Seed Quality

Almost all seed is sold on a PLS (pure live seed) basis and even if it is sold on a bulk basis, the only means of determining what you are getting for your money is to ask for and determine for yourself the PLS price per pound you are paying. The seed purity is given in percentage, for sake of argument 90%. The viability for Kochia prostrata seed is most likely given in percentage TZ, (tetrazolium), a term for the laboratory process involved. Lets assume the TZ on our particular lot to be 65%. If you were paying $3.00 per bulk pound of seed, you would have to divide the bulk pound price by the PLS factor to determine your PLS price per pound. The PLS factor is simply the decimal product of the purity times TZ, in our case:

(Purity)X(TZ) = PLS Factor
(0.90)X(0.65)= 0.585
PLS price per pound= $3.00/0.585= $5.13 per PLS pound (rounded to nearest cent)

Another very important factor in determining the quality of seed is the bushel weight of the seed. This is a factor frequently overlooked by buyer and seller alike. If you are contemplating purchasing Kochia prostrata seed, be sure to ask for the specific bushel weight of the seed. If the seller says he does not know, caution should be taken!

If you look at Kochia prostrata seed under a microscope, it will look something like a cornflake with a seed embryo in the center. The lower your bushel weight, the more cornflake you are buying in relation to seed. Therefore, the higher the bushel weight the more pure live seed per pound. Good bushel weight for Kochia prostrata generally runs around 26 pounds per bushel or better.

All seed considered for purchase should meet certified requirements for seed in the state in which it was produced. It should carry a current analysis tag (test for viability or TZ should be within one year) or accompanying copy of the state seed lab report. If it is not purchased under these guidelines, then you run the risk of noxious weed contamination or inferior seed.

About 7X magnification of Kochia prostrata embryo
About 15X magnification of Kochia prostrata with endocarp intact	About 14X magnification of Kochia prostrata showing degradation of endocarp