• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.489-495
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• 1996

Seedling emergences of four rice varieties (Dongjinbyeo, Dadajo, Galsaekggarak-sharebyeo, and Italiconaverneco) and three barnyardgrass species(Echjnochloa oryzjcola, E. crus-gali var. crus gali E. crus-gali var. praticola) were evaluated in relation to soil strength. Soil strength was varied by compressing the entire volume of soil with a hydraulic jack so as to be 0.5, 1, 2, 3, 6kg /$\textrm{cm}^2$. Soil strength was measured with a penetrometer (Yamanaka type) and soil covering above the seed was 4cm deep. Experiments were conducted at two air temperature conditions of 17 and $25^{\circ}C$. At a soil strength of up to 2kg/$\textrm{cm}^2$, little or no decrease in seedling emergence occurred in all rice varieties and barnyardgrasses tested. Above that value, seedling emergence decreased progressively as the soil strength increased. The degree of decrease was greatest in Dongjinbyeo and smallest in Dadajo among tested rice varieties, and greatest in Echinochloa oryzicola among barnyardgrasses, being greater in barnyardgrasses than rice. Seedling emergence was delayed almost linearly as the soil strength increased. The delay was greatest in Dongjinbyeo among rice varieties and in Echinochloa oryzicola among barnyardgrasses. Mesocotyl length increased as soil strength increased up to 2 to 3kg / $\textrm{cm}^2$ in Dongjinbyeo and Dadajo in 17$^{\circ}C$ and $25^{\circ}C$, and up to 6kg/$\textrm{cm}^2$ in Galsaekggaraksharebyeo and Italiconaverneco in $25^{\circ}C$. Dongjinbyeo showed the least elongation of mesocotyl among rice varieties in any soil strength. The total length of mesotyl, first internode and incomplete leaf showed little variation with soil strength. The total length was longer than the 4cm covering depth in other varieties except Dongjinbyeo. This might have caused the lower emergence rate in Dongjinbyeo than other varieties in higher soil strength.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.228-234
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• 1993

Seedling emergence of 15 rice varieties (Gayabyeo, Chilseongbyeo, Samgangbyeo, Yeongsanbyeo, Yeongdeugbyeo, Hwajinbyeo, Palgongbyeo, Seomjinbyeo, Tamjinbyeo, Milyang 95, M 101, M 202, Newbonnet, Tebonnet, and Lemont) were tested at different soil moisture regimes and seeding depths. Submergence for four days immediately after seeding did not reduce emergence rate in all varieties. Under the flooded condition, the percentage of emergence of all varieties at 1.5cm seeding depth ranged 0～40%, it is much lower compared to uncovered control, and percentage of seedling survival ranged 0～24% due to death of some emerged seedlings. Under the field condition, one time flooding up to 10cm above the soil surface after seeding did not reduce the percent emergence of seedlings. The pF value of soil was 0 for few days after flooding or raining and Eh of soil ranged 443-453m V.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.297-303
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• 1993

Seedling emergence and .stand establishment in dry-seeded rice is unstable at present due to deep seeding, low temperature at seeding time, excessive drought or raining etc. This experiment was conducted to elucidate the effect of gibberellic acid(GA$_3$) on the seedling emergence and growth in dry-seeded rice. GA$_3$, IBA and Metalaxyl were treated by seed-soaking or-spray. Hwaseongbyeo, a japonica rice, was used. The seed-soaking treatment with GA$_3$ significantly increased the seedling emergence and plant height as compared with untreated seed. However, no difference was observed in IBA and Metalaxyl treatment. The optimum concentration of GA$_3$ to promote the seedling emergence and growth in dry-seeded rice was about 100ppm for seed-soaking and about 200ppm for seed-spray treatment. The seed-spray treatment of GA$_3$ with 200ppm promoted earlier and faster seedling emergence and elongated seedling height as compared with untreated seed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.525-532
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• 1995

The periods of germination and seedling emergence, epidermal cell size and the activities of peroxidase and amylase of 6 rice cultivars were examined to clarify the response to 3 temperature conditions, constant temperatures of 27$^{\circ}C$ and 17$^{\circ}C$ and alternating temperature of 24/1$0^{\circ}C$, in the dark condition. The periods of germination and seedling emergence were increased and the germination was delayed greater than the seedling emergence under 17$^{\circ}C$ and 24/l$0^{\circ}C$, compared with 27$^{\circ}C$. Lengths of epidermal cell of coleoptile and first leaf were reduced, but the widths were increased in the 17$^{\circ}C$ and 24/1$0^{\circ}C$, compared with 27$^{\circ}C$. The activities of peroxidase in the emerging shoots and amylase in the germinating seeds were reduced in 17$^{\circ}C$ and 24/1$0^{\circ}C$. There were significant correlations between peroxidase activities and the widths of epidemal cell of first leaf and between amylase activities and periods of germination. Varietal differences of all observations were remarkable in 17$^{\circ}C$ and 24 /1$0^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.274-285
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• 1996

