• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.193-200
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• 2017

BACKGROUND: Plant growth under smart greenhouse (that is plant factory system) conditions of an artificial light type is significantly depending on the artificial light sources such as a fluorescent lamps or Light-Emitting Diodes (LEDs) with specific spectral wavelengths regardless of the outside environmental changes. In this experiment, characteristics on the growth and compound synthesis of kale seedlings affected by light qualities and intensities provided by LEDs were mentioned. METHODS AND RESULTS: The kale seedlings which developed 3~4 true leaves were exposed by fluorescent lamps or LEDs lights of red (R), blue+white (BW), blue+red (BR) with 50 (L) or $100(H){\mu}mol/m^2/s^1$ photosynthetic photon flux (PPF) under hydroponic culture system of deep flow technique for 50 days. Shoot fresh weight increased under the RH, BWH, and BRH treatments with higher PPF. Shoot elongation of the seedlings decreased, and polyphenol synthesis promoted by the higher light intensity conditions. Sugar synthesis in the leaves was above 2 times greater under the RH treatment of monochromic red light quality with $100{\mu}mol/m^2/s^1\;PPF$ than $50{\mu}mol/m^2/s^1\;PPF$. CONCLUSION: The results show that the control of light quality and intensity in the smart greenhouse conditions with artificial lights significantly affects the growth and compound synthesis in the fresh kale leaves with higher culture efficiency compared to the conventional soil culture under greenhouse or field conditions. Researches on the optimum light intensities of the LEDs with special spectral wavelengths are necessary for maximum growth and metabolism in the seedlings.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.1-10
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• 2015

The bleaching phenomenon of otter spraints is indicates that the age of spraints (fresh or old spraints). As previous studies on the old otter faeces (spraint) have focused only on the external changes of spraints, it has been difficult to explain the difference of the decomposition rates among old spraints. We hypothesized that the micrometeorology difference caused by various characteristics of sprainting sites such as porosity and consistency of soil could affect the extent of the decomposition rate, the solar bleaching phenomenon of spraints used as a measure of the patterns of old spraints. Sprainting sites were classified into four types (Clay, Sand, Rock and Concrete spot) and each type was divided into two groups according to the sunlight condition (Sunny site and Shady site) to measure the effect of solar radiation. Micrometeorology of the sites were evaluated by measuring temperatures and humidities of the sites during the whole season. The variations in micrometeorology of the sunny sites according to the sprainting site types were examined with correlation analyses between the factors of micrometeorology. The analyses on the bleaching phenomenon of the spraints by micrometeorology showed that the highest rate of bleaching was found at the 'Rock spot' and 'Concrete spot' of the sunny site and especially in summer, the highest rate of bleaching ($63.4{\pm}7.6%$) was found at the 'Clay spot' of the sunny sites. The lowest rate of bleaching was found at the 'Sand spot' of the sunny sites. The above findings show that the difference in bleaching rates among sprainting sites was due to the seasonal or sunny condition. In addition, we found that the differences in thermal conductivity among sprainting site characteristics have resulted in different sprainting site temperature which have affected the rate of bleaching of spraints. In conclusion, this study suggests that studies of otters on their population size and home ranges using spraints as an indirect sign, should consider the effects of sprainting site characteristics and weather conditions.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.359-367
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• 2014

