Everyone wants higher quality seed – from the home gardener to the production grower. Seed testing and seed preservation improve seed quality.
Sprouts need only 5 minutes a day, matures in about a week and has more nutrients per calorie than any other type of food. Easy to grow and delicious!
Stephen was invited to provide an article on seed quality for Acres USA’s January 2017 issue that focuses on seeds. This is the article that was published in that issue.
Everyone wants higher quality seed – from the seed company, seed grower, breeder and home gardener to the production grower. Even people who do not garden or grow anything want better seed, though they may not realize it.
Education and quality seed is the focus of our company – Terroir Seeds. We make constant efforts to continue learning and educating our customers about how seeds get from the packet to their garden. We recently had the opportunity to visit several cutting-edge seed testing laboratories and the USDA National Center for Genetic Resources Preservation to learn even more about seed testing and preservation. We want to share an insider’s look into a side of the seed world that the average person may not know exists.
Let’s look at this need for higher quality seed from a different perspective.
Everyone is a participant in what can be called the “seed economy”. Everyone, that is, who eats or wears clothes!
Anyone who eats depends on seed of some sort for their daily food – from fruits and vegetables to grains, beans, rice and grasses for dairy and meat production. Seed is intimately tied into all these foods and their continued production. Without a continued, dedicated supply of consistently high quality seed there would be catastrophic consequences to our food supply.
Cotton, cotton blends, wool, linen, hemp and silk fabrics all come from seed. Cotton comes from a cotton seed, wool from a sheep eating grass and forage from seed, linen from plant stalks grown from seed, hemp from seed and silk from silkworms eating leaves that originated as a seed.
Even those who grow and cook nothing need better seed! They still eat and wear clothes.
Chile de Agua for sale at market
The Chile de Agua pepper from Oaxaca, Mexico is a prime example of how seed preservation works. A well-known chef specializing in the unique Mexican cuisine of Oaxaca needed this particular chile for several new dishes. This chile wasn’t available in the US, so we were contacted through friends to work on sourcing the seed.
We found two sources in the US of supposedly authentic Chile de Agua seed and another in Oaxaca, Mexico. After the Oaxacan seed arrived, and those from Seed Saver’s Exchange network and the USDA GRIN station in Griffin, GA we sent them to our grower for trials and observation. All three seed varieties were planted in isolation to prevent cross pollination.
Authentic Chile de Agua has unique visual characteristics, the most obvious being it grows upright or erect on the plants, not hanging down or pendant. Both seed samples from the US were pendant with an incorrect shape. Only the Oaxacan seed from Mexico was correct. We then pulled all the incorrect plants, keeping only the seed from the correct and proper chiles.
The next 3 seasons were spent replanting all the harvested seed from the year prior to build up our seed stock and grow a commercial amount sufficient to sell. This process took a total of four years to complete.
There are two major approaches to improving seed quality – seed testing and seed preservation. One verifies the current condition of the seed, while the other works to preserve previous generations for future study and use.
There are several different methods of seed testing, from genetic verification and identifying DNA variations to diseases to the more traditional germination and vigor testing.
Likewise, approaches to preserving the genetic resources of seed are varied – from a simple cool room to climate and humidity controls for extended storage to cryogenic freezing with liquid nitrogen.
At its most basic, testing of seed simply verifies the seed’s characteristics right now. Whether testing for germination, vigor, disease screening, genetic markers or seed health, the results show what is present or absent today. Changing trends in important characteristics are identified by comparing with previous results.
Seed germination testing
This trend analysis is a perfect example of seed testing and preservation working together, as previous generations of seed can be pulled for further testing or grown out and bred to restore lost traits.
Modern seed testing labs perform a staggering array of tests and verifications on seed samples.
Germination, vigor and physical purity are the standard seed tests for agricultural crops, flowers, herbs and grasses.
These three tests are critical for determining a seed’s performance in the field, and satisfy the US seed labeling law showing germination, physical purity and noxious weed percentages.
