• Korean Journal of Weed Science
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• v.31 no.2
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• pp.167-174
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• 2011

Weed control using cover crops has advantages of agricultural and environmental aspects which prevent soil erosion, nitrogen supply, improving soil physical properties, reduction of nitrate leaching, organic supply and control of weed occurrence. In this study, we evaluated the inhibitory effects of cover crops on the weed occurrence, growth and yield of soybean in cover crop-soybean cropping system. The treatments were consisted of 4 different mulching system such as crimson clover (Trifolium incarnatum) residue, hairy vetch (Vicia villosa) residue, rye (Secale cereale) residue and Polyethylene plastic(P.E.) mulch with no mulch treatment (control). Three cover crops were grown throughout the winter and were cut in next spring. And then 13 days old soybean seedlings were transplanted in each treatment field on $4^{th}$ June. Crimson clover, hairy vetch and rye mulch treatments reduced weeds density compared to control (73.0%, 98.0% and 85.3% respectively), on $26^{th}$ May. However, weed inhibition rate of crimson clover mulch treatment was sharply decreased to 4.17% on $6^{th}$ August, while hairy vetch and rye mulch treatments were continued high weed inhibition rate with 87.6% and 72.0% respectively. There was no inhibition effect of perennial, winter annual and broadleaf weeds inhibition in crimson clover mulch treatment. Height of soybean in crimson clover, hairy vetch and P.E. mulch treatment was 6.9%, 20.2% and 22.0% higher than that of control. But height of soybean in rye mulch treatment was lower than control on $13^{th}$ July. At harvesting, yields of soybean were in order of hairy vetch mulch treatment${\fallingdotseq}$ P.E. mulch treatment > crimson clover mulch treatment ${\fallingdotseq}$ rye mulch treatment > control.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.177-185
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• 1997

Twenty-four major ecological and physiolosical characters of the 54 accessions of taro(Colocasia antiquorum) were observed in the growing seasons of 1995 and 1996 in $Ch{\breve{o}}nju$, Korea. The average days to emergence of the 54 accessions were 21.7 and the accession which had the shortest days to emergence was Kurye #2. Petiole color of most accessions was green, except $Ich{\breve{o}}n$ #1, Iri #1, Puan #1 and Taiwan #1 which had purple petioles. All the accessions had cormels except Taiwan #1 which had long runners without cormels. Average yield of the accessions was 3,719 kg/10a and total carmel weight, average carmel number, average carmel and average corm weight were 787g/plant, 39.2/plant, 20.3g/cormel, and 263.6g/plant, respectively. Accessions $Ch{\breve{o}}ngju$ #1 and Wanju #1 showed superiority in the three important characters, total carmel weight/plant, average carmel weight, and corm weight. Multivariate analysis for the 24 characters indicated that petiole color and carmel type had relatively higher coefficient of variation, 56.8 and 44.4 %, respectively. Fifty four taro accessions could be classified into 11 groups with D(${\sqrt{D^{2}}$) value of 110 on the basis of phenotypical characteristics. Most accessions were inclued in Group II. The Group I in which Taiwan #1 was included was genetically the most distant from the other groups. Accessions with purple petioles were grouped into the three different subgroups in which green petiole accessions were not included, indicating high dissimilarity between the different petiole color accessions. All the accessions grouped into the Group VIII, $Ch{\breve{o}}ngju$ #1, Wanju #1, Wanju #3, and $Taech{\breve{o}}n$ #2, had higher bioogical yield. Some accessions collected from the same district showed a high dissimilarity by being classified into the different subgroups.

• Korean Journal of Medicinal Crop Science
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• v.12 no.4
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• pp.279-284
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• 2004

This experiment was conducted to evaluate on agronomic traits of Korean local adlay (Coix lachryma L.) germplasm, 281 cultivars (lines). The largest collected cultivars was from Kyungsangbukdo (56 cultivars), and the next was in the order of Cheonlabukdo (48 cultivars), Kyungsangnamdo (44 cultivars), Kyunggido (39 cultivars) Chungcheongnamdo (23 cultivars), Kangwondo (23 cultivars), Cheonlanamdo (17 cultivars), and Chungcheongbukdo (16 cultivars) in distribution of collected region for 281 cultivars. In the growth stages, days to emergence from seeding were required $16.4{\pm}2.03$ days, days to heading from emergence was required $73.6{\pm}5.87$ days, days to ripening from heading was required $52.3{\pm}4.91$ days and cultivation period was required $142.5{\pm}5.87$ days. Culm length was $210.3{\pm}16.39$ cm, no. of tiller per plant was $10.4{\pm}2.13$, culm diameter was $11.7{\pm}1.09$ mm, fruiting position was $4.6{\pm}0.82$ node, no. of main culm node was $11.1{\pm}0.78$, degree of lodging was $5.3{\pm}3.42$ and severity of leaf blight was $56.1{\pm}0.78$ in the growth characteristics of the germplasm. In the yield of component, no. of grains per $m^2$ was $5,938{\pm}2,152$, percentage of ripening was $67.7{\pm}33.12$, 1,000 grains weight was $123.8{\pm}33.76$ g and grain weight was $473.0{\pm}207.90$ g. Grain weight was correlates significantly positively with no. of main culm node, percentage of ripening and no. of grains per $m^2$ among agronomic traits. Correlation coefficient between grain weight and 1,000 grain weight was positive, while grain weight and severity of leaf blight was significantly negative. Correlation coefficient between grain weight and days to ripening from heading was significant negatively.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.233-239
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• 2004

