Why is this a problem? Because if disease or future climate change decimates one of the handful of plants and animals we've come to depend on to feed our growing planet, we might desperately need one of those varieties we've let go extinct. The precipitous loss of the world's wheat diversity is a particular cause for concern. One of wheat's oldest adversaries, Pucciniagraminis, a fungus known as stem rust, is spreading across the globe. The pestilence's current incarnation is a virulent and fast-mutating strain dubbed Ug99 because it was first identified in Uganda in 1999. It then spread to Kenya, Ethiopia, Sudan, and Yemen. By 2007 it had jumped the Persian Gulf into Iran. Scientists predict that Ug99 will soon make its way into the breadbaskets of India and Pakistan, then infiltrate Russia, China, and—with a mere hitch of a spore on an airplane passenger's shoe—our hemisphere as well.Roughly 90 percent of the world's wheat is defenseless against Ug99. Were the fungus to come to the U.S., an estimated one billion dollars' worth of wheat would be at risk. Scientists project that in Asia and Africa alone the portion of wheat in imminent danger would leave one billion people without their primary food source. A significant humanitarian crisis is inevitable, according to Rick Ward of the Durable Rust Resistance in Wheat project at Cornell University.
1970s – southern corn leaf blight – 15% of nation’s crop wiped out. Currently, 43% corn acreage planted to varieties derived from 6 inbred lines.
Mexico is considered the center of corn biodiversity.
Tomatoes, beans, peas, lettuces, peppers
Insects sometimes cross-pollinate self-pollinating plants. Except for corn, bagging is used to prevent cross-pollination of self-pollinating plants. Does not work for spinach – wind pollinated and pollen fine enough to pass through the bag.
Treated paper bags available from the Lawson Bag Company. Do not use glassine envelopes or plastic bags! Reemay is spun polyester cloth.
Annual varieties can be isolated by time. When the first crop is beginning to flower, sow the second variety. (corn, sunflowers, lettuce). Works best with varieties that have different maturity dates – otherwise, season may be too short to allow both to produce.
Need at least 2 cages – one for cabbage, one for kale crop. Remove cage from one group in the morning, replace at night. Remove cage from the 2nd group the next morning, replace at night. The process can be stopped when a sufficient number of seed pods have formed. To ensure seed purity, leave cages on both plant groups until all flowering has stopped.
The mechanics of plant breeding are not difficult. For cross-pollination, flowers are bagged before they open to prevent uncontrolled pollination or selfing. For perfect flowers, the petals and anthers of the flower to be pollinated should be removed before bagging. Next pollen from the male parent is gently brushed over the stigma of the female. The female is then rebagged to prevent further uncontrolled pollination. The seeds produced from the cross can be collected from the bag. Mature seeds must be cleaned and stored after they are harvested. Cleaning involves removing the ovary tissue surrounding the seed. Seeds from fruit with a fleshy ovary must be allowed to dry before storage. Generally, seeds must be stored to maintain a constant relative humidity – glass jars or ziplock bags work well. Low humidity and refrigeration slows respiration and keeps the seed viable for a long time.
Flowers are perfect – but unable to self pollinate. Insect pollinated. Inspect flowers – rogue for bolting or flowering in first season. Harvest as soon as heads are dry. Bend over a sack and cut from stalk to avoid losing seeds.
Isolation distance of one mile. Beginners should allow only one variety of oleracea to flower in a season. Some short-season broccolis will flower and produce seed in one season, when planted early. Self-incompatible – insect pollinated. Hold no longer than 4 to 6 weeks before replanting. Store at 32 to 40 F and 80 to 90% humidity.
Can plant as is or break apart with a rolling pin. Pollen can travel up to 5 miles. Can bag or cage. Dig root before the first killing frost.
Cross-pollinating by wind. Pollen carried up to 10 miles! Fine – penetrates mesh screens. Maintain a ratio of one male to two females. Prickly and smooth seeded varieties – wear gloves. When dry, strip stems in an upward motion, allowing seed to fall into a bag.
Heads of 10 to 25 florets. Bees and other hairy insects. All flowers on a head open in one day, close and never re-open.
Squashes belong to one of six species. Pepo is most common. Must be bagged and hand-pollinated to ensure purity.