Seed health testing screens for seed-borne pathogens like bacteria, fungi, viruses and destructive nematodes. Seed for commercial agriculture and home gardens are often grown in foreign countries and shipped into the US, and vice versa. Seed health testing verifies the incoming or outgoing seed is free of pathogens that could wreak havoc.
Seed vigor test
Plant breeders use the healthiest seed stock possible that is free of any pathogens which would compromise breeding efforts. Agricultural researchers use tested pathogen-free seed to avoid skewing results or giving false indications from unforeseen disease interactions.
Hybrid seeds need to be tested for genetic purity, confirming their trueness to type and that the hybrid crossing is present in the majority of the seed sample. Traditional open pollinated breeders will use genetic purity testing to confirm there is no inadvertent mixing of genetic variations, verifying the purity of the parental lines.
It is common to test heirloom corn for GMO contamination – called adventitious presence testing. This test identifies any unwanted biotech traits in seed or grain lots. This is an extremely sensitive DNA based test, capable of detecting very low levels of unwanted traits in a sample – down to hundredths of a percent. This relatively expensive test demonstrates the absence of GMO contamination, an important quality aspect in the heirloom seed market.
Genetic fingerprinting, also called genotyping, identifies the genetic make-up of the seed genome, or full DNA sequence. Testing with two unique types of DNA markers gives more precision and information about the genetic diversity, relatedness and variability of the seed stock.
Computer graph of DNA testing
Fingerprinting verifies the seed variety and quality, while identifying desirable traits for seed breeders. This testing identifies 95% of the recurrent parent genetic makeup in only two generations of growing instead of five to seven with classic breeding, saving time and effort in grow-outs to verify the seed breeding. Genotyping also accelerates the discovery of superior traits by their unique markers in potential parent breeding seed stock.
Using established open pollinated seed breeding techniques, genetically fingerprinted parents help produce the desirable traits faster and with less guessing.
To be clear, these are not genetically modified organisms – GMOs – they are traditionally bred by transferring pollen from one parent to the flower of another, just as breeders have done for centuries. No foreign DNA is introduced – a tomato is bred to another tomato, or a pepper to another pepper.
The difference is how the breeding is verified, both before and after the exchange of pollen from one plant to another. The genetic markers identify positive traits that can be crossed and stabilized, and those markers show up after the cross and initial grow-outs to verify if the cross was successful. If it was successful, the grow-outs continue to stabilize and further refine the desired characteristics through selection and further testing. If it wasn’t successful, the seed breeder can try again without spending several years in grow-outs before being able to determine the breeding didn’t work like expected.
There are several different types of seed preservation, just as with seed testing. The foundational level is the home gardener, grower or gardening club selecting the best performing, best tasting open pollinated varieties to save seed from. Replanting these carefully selected seeds year upon year results in hyper-local adaptations to the micro-climates of soil, fertility, water, pH and multiple other conditions.
Seed preservation work also happens with online gardening or seed exchange forums, regional and national level seed exchanges such as Seed Saver’s Exchange and governmental efforts with the USDA.
Many countries around the world have their own dedicated seed and genetic material preservation networks, such as Russia’s N.I.Vavilov Research Institute of Plant Industry. It is named for Nikolai Vavilov, a prominent Russian botanist and geneticist credited with identifying the genetic centers of origin for many of our cultivated food plants.
The Millennium Seed Bank Partnership is coordinated by the Kew Royal Botanic Garden near London, England and is the largest seed bank in the world, storing billions of seed samples and conduct research on different species. Australia has the PlantBank, a seed bank and research institute in Mount Annan, New South Wales, Australia.
The Svalbard Global Seed Vault on the Norwegian island of Spitzbergen is a non-governmental approach with donations from several countries and organizations. AVRDC – the World Vegetable Center in Taiwan has almost 60,000 seed samples from over 150 countries and focuses on food production throughout Asia, Africa and Central America. The International Center for Tropical Agriculture (ICIAT) in Colombia focuses on improving agriculture for small farmers, with 65,000 crop samples. Navdanya in Northern India has about 5,000 crop varieties of staples like rice, wheat, millet, kidney beans and medicinal plants native to India. They have established 111 seed banks in 17 Indian states.
