• Horticultural Science & Technology
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• 제32권6호
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• pp.812-818
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• 2014

Raising seedlings is important for fruit crops and is especially significant for strawberries as it accounts for 80% of their cultivation. However, there are few studies on raising seedlings of strawberries by hydroponics. Since strawberries show clear differences in growth characteristics based on cultivar, it is necessary to develop suitable fertilizer formula, concentration and pH for each cultivar, and also to examine the amount of nutrient feeding appropriate for each medium type. A key to raising seedlings of strawberries by hydroponics is the development of strategies to manage the concentration of nutrient solution. The mother plants of 'Daewang' strawberries were planted on hydroponics benches filled with cocopeat on March 28, 2012. Three nutrient solution treatments were employed during the term of raising seedlings: a type that supplied EC $0.6dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [0.6 (30) + 20]; a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [1.2 (30) + 20]; and a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 50 days [1.2 (50)]. The plants were then planted on hydroponics benches filled with cocopeat on September 20, and managed with EC $0.6-0.8dS{\cdot}m^{-1}$ strawberry nutrient solution developed by Yamazaki. After planting, shoot growth, flowering rate and fruit quality of the first cluster were investigated. The petiole length, leaf length, leaf width and crown diameter showed the highest grown in the [1.2 (50)] treatment, followed by [1.2 (30) + 20], and then [0.6 (30) + 20], indicating that the higher concentration of nutrient solution was preferable for raising seedlings. However, the growth differences among treatments gradually disappeared as growth continued, and the crown diameter especially grew to exhibit almost no difference at all among treatments. The point of flowering came first in [0.6 (30) + 20], followed by [1.2 (30) + 20] and then [1.2 (50)]. The [0.6 (30) + 20] treatment showed much earlier flowering than other treatments, which implies that low-concentration nutrient solution may be beneficial to the flowering of 'Daewang' strawberries while raising seedlings. There was no statistically significant difference among treatments in fruit length, fruit diameter and fruit firmness. Fruit weight in [1.2 (50)] treatment was significantly higher than other treatments. However, soluble solids of fruit was the lowest in [1.2 (50)] treatment. Together, the results of this experiment imply that it is better to supply EC $0.6dS{\cdot}m^{-1}$ solution for 30 days and then supply only water for 20 days to adequately manage concentration of nutrient solutions during the period of raising seedlings of strawberries by hydroponics.

• Journal of agriculture & life science
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• 제53권1호
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• pp.13-21
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• 2019

This study was carried out to acquire basic data for a long-term hydroponic culture through investigating water and inorganic ion uptake characteristics at different EC level of nutrient solution of three tomato varieties. Three different tomato varieties, the European type(cv. Daphnis), the Asian type(cv. Super Doterang) and cherry type(cv. Minichal), were used for the investigation. Also, the deep flow technique(DFT) was applied. The three different electrical conductivity(EC) level(1.0, 2.0, 3.0, and 4.0 dS·m-1) of hydroponic nutrient solution were used as variable. At a high EC level of nutrient solution, the leaf area and fresh weight decreased in the early stage, and its growth(plant height, leaf number, leaf area, fresh-weight) was poor with salt stress. Result showed that the higher the EC level of the nutrient solution, the lesser was water uptake. The water uptake was not significantly different from varieties in the first survey, but In the second survey, the 'Daphnis' did not show a significant decrease in water uptake in the EC level higher than 2.0 dS·m-1., on the other hand, 'Super Doterang' presented very low water uptake. At a low EC level, N, P, and K, were absorbed more than the concentration of the irrigation water, while Ca, Mg, S uptake were low. At a high EC level, almost ions absorbed less than 50% of the initial concentration of irrigation water. Thus, imbalance among ions was severe at low EC level compared to high EC level. 'Daphnis' was a variety that effectively utilize nutrients under nutrient stress, showing high absorption at low concentration condition and low absorption at high concentration condition. However, 'Daphnis' suffered most seriously by absorbing nutrients excessively.

