Cleaning Seeds With an Aspirator

How to Build and Use an Aspirator

Seed Purity Is

• How much of a seed lot is pure seed• Weight of pure seeds ÷ total weight of seeds • Raised when trash is removed• An important measure in managing seeds– Test for weeds and other species more easily, at less

cost– Pure seeds are more accurately sown and

germinated– Reduce storage volume, more seeds fit in freezer

What An Air Cleaner Does

• Seed lots with trash lighter than the seeds (or heavier than the seeds) can be cleaned (raised in purity)

• Seeds are fed into an upward moving column of air where the light particles are lifted into a settling chamber and heavy partitcles fall to the bottom of the air column

Aspirator: An air cleaner using vacuum to remove light trash from seeds

Control ports to adjust vacuum, cover with something to increase vacuum in seed drop tube

Seed drop tube made from drink bottle

Funnel to feed seeds into drop tube below air exhaust

2 x 1 ½ inch adapter, seems to fit most vacuum inlets

Two inch electric conduit connector

Seed aspirator made from repurposed parts

Extra port to bleed off additiional vacuum for very light seeds

Set up for very light seeds

Stock pot settling chamber

Shop vacuum

Under side of the stock pot cover

Vacuum control ports

45 elbow to defect light particles to bottom of settling chamber (stock pot)

Female adaptor screwed on to conduit connector

Adjusting the Aspirator

• Seeds are fed in a narrow uniform stream on to the side of the funnel and into the seed drop tube

• The control ports are gradually closed until the desired amount of trash is removed– Seeds fall down the seed drop tube– Trash goes to the settling chamber– A few good seeds lost for maximum trash removal

Lomatium seeds separated in the column blower

Lighter insect damaged seeds

Heavier good seeds

Insect hole

Separating Weeviled Seeds From Whole Seeds With Lomatium spp

• At first glance it looks easy because there are holes straight through the bad seeds

• But removing the bad seeds does not work– To remove most of the bad seeds, many goods

seeds are also removed– To leave most good seeds in the lot, many bad

seeds remain– Why not if I have good equipment?

Sizing Seeds First

• The Lomatium seeds were sized with round hole screens: 16, 18 (bigger number large diameter hole)

• Then each size cleaned separately in the aspirator and an excellent separation of good and bad seeds was obtained

• Next slide shows the reason for this result is that smaller (16) diameter good seeds weigh what larger (18 ) diameter bad seeds do

LODI 26

0

0.005

0.01

0.015

0.02

0.025

0.03

1 2 3 4 5 6 7 8 9 10

Individual seed number

Individu

al see

d weigh

t

16H

16L

18H

18L

Larger diameter light (18L) (bad) seeds weigh the same as smaller diameter heavy (16H) (good) seed

Why it is necessary to sizeSeed to remove lighterdamaged seed

How Clean Do I need the Seed?

• For genetic conservation: close to 100% pure• For automated sowing in containers: close to

100% pure• Sometimes answer is not clear, weigh different

needs against cost of extra cleaning– Is the lot clean enough to sample and test

accurately?– Will the seed flow through seeders?– Will the customer pay for extra purity?

Quality Seed Does Not Cost, It Pays