It has been estimated there are about 6 million seed samples stored in about 1,300 seed banks throughout the world.
Seed banks aren’t the only ways to preserve a seed. Botanical gardens could be called “living seed banks” where live plants and seeds are planted, studied, documented and preserved for future enjoyment and knowledge. Botanical gardens range from established and well-supported large city gardens to specialized and smaller scale efforts to preserve a single species or group of plants.
100 year old Native American corn in herbarium
An herbarium is another form of seed bank with a single purpose of documenting how a plant looked at a specific location at a specific time. Herbaria are like plant and seed archeological libraries with collections of dried, pressed and carefully preserved plant specimens mounted and systematically cataloged for future reference.
An herbarium can show what corn grown by the Hopi tribe a century ago looked like, or how large the seeds and leaves of amaranth were 50 years ago. Different herbaria focus on certain aspects such as regional native plants or traditional foods grown by native peoples during a specific time.
50 year old Amaranth in herbarium
The USDA plays two important roles in seed preservation that is little understood outside those in the seed industry.
The first is the Germplasm Resources Information Network or GRIN for short. It is also known as the National Plant Germplasm System. This collaborative system works to safeguard the genetic diversity of agriculturally important plants. Congress funds the program but it partners with both public and private participants. Many of the seed banks are on state university campuses with private sector breeders and researchers using the available seed resources.
USDA National Center for Genetic Resources Preservation cold vault
There are 30 collection sites that maintain specific seed stock and conduct research on them. Some are dedicated to a single crop like the Maize Genetic Stock center in Urbana, IL which collects, maintains, distributes and studies the genetics of corn. Potatoes are maintained and studied in Sturgeon Bay, WI and rice is kept in Stuttgart, AR. Others maintain regional varieties like the UC Davis location that focuses on tree fruit and nut crops along with grapes that are agriculturally important in the central valley of California.
The second role is the USDA National Center for Genetic Resources Preservation (NCGRP) in Fort Collins, CO. This is the “back-stop” for the GRIN system as well as other private, public institutions and government programs around the world. They store the foundational collections of all the GRIN locations while also working with organizations such as the International Maize and Wheat Improvement Center in Mexico, the International Rice Research Institute in the Philippines and the International Plant Genetic Resources Institute in Rome.
Founded in 1958, the NCGRP maintains, monitors and distributes seed and genetic material samples from their long-term backup storage. After receiving seed samples, they test, clean and condition the seed for the proper long-term storage environment.
USDA NCGRP’s liquid nitrogen vault
Two long-term storage methods are used. One is a traditional low temperature/low humidity storage and the other is liquid nitrogen storage. The traditional storage is kept at 0°F and 23% relative humidity. Seeds are kept in heat sealed, moisture proof foil laminated bags.
Before seeds are stored in liquid nitrogen a sample is given a liquid nitrogen test to ensure the extreme cold won’t damage the seeds. The sample is exposed to liquid nitrogen for 24 hours, then germinated after coming back to room temperature and evaluated for any germination issues.
If the test results are normal the seeds are stored in clear polyolefin plastic tubes that are barcoded and sealed. The filled tubes are arranged in metal boxes, labeled and stored in liquid nitrogen tanks.
USDA NCGRP’s liquid nitrogen vault sample straw
The vault housing both storage areas is completely self-contained and separate from the adjoining buildings. It has its own backup generator, can withstand up to 16 feet of flooding, tornadoes and the impact of a 2,500-pound object moving at 125 miles per hour. It also has a full suite of electronic security.
If these approaches and techniques seem extravagant, it is with good reason. Our food availability and security increasingly relies on intensive production of fewer variety of crops that are very similar genetically. Along with increased production is increased vulnerability on a larger scale to pests, diseases and other stresses.
