Volume 1, No. 2, 1976

Download Cover and Index

(pp. 1-23)
Proceedings of AOSA Bicentennial Symposium Seed Vigor and Deterioration
Hershey, Pennsylvania
June 22, 1976
Download entire article

(pp. 18-32)
Measurement of Seed Vigor
Don F. Grabe1
As preparation for this talk, it seemed appropriate to determine the state of the art of vigor testing in the member laboratories of the AOSA and SCST. Each of the laboratories was sent a questionnaire which asked several questions regarding their vigor testing programs.
Download entire article

(pp. 33-57)
New Methods for Maintaining Seed Vigor and Improving Performance
Anwar A. Khan, Joseph W. Braun, Kar-Ling Tao1
W. F. Millier and Robert F. Bensin2
No biophysical or biochemical means is known to man that will stop the process of aging in living systems and seed is no exception. However, attempts are continuously being made to slow down the rate of deterioration. The process of aging in seeds is accompanied by gradual deterioration and loss of vigor.

A mature seed during processing, in transit, in storage, or in the soil is subject to damage and deterioration by such factors as mechanical injury, infection by microorganisms, insect infestation, supraoptimal and suboptimal temperatures, drought, flooding, salinity, and toxic gaseous and chemical environments. These factors often initiate secondary responses such as induction of dormancy, generation of heat by the action of microorganisms and insects, and permeability changes by shifts in the chemical environment, all of which have been related to seed deterioration.
Download entire article

(pp. 58-74)
Seed/Seedling Vigor and Field Performance1
J. S. Burris2
A discussion of seed vigor and field performance presupposes that vigor is a significant tangible entity. Because others in this symposium deal with the definition of vigor and how  it can be measured, I will discuss manifestations of vigor in the field.
Download entire article

(pp. 75-85)
Standardization of Vigor Tests
James C. Delouche1
Vigor testing of seed is surrounded by much confusion and controversy. The confusion is mostly associated with the multitude of vigor tests developed and promoted during the  past 25 years, the lack of workable definitions of seed vigor and vigor tests, and excessive variability in vigor test results and their interpretation.

The controversy in seed vigor testing derives from the fear of some and the hope of others that vigor tests will become more widely recognized as a major means of establishing the planting value of seed, and  permitted or required in seed labeling.
Download entire article

(pp. 89-97)
Some Genetic Aspects of Seed Vigor1
William R. Kneebone2
Seeds have often been compared to batteries, and it is a good analogy. They can absorb and accumulate a charge or potential. The amount which can be accumulated is finite, varying with the accumulator. Some may leak charges rather quickly, others maintain them. Some are capable of rapid release on call, others not. Release may be peaked or sustained.

The ideal seed and the ideal battery attain and keep high charge levels, releasing energy when needed. The maternal plant is the source of charge for the seed and other seed properties are products of the engineering of the seed itself. Engineering of living organisms, in turn, is genetic and, in this sense, all seed vigor is genetically determined.
Download entire article