• 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 CROP SCIENCE
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• v.34 no.2
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• pp.113-119
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• 1989

In 1988 the tolerance of corn, sorghum, sorghum-sudangrass. and pearl millet hybrids to simazine and alachlor was tested in field during the growing season and pots during the summer and fall. In field and summer pot experiments(Exp.) the above mentioned four crops were tested at the ratios of simazine WP (50% ai, g/10a) ; alachlor EC (43.7% ai. ml/10a) of 130: 0, 100: 0, 70: 200, 0: 300 and 0: 400 and a sorghum hybrid was tested at 0, 50, 100, 200, 300, and 400ml/10a of alachlor and 70g/10a of simazine+ 200ml/10a of alachlor in fall pot Exp. In corn emergence rate, percent stand, plant height of seedlings, and dry matter(DM) yield were not affected by simazine and alachlor in all Exps. In sorghum and sorghum-sudangrass early growth and DM yield were not affected by simazine and alachlor in field Exp. In contrast, simazine reduced height and dry weight of seedlings slightly without any deterimental effects on emergence and survival rates. but alachlor reduced survival rate, plant height, and dry weight of seedlings significantly in summer pot Exp. In fall Exp. alachlor did not affect emergence rate of a sorghum hybrid, but survival rate, plant height, and dry weight of seedlings reduced with increased levels of alachlor when applied higher than 100ml/10a. In pearl millet simazine did not affect emergence rate, plant height, and DM yield in field, but reduced survival rate, plant height, and dry weight of seedlings in summer pot Exp. However, alachlor reduced DM yield significantly due to a lower percent stand even in the field. In summer pot Exp. although emeregence rate was slightly reduced, all seedlings were dead after emergence. Simazine did not control grasses such as Digitaria sanguinalis, Setaria viridis, Echinochloa crusgalli effectively, but controlled broadleaf weeds. Alachlor controlled all grasses, Porluraca oleracea, and Amaranthus mangostanus, but did not control Acalypha australis and Chenopodium album. A combination of simazine and alachlor controlled weeds more effectively than either simazine or alachlor alone.

• Korean Journal of Medicinal Crop Science
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• v.23 no.1
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• pp.27-36
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• 2015

Shading and soil environment are the main factors of growth and yield in ginseng (Panax ginseng C. A. Meyer). Ginseng yield is directly related to survival rate because of increased missing plant for their growing period. Under field conditions, diseases and pests significantly affect plant survival rate. We evaluated the seedling establishment, growth and ginsenoside of the ginseng plants, under controlled management conditions in a plastic greenhouse, when their treated with different types of organic matter. Ginseng seeds were sown at a rate of three seeds per hole, and the seeding space measured $10cm{\times}15cm$. Compared to the control, treatment of cattle manure vermicompost (CMV) was shown to increase seedling establishment and decrease ginsenoside content. Root weights of plants treated with CMV were higher than those of plants treated with other types of organic matter. In addition, seedling establishment of 2-year-old ginseng plants was decreased when it was compared to that of 1-year-old ginseng plants. Our results indicated that organic matter type and rate were associated with seedling establishment, growth characteristic and ginsenoside content in greenhouse of ginseng direct-sowing culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.15-18
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• 1998

Receptivity of corn silk to pollen decreases with time. For effective pollination, it is important to study the receptivity of corn silks in relation to time elapsed after their emergence. Two commercial corn hybrids, 'Kwanganog' and 'Suwon 19', were tested for their silk growth and effects of delayed pollination on kernel development for 1 to 13 days after emergence of the first silk. Silks elongated rapidly for the first 3 days and then gradually decreased. Silks grew more than 30mm per day for the first 3 days and stopped growing on the 11 or 12th day after emergence of the first silk. Filled ear length decreased slowly for the first 8 days, and then decreased rapidly. Similar trends were observed for number of kernel rows and number of kernels per row or ear. The highest numbers of kernels per row or ear were observed when plants were pollinated 2-4 days after silking. These numbers decreased gradually up to 8 days, and then decreased sharply. This result indicates that 8 day-delayed pollination has no influence on kernel development. There were negative correlations between silk length and ear characteristics except kernel weight. Silk growth rate was positively correlated with filled ear length, row number, and kernel number. It might be assumed that delayed pollination by one week after the first silk emerged would not affect on kernel set.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.305-309
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• 1991

This experiment was conducted to investigate the effect of shattered grain by combine harvesting at the previous year on rice plant emergence at different planting methods and plant characteristics, The results are follows : Combine harvesting greatly influence on shattered grain of Samgangbyeo as Tongil variety (49.5kg/10a) compared to that of Nagdongbyeo as Japonica variety(27.8kg/10a), while Nagdong-byeo showed higher germination rate than Samgangbyeo, whether transplanted and direct seeded. Emergence of volunteer and seed mixture were lower in transplanted than in direct seeded. In variety test. Japonica variety showed higher emergence of volunteer rice and seed mixture than Tongil variety. Generally, no significant difference in yield components were observed with different varieties by the volunteer rice. But the volunteer rice caused by combine harvesting decreased culm length, panicle length, spikelet number, panicle number and ripening ratio. except l000-grain weights.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.305-322
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• 2024

