siberia, where he grows watermelons. Although agricultural experts in Siberia claimed that watermelons wouldn’t grow in Siberia, Dima after several years produced a single, small, tennis ball-sized fruit. He carefully saved the only two seeds produced by the melon and planted them the following spring. Success again. Dima saved several seeds from the largest fruit. Ten years later, Dima was well into his "melon adventure" with his garden consistently producing kilo-sized melons. He created a unique, new treasure, contributing to genetic diversity besides enjoying fresh watermelons in the short Siberian summer.
For further information contact Bill McDorman at www.seeds trust.com.
Bill McDorman of Seeds Trust in Cornville, AZ, is a pioneering authority in seed saving and high elevation horticulture. Dana Prom Smith, a Master Gardener volunteer, is coordinating editor for the Master Gardener Column. He can be contacted at stpauls@npgcable.com. For gardening questions, call the Master Gardener Hotline, 774-1868, x19, or visit MG Web site: highelevationgardening.arizona.edu.
Posted by maxmaddy at May 18, 2008 7:05 AM