Volume 16, No. 1-2, 1992

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(pp. 1-8)
Reducing Dormancy in Pensacola Bahiagrass1
S.H. West2
This study evaluated accelerated aging (AA) (41 *C-100% RH) technique for Increasing germination by reducing dormancy In Pensacola bahiagrass seed. The objective was to  age the seed sufficiently to increase germination up to or near maximum viability without reducing vigor or storage potential. The [AA) treatment resulted in an increase in total germination from 50 to 95% in the seed lots of this study.

The rate of germination also was increased by the aging. In the AA treated seed only 14 days were required to attain a germination percentage equivalent to that of 28 days in the unaged seed. A more rapid germination rate would reduce the time needed for laboratory germination tests and may improve stand establishment. While the stresses of high temperature and humidity age the seed and thereby increase total germination and speed of germination, these stresses have the potential for reducing vigor and storage life of the seed. Aged seed planted in sand and incubated in a low temperature stress (25°C) showed greater  emergence (30%) then unaged seed (12%) when counted 14 days after planting. In a test to evaluate the effect of aging on viability after storage, germination of aged seed was net  reduced after 1 year of storage.
Additional index words: germination, accelerated aging, aging, vigor, storage, Paspalum  notatum.
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(pp. 9-16)
Influence of Three Commercial Seed Coatings on Alfalfa Seedling Emergence, Nodulation, and Yield
D.J. Thompson and D.G. Stout1
Commercial lime seed coatings from three companies were tested for their ability to influence alfalfa (Medicago sativa L.) seedling emergence, nodulation, and forage yield. Seedings were made at three sites in interior British Columbia, differing in elevation and environment, during each of two years, 1987 and 1988.

Only one seed coating, Rhizo-Kote, increased seedling emergence, by an average of 21 % over six seedings. At the one site where there was a response to inoculation, all three coatings resulted in root nodulation similar to field inoculation of bare seed with peat-based inoculum by the water slurry method. Seeding-year yield from preinoculated coated seed was similar to yield from field inoculated bare seed. Although Rhizo-Kote improved seedling emergence, it did not increase yield.
Additional index words: alfalfa, Lime coating, Seedling emergence, Yield, Root nodulation.
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(pp. 17-23)
Germination of Freshly Harvested and After-ripened Crambe (Crambe abyssinica Hichst. Ex. R.E. Fries) Seed1
T.J. Gutormson, K.L. Larson and T. Waqar2
Seed dormancy levels of 18 and 12% were detected for lndy and Meyer cultivars of crambe (Crambe abyssinica Hochst, ex. R.E. Fries), respectively, when tested according to current Association of Official Seed Analysts (AOSA) "Rules for Testing Seeds". Prechill treatments at 5°C and 10°C for 5d were unable to break seed dormancy completely. Gibberellic acid at the 0.050/0 concentration and 0.2% KNO3 as substrate moistening agents reduced

seed dormancy levels to 0 and 2%, respectively. However, gibberellic acid did increase abnormal seedlings and reduced seed lot viability (germination plus dormancy percentages). Distilled water and 0.2% KNO3 as substrate moistening agents produced comparable seed lot viabilities. The latter treatment, however, reduced dormant seed levels to 2% compared with 12% for distilled water. Presence of light during the germination testing period, compared with absence of light, increased 4d germination percentages but not 7d germination percentages. Temperature regimes of 20°C and 25°C did not affect germination significantly across all viability parameters. The dormancy mechanism of crambe seems related primarily to physical restrictions.
Additional index words: Gibberellic Acid, Prechilling, Dormancy, Potassium Nitrate.
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(pp. 24-29)
Comparison of Crepe Cellulose Paper Products as Germination Substrates for Corn (Zea mays L.) and Soybean [Glycine max(L.) Merr.] Seed1
T.J. Gutormson and J.S. Burris*
Crepe cellulose paper utilized as a germination substrate has traditionally been manufactured from virgin wood fibers. This study was initiated to compare Kimpak (K-22) (manufactured with virgin fibers) with Bleached Custom Wrap (BCW) (manufactured with recycled fibers) as germination substrates for corn and soybean seed.

Standard, sand, and cold germination tests all incorporated crepe cellulose paper as a substrate. Standard germination tests on corn initially showed BCW to produce a result 2% lower than K-22 did; however, an additional experiment of 10 seed lots found no significant differences. Sand and cold test normal seedling percentages were not significantly different between substrates. Soybean standard, sand, and cold test germination responses were not significantly different across any parameter regardless of substrate. Physical comparisons of substrates showed no significant difference between K-22 and BCW water-holding capacities. According to the data from seed lots tested in these studies, it seems that when used as a substrate for corn and soybean germination tests, BCW provides germination responses similar to those of K-22.
Additional index words: Kimpak, Bleached Custom Wrap, Germination, Substrate, Tray Method
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(pp. 30-38)
Post-Germination Growth Related to Time-to-Germination for Four Woody Plants1
D.T. Booth and D.R. Morgan2
Poor seedling survival reduces the effectiveness of revegetation efforts utilizing woody plants. Seedling survival might be increased by faster post-germination growth. To explore the relationship between germination rate and post-germination growth, we studied four species of woody plants that are important to western range and forest lands, and that exhibit different embryo morphologies.

The seeds were germinated using standard methods. Germination and seedling axial elongation were measured daily for 30d. Data were analyzed by linear regression. Mean germination time was 11.3, 7.9, 3.8 and 1.3d for Cercocarpus montanus, Pinus ponderosa, Purshia tridentata, and Artemisia tridentata, respectively. Post-germination cumulative growth was significantly related to time-to-germination through 10d of seedling growth for Artemisia, Purshia and Cercocarpus, and through 15d of growth for Pinus. The regression line was positive for Purshia and negative for the other species. The results imply that time-to-germination might be used as a basis for culling inferior gerrninants/seedlings of several species of woody plants, however, it is most likely to be successfully applied to Pinus, or to seeds with similar embryo morphology.
Additional index words: Germination rate, Seedling vigor, Fluid drilling, Revegetation, Pinus, Purshia, Cercocarpus, Artemisia
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