4 Factors For Seed Testing

A plant is no better than the seed from which itseedlings. Some of the organisms can be spotted by
comes! Although this garden truism has probably beendirect microscopic examination. Others are detected
known since man first began to cultivate plants, lawsby special isolation techniques in which the seeds are
to protect farmers and gardeners against the sale ofplaced on special growth medium in the laboratory, and
inferior or worthless seed are of recent origin.the parasitic organisms then grow out of the seed
Most states now have rules and regulations pertainingonto the special food. But it can be avoided by treating
to the labeling and sale of seeds. They also maintainthe parasitic organism just like in lawn fungus
seed-testing laboratories, the function of which is totreatment.
determine whether the seeds meet theseGenetic purity is probably the most difficult factor to
requirements. Such laboratories conduct routine testsascertain. Such methods as the use of ultraviolet light.
according to a strict set of official rules and can quicklydisease-resistance tests of seedlings, and special field
uncover violations.tests are used to determine this quality. Seed testing in
Reliable seedsmen always aim to produce andAmerica is on an unusually high plane. All official testing
distribute seeds of high quality at a reasonable cost tolaboratories in this country are members of the
the consumer. The larger seed concerns have theirAssociation of Official Seed Analysts. This association
own seed technologists to help further this objective.has a strict code to which all members must adhere.
Four factors are known to affect seed quality:Its methods and rules for seed testing are revised
mechanical purity, percentage of germination, presencecontinuously to keep pace with new developments.
of disease and genetic purity. Mechanical purity refersSuch rules cannot remain static because new varieties
to the percentages of pure seed, inert matter andof plants are constantly being introduced and
weed seed. Obviously the packet must consist almostconsequently new methods for analyzing and testing
entirely of the kind of seed printed on the label. Thetheir seeds must be devised.
presence of more than a trace of inert matter not onlyThere also is a Society of Commercial Seed
suggests that the seed has been improperly cleanedTechnologists whose membership is restricted to
but also that such matter may carry insect pests ortechnologists presently employed in a seed firm or an
parasitic microorganisms.independent commercial seed laboratory.
The percentage of germination is extremely importantFinally there is an international seed-testing association
because it indicates the number of seeds that can beto which most of the free nations of the world belong.
expected to produce normal plants under favorableIts members meet every three years to set up
conditions.methods and rules for the testing of seeds that are
Disease organisms present on seeds are undesirableexchanged among member nations.
because they may cause blights or rots of the