• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.6
• /
• pp.516-526
• /
• 2003

Thirty-six barley varieties including Korean modern and local varieties were tested for drought-tolerance in the field of plastic rain shelter, Drought treatment was initiated at initial tillering stage (March 27, 2002) by withholding irrigation and lasted until harvest. Soil water potential maintained at around -0.05㎫ in the control plot and varied from -0.05㎫ (at the initial stage of drought treatment) to -0.29㎫ in the drought treatment plot. At forty days after drought treatment, relative water content (RWC), osmotic potential (OP), osmotic adjustment (OA), and $^{13}\textrm{C}$ discrimination ($\Delta$) were measured and then plants were sampled for leaf area index (LAI) and dry weight (DW). Barley was harvested at maturity for determining DW, grain yield, 1000 grains weight and number of spikelet. The tested varieties revealed wide spectrum of drought tolerance. Dongbori-1, Chalbori, Changyeongjaerae, Samdobori and Weolseong 87-31 showed strong drought-tolerance while Songhagbori and Suwonmaeg360 showed weak drought-tolerance. The drought injury indexes (drought/control ratio) of DW and yield revealed significant positive correlation with leaf RWC in drought treatment plot and $\Delta$ in the control plot, but obvious negative correlation with leaf OP and OA under drought condition. In addition, all the drought indexes of OP, $\Delta$ and RWC showed obvious positive correlation with the drought injury indexes of DW, 1000 grain weight and yield. Thus, OP and RWC under drought condition and $\Delta$ under well-watered condition would be used as the evaluation criteria for drought- tolerance of barley genotypes. However, further investigation is needed for the relationship between $\Delta$ and drought-tolerance as the other reports were not consistent with our result.

• Research in Plant Disease
• /
• v.8 no.3
• /
• pp.166-170
• /
• 2002

Powdery mildew of mug bean was found in Suwon on September 2000. Many white and powdery mycelial colonies appeared on leaves of the plants. Conidia with fibrosin bodies were ellipsoid to elongate-ellipsoid, 25~38$\times$16~22 ${\mu}{\textrm}{m}$ in size and farmed in chains. Conidiophores were erect on superfical mycelium, 67~100 ${\mu}{\textrm}{m}$ in length. Foot cells were cylindric with 37~65$\times$10~11 ${\mu}{\textrm}{m}$ in size. Appressoria were indisdinct. Germ tubes from conidia were simple, not branched. Dark brown cleistothecia were observed on the leaves of mung bean. Cleisto-thecia were globose or subglobose, 85~1130 ${\mu}{\textrm}{m}$ in size. Wall cells were irregularly polygonal with 15~45$\times$7~26 ${\mu}{\textrm}{m}$. Appendages were mycelioid, 6-11 per ascocarp, coloured, throught when mature or paler upwards, 1~7 septa, 192~223$\times$5~7 ${\mu}{\textrm}{m}$ in size. A single sun had in a cleistothecium and was ovoid or subglobose with 62~95$\times$50~67 ${\mu}{\textrm}{m}$ in size. Ascusspore had 8 spores in an ascus and rarely developed, mostly imatuna ellipsoid-ovoid with 16~24$\times$12~16 ${\mu}{\textrm}{m}$. On the basis of morphological characters of the conidial stage and teleo-morph, the fungus was identified as Sphaerotheca phaseoli.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.16 no.1
• /
• pp.36-41
• /
• 1987

In the refrigerated storages of fishery products, the lipid oxidation of the meats had been the major deterioration factor. For the effective utilization of mackerel, Scomber japonicus, and yellow corvenia, Pseudosciaena manchuria, which are major costal fish in Korea, and were studied about oxidative rancidity during the refrigerated storage at $-18^{\circ}C$ and the effect of different temperatures upon the cooked meat. We detected the results followed. 1. The Induction period of refrigerated storages had 20 days for fresh meat and 60 days for cooked meat. 2. Peroxide and TBA value of cooked meats had half amount values In the comparison with those of fresh meats, 3. Values of mackerel had double amount than those of yellow corvenia in peroxide and TBA value as if the different values come from different fish species, 4. The rancidative degree of the different temperatures on the samples had the least amount at $-5^{\circ}C$ among several kinds of storage temperatures.

