Throw seed in water and skim off
the ones that float; thereby separating the light floating seed
from the heavy sinking seed.
Is that it? Is that all there is
to it?
Doesn’t seem very
technical, and a bit messy, and why not just separate the heavy
seed from the light seed using a gravity table. (Seed Tech
Newsletter #12 “Seed
Conditioning – Separating the Good from the Bad”)?
Why would anybody want to use
liquid?
Liquid Density Separation
(LDS) is Very Precise
Place 3 cups of water in a row.
In the first cup, add a non-phytotoxic salt or other tiny
particle that won’t hurt the seed. In the second cup, add one
half the salt or particles, and in the third cup add nothing.
Now…drop seed into each cup. What happens?
![](graphics/15.jpg)
All the seed floats in the cup on
the left with the most particles. All the seed sinks in the cup
on the right with no particles, and the cup in the middle is
somewhere in between. OK…take the cup on the left where all the
seed floats, and add water in small increments; diluting the
liquid. As the liquid is diluted, the heaviest seed starts to
sink. You can collect seed with a specific seed density at the
bottom of the vessel, with each addition of water, and very
precisely separate seed by its density.
Not for Field Corn
As you probably already realize,
this type of separation is not for high volume, relatively low
cost seed. When seed is worth thousands of dollars per pound,
this type of procedure can pay. Certain species are also better
suited to this process. Seed that matures inside a wet fruit,
like tomato or pepper seed, seem to respond better to the
procedure.
Next. we’ll talk about “Seed Fungicides and
Insecticides…What’s out There?”
Keith