These experiments were conducted to evaluate the effects of seed coating with ten environmentally acceptable polymers, on germination percentage, water uptake, respiration, emergence and seedling growth characteristics. The water absorption of polymer-coated seeds in saturation condition was highest in klucel and lowest in polyvinyl pyrrolidone(PVP), and that in water was highest in klucel and lowest in maltrin. Respiration rates of polymer-coated seeds in Hwayoungbyeo and Ilpumbyeo were lower than those of none-coated seeds, and those in Daecheongbyeo and Jinmibyeo were higher than that of none-coated seeds, and those of sepiret coated seeds were higher than PVP coated seeds. The germination polimer-coated seed was reduced by one percentage by coating with seed coating machine. Germination percentage was not affected by any of polymer coating in high quality seed, but there were significant effects in low quality seed coating with waterlock, surelease 46 and sepiret significantly reduced germination some cultivars. Germination percentage after accelated ageing treatment were slightly higher most of polymer-coated seeds than in none-coated seeds, but those of sepiret-and klucel-coated seeds were lower significantly. Germination percentage of seeds coated with daran 8600, rnaltrin, sacrust and opadry were enhanced slightly under cold test other polimers reduced germination. The seedling height of polymer-coated seeds were longer than those of none-coated seeds, but those of waterlock, PVP and maltrin coating seeds were shorter, seedling hight was shortened by polimer coating under cold test. Polymer-coated seeds showed higher emergence percentage, shorter emergence time in field condition. The highest emergence percentage and the shortest emergence time was shown at 90% soil moisture content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.174-182
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• 1993

Performance of 3 indica ${\times}$ japonica(Chilseungbyeo, Samgangbyeo, and Gayabyeo), 7 japonica(Yeongsanbyeo, Yeongdeugbyeo, Hwajinbyeo, Palgongbyeo, Seumjinbyeo, Tamjinbyeo, and Milyang 95), and 2 indica(Tebonnet and Lemont) rice varieties was tested at 1, 3, 5, and 7cm seeding depths in a growth chamber and field. In the growth chamber the number of days from seeding to seedling emergence increased as seeding depth increased, while percent germination and emergence and emergence / germination ratio decreased. However, in the field seedling emergence at 1em seeding depth delayed slightly compared to 3cm probably due to lack of soil moisture. The number of seedlings and maximum tillers at 1, 3, and 5cm seeding depths was similar, but it was higher compared to 7cm seeding depth. Yield and yield components were similar among the seeding depths when all the varieties averaged although 1,000-grain weight was slightly higher at 7cm deeding depth compared to others. At 1cm seeding depth the length of mesocotyl of all varieties was similar and ranged 0.1-0.2cm and that of coleptile ranged 0.8-1.1cm. As seeding depth increased up to 7cm Tebonnet which showed the highest percent emergence emerged by elongation of both mesocotyl and coleoptile, while the other varieties emerged largely by elongation of coleoptile.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.134-141
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• 1989

In order to estimate field seedling emergence and grain yield by the information collected from various laboratory seed vigor tests, each two malting and naked barley cultivar seeds were artificially aged according to the standard aging treatment suggested by the Association of Official Seed Analysts. The seed vigor tests adopted were warm- and cold-germination test, tetrazolium vigor test and electrocon. ductivity test. Field emergence of malting barley (Y) was estimated by Y=-2.962+0.229X$_1$ (% warm germination) -0.001X$_2$ (vigor of warm germination test: WGT) +0.354X$_3$ (vigor of cold germination test: CT) -0.558X$_4$ (% cold germination). The multiple correlation coefficient indicated that % warm germination. was contributed 64 % of the variation in seedling emergence rate of malting barley. The vigor of warm and cold germination tests, and % cold germination contributed additional 4, 7, and 9%, respectively, upon addition of the variables into regression. For naked barley, the regression equation of emergence rate was less efficient(R$^2$=54%) than that of malting barley(R$^2$=84%). A model to predict grain yield by the results of various seed vigor tests was not evaluated for both malting and naked barlev.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.88-99
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• 1996

