Agriculture Reference
In-Depth Information
3. Different interpretation of the Rules. It is extremely dificult to describe certain test procedures
and deinitions of biological variation unambiguously in writing, particularly after being trans-
lated into several languages. Many of the described procedures also leave it up to the analyst to
make decisions, as only minimum requirements are indicated. The amount of grinding of large
seeds for moisture tests is only deined as limits for amounts of certain particle size fractions, and
subjective interpretation of abnormal seedlings is an example of an arbitrary differentiation of a
biological spectrum.
4. Laboratory facilities. The quality of germinators, moisture meters, and other equipment, as well as
their maintenance and calibration, may lead to undetected differences in test conditions.
5. Changes in physiological seed quality. Seeds are living organisms, and their response to germina-
tion test conditions may change if the tests are conducted several months apart. This is particularly
true when the seeds go through after-ripening and their dormancy status charges or when storage
conditions are less than optimal. Low viability may lead to variable results since deteriorated seeds
can be more sensitive to test conditions such as moisture content of the substrata, temperature, and
the presence of microorganisms.
6. Analyst knowledge and experience. The analyst must be able to recognize and control the various
factors that lead to unreliable data. Subjectivity in interpreting results among analysts is one of the
factors that lead to variability among test results.
LAborATory ACCrEdITATIon
Traditionally, seed testing organizations in the United States and Canada have not certiied laboratories,
but they have certiied the competence of individual analysts in various ways, while laboratories in Europe
have opted for laboratory accreditation. However, this has changed in recent years. Laboratory accredita-
tion today is a documented process by which an authorized accreditation body gives formal recognition
that a seed laboratory (oficial, private or commercial) is capable of performing seed testing duties that
are determined in a pre-accreditation request. Among the accreditation bodies for seed laboratories are
ISO (International Organization for Standardization; ISTA (International Seed Testing Association); USDA
(United States Department of Agriculture); and CFIA (Canadian Food Inspection Agency).
Principles of Accreditation
Accreditation establishes international credibility for accredited laboratories, which may minimize the need
for retesting seeds in different countries. It also contributes to improved proiciency and eficiency, thus
reducing costs. The ultimate goal of accreditation is to improve the personnel and operational performance
of seed testing laboratories and increase their competence. Accreditation confers status and credibility on
a lab and promotes acceptance of the accredited laboratory's results. In addition, accreditation may be a
requirement for government or business contracts.
To become accredited, a laboratory must develop and implement a quality management system as
deined by the particular standard under which it will be accredited, submit its documentation for review,
undergo an on-site audit, and complete any mandatory corrective action resulting from the audits. The
laboratory also may be required to maintain membership with the accrediting body or other professional
organizations, perform well on proiciency testing, or maintain speciic analyst
certiication
.
The scope of a laboratory's accreditation is a document describing what tests, methods or species
the laboratory is accredited to perform. A laboratory's quality system should be appropriate to its scope
of accreditation. Additionally, the scope determines what test results the laboratory is allowed to report on
oficial documents such as ISTA certiicates or USDA ASL reports of analyses.
