• Korean Journal of Environment and Ecology
• /
• v.12 no.1
• /
• pp.91-101
• /
• 1998

Two large communities of Vicex rotundifolia were discovered for the first time at the beach of Pyonsanbando National Park. The growth environment and morphological characters of the communities were examined and analyzed to provide some basal data which would be helpful to establish measures for protection and to utilize the communities rationally. The results are as follows; The habitats of Vitex rotundifolia are located at Chakeundang beach of Kyokpo-ri and Kosapo beach of Woonsan-ni, Pyonsan-myon in Pyonsanbando National Park. The total area of this two communities was measured to be 2,755m$^{2}$ and 523m$^{2}$ of it was damaged. Two varieties, 49 species, 43 genera and 28 families as trees and shrubs were collected from inside of and the vicinal areas of the communities. Koelreuteria paniculata and Rosa rugosa were discovered and collected in these areas for the first time to be documented with the communities of Vitex rotundifolia. The largest individual of Vitex rotundifolia within the polulations reaches or 3.5cm in diameter at root collar and 6m in length of the runner on aboveground. The individuals of Vitex rotundifolia within the communities show good growth condition which the mean leaf length was measured to be 4.5cm, the mean leaf width 3.3cm, the mean leaf area 11.8cm$^{2}$ and the mean flower length 10.0cm. Vitex rotundifolia has been mostly recorded to be an evergreen shrub. But the present study discovered that it is rather deciduous.

• Korean Journal of Agricultural Science
• /
• v.2 no.1
• /
• pp.179-185
• /
• 1975

This trial was conducted for the selection of drought registance strains and other main characters of orchard grass. Some preliminary results obtained are as follows : 1. The initial growth of orchard grass in sufficient soil moisture condition showed highly significant differences among the varieties. Turkey's D=0.84. However, in proceeding the growth, the grass height among the varieties showed non-significant. 2. Addition of nitrogen fertilizer before first flowering tended to increase the grass height occationally significantly, compared to the control. 3. The survived varieties on the drought soil moisture condition had more numbers of tillering than the wilted significantly except some varieties. However, in grass height between the survival and the wilted, almost varieties showed non-significant differences. 4. In the varierties of Metia, Phyllox and Dorise, all individuals were survived in drought soil moisture condition and showed almost the same growth responces with willted ones comparatively. The plant height and the numbers of tillering of these 3 varieties were as follows: Merita; 26.4 cm 24.2 ea, Phyllox; 31.4 cm 24.6 ea. Dorise; 26.8 cm 35.6 ea.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.3
• /
• pp.161-169
• /
• 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
• /
• v.47 no.5
• /
• pp.356-360
• /
• 2002

The seedlings of yacon (Polymnia sonchifolia Poeppig ＆ Endlicher), which were cuttings, plug seedling (PS), crown bud before sprouting (CBBS), crown bud after sprouting (CBAS), and divided seedling after budding (DSAB) were planted at 70$\times$50 cm planting distance on ridge; that was interow spacingintrarow spacing, and about 28,500$\pm$71 plants/ha. CBBS didn't need work and equipment to raise seedlings. PS and DSAB grew taller to 140.5 and 143.3cm, respectively, than others at 150 days after planting. In the changes of plant height, PS and DSAB showed taller than others during growth period, cuttings, CBBS, and CBAS grew rapidly in middle growth stage. Excepting main stem and petiole length, other characters were significant for seedling. Fresh weights were different among seedlings. Even though the yield of plants grown from CBAS and CBBS were lower with 34.7 and 36.4 ton/ha, respectively, than 3.6 ton/ha of DSAB; its yield index were over 95%, hence, those of plants grown from cutting and PS were lower with 73 and 87%, respectively. The ratio of tuberous roots over 200g to total tuberous roots per plant was the highest from DSAB. Most of tuberous roots were under 200g per tuberous root from cuttings. CBBS, CBAS, and DSAB are suitable to use seedlings for high yield of yacono. Yacon plant by DSAB much produced tuberous root of over 200g.