• Korean Journal of Environmental Agriculture
• /
• v.14 no.1
• /
• pp.1-6
• /
• 1995

This experiment was carried out to clarify the evapotranspiration and water use efficiency in rice plant canopy. Two rice cultivars, Daechungbyo(japonica type) and Samgangbyo(Tongil) were planted on the field of Suwon Weather Forecast Station in 1989. Evapotranspiration, dry matter production and leaf area of rice plant were measured to investigate the water use efficiency. There was significant correlation between cumulative evapotranspiration and dry matter production of aboveground. The parameter of linear regression was 4.13. The ratio of cumulative top dry matter production per cumulative evapotranspiration was increased until $5.5{\sim}5.9$ leaf area index. The de Wit's "m" value revealed maximum record at heading-flowering stage. At the harvest, the values were ranged from 175.5 to 191.7. The parameter of cumulative solar radiation to dry matter production was $1.011{\sim}1.248$. The evapotranspiration ratio(g.water/g.DW) of Samgangbyo(278) was higher than that of Daechungbyo (299.9). The efficiency of evapotranspiration(g.DW/g. water) was 1.58 in Daechungbyo and 1.98 in Samgangbyo.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.26 no.1
• /
• pp.31-38
• /
• 2006

This experiment was carried out to determine the effects of different sowing dates and cultivars on the forage yield and quality of winter rye (Secale cereale L.). The experiment was conducted in a split plot design with three replications. The main plots consisted of two sowing dates such as early (15 September) and late (30 September). The subplots consisted of rye cultivars of five different maturity groups such as 'Kodiak' (Late), 'Koolgrazer' (Early), 'Danko' (Late), 'Homil22' (Medium) and 'Olhomi1' (Early). Dry matter (DM) content at early sowing (19.7%) was higher than those at late sowing (17.8%), while crude protein (CP) and total digestible nutrients (TDN) contents at early sowing (16.6% and 61.6%) were lower than those at late sowing (16.8% and 63.1%). Although DM content of early maturing cultivars (Koolgrazer and Olhomi1) was higher than the other cultivars, CP and TDN contents of those were lower compared to other cultivars. The contents of fiber components (ADF, NDF and cellulose) at early sowing were higher than those at late sowing, while ADL and hemicellulose at early sowing were lower than those at late sowing. ADF and cellulose of early maturing cultivars were higher than those of the other cultivars, while ADL and hemicellulose of Danko were higher than that of the other cultivars. DM, CP, In vitro dry matter digestibility (IVDMD) and TDN yields at early sowing were higher than those at late sowing, and early maturing cultivars were higher than those of the other cultivars. Results of this study indicate that forage production technology in combination with early sowing and use of early maturing rye cultivar could enhance both production and quality of rye.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.6
• /
• pp.698-703
• /
• 1996

To elucidate the proper nitrogen application method for machine transplanting of rice infant seedling in no-tilled paddy, Dongjinbyeo was used and nitrogen was applied five methods including conventional application method. Leaf color was darker at 80% of total nitrogen was applied as basal and lighter at 20% of total nitrogen was reduced than conventional application method in tillering stage, but wasn't significantly different after panicle formation stage among the application method. And it was thinner at tillering stage and was darker after panicle formation stage in no-tilled paddy compared with tilled paddy. Tiller number, LAI and top dry weight were more at 80% of total nitrogen was ap-plied as basal than conventional application method, and more in tilled paddy than no-tilled one at tillering stage, but at heading stage they were highest at top dressing applied 25 days after transplanting. C.G.R was highest at top dressing for tillering was delayed and it was lower in no-tilled paddy at tillering stage but was higher after panicle formation stage than in tilled one. Yield was highest at top dressing time was delayed among nitrogen application method, but wasn't significantly different between tilled method in same nitrogen application method.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.2
• /
• pp.208-214
• /
• 1985

