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Effect of Soybean Seed Vigor and Size on Seedling Growth
D.B. Egli, D.M. TeKrony and R.A. Wiralagaz
Soybean [Glycine max (L.) Merrill] seed vigor can affect yield either indirectly by influencing plant populations or more directly by affecting plant growth. Greenhouse experiments were conducted to evaluate the relationship between seed vigor and seedling growth.
Additional index words: Glycine max (L.) Merrill, Growth analysis, Germination, Physical injury, Conductivity.
Sterase Isoennzyme Electrophoresis as a Method of Separating Colonial and Creeping Bentgrass Mixtures1
G.W. Freeman and F.A. Yoder, Jr2
Rapid and efficient methods are needed to differentiate between creeping bentgrass (Agrostis palustris Huds.) and colonial bentgrass (Agrostis tenuis Sibth.) species and to complement both visual evaluation of seeds and growth chamber tests. This study was initiated to determine if varying proportions of colonial bentgrass seeds could be detected in creeping bentgrass seeds using esterase isoenzyme polyacrylamide gel electrophoresis (PAGE) and to determine at what lower proportion level esterase isoenzyme PAGE was no longer capable of resolving the creeping bentgrass admixture.
Additional index words: Agrostis palustris Huds., Agrostis tenuis Sibth., Species identification, PAGE.
The Effect of Seed Treatment on Laboratory and Field Performance of Navy Bean (Phaseolus vulgaris L.) Seed Exposed to Prolonged Wet, Humid Weather Prior to Harvest1
L.O. Copeland, R. Baalbaki and N.B. Lee2
Chemical treatment of navy bean (Phaseolus vulgaris L.) seed exposed to prolonged wet, humid weather prior to hatvest improved germination more in cold and warm soil tests than in standard warm germination tests at all levels of quality between 56 and 97% germination. However, performance in all tests was improved by seed treatment, especially at lower quality levels. There was no consistent increase in performance after six weeks of storage under warm laboratory conditions. Both laboratory germination and field emergence were improved by most combinations and concentrations of seed treatment chemicals.
Additional Index Words: Germination, Cold test, Warm soil germination.
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The Effect of Seed Treatment on Laboratory and Field Performance of Soybean (Glycine max L.) Seed Exposed to Prolonged Wet, Humid Weather Prior to Harvest1
L.O. Copeland, R. Baalbaki, and N.B. Lee2
Chemical treatment of soybean (Glycine max L.) seed exposed to prolonged wet, humid weather prior to harvest resulted in more improvement in cold soil tests than either standard germination tests or warm soil tests over untreated controls at varying levels of quality between 51 and 92% germination. However, results of all tests were generally improved by seed treatment, especially at the lower quality levels, as was field emergence.
Additional Index Words: Germination, Cold test, warm soil germination.
Effect of Geographical Location of Seed Production on Performance of a Hybrid Alfalfa1
Alfalfa seed is mostly produced in geographical locations other than where it will be planted for forage production. The effect of geographic area of seed production on performance of the progeny of hybrid alfalfa (Medicago sativa L.) seed is not well known. This study was conducted to determine the effect of geographic location of alfalfa seed production on the performance of the progeny.
Plants grown in trials at Reno and Logandale, Nevada showed no significant (P=0.05) difference in plant height, dry matter yield or crown diameter due to geographical location or environment of seed production in alfalfa clone 191.
Additional index words: Seed quality, Environment, Seedling vigor, Medicago sativa L.
Effect of Freeze-thaw Cycles on Hard-seededness of Alfalfa
Freezing at an ultralow temperature and thawing was shown in 1930 to decrease hard-seededness of alfalfa but the method has never been applied commercially. Freezing equipment now exists that could be adapted for freezing batches of alfalfa seed. Thus this study was conducted to evaluate the effectiveness of freeze-thaw treatments to reduce hard-seededness of two alfalfa seed lots known to have hard seed. A study was also conducted to determine if freeze-thawing of seeds has any negative effects on subsequent plant growth.
Additional index words: Medicago, Germination, Seedcoat, Permeable, Temperature.
The Relationship between the Tetrazolium Test, Soil Cold Test and Standard Germination Test in Assessing Sorghum [Sorghum bicolor (L.) Moench] Seed Quality1
S. Paliwal, C.C. Baskin, and J.C. Delouchez2
Tetrazolium tests, soil cold tests, and standard germination tests were conducted on 40 lots of grain sorghum [Sorghum bicolor (L.) Moench]. Based on tetrazolium evaluations, seeds were grouped into high vigor, medium vigor, low vigor, and non-germinable categories. The high plus medium vigor categories of tetrazolium were significantly correlated at the 0.01% level of probability with emergence in soil cold test (r=0.936). The high plus medium plus low vigor categories were significantly correlated at the 0.01% level of probability with standard germination (r=0.900). These results demonstrate the potential of the tetrazolium test for assessing seed quality in sorghum.
Additional index words: Germination, Vigor testing, Seed quality evaluation.
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Plant Diasphore Funcitons1
Diaspore has previously been defined in the botanical sense, as a disseminule; especially one specialized for dispersal. That definition implies that diaspore morphology reflects the single function of dispersal. The plant science literature is reviewed, and ample evidence presented to show that diaspore structure and function reflect many facets in the processes of seedling recruitment. The functions reviewed include dispersal, protection, seed positioning and orientation, seed fixation, moisture adsorption, light filtering and regulating seed respiration. An enlarged definition of diaspore is offered to reflect a multiple-function concept.
Additional index words: Disseminule, Seedbed ecology, Native plants, Plant recruitment, Dispersal unit, Seedling vigor, Seeds
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