By collecting, preserving, testing, studying and distributing seeds and genetic materials immediate food system challenges can be met along with solutions and adaptations for future needs. Changes in growing conditions due to population growth, weather variability, transitions in land use and economic development all make the need for quality seed more important.
All the players in the seed economy support and advance the knowledge and quality of our seed used today. Just as the home gardeners and garden clubs preserve local seed varieties, seed companies are a “back-stop” for them. Seed banks and research facilities back up the seed companies and provide material for seed research.
Would you like a fresh food that grows in any climate, at any time of year and needs no soil or sunshine? One that you only spend 5 minutes a day with, matures in about a week and has more nutrients per calorie than any other type of food?
How about one that has no waste in preparation for eating and is tasty?
Welcome to the incredibly diverse, tasty and nutritious world of sprouts.
Whether it is well known leafy sprouts like Alfalfa and Red Clover, or the loved Mung bean sprouts used extensively throughout Asian cooking, sprouts are tender, crisp tiny plants that have flavors from mild and nutty to sweet, tangy and peppery. Their crunchiness and texture vary as well from the delicate Alfalfa and Clover to the thick and hearty Mung bean sprouts that hold up well to the heat of stir-frying.
Sprouts don’t require any sort of “Green Thumb”, just pay attention to the rules above.
Rinse a couple of times a day to keep the seeds/sprouts moist. This also flushes away carbon dioxide and metabolic wastes that could cause spoiling. Use cool water when rinsing to ventilate and cool the sprouts to prevent overheating. Sprouts generate warmth as they grow. The optimum room temperatures are between 70 – 85°F.
Using the sprouting lid helps maintain proper drainage, preventing excess moisture that can cause mold. Young sprouts are very tender, so keep the sprouting container away from cold drafts, direct heat or light.
Sprouts expand 6 – 10 times their initial volume in just a few days, so give them plenty of room to grow. The 1 1/2 tablespoon volume of seeds grows to almost fill the quart jar!
Sprouts are very light sensitive and should be covered until the final day or two of the sprouting cycle.
Now you know the rules, here’s how easy it is to grow your own sprouts! It only takes about 5 minutes each day.
The tools and ingredients are super simple! You need a sprouting lid, a tablespoon measure, a glass quart jar and a towel to cover the jar.
What you sprout is up to you – we offer several different sprouts and mixtures to suit different taste buds.
Start by measuring out 1 1/2 tablespoons of sprouting seeds into a glass quart jar.
Fill the jar with warm water – not hot! This is the only time you will not use cool water in the sprouting process. The warm water helps start the sprouting process and speeds up the softening of the seed coat.
After the jar is full of warm water, screw the sprouting lid on, swirl the seeds well for several seconds and pour out the water through the lid.
Refill with warm water to cover the seeds about 3 times their depth. Let soak overnight and keep away from light.
The easiest way to keep the sprouting seeds away from light is covering them with a towel. The sprouting process does not need light.
Let the jar and seeds sit overnight.
The next morning, this is what you should see once the towel is removed. The water will be slightly darker than yesterday and the seeds will be noticeably larger from absorbing water.
Dump the water out,
rinse with cool water, fill to about 3/4 full and swirl to separate any seeds stuck together,
then pour the water out again.
The sprouts look like this on the first day – still seeds! The sprouting process has started, and you’ll see the results on the second day.
After rinsing and draining, cover the jar with a towel and put in a convenient place where it is in a steady temperature with no cold drafts where it can drain without causing problems.
This place is often the kitchen dish drainer. We like to tip the jar lid downward to drain excess moisture off easily. Our duck eggs comfortably share the space!
This is the process you will repeat a couple of times each day. Rinse with cool water, pour out, cover with a towel and tip the jar lid downward to drain excess moisture.
At two days, the sprouts were just beginning to split their seed coats, with a few showing a small sprout tip peeking out here and there.
This is the third day. We rinsed and drained the sprouts and inspected them.
Sprouts at three days. Most of the sprouts have split the seed coats and have started growing.
