• Horticultural Science & Technology
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• v.33 no.2
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• pp.268-275
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• 2015

We evaluated the effect of mixed liquid fertilizer (MLF) on growth responses of plants and soil chemical properties. To do so, a pot experiment with cherry tomatoes (Lycopersicon esculentum var. cerasiforme) using loam soil was conducted for 81 days in a temperature-controlled glasshouse, and four N fertilization treatments were laid out in a completely randomized design with three replicates: control (C), chemical fertilizer treatment (CF), and two rates (MLF-0.5 and MLF-1.0) of MLF treatment. Soils were periodically sampled and analyzed for pH, EC, total N, inorganic N and total C, and growth characteristics of cherry tomatoes were measured. During the experimental periods, the pH of MLF soils was higher than that of CF soils. Soil total-N content increased right after CF-application and ultimately decreased to the level of the control (C) soil, while MLF-application slightly increased the level of soil total-N and this level remained unchanged throughout the experiment. The levels of soil inorganic N content increased after application of CF or MLF, but the initial increase disappeared in 56 days after transplanting (DAT). The dry weight of shoots and roots increased in CF or MLF plants, while the number of fruit increased only in MLF plants. Whereas soluble solid contents were higher in MLF plants than in the other (C and CF) plants, the titratable acidity was not different among treatments. However, no consistent effect of N treatments on major elements of the organs of cherry tomatoes was found. The amounts of N taken up by plants were 0.91 g for CF, 0.61 g for MLF-1.0, 0.43 g for MLF-0.5, and 0.25 g for control treatments, resulting in greater N efficiency for CF than for MLF.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.208-217
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• 2020

A biopolymer based on microorganism-derived β-glucan and xanthan gum is being studied as a new eco-friendly material that stabilizes the riverbank slope, and also promotes vegetation growth. However, it is still inconclusive whether biopolymers have a positive effect on plant performance in the riverbanks which are subjected to various climatic factors and plant competitions. For a practical ecological evaluation of the biopolymers, their effect on plant growth promotion was studied in a natural environment. Considering the relationship between competition and plant community formation, the effects of biopolymers on competition were also investigated. For four plant species (Echinochloa crus-galli, Pennisetum alopecuroides, Leonurus japonicus, and Coreopsis lanceolata), the biopolymer effects under intra/interspecific competition were tested at the riverbank (20 m × 10 m) near Samjigyo Bridge in Damyang-gun, Jeollanam-do. A biopolymer powder was mixed with water and commercial soil following the manufacturer's recommendations. The soil mixed with the biopolymer was filled in a pot or applied to the surface of the commercial soil with a thickness of 3 cm. Across the competition treatments, the biopolymer treatment promoted root growth of the target plant species and decreased the specific leaf area. The total biomass and shoot dry weight of P. alopecuroides increased in response to the biopolymer treatment. The competition treatment decreased the total biomass and shoot dry weight compared to the case without competition. Notably, such a competitive effect was similar in all the biopolymer treatments. Thus, biopolymers, when mixed with soil, promote the growth of some plant species, but do not appear to affect the competitive ability of plants.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.441-445
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• 2005

Researches on estimating national-scaled forest biomass are being carried out to quantify the carbon stock of forests with the Kyoto Protocol. In general, estimates of national-scaled forest biomass are based on forest inventory data which provides estimates of forest area, stem volume, and growth of stem by age classes. Estimates of forest biomass are, however, obtained by converting stem volumes to dry weight with stem density and thereafter to whole tree biomass with biomass expansion factors (ratios of whole tree dry weight to stem dry weight). Pinus densiflora is widely distributed and one of the most economically important timber species in Korea. The species are largely grouped into two ecotypes of Geumgang and Jungbu. Stems of Geumgang type trees are straight and high compared to those of Jungbu type trees. The objective of this study was to determine and compare stem density and biomass expansion factors fore two ecotypes of Pinus densiflora according to stand age. Stem density of both ecotypes of Pinus densora increased and biomass expansion factors of them decreased with increasing tree age. In he same age class, stem density and biomass expansion factor of Geungang type Pinus densiflora were lower than those of Jungbu type Pinus densiflora. There were statistically significant differences in stem density and biomass expansion factors between Geumgang type and Jungbu type Pinus densiflora in 0-20-year-old stands and 40-60-year-old stands. Our results suggested that the reliability of the national forest biomass inventory could be improved by applying the ecotype- and age-dependent stem density and biomass expansion factors.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.3
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• pp.3059-3088
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• 1973