This study was carried out to determine the effects of seed storage methods and pre-treatments on seed germination, soil types and shading conditions on potted seedlings growth of S. sieboldiana var. pendula and S. sieboldiana for. xanthocarpa, endemic species in Korea. The seed germination rate of S. sieboldiana var. pendula was the highest at 48.6% when seeds were treated with stratification for 60 days and then soaked in 100 ppm $GA_3$. And seed germination rate of S. sieboldiana for. xanthocarpa was the highest at 51.4% when seeds were pre-chilled for 30 days and then soaked in 100 ppm $GA_3$. And potted seedlings of S. sieboldiana var. pendula showed the best quality under 50% shading in bedsoil with the growth characteristics of plant height (41 cm), number of leaves(8), leaf width (16 cm), leaf length (18 cm), root length (22 cm), fresh weight(aerial part/root part; 20/6.9 g) and dry weight(aerial part/root part; 4.5/2.0 g). And potted seedlings of S. sieboldiana for. xanthocarpa showed the best quality under non-shading in bedsoil with the growth characteristics of plant height (39 cm), number of leaves(10), leaf width (12 cm), leaf length (15 cm), root length (22 cm), fresh weight (aerial part/root part; 21/13 g) and dry weight (aerial part/root part; 4.2/2.2 g). Therefore, seeds treated with stratification or prechilling and then soaked in $GA_3$ were effective in germination of S. sieboldiana var. pendula and S. sieboldiana for. xanthocarpa, and potted seedlings should be cultivated in bedsoil under non or 50% shading condition.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.736-745
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• 2016

This research was conducted to evaluate the impact of various pre-planting $NH_4{^+}:NO_3{^-}$ ratios on the growth of plug seedlings of 'Bool-am No.3' Chinese cabbage. With fixation of the pre-planting N concentrations to $300mg{\cdot}kg^{-1}$ in a peatmoss+coir dust+perlite (3.5:3.5:3, v/v/v) medium, the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, 100:0. Then, the each of root media containing various ratios of $NH_4{^+}:NO_3{^-}$ as well as equal concentrations of other essential nutrients was packed into 72-cell plug trays. After seeds of 'Bool-am No.3' Chinese cabbage were sown, the seedling growths were measured 2 and 4 weeks after sowing. The weekly analysis of root media and end-crop tissue analysis for mineral nutrients 4 weeks after seed sowing were also conducted. As the seedlings grew up, the pH of the root media increased, however ECs in all treatments of $NH_4{^+}:NO_3{^-}$ ratios decreased. The concentrations of K, Ca and Mg in root media were higher in the treatments of $NH_4{^+}:NO_3{^-}$ (100:0) and $NH_4{^+}:NO_3{^-}$ (73:27) than those of $NH_4{^+}:NO_3{^-}$ (0:100) and $NH_4{^+}:NO_3{^-}$ (27:73) 2 weeks after seed sowing. But the concentrations of K, Ca, Mg and Zn were get lowered in all treatments and the differences among treatments were not significant 4 weeks after sowing. The highest $NH_4{^+}$ and lowest $NO_3{^-}$ concentrations of the root media were observed in the $NH_4{^+}:NO_3{^-}$ (100:0) among all treatments. Contrary to these, the treatment of $NH_4{^+}:NO_3{^-}$ (0:100) had the lowest $NH_4{^+}$ and highest $NO_3{^-}$ concentrations. The seedling growth in terms of fresh and dry weights of aerial part were the highest in the treatment of $NH_4{^+}:NO_3{^-}$ (23:73) at 2 weeks after sowing and those of $NH_4{^+}:NO_3{^-}$ (50:50) at 4 weeks after sowing. The survival rate of seedlings in $NH_4{^+}:NO_3{^-}$ (100:0) treatment were 19% and the growth of aerial part 4 weeks after sowing was the poorest among all treatments tested. The results mentioned above indicate that the pre-planting $NH_4{^+}$ ratio in inert media should not exceed 25% in plug stage 1 through 3 (until 2 true leaf development) and 50% in plug stage 4 (after 2 true leaves to transplant).

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.152-159
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• 1976