The aim of this study was to investigate the effects of artificial light sources on the germination and seedling vigor of lettuce, aiming to identify the optimal artificial light source for producing high-quality seedlings. Lettuce cultivar of 'Tomalin' and 'Seonpunggold' exhibited the highest seed emergence in the Metal halide(MH) lamp and High-pressure sodium(HPS) lamp treatment group, while the emergence rate parameter, T50, was the fastest in the HPS lamp treatment group. Both cultivars showed good growth characteristics such as number of leaves, root length, and stem diameter under RGB-LED, and their seedling vigor was excellent as well. The plant height was smallest in the Red + Green + Blue LED treatment, but the leaves were round and thick, resulting in higher biomass and dry weight. Single light sources of Red LED and Blue LED led to reduced growth compared with that under the mixed light treatments. Chlorophyll content in lettuce varied with the type of artificial light, with both cultivars exhibiting the highest chlorophyll content in the Red + Green + Blue LED treatment. The most suitable artificial light for lettuce seedling growth was the Red + Green + Blue LED treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.325-330
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• 2004

This study was carried out to determine adequate planting date, to compare the growth characteristics between early and late maturing cultivars, and to provide the data for the cultivation techniques of soybean [Glycine max (L.) Merr.] in double cropping system with winter crops on paddy field in Korea. Cultivars were planted on 26 May, 16 June, and 7 July with a planting density of $70cm(row\;widtb)\;{\times}\;10cm$ (planting spacing). Seed yield of soybean planted on June 16 and July 7 was approximately $37\%\;and\;53\%$, respectively, less than that of conventional planting date of May 26 in Pungsan-namulkong, and planted on June 16 and July 7 was about $30\%\;and\;37\%$, respectively, less then that of conventional planting date of May 26 in Hanamkong. The number of pods and seeds per plant decreased as planting date delayed. Seed weight increased in Pungsan-namulkong but decreased in Hannamkong as planting date delayed. The flowering date was late in delayed planting plots, but it was shorted for days from emergence to flowering and from emergence to maturity. The plant height of Hannamkong was greater than Pungsan-namulkong from the emergence to flowering stages, but in contrast, it was greater in Pungsan-namulkong than Hannamkong after flowering stage (50d after emergence) when it planted on May 26. There were no significant differences between two soybean cultivars at planting dates of June 16 and July 7. Leaf number, leaf area, and dry matter were also reduced by late planting, and Both of them were shown in high reduction at the later planting. There was a high significant difference at the flowering $(r\;=\;0.87^{**})$ and pod formation $(r\;=\;0.91^{**})$ stages between leaf dry matter and seed yield. Crop growth rate (CGR) was greater at $R2\~R3$ growth stages compared to $R3\~R4\;or\;R4\~R5$ growth stages in two soybean cultivars and the greatest CGR was obtained at planting date of May 26 in two soybean cultivars except for R4-R5 growth stage in Pungsan-namulkong. There was a highly significant positive difference between the seed yield and the leaf area index (LAI) across R3 to R4 and R2 to R3 stages. The photosynthetic rate $(P_N)$ of the uppermost leaf position had no significant difference among planting dates and between two soybean cultivars. However, $P_N$ of the $7^{th}$ leaf position increased as the planting date delayed.

• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.305-313
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• 2017

We investigate that the impact of freshwater organism exposed to the salinity environment by the frequent rainfall following climate change. To evaluate the stress response following salinity exposure, we assessed the survival rate, molting success rate, the developmental period and mouthpart deformities in Chironomus riparius. In addition, we measured the molecular responses of biomarker gene, gene expression of heat shock protein 70 (HSP70) in C. riparius exposed to salinity after 96 hour. The C. riparius survival rates were showed on time dependent manner and not observed survival organisms above 15 psu at day 4. The pupation and emergence of C. riparius were not seen above 15 psu, and the molting success rate was less than 20% at 10 psu. The developmental retardation of C. riparius was well observed in the pupation and emergence period and was delayed by 4 days at 10 psu compared to the control and 5 psu. The mouthpart deformities after salinity exposure at 96 or 72 hour were observed at 10 psu and 15 psu. The expression of C. riparius HSP70 level was significantly increased exposure to 5 psu and 10 psu. Thus, salinity has been caused to be various ecotoxicological and molecular stress responses on freshwater organisms similar to harmful substances such as EDCs and so on.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.15-20
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• 1981

To analyze the inheritance of emergence rate of brown plant hopper (Nilaparvata lugens) biotypes, six crosses among biotype 1, biotype 2 induced by rearing on Mudgo and biotype 3 these on ASD 7, were made. Each generation $(P_1,\;P_2,\;F_l\; F_2,\;BC_1,\;BC_2)$ of each cross was fed on the rice seedlings of Mudgo and ASD 7 varieties. The emergence rate of biotpe 2 on Mudgo was controlled by the one incomplete dominant gene in $biotype\;l{\times}biotype$ 2 coross, however, that of biotype 3 on ASD 7 was controlled by one incomplete recessive gene in $biotype\;l{\times}biotype$ 3 cross. The genes involved in biotype 2 and biotype 3 were not identical, however, their allelic relations are not clear.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.128-133
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• 1993

This experiment was carried out to evaluate the germination characteristics of Korean red rice seeds. Ten lines of the long grain and ten lines of the short grain Korean red rices were tested for dormancy, shoot emergence rate at different water and soil depth. Both the long and short grain type seeds of Korean red rice germinated over than 99% immediately after harvest, so that no dormancy was observed in the Korean red rices. Shoot emergence rate of the long grain red rices at 7cm of water depth and that of the short grain red rices at 11cm were 83.3% and 83.5% respectively, while those of the indica check Samgangbyeo and japonica check Seomjinbyeo were 0%. Shoot emergence rates of the long and short grain red rices at 7cm of soil depth were 71.1% and 73.9% respectively, while those of the check varieties Samgangbyeo and Seomjinbyeo were 40.0% and 28.0% respectively. Thus, the Korean red rices were expected to be useful germplasm source for direct seeding.