Agriculture Reference
In-Depth Information
of seed vigor tests required additional background concerning this “new” topic. To accomplish this, the
Handbook was divided into two parts. Part I was entitled “Seed Vigor: Its Meaning and Importance” and
provided a historical context of vigor development, the deinition of seed vigor, types of vigor tests, and
the applications of vigor test information. Part II was composed of suggested procedures for the seven
vigor tests. It was printed in a loose-leaf style similar to the “Rules” to accommodate subsequent changes
in procedures. The unusual appearance of the Handbook included a black cover with white lettering. These
colors were selected because the Handbook represented a philosophical movement of a subject previously
considered as vague and gray to one that was well deined in “black and white” terms.
With the publication of the Handbook in 1983, Dr. Dennis TeKrony was asked to chair the Committee.
In 1984, under his leadership, the objectives of the Committee were deined as: 1) to improve test proce-
dures in the Handbook (move from “suggested” to a new category called “recommended” procedures)
and 2) to broaden the range of species covered. In addition, an educational pamphlet “Understanding Seed
Vigor” was published. This pamphlet was a four-page, lay summary of seed vigor that could be easily
understood by the agricultural community. During this period, the committee aggressively pursued stan-
dardization of its most promising vigor tests: accelerated aging, conductivity, and cold tests. By 1987, the
accelerated aging test was signiicantly revised and improved and became the irst vigor test for soybean
seeds to be moved from the “suggested” to “recommended” vigor test section. During this same year, over
1,000 copies of the Handbook were sold. In 1989, revisions of the accelerated aging, conductivity, and
cold test procedures were completed and published. With increasing reliability and standardization of test
results, the Committee set out to evaluate tolerances for vigor test results. This irst evaluation was com-
pleted in 1991. At that time, the Committee began evaluation of the cold test for other crops besides corn.
Dr. Jan Ferguson became the ifth chair of the Committee in 1991. The Committee continued to focus
on the movement of the most reliable vigor tests into the “recommended” vigor test section. In 1993,
the “Understanding Seed Vigor” pamphlet was updated and published. A major future objective of the
Committee remains an effort to expand vigor tests into other crops beyond those with traditional agronomic
focus.
In 2002, another revision was made to the AOSA Seed Vigor Testing Handbook which included the
accelerated aging, conductivity, controlled deterioration, cold and saturated cold tests. The most recent revi-
sion was published in 2009 and is divided into four parts. The irst two parts focus on the history of vigor
testing, challenges to method standardization, variables in vigor testing, tolerances, presentation and inter-
pretation of results as well as a general review of vigor testing and its applications. The third part covers
the principles of individual tests, while the last part describes detailed test procedures. Seed vigor tests are
grouped into ive categories: aging tests, cold tests, conductivity tests, seedling performance tests and tetra-
zolium tests. The 2009 handbook differs from previous versions in many important respects. The number of
tests has been expanded and all procedures were updated and presented in a standardized format. A detailed
discussion on identiication of and sources of variation was added and tolerance tables for many tests were
included. Finally, the 'recommended vs. suggested species' approach has been abandoned, and the previous
designation of “Recommended species” has been changed to “Species commonly evaluated by this test.”
SEEd VIGor TEST bEnEfITS
Why Test for Seed Vigor?
This question is seldom asked because there is an intuitive answer: “Because it is important to know how
seeds will perform in the ield.” But, there are even more subtle rationales for testing seed vigor than this.
We test seeds because “a seed lot is composed of a population of individual seed units; each possessing
its own distinct capability to produce a mature plant. A seed vigor test is an analytical procedure to evalu-
ate seed vigor under standardized conditions. It enables a seed producer to determine and compare the
vigor of a seed lot before it is marketed” (McDonald, 1988). Thus, we test seeds not only to determine