An attempt to evaluate yield response and efficiency of N fertilizer was made with the data obtained from various rice cultivars during 1978 to 1983. 1. The optimum rate of N fertilizer for maximum yield varied from 13.9 to 28.0 kg/10a with rice varieties. 2. The cultivars with high optimum N levels were high in N content (straw) and N uptake (straw+grain) at harvesting stage, but low in production efficiency and use efficiency of N. 3. The yield increment at the optimum rates of N in comparison with no N application among the rice varieties were 29-101%. 4. The cultivars with hish yield increment at optimum rate were high in the N content (straw+grain), and production efficiency at harvesting stage.

• Polymer(Korea)
• /
• v.29 no.2
• /
• pp.127-134
• /
• 2005

The relationships among mechanical properties, rheological properties, and morphology by reactive extrusion based on commingled pckaging film wastes contains polypropylene (PP) pckaging film system [PP/polyethylene (PE)/aluminum (Al)/poly(ethylene terephthalate) (PET)] and Nylon packaging film system[Nylon/PE/linear-low density polyethylene (LLDPE)] were investigated to improve the compatibility and toughness of these wastes using various compatibilizers such as ethylene vinylacetate (EVA), styrene-ethylene/butylene-styrene triblock copolymer (SEBS), styrene-ethylene/butylene-styrene-graft-maleic anhydride copolymer (SEBS-g-MA), polyethylene-graft-maleic anhydride (PE-g-MA), polypropylene-graft-maleic anhydride (PP-g-MA) , polyethylene-graft-acrylic acid (PE-g-AA) and polypropylene-graft-acrylic acid (PP-g-AA). Compared with simple melt blend system, the blends showed improvement of about $50\%$ increase in physical properties when SEBS and EVA were added. However, SEBS-g-MA thermoplastic elastomer which is highly reactive with amine terminal group of nylon, resulted in about $200\%$ increase in impact strength. This compatibilization effect resulted from the increase of interfacial adhesion and the reduction of domain size of dispersed phase in PP/Nylon blend system.

• Korean Journal of Soil Science and Fertilizer
• /
• v.7 no.4
• /
• pp.221-225
• /
• 1974

The field experiment was conducted to find out the effect of inoculation of Rhizobium and interaction between amount of nitrogen and inoculating in soybean with 4 replicated split plot design. Main plot was 4 level of nitrogen 0, 2, 6, 12kg/10a and subplot was inoculation and uninoculation. The results are summarized as follows. 1. The yield of soybean did not show any significant difference among nitrogen level or between inoculating but yield of inoculated plot was a little increased than that of uninoculation. 2. At four leaves stage and flowering stage, the weight of nodules in root was decreased with incresing amount of nitrogen significantly and uninoculation caused a reduction compared with modulation significantly and those tendency was same in plant height, and those difference among treatment was more distinct in four leaves stage than in flowering stage. 3. After harvest, total nitrogen content in soil was not only increased with increasing nitrogen level but also was more increased in inoculated plot than in uninoculated plot except nitrogen 0kg/10a level. Inoculation of Rhizobium raised 15kg of nitrogen per l0a at 6kg nitrogen level compared with uninoculation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.4
• /
• pp.334-341
• /
• 1992

The effects of the various pattern of paddy-upland switching system on rice yield and the nutrient absorption characteristics were examined in the paddy field of Seokcheon silty soil for three years from 1989 to 1991. The obtained results of the two years from 1990 to 1991 are as follows : 1. Rice grain yields were high in the order of potato-cabbage>soybean>continuous paddy plot for the second and third year. Among the rice yield components the numbers of grains per panicle and the rate of ripening grain exerted the yield increase. 2. The contents and absorption amounts of nutrient in harvested straw plant increased with the incease of rice yields during the second and third year(1990~1991). The amounts of all nutrient absorption increased with the increased level of nitrogen fertilization at the third year(1991). 3. The periodical change of leaf green color was responded well with the content of ammonia concentration of soil solution.