This experiment was conducted to select genotypes that were high-yielding and adapted to the soil and weather conditions in Korea, from 13 Fawn deri ved progenies which represented in the previous study. Comparisons were made in various leaf and plant characteristics, and forage productivities, between the 13 polycross progenies of high-yielding Fawn and control varieties including Fawn, Alta, and Kentucky 31. The results obtained were summarized as follow; Genetic differences between the polycross progeny group and the control group were recognized in leaf fresh weight but those between two groups in leaf dry weight were not observed. Leaf area of all derived progenies and control varieties were appeared to have individual genetic differences and, moreover, the leaf area of the polycross progeny group was larger than that of the control. Differences between polycross progeny group and control group in leaf width were not significant. However, leaf length exhibited significant differences among all polycross progenies, and control varieties between two groups, and among polycross progenies but no differences were observed among control varieties. Tiller number, plant height, and plant width of the polycross progeny group were larger than those of the control varieties when measured before and after harvest. Panicle length among all polycross progenies and control varieties showed minor differences. However, significant differences were found between the polycross progeny group and control group, as well as among the polycross progenies and control varieties within each group in culm length. Above characteritics in the leaf fresh and dry weight, area and length, plant width and height, and tiller number showed positive correlations with the forage yields, respectively. Forage yields of the polycross progenies were higher than those of the control varieties and the variation of the yields among the genotypes were great.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.260-270
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• 2011

This study was carried out to examine the effect of rice bran, barley bran, burned rice bran, and burned barley bran on the growth and yield of Chinese chive (Allium tuberosum Rottler), taro (Colocasia esculenta), and weed control. When the above 4 brans were examined 13, 27, 41 and 57 days respectively after application, the plant height of Chinese chive applied with burned barley bran was significantly higher than non-treated control, whereas the other brans did not have any distinct effect on the plant height or population number of Chinese chive. However, when examined 57 days after the application of the above 4 brans, all the plants applied with brans showed more than twice the improvement in shoot fresh weight compared with non-treated control. A chemical analysis of soil 57 days after the application of the above 4 brans showed that the soils were richer in available phosphate and organic matter. Shoot fresh weight of Chinese chive at 2 weeks after cutting was significantly higher in barely bran treated plot than in non-treated plot. In the case of taro, only taro plots transplanted when 10 cm tall and applied with barley bran showed an improvement in growth increment of both the underground and above parts. However, when sowed seeds after the application of the 4 brans, the yield of taro was reduced by the brans. Thus this research indicates that the effect of brans is differ based on the amount of bran application as well as crops. The effect of weed control on Echinochloa crus-galli, Digitaria clliaris, Chenopodium album, and Solanum nigrum as affected by brans was very low in pot conditions. Weed efficacy of the brans was also very low in field conditions. Growth of Chinese cabbage and garland chrysanthemum was inhibited 63% and 37% by rice bran at $4,000kg\;ha^{-1}$, respectively, but other crops such as maize, squash, cucumber, and Chinese chive were inhibited by 0-20%. These results were similar to that of barley bran except for Chinese cabbage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.245-250
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• 2005

This experiment was conducted to compare the frech and dry matter yields and feed values of Sorghum$\times$Sudangrsss Hybrid in accordance with different nitrogen and potassium fertilizer sources at the Dae-Ho reclaimed tidal land, Korea from 2003 to 2004. Soil salt contents of ammonium sulfate plots(T3, T4, T5) were higher than that of the urea plot(T2), but that of potassium sulfate plot(T6) was the lowest. The fresh yields of ammonium sulfate plots(T3, T4, T5) and potassium sulfate plot(T6) were higher than that of the urea plot(T2) as $173\%,\;173\%,\;144\%\;and\;90\%$. respectively. The dry matter and total digestible nutrient(TBN) yields were similar tendency like the results of the fresh matter yields. The crude protein(CP), neutral detergent fiber(NDF) and acid detergent fiber(ADF) contents of ammonium sulfate plots(T3, T4, T5) were higher than those of urea plot(T2), but those of potassium sulfate plot(T6) were the lowest. On the other hand, TDN content in potassium sulfate plot(T6) was the highest. It was desirable to use ammonium sulfate$(20\~30kg\;N/10a)$ and potassium sulfate fertilizer$(15kg\;K_2O/10a)$ than those of urea and potassium chloride fertilizer on reclaimed tidal land in view of forage production and its feed value.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.158-165
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• 1992