The Object of research was laid on the dry paddy field which had a low level of underground water, rather than on a paddy field with a high level of underground water. In the treatment of the clay paddy field before transplanting we employed 3 kinds of methods; deep plowing, development of cracks by drying the surface of the field under which pipe drain was built. This study was to find which one, among these three methods, is the most effective to let roots extend to deep zone and increase the yield of rice and at the same time, for trafficability of large scale machinery which will be introduced to the harvest, in the light of the earth bearing capacity in relation with underground drainage. In the treatments of plots, 1) the kyong plot was plowed 39 days before transplanting and dried, 2) the kyun plot was plowed again 2days before transplanting after plowing 39 days before transplanting, leveling field surface in the saturation with water and developing the cracks by drying, 3) the kyunam plot was plowed again 2 days before transplanting after setting the drainage pipe and at the same time plowing 39 days before transplanting, leveling field surface in the saturation with water and developing the cracks by drying. Also each plot above had three different levels of soil depth, respectively; that is 15cm, 25cm, 35cm. The kyong plot with 15cm-depth was he control. The results obtained were as follows; 1. The kyunam plot showed a remarkably lager amount of water consumption by better underground drainage than the kyong and the kyun plot, and the kyong plot indicated a greater amount of water consumption than the kyun plot. Therefore the amount of available rainfall was decreased in the order of kyunam>kyong>kyun. The net duty of water decreased in the order of kyunam>kyong>kyun and its showed about 105cm in depth at the kyunam plot, about 70cm in depth at the kyong plot and about 45cm in depth at kyun plot, regardless of soil depth. 2. According to the tendency that the weight of the total root was effected by the maximum depth of the crack, it seemed that the root development was more affected by the depth of the crack than by only the crack itself. The weight of the total roots tended to increase as the depth of the crack got deeper and deeper, and the weight of the total roots was increased in the order of kyun<kyunam<kyong. 3. In the growing of the plant height, the difference did not appear at the beginning of growing(peak period of tillering) of any plot, But for the mid period of growing(ending period of tillering) to the period of young panicle formation, the deeper the depth of plot is, the more the growing goes down. On the contrary at the late period of growing, growth was more vigorous in the plot with deep depth than in the plot with shallow depth. Since the midperiod of growing, in the light of experimental treatment, the kyun plot was not better in growing than the other two plots and no remarkable defference was shown between the kyunam and the kyong plot, but the kyunam plot had the tendency of superiority in growing plant height. 4. As the depth of plot went deeper, the decreasing tendency was shown in the number of tillers through a whole period of growingi. When the above results were observed concering each plot of experimental treatment, the kyun plot was always smaller in the number of tiilers than the kyunam and the kvong plot, and the kyong plot was slightly larger than the kyunam plot in the number of tillers. 5. When each plot of the different experimental treatments was compared with the control plot(15-kyong), yield(weight of grains) was increased by 17% for the 35-kyong plot, by 10% for the 35-kyunam and yields for the other plots were less or nomore than the control plot. On the whole, as the depth of plot went deeper, yields for plots was increased in the order of kyong>kyunam>kyun. 1% of significance between the levels of depths and 5% of significance between the treatments were shown. 6. The depth of consumptive water which was more effective on the weight of grains is that of the last half period. When the depth of consumptive water was increased at the range of less than 2.7cm/day in the 15cm plot, 3.0cm/day in the 25cm plot and 3.3cm/day in the 35cm plot, the weight of grains was increased, and at the same time the weight of grains was increased as the depth of plot went deeper. The deeper plots was of advantage to the productivity at the same depth of consumptive water. 7. The increase in the weight of grains in propertion to the weighte of root showed a tendency to increase depending on the depth of plot at each plot of the same weight of roots. The weight of roots and grains together increasezd in the order of kyun>kyunam>kyong, considering each treatment of experimental plot. The weight of grains was in relation to the minimum water content ratio during the midperiod of surface drainage and the average earth temperature was mainly affected by the minimum water content ratio because it was relatively increased in proportion to the water content ratio(at less than 40%) 8. The weight ratio of straw to grain showed an increasing tendency at the plot of shallow depth and had a relation of an inversely exponental function to the weight of roots. At the same depth of plot except the 15cm plot, the weight ratio of straw to grain was increased in proportion to the depth of consumptive water. The weight of grains was increased as the depth of consumptive water was increased to some extent, but at the same time the weight of ratio of straw to grain was increased. 9. At a certain texture of soils the increase in the amount of the cracks depends on meteorological conditions, especially increase in amounts of pan evaporation. So if it rains during the progressing of field drying the cracks largely decrease. The amount of cracks of clay soil had relation of inversely exponental function to the water content ratio(at more than 25%). The maximum depth of crack kept generally a constant value at less than 30% of water content ratio. 10. The cone index showed the tendency that it was propertional to the amount of cracks within a certain limit but more or less inversely proportional over a certain limit. The water content ratio at the limit may be about 25%. 11. The increase in the cone index with the progressing of time after final surface drainage showed the tendency that it was proportional to the depth of consumptive water at the last half of growing period. Based on the same depth of if the cone index in the kyunam plot was much larger than in the other two plots and that in the kyong plot was much smaller than in the kyun plott, as long as the depth of plot was deeper, especially in the 35-kyong plot. 12. In the light of a situation where water content ratio of soil decreased and the cone index increased after final surface drainage the porogress of the field dryness was much more rapid in the kyunam plot than in the kyong plot and the kyun plot, especially slowest in the kyong plot. In the plot with deeper zone the progress was much slower. The progress requiring the value of the cone index, $2.5kg/cm^2$, that working machinary can move easily on the field changed with the time of final surface drainage and the amount of rainfall, but without nay rain it required, in the kyunam plot, about 44mm in total amount of pan evaporation and more than 50mm in the other two plots. Therefore the drying in the kyunam plot was generally more rapid in the kyunam plot was generally more rapid over 2days than in the kyun plot, and especially may be more rapid over 5days than in the 35-kyong plot.