Food dehydrator – 85F
Transcript of "Grow Your Own, Nevada! Spring 2012: Saving seeds from your garden"
Saving Seeds for aFood-Secure FutureHeidi KratschArea Horticulture Specialist
What is a Seed?O Product of sexual reproductionO Maximizes genetic diversity
Genetic diversity is decreasing O 95% of human food needs now provided by just 4 crops: rice, wheat, corn, potatoes. O Industrial agriculture focuses on only a handful of cultivars. O 75% of agricultural genetic diversity disappeared in the last century.
Wheat Stem Rust (Ug99)O First identified in Uganda in 1999.O Has spread through Africa into the Middle East.O ~90% of world‟s wheat is defenseless against this virulent strain. Puccinia graminis
Step 1: Avoid growing F1 hybridsO Almost all corn seedO Many varieties of cross-pollinated speciesO Must buy new seeds every year
Choose open-pollinatedO Come true to typeO The easiest are self-pollinated: beans, peas, tomatoes, peppersO Heirloom varieties – saved through generations of families and neighborsO History goes back 12,000 years!
Overwintering BiennialsO Biennials include: O Carrot, celery, O Seed-to-seed method parsley vs. O Beet, chard O Leek, onion O Seed-to-root-to-seed O Rutabaga, turnip, method parsnip O Broccoli, kale, brussels sprouts
Onions (Allium cepa) Cepa groupO Biennial, self- pollinatingO Overwinter in ground or lift bulbs.O Bulbs – harvest seed first seasonO Seed – harvest Don‟t wait too long to seed second harvest seed or the seed season. heads will shatter!
Broccoli (Brassica oleracea)O Biennial, cross- pollinating (insect)O Will cross with all other plants of this species.O Do not eat plants grown for seed.O Use cold frame, small hoop house to overwinter.
Beets and Chards (Beta vulgaris) Up to 4 feet tall!Biennial, cross-pollinated (wind) – bag or cage
Spinach (Spinacia oleracea) Male plant with flowers Female plant with seedsDioecious, annual, cross-pollinating (wind)
Lettuce (Lactuca sativa)O Self-pollinating O Seeds ripen 12-24 days after flowering annualO Bolts in response to lengthening daysO Head-lettuce types need to be slit to allow seed stalk to emerge.
Squash (Cucurbita pepo) Acorn, crookneck, scallop, zucchiniO Monoecious, cross- pollinating (insect) annualO Cut fruit from vine and let sit for 3 weeks or longer before harvesting Male flower Female flower seed.
Pea (Pisum sativum)O Self-pollinating annualO Allow pods to dry on the vine.O Freeze pods in airtight container for 3-5 days to kill Peas and beans are easy for weevil eggs. beginning seed savers.
Carrot (Daucus carota)O Biennial, cross- pollinated (insect)O Use seed-to-root-to- seed methodO Umbels can be left to dry on the plant, orO Cut and air-dry.O De-bearding is unnecessary.
Corn (Zea mays)O Cross-pollinated (wind) annualO Tassels vs. silksO Grow in blocksO Susceptible to inbreeding depressionO Dry ears on the stalk, or remove and dry under shelter
Step 5: Clean seedsO Dry processingO Wet processing O Fermenting O Rinsing O Decanting
Step 6: Store seedsO Excellent storage produces vigorous seeds.O Two enemies: O High temperature O High moisture
Long-term storageO Cool, dry conditionsO EnvelopesO Moisture-proof container or freezer O Must be “very dry.”
Getting to “very dry”O Fan/air conditionerO Food dehydratorO Silica gelO Check daily until between 5- 7% moisture
Testing for DrynessO Weigh before and after drying slowly in an oven at low temperature.O Seed moisture content (%) = fresh seed weight – dry seed weight ÷ dry seed weight × 100%
Long-term storageO Frozen seeds last Supplies: up to 10 times O Seed Savers longer Exchange –O Store in paper www.seedsavers.org envelopes with silica gel “dessicant” for one week.O Allow frozen sealed jar to reach room
Keep good records O Keep a card for each variety. O Plant and variety O Source, date obtained O Germination % O Date stored O Accession number O Last year grown
Veggies generally not grown from seedO PotatoO GarlicO ArtichokeO AsparagusO Sweet potatoO Rhubarb