Agriculture Reference
In-Depth Information
Seed Storage Area
Good laboratory practices, seed laws, and quality assurance programs require that samples be stored for at
least three years after testing to provide for possible veriication of test results and for retests. Thus, seed
laboratories need to have a large storage facility conveniently located in which samples may be held after
the tests have been completed. The sample iling system should allow easy access to any sample. Adequate
lighting should be provided to aid sample identiication and prevent iling errors. Samples can normally be
moved to storage immediately after being planted for germination. If there is likelihood that samples may
be retested for germination, favorable humidity and temperature conditions of the storage area should be
provided. A useful rule of thumb proposed by Harrington states that the sum of the percent relative humid-
ity, plus the temperature (°F) should not exceed 100 for safe storage.
data Consolidation and office Area
All test results should be forwarded to the ofice and transcribed on a laboratory report, which is provided
to the customer electronically, by fax or by mail. Test results can be input into the computer database either
at the point of origin in the testing area, or entered later using information recorded by testing staff on a
testing card. Regardless of the mode of reporting test results, it is important that a system of checks, such as
requiring that all test reports be checked by the supervisor of germination and purity sections, be designed
into the system to ensure complete accuracy and conidentiality. The ofice personnel are the last check
point for reporting the inal results.
TyPES of TESTS
Purity Testing
Purity testing remains at the very core of most seed testing laboratories, thus in most labs the activities of
the entire laboratory should be designed around this area. It must be provided with optimum ergonomic
working conditions of light, space, and comfort. It should have ample natural light from windows facing to
the north (in northern climates) and be supplemented with luorescent light to provide minimum eye strain
over long periods of intense, focused seed examination. Depending on the size of the laboratory and number
of purity analysts, the purity testing area may be all one area or divided into separate areas or cubicles for
different analysts. There should be similar space for each analyst, but the space should be capable of modi-
ication for individual ergonomic requirements, tastes and preferences. This may be achieved with the use
of modules, which also provide some degree of privacy and opportunity for maximum concentration. Each
area should be equipped with a working surface on a table or desk of suitable height that will be comfortable
for each analyst. It should have easy access to a nearby bookshelf or reference library. Comfortable chairs
with adjustable back and seat are important for the comfort of the purity analyst.
The purity testing area should have convenient access to the receiving and dividing area. Samples
may be distributed to different purity analysts after working samples are subdivided and weighed or may
be picked up by analysts as they are ready to perform each test and/or procedure. Samples may also be
distributed by a supervisor to each purity analyst as the workload and skills warrant.
Most purity tests will be conducted by an analyst at a working board on a lat-topped table, along
with a forceps, a 2X to 10X hand lens and a folded 3 x 5 or 4 x 6 card to catch and pick up the sample.
However, well-equipped laboratories should have special equipment for aiding in purity separations. This
may include seed blowers, sieves, various mechanical separators and automatic inspection stations. These
can be used very eficiently to move the seed systematically throughout the analysis and may employ a
vacuum needle to remove purity ingredients or noxious weed seeds. Some equipment may aid in the separa-
tion of inert matter or contaminating weeds and other crops; others are designed to provide analyst safety by