• 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.

• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.91-97
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• 1994

To improve the productivity of peroxidase (POD) of cell line SP-47 derived from cell suspension cultures of sweet potato (Ipomoea batatas (L) Lam.cv White Star), we optimized culture conditions including the composition and concentration of plant growth regulators and carbon source, and the cell inoculum size. When one g (fr wt) of cells was inoculated into 50 mL TL medium supplemented with l mg/L 2,4-D and 30g/L sucrose in 300 mL Erlenmeyer flask at 25$^{\circ}C$ in the dark (100rpm), the POD activity per g cell dry wt was maximized to be about 6,800 units after 25 days of subculture, which was about 30 times higher than that of intact roots of horseradish plants grown in the greenhouse, but the cell growth was maximum after 15 days of subculture. The protein content per g cell dry wt maintained almost plateau and after 25 days of subculture decreased as culture Proceeded further whereas the POD specific activity (unit/mg protein) was about two times higher after subculture and continuously increased from 12 days to the end of cultures (40 days). The POD isozyme patterns showed almost the same regardless of cell growth stage, but some acidic isozymes were slightly increased after 25 days of subculture. These results indicate that POD activity in suspension cultures of sweet potato is closely associated with cell growth and stresses derived from cell culture renditions and medium depletion. Due to its high POD activity the SPL47cell line seems to be suitable for the mass production of POD.

• The Korean Journal of Food And Nutrition
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• v.26 no.2
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• pp.318-322
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• 2013

This study was designed to investigate changes in germination characteristics and color as well as the content of isoflavones of Eunhakong germinated under dark conditions. The wet weight of Enhakong was increased as germination progressed. It reached $299.7{\pm}15.0%$ at 60 h after the beginning of sprouting. The relative dry weight was consistently decreased as germination progressed, and it reached $65.8{\pm}8.2%$ at 60 h after the beginning of sprouting. The length of sprout was rapidly increased at the latter stage compared to the beginning of germination. Most soybean seeds were successfully germinated at 60 h after beginning of sprouting. The L value was considerably increased at the early stage of germination and it reached $63.4{\pm}0.7$ at 60 h. The a value was rapidly increased at the beginning of germination and decreased thereafter. The b value was increased at the beginning of germination and did not changed thereafter. It was confirmed that the total isoflavone content, in which the m-genistin was highest followed by daidzin, and than slightly decreased.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.167-174
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• 2017