A survey on nation-wide distribution of fresh-water algae occurring in paddy rice fields was conducted in 1991. The algae which were collected from the whole nation were classified into a total of 54 genera including 14 genera in the blue-green algae. 29 genera in the green algae, 1 genus in the stoneworts. 3 genera in the euglenoids and 7 genera in the diatoms. The green algae and diatoms occurring in plain regions were diverse in terms of the number of genera distributed, whereas there was no regional difference in diversity of the blue-green algae and the euglenoids. Among the green algae, the suspended unicellular algae such as the genera, Chlamydomonas, Pandorina and Gonium, were widespread in plain regions, but the multicellular algae such as the genera, Spirogyra, Oedogonium, Ulothrix and Hydordictyon, were major in mountainous and attitudinal regions. The filamentous green algae such as the genera. Cladophora and Rhizoclonium, were dominant in reclaimed saline fields. The blue-green algae Oscillatoria spp. and the diatoms Navicula spp. were abundant in soil flakes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.129-136
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• 1990

In the present report, two experiments were carried out with the purposes of knowing the differences of response among forage species to growing period and potassium level in culture solution, and investigating possible relation of the responses with occurence of grass tetany on grazing pasture. The results were as follows; (1) At 25 days after germination, fresh weight of top part as well as the sum of top and root parts of the forages increased rapidly. (2) Italian ryegrass was the highest in potassium (K) content but the lowest in magnesiurn(Mg) content among the three gramineous forages, while tall fescue showed the opposite result to it. And orchardgrass was intermediate of the two forage species (Experiment 1). (3) The K contents of forages generally increased, while Mg content became lower with the increase of K level in culture solution. The highest K contents of Italian ryegrass and orchardgrass were more than 3 times of the lowest values. The K contents of alfalfa and tall fescue increased in the narrower range. The decreases of Mg content of Italian ryegrass and orchardgrass were significant in the ranges of 5ppm to 25 or 50ppm KzO, while the content of the leguminous forages and tall fescue decreased up to 1000 level. (4) Fresh yield, water content and K content of the forages were significantly increased with the increase of K20 application levels up to 25 or 50ppm. (5) The K concentration of forage on a tissue water basis was higher at 50ppm than that at 5ppm $K_20$ level, especially for Italian ryegrass and orchardgrass with the value of 2.6times and 2.5times, respectively. However, the K concentration (tissue water) of leguminous forages increased gradually up to the level of lOOOppm (Experiment 2). It is suggested from the results that rapid changes of water content, Mg content and K concentration (tissue water) may occur to forage on a grazing pasture, when both growing period and K level in the soil affect the changes simultaneously. Under such conditions, plant water especially in Italian reyegrass and orchardgrass can function as toxic material to grazing ruminants.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.485-492
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• 2017

This study investigated to determine the microbial contamination levels of strawberries at harvest and distribution stages and to suggest a control measure for reducing the microbial contamination of strawberries by replacing worker's gloves used at harvest and distribution stages. According to the monitoring results, the contamination levels of total aerobic bacteria (TAB) were in the order of soil ($7.12{\pm}0.61{\log}_{10}CFU/g$), gloves ($6.06{\pm}1.80{\log}_{10}CFU/cm^2$), strawberry ($3.28{\times}0.98{\log}_{10}CFU/g$), and water ($3.08{\pm}0.55{\log}_{10}CFU/g$) at harvest stage. TAB of strawberry at was harvest stage reduced from $3.28{\pm}0.98{\log}_{10}CFU/g$ to $1.85{\pm}0.21{\log}_{10}CFU/g$ and $2.6{\pm}0.30{\log}_{10}CFU/g$ at cold and room temperature storage, respectively. By the replacement of worker's gloves and distribution temperature, TAB levels of the strawberries were significantly reduced when compared to those of the strawberries treated without replacement of worker's gloves and distributed at room temperature. For reusing the replaced gloves, washing with a commercial disinfectant, clorox, was effective to reduce microorganisms contaminated on the worker's gloves. These results demonstrated that appropriate replacement of gloves at the harvest and distribution stages is an effective method for reducing microbial contamination of fresh strawberries.