• Korean Journal of Organic Agriculture
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• 제18권3호
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• pp.363-375
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• 2010

Sustainable farming systems have remarkably increased in Korea due to the increase of environmental concerns caused by the conventional systems. This study was performed on eight-year-old 'Niitaka' pear tree s to investigate the effects of different organic fertilizers on soil chemical and microbial properties and leaf and bud developments. Treatment and applications included 10 kg of rice bran (RB), 10 kg of coffee bran compost (CBC), 10 kg of Chitin incubated compost (Micro keeper$keeper^{(R)}$, CIC), and 30 kg of the mixture of the RB, CBC, and CIC (RCC). Control received 60 g of NPK (16-11-12) chemical fertilizer. The organic fertilizers increased organic matter, nutrient concentrations such as P, K, Ca, and Mg, and microbial biomass in soils compared to the control. RCC had the greatest specific leaf weight (SLW), and the other treatments did not have a significant difference for the SL W. Leaf P and K concentrations were different among the treatments, but they were not affected by the amounts of the soil nutrients. No differences were observed in the leaf Ca and Mg concentrations in the treatments. Organic fertilizers had greater chlorophyll contents than the control but had similar flower bud characteristics to the control.

• Journal of Bio-Environment Control
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• 제12권3호
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• pp.121-126
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• 2003

Tomato (Lycopersicon esculentum M. cv. ‘Momotarou’) and hot pepper seedlings (Capsicum annuum L. cv. 'Nockkwang')were grown under the 24h photopeliod (12 hrs light period: 12 hrs dark period) and 6 h photoperiod (3 hrs light period: 3hrs dark period). As a result of this experiment, the following details were observed. Plant height, leaf area, total dry weight, and leaf chlorophyll content decreased in case of tomato seedlings when they were given 6 h photoperiod. But the same effect was not observed in case of hot pepper seedlings. The photoperiod, however, did not produce any significant effect on the uptake of N, P, K, Mg and Ca ions in their nutrient solutions with the exception of their Fe. On thc 10th day of treatment, leaf chlorosis started to become visible in tomato seedlings and at the same time the uptake of Fe went down when the 6h photoperiod was applied to both tomato and hot pepper scedlings. In addition to this phenomenon, the sucrose content in leaf increased in case of tomato plants which were treated with 6 h photoperiod; on the other hand, their glucose content was observed to have decreased.

• Journal of Bio-Environment Control
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• 제16권1호
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• pp.1-6
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• 2007

This experiment was conducted to possibility for leaf production of wasabi using hydroponics system. When they were grown in aeroponics and soiless culture such as saprolite and Coir, photosynthesis and transpiration rate were high and marketable yield $(leaf\;width\;11{\sim}13cm)$ showed $11.2{\sim}11.7$ of leaf number per plant and $52{\sim}53.8g$ fresh weight. In spring periods, the highest yield was 25.7 of leaf number per plant in nutrient solution of Yamasaki's solution developed in Japan in deep culture during 130 days. It showed be possibility that marketable leaves harvested one leaf every $2{\sim}4$ days though spring and fall culture periods using hydroponics controlled in environmental culture.

• Journal of Korean Society of Forest Science
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• 제34권1호
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• pp.73-85
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• 1977

The nutrient elements which are used in forest fertilization vary from country to country. The development of forest fertilization is influenced by different national interests and/or economic situtations. The fertilized area/year of each country is shown. As one can see, Korea will have one of the largest fertilized forest area in the world. Nevertheless, attention needs to be paid from the technical viewpoint, since the development has been very rapid. The fertilization techniques, kinds of nutrient element, amounts of dosage, types of fertilizers, estimation of their efficiency, leaf analysis, ecological or physiological aspects of forest fertilization, tree species, wood qualities, forest vegetation, damages such as deseases, insects, frost, wind and snow, are discussed in relation to forest fertilization. Finally, the problem of eutrophication of water is discussed. The technical assessment will become necessary in introducing new techniques into the field.