To identify the appropriate irrigation level for Pinus densiflora, a common reforestation species in Korea, we investigated their growth response characteristics according to different irrigation treatment levels for producing container seedlings with relatively high growth rate for higher survival rate when planted at the reforestation site. The container seedlings including control seedlings (no irrigation was applied) were grown in 104-cell trays were irrigated for 8 weeks from 15 weeks after seeding, at intervals of 1, 2, 3, 5, 7, 10, and 15 days. Analysis of the height growth, root collar diameter growth, and dry matter production of the container seedlings according to irrigation showed that the highest growth reaction was observed for the irrigation interval of 1 day. A shorter irrigation cycle resulted in better growth of the container seedlings, but overall, longer total root length were observed with an irrigation cycle of 3 days compared with cycles of 1 or 2 days. Quality index (QI) was the highest for the irrigation interval of 1 day, and tended to decrease with increase in the irrigation interval. Thus, it was determined that irrigation at intervals of 1-2 days was appropriate for growing Pinus densiflora container seedlings.

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.16-21
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• 2012

Since many pesticides cause various health and environmental problems, alternative measures to replace them are needed, and the bacteria producing the antifungal substances can be one of them. In this study, several rhizobacteria were isolated and their antifungal activities against some important plant pathogenic fungi were examined. Pseudomonas otitidis TK1 and Paenibacillus peoriae RhAn32 inhibited the growth of Fusarium oxysporum f. sp. niveum and F. oxysporum f. sp. lycopersici by 49.8% and 45.6%, and 45.1% and 48.3%, respectively compared to those of the control. P. peoriae RhAn32 also decreased the growth of F. oxysporum f. sp. raphani by 37.5%. This growth inhibition might be due to the production of antifungal substances, such as siderophore, hydrogen cyanide and chitinase, which were produced by these rhizobacteria. P. otitidis TK1 also produced plant growth hormones indole acetic acid and indole butyric acid at $293.41{\mu}g/mg$ protein and $418.53{\mu}g/mg$ protein, respectively. When P. otitidis TK1 and B. cereus TK2 were inoculated together with F. oxysporum f. sp. lycopersici to the 4 weeks grown tomato seedlings and incubated additional 8 weeks, the stem lengths of tomato increased up to 45.7% and 55.3% and root lengths were raised to 64.9% and 60.8%, respectively than those of the control group. The wet weights increased by 118% and 182%, respectively compared to the control group.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.40-45
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• 2014

In order to increase the persistence of plant growth promoting rhizobacteria (PGPR) in rhizpsphere soil, the growth of tomato was examined after the application of Arthrobacter woluwensis ED immobilized in alginate bead, which was known as PGPR. When tomato seedlings were treated with A. woluwensis ED of $1{\times}10^6$ cells g $soil^{-1}$ and incubated for 30 days in a plant growth chamber, the shoot length, root length, fresh weight and dry weight of the grown tomato plants treated with the suspended inoculants significantly increased by 36.2, 59, 51.1, and 37.5%, respectively compared to those of the uninoculated control. The treatment of the immobilized bacteria increased those by 42, 67.4, 62.5, and 60.4%, respectively compared to those of the uninoculated control. Therefore, the enhancement of tomato growth by the treatment of the immobilized bacteria was higher than those by the suspended inoculants. The effects of the inoculation on indigenous bacterial community and the fate of the inoculated bacteria were monitored by denaturing gradient gel electrophoresis analysis. The DNA band intensity of A. woluwensis ED in the tomato rhizosphere treated with the suspended inoculants continuously decreased after the inoculation, but the band intensity in the tomato rhizosphere soils treated with the immobilized inoculants showed the maximum at 1 week after inoculation and the decreasing rate was less than that of the suspended inoculants, which indicated the longer maintenance of the immobilized bacteria at rhizosphere soils. Therefore, encapsulation of PGPR in alginate beads may be more effective than liquid inoculant for the plant growth promotion and survival of PGPR at plant rhizosphere.