• The Plant Pathology Journal
• /
• v.27 no.3
• /
• pp.266-271
• /
• 2011

Physicochemical characteristics and heavy metal content of soils located along the drainage way of an abandoned mine at Busan, Korea ($35^{\circ}31'N$, $129^{\circ}22'E$) (contaminated soil; CS) and uncontaminated soils (50-70 m apart from the drainage way) (NS) were examined. Growth of tomato plants (Solanum lycopersicom cv. Rutgers) in CS and NS, development of the root-knot nematode (Meloidogyne incognita) as root-knot gall formation on tomato plants, and non-parasitic nematode populations in soil were also examined. Growth of tomato plants, root-knot gall formation, and non-parasitic nematode populations were significantly reduced in CS with higher As content, lower pH, higher electrical conductivity (EC), and lower available phosphate (av. $P_2O_5$) than in NS. None of the other physicochemical characters examined differed significantly between CS and NS (low and no significance) and were above or below the critical levels detrimental to plant growth and nematode development, suggesting that As may be the primary hazardous heavy metal in CS. The toxicity of As might be enhanced at low pH in CS because exchangeable forms of some heavy metals increase with the decrease of soil pH. The heavy metals, especially As, may have contributed to increasing EC and decreasing av. $P_2O_5$. Therefore, the effects of mine drainage contamination from the abandoned mine were derived primarily from contamination by heavy metals such as As. These may have been enhanced in toxicity (solubility) by the lowered pH, increased soil salinity (EC) and decreased av. $P_2O_5$. Our results suggest synergistic adverse effects on the plant and the nematode by decreasing osmotic potential and nutrient availability.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.2
• /
• pp.89-94
• /
• 2001

Sword bean belongs to the subgenus Canavalia in the genus Canavalia. White and reddish varieties in sword bean were tested to obtain the basic information for improving the yield, quality, and cultural environments through the quantitative growth analysis. Growing plants were sampled at intervals of 10 days from 20 days after sowing. Whole plant weight increased during the period of 11-20 days after sowing in both varieties. The weight of each organ between two varieties increased similarly except leaf area. Whole plant weight changed more close to pod weight than any other characters. The leaf areas of both varieties increased from 50 days after sowing, var. white displayed S type curved line but var. reddish displayed slow S type curved line. The SGR of whole plant weight in both varieties had 3 maxima and 2 minima, 3 maxima and first minimum were shown at the same period but the second minimum was shown at different period. Both varieties showed bimodal curved line. All SGR of each organ and leaf area were shown the 2 maxima and 1 minimum in both varieties. The changes of SLA and LAR were not remarkable between two varieties but these were united together with the maximum of whole plant weight and root weight. ULWR and ULWR were shown similar in both varieties. Reddish variety was more prosperous in early growth stage than white variety because SLA, LAR and LWR were high. In surplus weight, both varieties increased rapidly during the period of 111-120 days after sowing that was applicable to the maximum SGR of pod weight. Surplus weight of var. white increased markedly during the same period comparing those of var. reddish.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.5
• /
• pp.383-390
• /
• 1993

This experiment was carried out in the green house at Tokyo University of Agriculture in 1992 to investigate the relationship between lodging resistances and specific morphological characters and to examine the effects of nitrogen top-dressing and growth retardant on changes of the endogenous ethylene content in rice plant. Inabenfide did not affect significantly yield, yield component, chlorophyll content, and $CO_2 assimilation but, decreasing plant height when growth regulators were applied at booting stage, decreasing internode elongation, and increasing culm thickness and diameter of the third and fourth internode. While, nitrogen top-dressing usually showed to effect increasing vegetative growth such as plant height, tiller number, and morphological characteristics but, were not significantly affected the chlorophyll content and $CO_2 assimilation. Ethylene evolution was dramatically changed with nitrogen top-dressing and growth retardant. Application of Inabenfide at 15 days before heading inhibited ethylene evolution in the all nitrogen levels. Higher nitrogen top-dressing showed higher ethylene evolution than that of low nitrogen level. High positive correlation was detected between nitrogen application and ethylene evolution.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.31 no.1
• /
• pp.47-54
• /
• 2011

