Volume 14, No. 2, 1990

 Download Cover, Contents and Reports

(pp. 74-82)
Ethanol Evolution During the Early Germination of Artificially Aged Soybean Seeds
M.E. Reedy and A.D. Knapp
Corsoy 79 soybean (Glycine malt (L.) Merr.) seeds were artificially aged by either a high-moisture, high-temperature (>90% RH, 42°C) method or by a constant 12% moisture, high-temperature (42°C) method. Seeds were imbibed for up to 34 h, and ethanol evolution measured until radicle protrusion occurred. Ethanol evolution rates were greater for seeds with poorer viability and vigor, and the ethanol evolution peak rose with increased water uptake and aging.

Seed moisture at peak ethanol evolution also varied with aging treatments. Peak ethanol levels did not occur immediately before radicle protrusion. Delay in the attainment of membrane integrity, which resulted in lost viability and vigor and an imbalance between glycolysis and the citric acid cycle, may explain observed patterns of ethanol evolution. It may be possible to use ethanol measurements as a rapid assessment of seed vigor.
Additional index words: accelerated aging, viability, vigor.
Download entire article

(pp. 83-93)
Problems With the Tolearnce Tables for Noxious Weed Seeds1
Phillip L. Chapman and Arnold L. Larsen2
The Tolerance Tables for Noxious Weed Seeds have several deficiencies: they lack a clear statement of objective; they are based unnecessarily on an inaccurate approximation; and they allow for subjectivity as to when and how to retest a seed lot. This subjectivity greatly affects the probability that a seed lot will be declared out of tolerance. These deficiencies are discussed and graphs based on theoretical calculations are presented which describe estimated probabilities that a lot will be declared out of tolerance under several circumstances in which a seed lot is labeled correctly, or at least labeled in good faith.
Additional index words: Poisson distribution, probability of violation, randomness, sequential methods.
Download entire article

(pp. 94-103)
Germination of Sees of Columbia Needlegrass1
J.A. Young, EL. Emmerich, and B. Patten2
Columbia needlegrass [Stipa columbina Macoun.) is an Important native grass on western rangelands that would be a valuable species for use in revegetation treatments. The objective of this study was to further understand the germination requirements to help ensure the establishment of this species from seedlings.

The germination of seven collections or accessions was investigated at 55 constant and alternating temperatures. For dormant collections, prechilling, potassium nitrate (KNO3) and gibberellin (GA3) enrichment of the substrate were used to enhance germination. For some of the seed sources evaluated, appreciable germination occurred over a wide range of temperatures without prior treatment to enhance germination. Germination of these seed sources was greatly reduced at low incubation temperatures. The temperature regimes that most frequently supported optimum germination (optimum defined as nut lower than the maximum observed and its confidence limit at the 0.01 Ievel of probability) were 15/25o C. (15o C. for 16 h and 25oC. for 8 h in each 24 h period), 15/35o C. and 20/35o C. Dormant seeds of Columbia needlegrass had germination enhanced by GA3 enrichment from 0.289 through 0.867 mmol L-1,  and KNO3 from 0.001 through 0.1 mol L-1.
Additional index words: Stipa columbiana Macoun., rangelands, quadratic response surfaces.
Download entire article

(pp. 104-140)
AOSA Symposium Entitled "Seed an International Commodity"
J.S. Burris1
There is little doubt that we live in a vastly different world today than existed in 1908 when the Association of Official Seed Analysts was formed. Few would argue that we have not witnessed dramatic changes since 1939 when the first Rules for Seed Testing were published. The initial draft fully acknowledged the important contribution that the already decades old International Seed Testing Rules made to the American Rules. Over the last 50+ years the two sets of Rules have been expanded, refined, reviewed and revised to make them as accurate and precise as is reasonably possible.

Leading laboratories from all over the globe have contributed time and resources to this selfless task. But as we begin the last decade of the 20th century the combined impetus of the many changes that have occurred during the last five decades and especially the dramatic changes that have occurred in the last 10 years demand that we consider whether enough common ground exists such that the individuals responsible tor seed testing world wide could use one common set of reference Rules.
We are part of a global agricultural production system. The interdependence of which was made very clear following the North American drought of 1988. Suddenly many of the world markets for maize seed became potential suppliers to supplement the short supply available in the US. These po1ential new suppliers represented a whole new set of trade and quality standards to be considered. Fortunately these potential partners were basing their quality standards on a known set of published guides and schemes. Thus the transfer of seed stocks could proceed not impeded by differences in testing protocol or standards. Another important change in the seed industry has been the rapid entry of the multinational corporations. These acquisitions have resulted in immediate affiliations of producers in many countries with the common bond of corporate allegiance to a company located in the U.K., Holland, France, Switzerland, Japan or the US. These multicultural mergers have brought many challenges to seed stock transfer but fortunately not any disagreement on how the quality standards should be measured.
The process initiated during the last decade will accelerate as communications improve and trade restrictions diminish. The seed technologists have a vital role to play in this globalization process. The challenge is tor us to promote progress and the orderly transfer of germplasm . To do this may require discussion and compromise. The opportunities are great and the benefits are many not only to agriculture but also ultimately to the consumer. The following papers deal with various aspects of the challenges facing the AOSA and ISTA during their transition to supportive global partners.
Download entire article (free download)