• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.178-184
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• 2019

Strawberry ($Fragaria{\times}ananassa$) is one of the most important and popular fruit crops in the world, and 'Sulhyang' is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid ($GA_3$), and salicylic acid (SA) on growth and flower bud induction in strawberry 'Sulhyang' was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with $25^{\circ}C/15^{\circ}C$ (day/night) temperatures, 70% relative humidity (RH), and light intensity of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and $200mg{\cdot}L^{-1}$ of BA, $GA_3$, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with $GA_3$. However, the treatment of $200mg{\cdot}L^{-1}$ $GA_3$ promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of $200mg{\cdot}L^{-1}\;SA$, followed by $100mg{\cdot}L^{-1}\;SA$. Overall, results suggest that foliar application of $GA_3$ solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between $GA_3$ and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.171-181
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• 2021

The purposes of this study were to determine how changes in temperature affect germination rates and growth of hulled and dehulled barley, malting barley, and naked oat plants, and to measure chlorophyll content, photosynthetic efficiency, and secondary compounds (total phenol, total flavonoid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) in plants grown at 13℃ or 25℃). Various types of barley seeds were collected from areas with ideal conditions for barley cultivation, hereinafter referred to as IA, and also from areas where barley cultivation is more difficult due to lower temperatures, hereinafter referred to as LTA. Seeds were tested for seed vigor. While there were significant differences in the electrical conductivity values between seeds collected from certain specific areas, no significant differences were evident between IA and LTA seeds, regardless of the type of barley seed. When plants were grown at 25℃, there were no significant differences in germination rates, plant height, root length and shoot fresh weight between plants originating from IA and LTA. However, there were differences in the measured parameters of some specific seeds. Similarly, under the low temperature condition of 13℃, no differences in the emergence rate, plant height, and shoot fresh weight were evident between plants originating from IA or LTA, regardless of the type of barley. However, there were differences between some specific seeds. One parameter that did vary significantly was the emergence date. Hulled barley and malting barley emerged 5 days after sowing, whereas naked oats emerged 7 days after sowing. There were no differences in the chlorophyll content and photosynthetic efficacy, regardless of the type of barley. There were no significant differences in total phenol, total flavonoid content, and DPPH radical scavenging activity between plants originating from IA and LTA, regardless of the type of barley. However, there were differences between some specific seeds. In particular, for malting barley the total flavonoid content differed in the order of Gangjin > Changwon > Haenam = Jeonju > Naju. The results indicate that crop growth, yield and content of secondary compounds in various types of barley may be affected by climate change.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.97-105
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• 2023

Concentration of nitrogen, one of the major elements, and ratio of two nitrogen forms (NH₄⁺ and NO₃^-) in the nutrient solution affect the quality and food safety of fresh vegetable produce. This study was conducted to find an appropriate strength and NH₄⁺:NO₃^- ratio of a nutrient solution for growth and development of a Romaine lettuce (Lactuca sativa L. var. longiflora) 'Caesar Green', a representative leafy vegetable, grown in a home hydroponic system. In the first experiment, plants were grown using three types of nutrient solution: A commercial nutrient solution (Peters) and two strengths (GNU1 and GNU2) of a multipurpose nutrient solution (GNU solution) developed in a Gyeongsang National University lab. Plants grown with the GNU1 and GNU2 had greater shoot length, leaf length and width, and biomass yield than Peters. On the other hand, the root hairs of plants grown with Peters were short and dark in color. Tissue NH₄⁺ content in the Peters was higher than that of the GNU1 and GNU2. The higher contents of NH₄⁺ in this solution may have caused ammonium toxicity. In the second experiment, eight treatment solutions, combining GNU1 and GNU2 solutions with four ratios of NO₃^- :NH₄⁺ named as 1, 2, 3 and 4 were used. Both experiments showed more growth in the GNU2 group, which had a relatively low ionic strength of the nutrient solution. The growth of Romaine lettuce showed the greatest fresh weight along with low tissue NO₃^- content in the GNU2-2. This was more advantageous in terms of food safety in that it suppressed the accumulation of surplus NO₃^- in tissues due to the low ionic trength of the GNU2 subgroup. In addition, this is preferable in that it can reduce the absolute amount of the input of inorganic nutrients to the nutrient solution.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.33-43
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• 2016

