Seed Saving and Testing

1. Seed Saving and Testing
By Abram Bicksler, Ph.D.
International Sustainable Development Studies Institute
ECHO Asia Impact Center

2. Why Save Seeds?
Cost Effective
Promotes and Retains Biodiversity
to give away
to empower others
Because it can be fun
No other option

3. Some Simple Seed SavingTechniques
Open pollinated-‘heirloom,’ ‘traditional,’ ‘indigenous’
plants that have been domesticated over time and produce ‘true to type’ seeds
traits relatively stable; can be saved
hybrids
created from the cross of 2 parent plants and backcrossed multiple times to make the cross stable
do not produce ‘true to type’ seeds
loose ‘hybrid vigor’
saving seeds is not recommended and often illegal

4. Some Simple Seed SavingTechniques
Things to think about:
Self pollinated or cross pollinated?
Self-contain both male and female parts
Cross-often rely on insects and wind, may lose or water-down traits of varieties
use exclusion? How to maintain purity?
farm plan-labor, IPM, soil type
water source

5. Some simple seed saving techniques: farmer selection
can be as simple as farmers taking notice of valuable traits and tagging plants to harvest from later
can be by cross-pollinating plants with valuable traits
can be bagging fertilized flowers to prevent cross pollination
thousands of varieties of plants have come about this way

6. Some simple seed saving techniques: harvesting
often a compromise between moisture and seed loss
harvest when fully mature and moisture content is low
harvest before seeds potentially shatter (fall off plant) or rot
harvest before bad weather, pestilence, etc.
can hand pick or cut
in most cases, want to remove seeds from pods (beans), fleshy ovaries (vegetables), inflorescences (grains) before cleaning/processing

7. Seed Storage
Seed storage behavior
orthodox vs recalcitrant seeds
Orthodox or “normal” seeds slowly loose viability over time
cereals
many kinds of vegetables
recalcitrant seeds quickly loose viability
onions, mango, avocado, neem
remember that seeds are living organisms and can die in storage

8. Some simple seed saving techniques: cleaning
many dry seeds from pods or inflorescences can easily be winnowed
some pulpy fruits (tomatoes, eggplants, squash) need to be fermented for 2-7 days
promptly remove any damaged or diseased seeds

9. Some simple seed saving techniques: drying
the ideal seed moisture content for storage is 3-8%
can dry in the sun, or using any method to recirculate, heat, or remove the moisture from air
be sure the temperature does not exceed 41C (105F) for tree or high-oil seeds and 54C (130F) for most other orthodox seeds

10. Some appropriate drying methods

11. Some appropriate drying methods

12. Some appropriate drying methods

13. Storing Seeds
The most important thing for the long-term storage of seeds is the amount of humidity (ambient moisture) seeds are exposed to in storage
temperature used to be thought most important
you spent great effort cleaning and drying seeds to 3-8% humidity
don’t let them be exposed to high humidity again!
we are finding refrigeration not ideal: too humid

14. Storing seeds
rule of 100:
the combination of the temperature (F) plus the relative humidity (%) of the ambient environment where seeds are being stored should not be greater than 100
how to overcome?
climate controlled environment
desiccant
airtight containers
vacuum sealing

15. Some Appropriate storage methods

16. Some appropriate storage methods

17. Some appropriate storage methods

18. Testing seed viability
testing viability
why?
to determine what % of your stored seeds have survived
to determine how many seeds you need to plant
how?
by using a germination test
petri
ragdoll

19. testing seed viability
aseptic technique
most important aspect of seed viability testing
attempts to minimize contamination from fungi, molds, bacteria, etc
key ways to overcome:
clean all tools, surfaces, and hands thoroughly with alcohol or bleach
sterilize seeds before testing

20. testing seed viability: Sand

21. testing seed viability: rag doll

22. testing seed viability: petri

23. testing seed viability: petri

24. testing seed viability: petri

25. testing seed viability: petri

26. testing seed viability

27. some useful resources
the seed saver’s handbook. 2001. m. and J. Fanton
Seed to seed: saving and growing techniques for vegetable gardeners. 2002. s. Ashworth
IPGRI Genebank Resources (Biodiversity international). www.biodiversityinternational.org
farmer’s seed production: new approaches and practices. 1999. C.J.M. Almekinders and N. Louwaars

28. some useful resources
“building the bank”
ECHO Asia Seedbank brief #2: “aseptic technique”
echo asia notes: “testing seed viability” from upcoming EAN, october 2011.
ECHO asia notes: “build your own seed germination cabinet for testing seed viability,” january 2011.
echo technical note: “seed saving tips and technologies,” 2010.