A closer view shows how dramatic the change is from seeds to sprouts in just three days. Most of the sprouts have long “tails” or roots, long enough to make the seeds look small in comparison. There are only a few seeds that have not sprouted at this point.
The growth continues over the next few days.
Sprouts at five days. There has been lots of growth in the past two days, compared to the day three photos above. The jar is almost filled now.
Each day we rinse, drain and cover the jar with the lid pointed downward to encourage good drainage.
The close-up view shows the difference in growth and volume over the past two days. At three days, they had filled almost 1/3 of the jar opening, while today they almost fill the jar opening.
The growing phase is finished, the sprouts need some ambient light to green up and boost their nutrition. You can eat them now – this is what is sold in the stores, but a couple of days with the towel off starts the production of chlorophyll and seriously increases the nutrition content!
Sprouts at seven days. The growth has slowed down, but the sprouts are much greener now. We’ve left the towel off after day five. We continue the rinse and drain routine each day.
The young, tender cotyledons have turned from a pale light green to a richer, deeper green. This color indicates nutrition – amino acids, protein and carotene, among others.
The close-up view shows how the sprouts have expanded a little more, but the colors are much greener.
The sprouts are almost ready to eat!
After the sprouts have greened up a bit, they are ready for harvesting. This just means a good wash in a colander or large bowl of water to remove the seed hulls.
There are two methods of doing the harvest wash – in a colander and in a large bowl of water.
If you use the bowl of water method, make sure to start with a bowl about twice the size of the sprouts so you have enough space to work. Gently dump the sprouts into the bowl and add cool water to almost fill the bowl.
Work your fingers into the sprouts, opening them up and releasing the spent seed hulls. Some will float to the top, while others will sink to the bottom. Skim the floating hulls, then remove the sprouts and drain the water and hulls.
Replace the sprouts and repeat the process until there are very few hulls left.
We show the colander method in our photos.
Gently dump the jar full of sprouts into a colander. It may take some gentle shaking or a chopstick to loosen the sprouts if they’ve grown to fill the jar.
Gently but thoroughly wash the sprouts with a running stream of water. We alternate between a solid stream and a spray and use our fingers to work the sprouts around to release the hulls. Some are visible at the bottom of the colander.
It usually takes a couple of cycles of wash/rinse with finger agitation, then lifting the sprouts out and washing the hulls out of the colander. Once you have very few hulls left the sprouts are ready to eat or store in the fridge.
Store sprouts in the refrigerator using the glass jar and sprouting lid as they still need to breathe and be rinsed once a day. Just make sure to set the jar lid down to drain for about 15 minutes before putting back in the refrigerator. They will last about a week, but usually will be eaten in just a couple of days!
Once the sprouts are cleaned they are ready to eat! We love our fresh sprouts on sandwiches of any kind – or on a fresh burger of locally raised heritage beef with homemade mayonnaise! Sprouts bring a fresh crunch and taste of fresh growth no matter what time of year it is.
If you find sprouts as delicious as we do, try succession sprouting. This is the same concept as succession planting in your garden but with sprouts.
Depending on how much you and your family eat, start a batch every third or fourth day to keep a fresh supply of sprouts on hand. You will need a sprouting lid for each batch, so you might need 2, 3 or 4 lids. With simple care the lids will last several years.
Now you see how simple it is to grow your own home-grown sprouts, saving you time and money while having delicious fresh greens any time of year! If you have a spare 5 minutes a day and enough room for a quart jar, you can grow sprouts.
Once you’ve sprouted a couple of times and have the timing down it will feel second nature to always have fresh sprouts on hand.
Seed Testing and Preservation: A Behind the Scenes Look at Seed Testing Labs and the USDA
Everyone wants higher quality seed – from the home gardener to the production grower. Seed testing and seed preservation improve seed quality.
How to Grow Sprouts at Home
Sprouts need only 5 minutes a day, matures in about a week and has more nutrients per calorie than any other type of food. Easy to grow and delicious!