Pinellia tripartita(Blume) Schott is a herbaceous perennial plant belonging to the Araceae and distributed on Asia including of Korea, Japan, and China. P. tripartita is often used for gardening but has not been developed mass-breeding methods. In this study, we compared the tuber growth in different combinations of mixed soils used six compositions. Tubers used to study was cultured in vitro and divided into two groups. Type I was diameter more than 1cm and the group of Type II was diameter below than 1cm. Enlargement of tubers and growth of aerial parts were measuring the plant height, number of fresh leaves and dead leaves, number of bullets, tuber size, and fresh / dry weight. The size/weight and numbers of tubers from the mixed soil B (coir 68.0%, peat moss 14.7%, perlite 3.0%, vermiculite 7.0% and zeolite 7.0%) were the best grown up for eight weeks. In case of Type I, GI (Growth index) of tuber size and weight were 45% and 101%, respectively. The difference of growth was doubled compared to the bad growth treatment as the mixed soil E(Coir 14.3%, peat moss 14.3%, perlite 42.9%, vermiculite 14.3%, and zeolite 14.3%). These results could be used as the basic information for the similar experimental design for the P. ternata.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.5
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• pp.341-349
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• 2004

This study was conducted to compare the effects of arbuscular mycorrhizal fungi (AMF) on the growth and fruit yield of hydroponically grown cucumber and tomato plants in solid medium culture. Mycorrhizal fungus Glomus sp. was collected from plastic film house soils of cucumber and tomato and inoculated to the experimental crops at the time of seeding and transplanting. Root infection of cucumber and tomato plants by AMF was more significantly increased when the AMF was inoculated at seeding stage than at transplanting stage. In the infected roots of cucumber and tomato, mycorrhizal hyphae was easily observed but vesicle and arbuscule were rare. Overall plant growth was increased with AMF inoculation and the growth was higher when AMF was inoculated at seeding stage. Fresh weight of each fruit of cucumber and tomato and sugar content in tomato fruits were significantly increased with AMF inoculation at seeding stage. The AMF inoculation also increased fruit yields of cucumber and tomato.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.77-88
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• 2011

This study was carried out to investigate the effects of soil depth and planting density on the growth of lettuce, crown daisy, and strawberry on a rooftop condition using artificial soil as a growth media. The vegetable crops showed better growth for plant height (cm), plant width (cm), plant fresh weight (g), and Fo, Fm and Fv/m on 20cm depth soil than 10cm depth soil except strawberry. Planting density of $16/m^2$ and $64/m^2$ did not show significant differences on the growth of the crops. Soil moisture content and EC were low for 10cm depth soil in lettuce plots, whereas there was no significant differences on soil moisture and EC between two soil depth in strawberry plots. Hunter's L, a, and b values showed the leaf color of lettuce dark green on 20cm depth soil and reddish on 10cm depth soil. Results showed that soil depth suitable for crop growth on rooftop conditions was 20cm rather than 10cm. Growth response of the crops showed no significant difference between $16/m^2$ and $64/m^2$, indicating that planting density of 64 $plants/m^2$ could be practiced on rooftop conditions. Lettuce growth rapidly changed in control treatment in which leaves were not pinched out, while slowly changed in plants which leaves were periodically pinched out. In the case of control plot, it was impossible to harvest because withering of lower leaves after blossom on June 22. The plant of crown daisy in which pinching was not conducted, blossomed on June 7, and the plants were removed since its aesthetical value was lost. Strawberry seemed to be a suitable vegetable crop for rooftop conditions based on its high covering rate and extended growth period until late October. The soil depth 20cm and planting density 64 $plants/m^2$ were suitable for vegetable crops on green roof system using artificial soil.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.1
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• pp.52-60
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• 1995

This experiment was carried out to determine the effect of nitrogen application level of cattle sluny(T1:150, T3:250, T53.50 kglha) and chemical fertilizer(T2:150, T4:250, T6:350 kg/ha) on the growth characteristics, dry matter yield and chemical soil property of Sorghum-Sudangrass hybrid [Sorghum bicolor L. Moench]. The results obtained are summarized as follows: Mean stem diameter was significantly increased by increasing nitrogen application level of cattle slurry and chemical fertilizer. Especially, T6 treatment was the highest as 11.1 mm, while T1 treatment w a the lowest as 0.3 mrn. According to the same level of nitrogen application, cattle slurry treaunent(T1, T3 and T5) were showed a lower mean stem hardness than chemical fertilizer treatment(T2, T4 and T6). Especially, T3 treatment was the softest at 0.7 kg/$cm^2$. The dead stubble and tiller number were increased by increasing nitrogen level of cattle slurry and chemical fertilizer(P