This research was conducted to determine the effect of soil pH change followed by leaching with ground water on crop growth, yield and nutrient uptake of strawberry. Treatments were leaching with ground water (A), hydrated lime application of dissolved portion in $500g{\cdot}L^{-1}$ solution followed by leaching (B), application of $Al_2SO_4$ solution with the concentration of $0.75g{\cdot}L^{-1}$ followed by leaching (C), pH elevation by (B) followed by pH lowering by (C), then leaching (D). Soil samples taken before experiment had 6.0 in soil pH. But the pH of all treatments taken after pH changes and leaching were in the range from 5.8 to 6.2 without statistical differences among treatments. Electrical conductivity of soils taken before experiment was $1.82dS{\cdot}m^{-1}$ and those of (A), (B), (C), and (D) were 1.65, 1.72, 1.71 and $1.83dS{\cdot}m^{-1}$, respectively. The plant height in treatment (C) was 20.4 cm at 80 days after transplanting which was the highest among treatments tested. The other growth characteristics did not show statistical differences among treatments. Tissue contents of Fe, Mn, Zn, Cu and B in treatment (C) were higher than those of other treatments at 80 days after transplanting. The treatment (C) had the highest number of special sizes and fruit weight per 50 plants such as 137 and 3.784 g, respectively. The treatment also had 3.123 kg in total fruit weight and 2,489 kg in marketable fruit weight per 10 are. The treatment (B) also had good results such as 2,820 kg in marketable fruit weight per 10 are.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.161-169
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• 2005

With various Korean domestic soybeans, growth and yields analysis were conducted to select the suitable soybean cultivars for cultivation in paddy field. Distinctive aspects of the soybean growth were observed in paddy field such as retarded growth of top plants and roots, relatively higher T/R ratio followed by overgrowth of top plant. However, growth and yields were significantly different among the cultivars showing 134kg/10a in Paldokong and 385 kg/10a in Doremikong. At V5. and R2 stage, highly positive correlations $(r=0.76^{**}\~0.91^{**})$ were observed between leaf area and dry weight of top plant and/or root. T/R ratio was negatively correlated with dry weight of root $(r=-0.37^*)$ at V5 stage, while significantly correlated with leaf area $(r=-0.37^{**})$ and dry weight of top plant $(r=0.65^{**})$at R2 stage. Among the characters, only 100-seed weight was significantly correlated with yield. Considering the growth characters, 37 cultivars could be included in 3 different groups and genotypic properties such as maturity and growth habit were similar in each group. Nine cultivars in group 1 showed retarded growth from V5 to R2 stage, relatively lower T/R ratio, and good seed ripening. Average yields of the cultivers was 257kg/10a. In group 2, 12 cultivars showed higher T/R ratio due to overgrowth of top plant and lowest average yields (230 kg/l0a) due to poor seed ripening. Sixteen cultivars in group 3 grew fast from V5 to R2 stage representing late maturity traits, low T/R ratio, and good seed ripening. Average yields of the cultivars was highest among groups showing 270kg/l0a. In results, stable self-sufficiency of soybean yields could be expected by selective cultivation with high yielding cultivars ranging from 301 to 385kg/10a, such as Shinpaldalkong 2, Sohokong, Doremikong, Keumkangkong, Bukangkong, Dajangkong, and Geomjeongkong 2, or with cultivars included in group 3.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.548-555
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• 1994

To compare the tolerance of crops to acid rain at different growth stages a simulated acid rain (SAR) of pH 2.7 was applied to rice, soybean, and hot pepper from vegetative growth stage to harvest (Veget.-Harvest) and from reproductive growth stage to harvest (Reprod.-Harvest). Visual damages of crops by SAR were greater in the order of rice < hot pepper < soybean and greater at Veget.-Harvest than at Reprod.-Harvest treatment. Chlorophyll content of all crops was greater in the order of Veget.-Harvest < Reprod.-Harvest treatment < control, but photosynthetic activity was not affected by SAR treatments. Nitrogen concentration and uptake of rice plants at harvest were similar among SAR treatments, but those of soybean and hot pepper were greater at Veget.-Harvest treatment than at Reprod.-Harvest treatment or control. Sulfur concentration of all crops was not affected by SAR treatments, but total sulfur uptake of soybean was greater in SAR treatments than untreated control. Grain yield of rice and soybean was not affected by SAR although grain fertility, percent ripened grains, and 1,000-grain weight of rice at Veget.-Harvest treatment were lower compared with Reprod.-Harvest treatment or control. Fruit dry weight of hot pepper was greater in the order of Veget.-Harvest < Reprod.-Harvest < control due to decreased fruit number per plant and average fruit weight. At one time application of SAR at flowering stage, brown spots were observed on the spikelets of rice at below pH 2.3. Petals of soybean and hot pepper were wilted at pH below 1. 7 and 2.0, respectively, but fruit setting was not affected by the pH of the SRA.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.441-449
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• 1996

