The journey from seed harvested from the field to a clean, uniform seed lot with good vigor and germination characteristics can be a long trip.  Here are a few tools that seedsmen can use, when separating the good from the bad. 

General

The Cripen cleaner (right), or something like it, has been around for at least 70 years.  It uses air to separate the light material off and different screens to separate the trash and weed seeds from the good seed.

The gravity table (left) uses both air and gravity to separate the heavier seed from the lighter seed.  Enough air is blown through the perforations in the tabletop to lift the lighter seed off the table. 

The table is slanted downward, but vibrates upward so the heavier seed that still has contact with the tabletop is moved upward and falls off the top part of the table into a separate bin. 

The light seed, not having contact with the table, moves downward, by way of gravity, and falls off the lower end of the table into its own “light seed” bin.

Separating Seed by Color

The color sorter (right) uses an electronic eye that can pick up different colors according to the way the machine is adjusted.  As seed falls down a shoot, it passes through the electric eye. If the color of the seed is different than the desired color, the electric eye will activate a sudden burst of air that pushes that seed into a reject bin while the rest of the seed passes through to another bin.

Separating Round Seed from Flat seeds

Seed is poured into this Spiral (left).  The rounder shaped seed “rolls” to the outside of the spiral as it goes downward, and then off the side of the spiral into a shoot to a bin.  The flatter seed does not “roll” as well and stays closer to the center as it goes down the spiral.  The flatter seed that stays near the center of the spiral goes into a different shoot and a separate bin. 

Separating Big Seed from Little Seed

This indented cylinder (right) rotates as seed is poured into it. Seed that fits into the “indent” inside the cylinder is carried up and dropped into a separate compartment in the center, which leads to one bin. The seed that is too big to fit into the “indent” stays at the bottom of the cylinder and is funneled into a different bin.

There are many more ways in which a seedsman turns seed he harvests into seed that a vegetable grower can plant with good results, but that’s all the time we have for now.

I’m putting together a new set of topics for the next newsletters.  If you have a topic that you would like me to report on, please drop me an email (k.kubik@hmclause.com), and I’ll try to include it in the next line-up. 

Keith
k.kubik@hmclause.com