• Korean Journal of Organic Agriculture
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• v.7 no.1
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• pp.129-135
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• 1998

This study was conducted to clarify the plant growth promoting effects of the various rhizobacteria on the growth of hydroponically grown tomatoes in rockwool, perlite and cocopeat cultures. Strains in terms of $Azospirilham\;sp.(4.5{\times}10^7cells/g),\;Rhodopseudomonas\;sp.(5.8{\times}10^5cells/g),\;Pseudomonas\;sp.(6.1{\times}10^6cells/g$), fusant of $Bacillus\;sp.\;and\;Corynebacterium\;glutamicum(9.1{\times}10^5cells/g$) was bacterialized into the root zone of tomatoes before sowing. Overall growth of tomato plants was promoted by bacterialization of the various rhizobacteria. Strains which showed the highest plan growth promoting effects of hydroponically grown tomatoes was Azospirillum sp., and optimum cultural substrates for the plant growth promotion by rhizobactera were in the order of cocopeat > perlite = rockwool cultures.

• Journal of Bio-Environment Control
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• v.16 no.1
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• pp.62-66
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• 2007

This study was carried out to develop the stable plug seedling production for hydroponics of spinaches by various nursery media, plug tray size and seed number per plug tray cell. When plant grown in various nursery media, the seeding stand rate was shown in order of granular rockwool with good water retention, granular rockwool>granular rockwool mixed with pearlite>cocopeat>pearlite>poly urethane foame. Thus, poly urethane foame indicated the lower seedling stand rate. There was no difference in growth of the seedlings md the seeding stand rate by the plug tray size, and no significant difference in the plant height and the number of leaves among the seed number per plug tray cell. But, leaf area of plant in 2 grains seeding per cell was $113.0cm^2$, was wider in compared with 5 grains seeding of which leaf area was $88.0cm^2$. Accordingly, the leaf area per plant decreased as more and more the number of seeds per plug tray cell increased. The fresh weight of a plant per plug tray cell was the heaviest with 12.5g in the 2 grains, and the total fresh weight of plants per cell was 33.9g in 4 grains seeding, thus it tended to was bigger compared with other treatments. Consequently, given that the number of seeds per cell was decreased, the fresh weight of a plant increased. On the other hand, the total fresh weight per cell showed a tendency to be reducing as more and more the number of seeds per plug tray cell decreased. The yield in the 4 grains seeding was increased by 46% as $14,910kg{\cdot}ha^{-1}$ in compared with the yield in 2 grains seeding as $10,200kg{\cdot}ha^{-1}$.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.173-178
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• 2013

Experiments were conducted to investigate the optimum concentration of nutrient solution for strawberry 'Maehyang' bred domestically for exportation in hydroponics. Nutrient solutions for strawberry, which was made by Yamazaki, were supplied electrical conductivity (EC) 0.6, 0.8, 1.2, and $1.8dS{\cdot}m^{-1}$ after planting on cocopeat medium during the experiment period. Growth of shoot of strawberries did not show any statistical differences among treatments. Fruit length showed the longest in EC 0.8 and $1.2dS{\cdot}m^{-1}$, followed by 0.6 and $1.8dS{\cdot}m^{-1}$ in the first and third cluster. It showed the shortest in EC $1.8dS{\cdot}m^{-1}$ in the second cluster but there were no significant differences among treatments in the fourth cluster. Fruit diameter did not show significant differences among treatments in the first and second cluster but was the longest in the lowest concentration EC $0.6dS{\cdot}m^{-1}$ in the third cluster. The shortest was in EC $1.8dS{\cdot}m^{-1}$ in the fourth cluster. The heaviest mean fruit weight appeared in EC 0.8 and $1.2dS{\cdot}m^{-1}$, and the lightest was in EC $1.8dS{\cdot}m^{-1}$ in the first cluster and also lightest in EC $1.8dS{\cdot}m^{-1}$ but no significant differences was found among other treatments in the second & third cluster. Also the fruit weight was significantly light in plants grown in EC $1.8dS{\cdot}m^{-1}$ than $0.6dS{\cdot}m^{-1}$ in the fourth cluster. Soluble solids content of fruit was the highest in EC $0.6dS{\cdot}m^{-1}$ in all cluster. As a result, we came to the conclusion that the optimum EC for strawberry 'Maehyang' was EC 0.8 - $1.2dS{\cdot}m^{-1}$ during low temperature season. This result will be utilized as an indicator for strawberry hydroponics.

• Horticultural Science & Technology
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• v.32 no.6
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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.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.248-255
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• 2011

For the environmental friendly soil management on the cultivation of crops in the greenhouse, organic materials, such as the by product-fertilizer derived from livestock manure, rice straw, mushroom media, rice hulls, wood sawdust, and cocopeat, were used as carbon sources adjusting the ratio of carbon to nitrogen to 10, 20, and 30 based on the inorganic soil N. In each C/N ratio of greenhouse soil, watermelon was cultivated in the greenhouse as crop for experiment for the spring and summer of the year and the experimental results were summarized as follows. The concentration of T-C in the organic materials applied were between $289{\sim}429g\;kg^{-1}$, In the C/N ratio of 10, using watermelon as the crop cultivated during the second half of the year in the greenhouse soil, the $NO_3$-N and EC were reduced by 21 to 37%, and 26 to 33%, respectively, except the by product-fertilizer from livestock manure, compared to the soil $NO_3$-N and EC used in the experiment. After the watermelon was cultivated in soils that C/N ratios were controlled as 10, 20, and 30 with wood sawdust adding as carbon sources in the three soils with the different EC values, EC values of the soils were reduced by 33, 42, and 39%, respectively, compared to the soil EC used in the experiment. The weight of watermelon was 10.1-13.4 kg per one unit, and, of the three soils with different EC values. In the soils with three different EC values controlled at C/N ratio of 20, the weight of watermelon was good. The degree of sugar of watermelon were 11.8 to 12.3 Brix, which means that the difference between the treatments was not significant. In conclusion, the C/N ratio of 20 controlled by the proper supply of organic materials according to the representative EC values shown in the greenhouse soils was optimal condition enough to maintain the soil management for the organic culture with the proper nutrient cycling.