In recent years dry direct-seeding of rice has been encouraged by the government and increasingly practiced by farmers in Korea. This has been bringing up an increased occurrence of weedy rites. Some farmers in the southern region dare to sow the rice before winter after harvest, while most farmers wish to sow as early as possible in the spring to secure the growing period, and to disperse the intensive labor in early May. The purpose of this study was to determine the feasibility of moving the sowing of rice to an earlier date under dry direct-seeding, and to elucidate the nature of emergence of an old strain of rice, weedy rites, and barnyardgrasses tinder this farming practice and their adaptive competence over present cultivate. The presently recommended rice cultivar, Dongjinbyo and an old rice strain, Dadajo which prevailed in early 1900s, almost could not emerge from soil deeper than 6cm and could emerge to only 5.3% at best from 1cm deep loamy soil field when the seeds were sown on Nov. 28. However, two strains of weedy rites being weedy for over 200 years emerged by 17.0 to 63.0% from the loamy and sandy clay loam field 1 to 6cm deep. Emergence of the weedy rites was greater in the loamy soil and at a shallow depth, and negligible from the soil depth of 9cm. Barnyardgrasses sown on Nov. 28 emerged by 13.4 to 51 % from the 1 to 3cm deep loamy soil, and 8.6 to 46.7% from the 1cm deep sandy clay loam. Echinochloa crus-galli var. crus-galli emerged more than var. praticola, and var. oryzicola least. Most of the non-emerged barnyardgrasses seem to have entered secondary dormancy. Seeding rice a month earlier than the season lowered the emergence of Dongjinbyo by ca. 10, 18, and 26%, respectively at 1, 3, and 6cm soil depths, indicating that moving the seeding date a month earlier is impractical. The old strain, Dadajo sown in the soil at a depth of 6cm responded similarly. However, the strain has shown a significantly higher ability in emergence from 9cm deep soil. Weedy rices sown a month earlier A month earlier sown weedy rices have shown very similar emergence rates at various soil depths to those sown on May 1. Barnyardgrasses have also shown similar emergence rates when sown between April 3 and May 1. Like barnyardgrasses, the old strain and weedy rices apparantly posessed a greater adaptability to emerge under lower temperatures, and from deeper soil ; Dongjinbyo${\leq}$ Echinochloa species in that order. However, emergence- speed under lower temperature(sown on April 3) was faster in the order of weedy rice

• Korean Journal of Plant Resources
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• v.13 no.1
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• pp.41-47
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• 2000

This study was conducted to evaluate development of seed pellet technique such as pellet polymer search, the shape formation and hardness, the germination and emergence rate of the pellet seeds for labor-saving and reducing production cost in onion(Allium cepa L.) cultivation. The pellet seeds shape formation was good such as kaolin, clay, ash, and gypsum, and clay was good shape formation but surface of pellet seed was cracked during the drying. PG(pearlite + gypsum) as pellet material and PVA as binder were the best among the material in consideration with shape and hardness together. The hardness of the pellet seeds was affected by polymers, the kinds and concentration of binders, and that degree was large at polymer. The high hardness polymers were gypsum and coal ash, but burned lime was the lowest hardness among the pellet material. The germination(GP) and emergence percentage(EP) of pellet seed with PG in vitro were the highest among the material, and that was 93.6, 91.8%, respectively. The EP of pellet seed with PG at 20, $25^{\circ}C$ were 91.3, 92.0%, respectively, The EP of pellet seed were over the 91%, and those did not show difference with field moisture capacity , and that of 5 and 6mm size seed were the highest as 92%, respectively. and other size seeds showed over 90%, too. The EP of pellet seed with PG was decreasing as increasing the sowing depth, and that of at 10mm sowing depth was the highest as 92.7%. The time to 50% emergence of that under 70% field moisture capacity was 158h, and that was delayed at 20h compare to control seed.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.252-257
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• 1994

The sprouting characteristics of Scirpus planiculmis and storage methods of corm for the herbicide screening were investigated under both laboratory and greenhouse conditions. Sprouting and elongation of S. planiculmis corms were continued during storage at low temperature ($5^{\circ}C$) and wet condition. However, sprouting of corm was failed when the surface water was removed from the corm, and elongation was reduced by the treatment of 0.5-1.0% sodium chloride(NaCl) solution. Alternate temperature was more effective on the sprouting of S. planiculmis corm than constant temperature. Optimum temperature for the sprouting of S. planiculmis corm was alternation between $25^{\circ}C$ to $35^{\circ}C$. Storage at $-20^{\circ}C$ for 10 min. or 14.7% dehydration made the corm of S. planiculmis to fail for sprouting. S. planiculmis corm was more tolerant to sodium chloride than Echinochloa crus-galli or Oryza sativa(Donginbyeo) seeds. Sprouting rate was decreased by cutting of the corm. Sprouting percent by vertical cuttings, horizontal cuttings, and vertical plus horizontal cuttings were 72, 56, and 28%, respectively.