Volume 23, No. 1, 2001

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SYMPOSIUM: Promoting Professionalism in Seed Analysis (free download)
A Simple Method for Orienting Very Small Specimens for Paraffin Sectioning (free download)
A Technique to Facilitate the Paraffin Sectioning of Hard or Brittle Plant Material (free download)

(pp. 21-34)
Accelerated Aging Test for Corn Seed
J.M.Woltz* and D.M. TeKrony
Although the accelerated aging (AA) test is recommended to measure soybean (Glycine max (L.) Merrill) seed vigor, a uniform AA procedure has not been developed for testing  corn (Zea mays L.) seed. This study evaluated the effect of aging time, temperature and seed treatment on corn seed germination and related AA results to cold test germination and field emergence.

Forty grams of fungicide treated and untreated seed from four seed lots across two hybrids were aged at 41 and 45°C for 72, 96 and 120 hours. Aging treated seed for up to 120 hours at 41°C caused no reduction in germination, however, significant reductions in germination occurred after 96 hours for untreated seeds. Both treated and untreated seed aged at 45°C showed significant reductions in germination after 72 hours. Two AA treatments (41°C, 96 hours, 45°C, 72 hours) which gave the best separation in seed lot vigor were compared to tray cold test germination across many additional seed lots and several hybrids. Both AA procedures were highly correlated with each other, however, the germination levels were lower using the 45°C, 72 hour treatment. Neither AA procedure related well to cold test germination for treated seed. Standard germination, AA (45°C, 72  h) and cold test germination were related to field emergence in nine experiments across three years. A field emergence index (FEI, mean field emergence/mean standard germination x 100) for each planting date showed a range in field conditions from severe stress (FEI = <65) to near ideal (FEI = 97). The prediction accuracy (proportion of seed lots in each experiment that had !70 or 80% field emergence) was high for standard germination only in near ideal field conditions. As stress increased in the seedbed (FEI 75 to 90), at a minimum acceptable vigor level of !80%, both AA and cold test accurately predicted field emergence. Thus, the seed industry may want to consider both tests when screening genotypes for maximum field performance.
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(pp. 35-49)
Comparison of Four Purity Testing Methods for Festuca brevipila R. Tracey and F. ovina L.
Deborah J. Lionakis Meyer
Comparisons among the AOSA purity testing method for hard fescue (Festuca brevipila R. Tracey) and sheep fescue (F. ovina L.), and three other more efficient methods were made by the AOSA Purity Subcommittee. Percent pure seed, number and type of seed unit attachments, quantity of inert matter recovered from attachments, time required for inert recovery, and laboratory performance were examined. Two alternate methods produced nearly identical purity results to the AOSA Method, with reduced analysis time requirements and no significant differences.
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(pp. 50-57)
Three-dimensional Seed Visualization Using QuickTime VR
Yusaku Sako, Kikuo Fujimura,Miller McDonald, and Mark Bennett
Seed identification manuals are used by seed analysts as references to identify seeds. However, the success of this task is limited because such manuals only supply two-dimensional seed photographs and diagrammatic representations. In this study, a new, three-dimensional representation of seeds is described to supplement these traditional photographs and drawings.

QuickTime VR is a promising method for viewing three-dimensional objects on a computer screen.Unlike traditional computer media such as static images or movie clips, it permits the user to rotate the object and view it from various angles on the computer screen, giving the viewer the sense of examining a hand-held object. In this study, an interactive computer medium is developed using QuickTime VR technology to allow the user to experience the sensation of examining actual seeds. This approach allows examination of virtual seeds from any angle, permitting more accurate identification by seed analysts and serving as an excellent instructional medium for those who study seeds.
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(pp. 58-67)
Predicting the Longevity of Finger Millet and Vegetable Amaranth Seeds During Storage Under Controlled Temperature and Moisture Content Conditions
E.Mutegi, A. K.Misra, and D.K. Kiambi
Seeds of finger millet (Eleusine coracana (L.) Gaertn. var. KAT/FM-1) and those of Amaranth (Amaranthus hybridus (L.) ssp. cruentus (L.) Thell.) were stored in hermetically sealed, laminated aluminum foil packets, for up to 252 days at different constant conditions, which included combinations of temperatures ranging from 15° C to 40° C and moisture contents ranging from

5.3% to 17.3% (fresh weight basis). Seeds were sampled from storage for viability determination at different intervals depending on the storage regimens. Viability decline during storage was generally rapid at higher temperature and/or moisture content combinations. The effect of storage conditions on viability was quantified using viability equations. For each of the two species, the estimated periods for viability to fall to 50% (p50 value) decreased with an increase in the storage temperature and/or moisture content. Viability constants for each of the two species were obtained and used to predict longevity at various non-extreme hypothetical storage conditions. At comparative storage temperature and moisture content combinations, seeds of the two species differed considerably in longevity. The constants obtained in the present study could be applied in predicting storage life of seeds of the two species, especially under short to medium-term storage conditions.
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(pp. 68-77)
Intra-specific Variability in Germination Behavior and Seed Testing Protocols: The Challenge of Intermountain Species
Stanley G. Kitchen
The seed trade in the United States markets an ever-growing list of native species in  response to increased demand from horticultural and revegetation users. Proper  germination timing is critical for these wildland-adapted species and is often regulated through various forms of seed dormancy. Significant within-species variability in seed germination behavior is common for broadly adapted species of the Intermountain West (USA).