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.447-451
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• 2004

This study was conducted to establish the proper techniques of the recirculating wick hydroponics for safe seed tuber proliferation of potatoes (Solanum tuberosum L. CV. Dejima). To achieve these, several intact tubers (5, 10 and 20 g) and cut seed-pieces (two or four) were treated in wick hydroponic system beds. A polystyrene box (31cm in width, 20cm in height, 51cm in length, and $0.031m^3$ in volume) was placed on a styrofoam hox. Eight wicks $(width\;1.5cm\;{\times}\;length\;40cm) $ were put into each polystyrene hox and the boxes were filled with perlite + peatmoss (1 : 2, v/v) medium. Top fresh weight per plant increased with increasing the tuber size from 10 to 30g/tuber. As the tuber size increases from 10 to 30 g/tuher in case of uncut tuber, the marketable tuber (>5g) production per plant increased from 83.8 to 141.8 g/plant and the marketable tuber (>5g) production per plant of cut tuber was slightly higher than that of uncut treatment. Total tuber yield ranged from 4.16 to $6.56kg/m^2$ and the percentage of seed tubers was greater than $97\%$ for all treatments. These results indicate that seed tuber should be cut to produce large tuber $(\geq10g)$ in the recirculating wick hydroponic system.

• Korean Journal of Environmental Agriculture
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• v.1 no.2
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• pp.116-122
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• 1982

Investigation on the water quality of Hwangguji River and experiment on the effects of nitrogen and soil improvements were carried out in the paddy field irrigated with polluted water of the river. The obtained results are as follows: 1) Amount of COD and $NH_4-N$ in water of the river were 54 ppm, 65 ppm, during the seeding time, and were 52 ppm, 512 ppm during the transplanting time respectively. Their concentrations were over the standard levels. It seemed that the water pollution was mainly caused by organic waste matters. 2) It seemed that the effective nitrogen level was $7{\sim}8$kg/10a in the paddy field irrigated with polluted water of the river. 3) The rice yields of potassium twice quantity application plot with N.P.K. fertilizer, the calcium application plot with N.P.K. fertilizer and the combined plot with potassium, wallarstonite, calcium and fresh straw, were increased 4, 5 and 8%, respectively, than that of the N.P.K. fertilizer standard level plot.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.339-345
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• 2006

Accumulation of nitrate in green vegetables is undesirable due to potential risks to human health. Lettuce was cultivated in pots under greenhouse conditions with compost applications of 2,000 and 4,000 kg/10a, and the growth and nitrate accumulation of lettuce were compared with those found in the lettuce cultivated with chemical fertilizers of recommended levels. Content of $NH_4-N$ in the soils of compost applications were much lower than those found in the soil of chemical fertilizer application. Two weeks after lettuce transplant $NH_4-N$ was not found in the soils of compost applications, and in the soils of chemical fertilizers application $NH_4-N$ was not found three weeks after lettuce transplant. One week after lettuce transplant content of $NO_3-N$ was much higher in the soils of compost applications, and the contents were rapidly decreased. While, the content of $NO_3-N$ in the soil of chemical fertilizers application was rapidly increased due to the nitrification of $NH_4$ released from the applied urea. At the time of harvest contents of $NO_3-N$ in the soils of compost applications were less than 1.4 mg/kg, but in the soil of chemical fertilizers application the content of $NO_3-N$ was 54.2 mg/kg. Contents of $NH_4$ in lettuce were about 20 mg/kg FW and were not much different among the treatments. However, contents of $NO_3$ in lettuce were significantly different between the treatments of chemical fertilizer and compost. There were significant differences in fresh and dry weights, and growth of lettuce in the compost treatment of 4,000 kg/10a was highest among the treatments. These results indicate that the cultivation with compost only as N source can produce higher yield of lettuce and significantly reduce nitrate accumulation as compared to the conventional cultivation with chemical fertilizers.