• The Korean Journal of Ecology
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• 제19권5호
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• pp.487-496
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• 1996

This study was conducted to investigate pollutant loading, were quality and plant distribution of 8 streams which are tributaries of the Youngsan River. The nitrate reductase activity (NRA) and nutrient removall capacity of the most frequently occurring aquatic plants on streamside were also determined. As a result, the pollutant loading appeared to be correlated with the area of watershed, while the water quality was related to the land use pattern of each steam. The aquatic plants were distributed differently among the streams; Hydrilla verticillata - Potamogeton crispus, Numphoides peltata - Hydrocharis dubia and Polygonum thunbergii - Phragmites japonica were dominant at the Orye Chon, Jungan Chon, Whangryong River and Jiseok Chon, while potamogeton crispus - Lemma paucicostata, Zizania latifolia - Phragmites communis were dominant at the Youngam Chon and Munpyeong Chon. Persicaria hydropiper and Echinochloa crus-galli var. oryzicola were dominant at Kwangju Chon which was polluted with domestic wastewater. >From the measurement of leaf NRA for dominant species, the highest value of NRA was shown by the Polygonum thunbergii, followed by Oenanthe javanica > Phragmites communis > Zizania latifolia > Lemma paucicostata. The highest nitrogen and phosphorus removal capacity was found in Phragmites communis.

• Korean Journal of Agricultural Science
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• 제46권1호
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• Journal of Bio-Environment Control
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• 제8권3호
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• pp.172-182
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• 1999

Leaf lettuce(Lacaug sativa L.) was cultivated in deep flow culture to investigate growth and yield in relation to different reusing method of nutrient solution after once cultivation. Five different treatments were allocated to the nutrient solutions - Control(total renewal of solution), NSS(nutrient solution supplement), U control, NSAC(nutrient solution analysis and compensation), NSAC and Humus supply(NSAC with supply of Humus). The pH of solution was kept stable below 7.0 during 4 successive culture in NSAC and NSAC and Humus supply. U was sharply declined in NSS as the number of cultivation was increased. Gmwth and yield of NSAC was similar to those of Control because nutrient elements were kept the balance to the better growth, while the lettuce grown in NSS and EC control was shown lower growth rate. In the nutrient solutions, Content of N $O_3$-N and N $H_4$-N were remarkably decreased after the cultivation in all treatments. Ca and Mg were shown to be accumulated in nutrient solution regardless of culture times and treatments. After the first culture in NSAC and Humus supply, total N and P$_2$ $O_{5}$ content in leaves were lower than any other treatments, but Ca content was higher. Those were not significant as following cultures, and no significant difference of K and Mg content were shown among the treatments.

• Journal of Bio-Environment Control
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• 제16권3호
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• pp.199-204
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• 2007

This experiment was conducted to investigate the effect of nutrient solution strength on the growth of miniature multiflora P. amabilis and P. Taisuco Red Jewel at two growth stages during four months cultivation in an ebb and flow system. Early stage plants gained the biggest leaf length and width when nutrient solution strength was EC 0.5 or $1.0dS{\cdot}m^{-1}$ in P. amabilis, and EC $1.5dS{\cdot}m^{-1}$ in P. Taisuco Red Jewel. Root length and weight were the greatest when nutrient solution strength was EC $0.5dS{\cdot}m^{-1}$ in both cultivars and this trend was also found in middle stage plants. Fresh and dry weights of leaves increased as nutrient solution strength was elevated and were the greatest when nutrient solution strength was EC $1.5dS{\cdot}m^{-1}$ in P. amabilis. On the contrary elevation of nutrient solution strength decreased fresh weight of roots, being the greatest when nutrient solution strength was EC $0.5dS{\cdot}m^{-1}$. This trend was also found in P. Taisuco Red Jewel and P. amabilis at middle growth stage. The T/R ratio and chlorophyll content increased with nutrient solution strength and were the greatest regardless of cultivar and growth stage when nutrient strength was EC $1.5dS{\cdot}m^{-1}$.