High levels of intra-specific variability in germination behavior make selection of a single, best germination test problematic. Protocols employing multiple tests can be effective in determining both seed viability and dormancy for variable species. The ability to deliver meaningful seed quality information for native species will be enhanced as a multi-method philosophy is further embraced and utilized by seed analysts and their organizations.
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(pp. 81-84)
Three-Day Count as a Vigor Test for Cottonseed
Charles C. Baskin
The number of strong seedlings in germination tests of acid delinted cottonseed [Gossypium hirsutum(L.) and Gossypium barbadense (L.)] after three days at 30°C were compared to cool germination test results. Three comparisons were conducted, two with G. hirsutum L., (30 and 24 seed lots) and one with G. barbadense L., (seven seed lots).

In the thirty seed lot comparison with G. hirsutum L., the 3-day count averaged 78.4% and cool germination test averaged 75.3%. Sixty percent of the 30 seed lots had 3-day counts that were ± 7 percentage points of the cool germination test. In the second comparison of twenty four seed lots with G. hirsutum L., the 3-day count averaged 81.5%and cool germination averaged 81.4%. Ninety-one percent of the seed lots had 3-day counts that were ± 7 percentage points of the cool germination test. In the seven seed lot comparison with G. barbadense L., the 3-day count averaged 81.0% and the cool germination test averaged 79.5%. Six of the seven lots had 3-day counts that were ± 7 percentage points of the cool germination test. These data suggest that counting strong normal seedlings after three days at 30°C may be an acceptable alternative vigor test for cottonseed where facilities and equipment for a cool germination test are not available.
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(pp. 85-87)
Evaluation of a Nondestructive Seed Fill Determination Method for Use with Native Juniper Seed
Yvonne Warren and Carlton Britton
A common nondestructive method to obtain filled seed is to place them in water and select the seeds that sink. We used two techniques to evaluate this method in determining native juniper seed fill. Seeds were placed in water and separated into groups that sank and floated.

The fill status of the two groups was determined by opening and visually inspecting the contents of 1000 seeds from each group and by viewing x-ray films of 1935 seeds that sank. Though more filled seeds sank than floated (χ2 = 313.72, p<0.05) and the number of filled seeds observed in opened versus x-rayed seeds did not differ (χ2 = 1.2281, p> 0.05), approximately 30% of seeds that sank were not filled. This error can be attributed  to empty seeds that sank having thickened coats. Use of this nondestructive method in conjunction with x-ray eliminated the error and allowed selection of 100% filled seed.
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(pp. 88-91)
Germination and α-amylase Activity in the Grains ofWheat, Treated with Chloroindole Acetic Acids
A. Ahmad, S. Hayat, Q. Fariduddin and Shazia Alvi
The grains of Triticum aestivum (L.), c.v.HD-2204, were imbibed in 10-6 or 10-8 M aqueous solutions of IAA; 4-ClIAA; 5-ClIAA; 6-ClIAA; 7-ClIAA; 4,6-Cl2IAA or 4,7-Cl2IAA for 6, 12 or 24 hours and transferred to distilled water for germination up to 96 hours. Monochloroindole-3-acetic acids, irrespective of their concentration and duration of soaking, improved germination (%) and the activity of α-amylase, noted at three durations of soaking. Dichloroindole-3-acetic acids were as effective as IAA. Twelve hours soaking in 4-ClIAA  proved best but was closely followed by 7-ClIAA.
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(pp. 92-97)
Effect of Bean Ladder Usage on Mechanical Damage During Soybean Seed Conditioning
F. S. Shah, C. E.Watson, N. D.Meredith, P. A. Bohn, and B.Martin
Post-harvest soybean [Glycine max (L.) Merr.] seed conditioning operations can inflict mechanical damage to the seed. The objectives of this study were to 1) quantify the amount of mechanical damage at each impact point during seed conditioning and 2) evaluate the effect of the bean ladder in minimizing mechanical damage and improving seed quality during conditioning.

Soybean seed from a single seed lot of cultivar H6686 were loaded into two storage bins, one with a ladder and the other without a ladder. Seed were sampled at five stages during receiving and nine stages during cleaning and bagging and evaluated for moisture content, germination, and percentage of cracked seed coats (CSC). The seed in the bin filled with the bean ladder had a significantly lower proportion of CSC and significantly higher germination than seed in the bin without a ladder. Seed sampled from the bin without the ladder had a consistently higher percentage of CSC at most drop heights; however, the difference was significant only at the greatest height, 25.1 m. Seed sampled from the bin with the ladder exhibited significantly higher germination than seed from the bin without the ladder at drop heights of 16.8 m or greater. Seed removed from the bin with a ladder had significantly higher germination at the end of the cleaning and bagging phase than the seed from the bin without a ladder. The bean ladder helped reduce mechanical damage during the receiving phase and maintained a higher level of seed quality at the end of the cleaning and bagging phase compared to thebin  without a ladder.
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