High Tech Seed Cleaning Low Cost Alternatives

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.

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

After collection Before cleaning Fruit typeMoist and fleshy Dry and can be dried Dry but must not dry How handle? Keep cool Keep moist Keep cool Allow to dry Keep cool Do not allow to dry ExamplesJuniper, dogwood, plum Most seedsBig leaf maple

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.

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

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

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

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

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

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 110 o F –Psychrometric table is our guide

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

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

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.

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

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.