This experiment was carried out to know adaptability and forage production and quality of corn hybrid for silage at paddy field of Jeonnam and Cheonan region. The growth, forage production and quality of silage corn in normal condition showed much better than drought condition at paddy field. Among the growth characteristics, 'Kangdaok' hybrids was somewhat strong for drought stress, then and good at stem diameter, drought stress, sugar content, stay green, disease and insect resistance. Fresh yield of 'Kwangpyongok' and 'Kangdaok' hybrid at drought paddy field were the highest as 9,714kg and 9,126 kg/ha per ha among corn hybrids. Among the ten hybrids, dry yield of 'Kangdaok' hybrid at drought paddy field was the highest as 5,548 kg per ha. The result of this study showed that 'Kangdaok' hybrid had good growth characters and forage productivity at drought condition and dry matter yield and TDN yield also were 21.6% and 19.3% level compared with normal paddy field.

• Korean Journal of Plant Resources
• /
• v.29 no.3
• /
• pp.339-346
• /
• 2016

This study was carried out to develop an effective seed propagation method for Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai by analyzing seed dormancy types and germination characteristics. Seeds were collected between September to October at Gangwon province, and well-selected seeds were used while being dry-stored at 4±1℃. The seed size ranged 4.52 × 1.58 ㎜ and the weight of thousand seeds were 1,603.5 ± 0.02 ㎎. The moisture content was 7.2%. Seeds were achene type, and morphology characters showed an elliptical shape and rough texture, and light brown in color. Moist-chilling treatment was conducted for dormancy breaking because the seeds had an undeveloped embryo of liner type. The embryo had developed during a moist-chilling period, constantly, and fully developed in 10 weeks. Consequently, it seemed to be non-deep complex or intermediate complex type of morphophysiological dormancy, and embryo dormancy was broken by wet-chilling for 10 weeks. After 10 weeks of wet-chilling treatment, seed germination began. Germination percentage was higher in dark condition raher than light condition and recorded the maximum at 25℃ in the dark (16.3%). A pre-soaking treatment with a combined plant growth hormones promoted germination and shortened T₅₀. Specifically, seed germination of 84.5% was achieved by pre-soaking of seeds with a combined solution of 500 ㎎/L GA₃ and 10 ㎎/L kinetin for 24 h after a wet-chilling treatment for 10 weeks. Thus the effect of plant growth hormones coupled with chilling temperature on seed breaking dormancy provide asubsequent growth of seedlings for successful plantation.

• Korean Journal of Poultry Science
• /
• v.50 no.1
• /
• pp.31-39
• /
• 2023

The objective of this study was to investigate the effect of exogenous protease supplementation in diets formulated with poultry by-product meal on growth performance, small intestine magnitudes, and meat physiochemical characters in broiler chickens from 21 to 35 days post-hatch. A total of 120, one-day-old "Arbor Acres Plus" broiler chickens (male: female - 50:50) were allocated one of two dietary treatments to give six replicates and ten birds per cage. Two dietary treatments included a control diet (CON) and a diet supplemented with protease (CON+Pro). At day 35, body weight and feed intakes were measured to calculate the feed conversion ratio for the entire experiment period. Two birds from each pen were euthanized to measure the relative lengths and relative weights of three small intestine sections and meat samples were collected for physiochemical characteristic analyses at 35 days post-hatch. Exogenous protease supplementation did not influence (P>0.05) growth performance but showed a tendency to improve FCR (P=0.082). Protease supplementation showed a tendency to reduce proximal small intestine length (P=0.091). Broilers offered dietary treatments influenced minced meat color where protease supplementation resulted in lower CIE b^* (P<0.001) colorimetric value for yellowness and showed a significant trend (P=0.059) on reducing meat redness CIE a^*. In conclusion, the addition of exogenous protease to a broiler diet formulated with poultry by-product meal did not affect the growth performance, small intestine magnitudes, and meat physiochemical parameters (except CIE b^*) in broiler chickens.