High Tech Seed Cleaning

1. High Tech Seed Cleaning Low Cost Alternatives

2. Initial Steps in Seed Preparation • Adapted seed source (Often local) • Locate mature flowering plants of desired species • Flowering in the spring is the first sign there will be seeds to collect. • Can make preparation to grow plants if we know we will have seeds.

3. Initial Steps in Seed Preparation • Monitor seeds as they are maturing and at harvest • Will there be enough for our plans ? • Is the quality good enough to collect ? • Are there good seeds ? • Are they mature ? • Need to know seed structure • Cutting test or pinching is an option to evaluate seeds in the field

5. After collection Before cleaning

6. After collection terms • Keep Cool: If you would be hot then your seeds are hot. Do not let your seeds feel hot. • Keep Moist: keep fruit from drying and becoming hard, but do not let it ferment – ventilate. • Allow to dry: put up on racks in thin layers (1 inch) where air can reach seeds. • Do not allow to dry: must keep in sealed container (plastic bag) or a damp location or water.

7. Steps in cleaning • Extraction: remove seeds from fruits • Clean: remove trash from seeds • Upgrade: eliminate additional trash, bad seeds • Prepare for storage

8. Extracting fleshy fruit • Fruit must be soft enough to crush easily with your fingers • Water soak will soften • Can take 1 to many days or a week or more • Must change water daily to prevent fermentation • Extraction will damage seeds if fruit is not soft. • A juicer will macerate fruit • Wash pulp away on a screen

9. Extracting dry fruits • Dry fruit that opens (cyprus) • Must give room for fruit expansion • Shake fruit to remove seeds • Dry fruit that does not open (mt mahogany) • May require breaking fruit open (pods) • Fruit may be the “seed” and require only drying

10. Drying fruits • Open air drying on screens or sheets will work • Air movement over the seed will help • Seeds must be in thin layers and turned often • A seed dryer may help • Easier drying • Faster drying

11. What is a seed drier? • Two boxes • Screen-bottomed top box holds the seeds • Bottom box has a fan to force air through seeds • Boxes fit tightly together so little or no air escapes except through the seeds. • Device that dries seeds quickly, easily, uniformly

12. When will seeds and fruits dry? • Relative humidity usually less than 30% • Heat may be needed to dry the air • When to add heat? • How much heat is needed? • Should never use heat above 110oF • Psychrometric table is our guide

13. Cleaning • Seeds from fleshy fruits need drying • Some dry seeds may need appendages removed • Tail on mountain mahogany – leather gloves • Wing on pine seed – rubbing board • Cotton on willow or aspen – vacuum cleaner

14. Cleaning - Screens • Types of Screens • Hardware cloth of different sizes • Purchase hand screens (come in many sizes) • Soil sieves very small seeds (aspen) • Trash over/seeds through: sclaping • Seeds over/trash through: sieving • Separate by diameter or thickness, not length

15. Cleaning - air • Pour seeds out in front of a fan • Lighter particles fall farther from the fan than do heavier particles • Work best with larger seeds • Vacuum trash up from seeds on a screen • Spread seeds out in a layer one seed deep. • Come down on seeds slowly with vacuum, stopping when trash is lifted up.

16. Upgrading • Hand pick trash • Water floatation • Seeds float and trash sinks • Trash floats and seeds sink • Use a sieve or drink bottle • Fan to blow out empty seeds. • Check seeds to see if full • Thin seeds on a light table • Some can be pressed lightly • Cut a few

17. Preparing for storage • Dry the seeds over night on a drier or in a dry room • Seal in plastic bag or bottle to protect from moisture • Not need this step if sowing seeds in a few weeks.