This study was conducted to find the changes of growth, seed yield and several characteristics of sesame by leaf spray of boron as a solution which is likely to be lack in the soil. It is carried out at low land developed 5 years ago. The amount of 200l /l0a boron as boric acid is sprayed in each treatment at the 11 node stage of sesame in main stem. The spraying concentrations of boric acid are 0.0, 0.2 and 0.4% in each treatment of the level low plot and the ridge height 15cm plot. The result shows that leaf area is increased in proportion to the concentration of boric acid in each treatment of the level low and the ridge height 15cm, and the degree of increase of each node order is remarkable in lower leaves and is more remarkable in the treatment of level low plot. The effects of leaf spray of boric acid are not only the increase of leaf area but also dry weight, no. of capsule per plant, 1,000 grains weight of capsule setting under middle position. As a result, the amount of seed is increased in 53% in the treatment of level low. The change of major characteristics according to leaf spray of boric acid is generally great in the treatment of level low. Especially the increase of leaf area in the part of upper leaves and low leaves is effective to improve other characteristics.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.21-27
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• 1998

This experiment was conducted to increase aromatics in roots of Condonopsis lanceolata by applications of organic matters. Fresh root wt. was increased by conifer/moss application to 79.1g per plant. Crude protein content was also higher at rice straw application than native soil application and crude saponin content was increased by conifer/moss application, but contents of crude fat, fiber and ash were not different in all treatments. Although contents of K, Ca, and Mg were increased by rice straw application, Fe, Mn, Zn, Na and Cu were not significantly different in all treatments, The highest free amino acid was arginine, it was increased by the application of fallen leaves and the highest yield (0,008%) of essential oils was obtained by conifer/moss application. As a result, to produce C. lanceolata plant showing higher quality and aromatic essential oils, it was considered that the most effective organic matter showing high yield and higher aromatic constituents was conifer/moss application of over 3M/T per 10a.

• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.121-128
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• 1999

This experiment was carried out to establish effective weed control system in the cultivation of Coix lachryma-jobi L. The effect of annual weeds artificially transplanted on the growth of Coix lachryma-jobi L. were that the higher the density of weeds, the lower the yield considerably by reducing number of grains and tillers per plant. Among four weeds of Echinochloa crusgalli galli P. BEAUV., Digitaria sanguinalis $S_{COPOL}$., Chenopodium album L., and Portulaca oleracea L., weed of Portulaca oleracea L. reduced adlay yield most by 182.6kg/10a and it was judged to be the most injurious weed to adlay production. Among four weed control systems, which are one herbicide treatment, one herbicide treatment + one cultivating work with cultivator, two times cultivating work with cultivator and two times hand-weeding, the control system of 'one herbicide treatment + one cultivating work with cultivator' showed the lowest amount of weed growth by 7.34 weeds per $m^2$ in comparison with control plot of 35.00 weeds per $m^2$. Among four weed control systems, the system of 'two times hand-weeding' had much more amount of light penetration in adlay canopy with 791.9 mol than any other systems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.747-756
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• 1995

To find out the optimum application method of slow-releasing fertilizer(SRF) and conventional fertilizer(CF) with different fertilization rate under two culture methods[l0-day old seedling machine transplanting(MT) and direct-sowing on dry paddy(DS)] in the south-western region(clay loam soil) of Korea, used were Chosun slow-releasing fertilizer(silicate latex coated fertilizer: N-P$_2$O$_{5}$-K$_2$O =18-12-13) and conventional fertilizer. Plant height and number of tillers with different two culture methods were higher at MT than DS in early growth. The ratio of dry weight in heading stage was higher at CF than SRF in MT than DS and especially, SRF 80% + CF 20% than SRF 100% or CF 100%. Leaf area index (LAI) in heading stage was higher at CF in MT but higher at SRF in DS than their counterparts. Chlorophyll content was higher at SRF than in CF expect for heading stage(HS), especially in DS. It was highest at HS in CF without its difference during maximum tillering stage(MTS) and panicle formation stage(PFS), while highest at PFS in SRF with tendency of gradual increase and decrease before and after PFS, respectively. Heading was delayed 2~3 days at SRF in two cultrue methods and 4~5 days at SRF in DS in comparison with CF in MT with delay of 2 days at DS compared with MT. Culm length was longer at CF in MT and at SRF in DS than their counterparts. Panicle number per m was more at SRF and in DS. Filled grain ratio was higher at CF and in MT. Yield was obtained 101 and 100% at 100% and 80% level of SRF in DS respectively, and 96% at 80% level of CF in MT, compared with conventional application method (516kg /l0a), and increased 2~4% at DS and 0~3% at MT in SRF. Yield was high in order of 100%(SRF) =80%(SRF) + 20%(CF) > 100%(SRF) + 20%(CF) > 80%(SRF) at MT and 80%(SRF) + 20%(CF) =100%(SRF) > 80%(SRF) =100%(SRF) + 20%(CF) at DS.