• Journal of Bio-Environment Control
• /
• v.25 no.3
• /
• pp.193-199
• /
• 2016

The research discussed experimental results on slip resistance force of rafter-purlin connection of plastic greenhouse and suggested a test method for evaluating slip resistance performance of the connection. Slip resistance forces were measured by four kinds of constraint conditions for specimens, for example, fixing or rolling the end of specimen. According to tests, it is noticed that constraint condition is able to significantly affect the slip resistance force. From a post-hoc comparison result, slip resistance force of test under fixing ends condition was larger than those under the other three constraint conditions. But the slip resistance force results in the fixing ends condition had greater measure of dispersion and three times of standard deviation than those from other constraint conditions. Based on the results obtained, effect of constraint condition for specimen on the slip test should be studied to enhance reliability of evaluation test of the slip resistance performance.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.585-590
• /
• 2001

Bulbs of Lilium Oriental hybrids cv. 'Casablanca' and 'Marco Polo' were grown in a plastic house in alpine area of Pyongchang Kangwondo. Saw-dust, black film, reflective film, transparent film, and white/black double film were used as mulching materials to ascertain the growth of foliage, the quality of flower, and the size of bulbs. Foliage weights of both lilies were higher when lilies were grown with mulching materials than control. There were no differences of bulb weight among the control and mulching treatments, except delayed bulb growth in black film and white/black double film. Mulching cultivation with saw-dust and reflective film stimulated foliage growth, root growth and bulb production, but black film delayed the growth and development. Transparent and white/black double films showed no effects on foliage growth and bulb development than the control. As mulching materials tended to delay lily growth, including foliage and bulb, an extension of growing term might be better to produce high quality lilies than common cultivation in alpine area.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.465-470
• /
• 2001

This study was carried out to investigate the effect of application dosage and methods of selenium (Se) on mineral contents in garlic. The content of Se was higher in upland than paddy fields. Application of higher dosage of Se salt increased higher content of Se in leaf sheath and bulb of garlic. Se was detected also in the non-treated plot but its amount was negligible. Absorption of Se in garlic was higher when Se was applied in the form of sodium selenate. Foliar application of sodium selenate enriched Se content in garlic as compared with the soil dressing. However, Se content in garlic fluctuated depending on growing conditions. Se content of garlic grown on the artificial soil (vermiculite and commercial soil) in the plastic house was higher than the garlic grown in the paddy field. The growth of garlic was not affected by types, dosage and application methods of selenium. Mineral contents in garlic such as Mg, S and K were higher in the selenium treatment than control. However, this trend was not evident according to dosages of selenium fertilizers.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.525-529
• /
• 2013

As most of citrus, shiranuhi mandarin ((Citrus unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulata) mainly use the trifoliate orange (Poncirus trifoliata) as its rootstock which has dwarf and cold hardness in Korea. However, recently, scion root was observed in 'Shiranuhi' mandarin tree grafted onto the trifoliate orange. This study was carried out to find out effects of scion root occurrence on the fruit quality, flowering and yield of shiranuhi mandarin. For the experiment, we selected six farmers who have outbreak of scion root in their Shiranuhi mandarin orchards and surveyed the difference of fruit quality of shiranuhi mandarin hybrid between scion root and control (trifoliate orange root). In the results, flowering was severely decreased in scion root trees compared to control. As a result of survey of 174 Shiranuhi mandarins, 160 trees were proved to be scion root, and had less flowering. Fruiting of scion root also severely dropped compared to control and thus, yields of scion root (6.4 kg) reduced by 24% compared to control (26.7 kg). The fruit size, weight and soluble solid contents of scion root were significantly reduced, but there were no differences in acid contents and coloring of fruit. From the results, we concluded that scion root had negative influence on flowering, fruit size and the yields of Shrinanuhi mandarin hybrid.

• Journal of Mushroom
• /
• v.14 no.3
• /
• pp.105-110
• /
• 2016

This study was carried out to develop techniques for the log cultivation of Pleurotus pulmonarius. Soil landfill cultivation of the in plastic container boxes containing yield per log than but there was no difference in the yield from both spawn Hyangsan" variety. In the case of soil landfill cultivation in a shaded vinyl house, an Ailanthus tree gave a higher yield than that using poplar tree, and the yield of the Hosan" variety was higher than that of the Hyangsan" variety. With regard to proper tree species selection, willow and cherry trees were good for both the Hosan" and "Hyangsan" variet.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.4 no.1
• /
• pp.73-81
• /
• 1996

The expriment was carried out to clarify the fertilizer efficiency of a garbage-based compost in cultivation of leaf vegitables. 1. Only application of 8 tons per 10 of the compost did not have any growth injury to "Osaka-shirona" (a cultivar of Brassica pekinensis L.) in a pot experiment 2. In four continuous cropping with application of 3 tons per 10 a of the compost before every seeding, "Osaka-shirona" grew satisfactorily. 3. Osaka-shirona, spinich and garland chrysanthemum were cultivated under a plastic house applied with 2 tons per a of each of the garbage-based compost and cattle manure, delayed release fertilizer and bark compost on the market. There was no difference of the vegetable yields among the applied field, as well as of the contents of ${\beta}$-carotene, vitamin C, Ca and Fe.

• Korean journal of applied entomology
• /
• v.46 no.1 s.145
• /
• pp.117-122
• /
• 2007

This study was investigated the potential of ducks and fish trap for the control of golden apple snail, Pomacea canaliculata, in paddy field and water canals. The smaller size of duck (700g) preyed snails than the bigger one (1,300g). The consumption of two ducks was bigger under plastic house. They preyed over 90% on the second days of release. The release time of ducks was more effective at seven days after inoculation of snails than simultaneous. Duck could suppress the density of snails at any time from month after inoculation. Four ducks per $30m^2$ could control snails in an irrigation canals. The number of attracted golden apple snail per week was 216 in big fish trap $({\Phi}15cm)$ with menthol paste which for a carp.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.4
• /
• pp.449-455
• /
• 2012

Greenhouse and laboratory experiments were conducted to determine the effects of shade treatment and substrate components on plant growth and physiological activity of Taraxacum officinale. Substrates combined with coco peat and perlite (ratio 70 : 30 and 50 : 50, v/v) showed higher growth and yield than their single substrates (p<0.05). Shade treatment also significantly reduced plant height, root length, root diameter, leaf area, chlorophyll content, and fresh weight (p<0.05), compared to no shade. Contents of total phenolics [mg chlorogenic acid equivalents (CAE) $kg^{-1}$ DW] and total flavonoids [mg naringin equivalents $kg^{-1}$ DW] showed higher amounts in shoot parts than root parts of T. officinale, with shade than no shade. The antioxidant potential of the methanol extracts from the plants dose-dependently increased. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was higher in leaf parts than in root parts of the plants, and no shade than with shade.

• Journal of Bio-Environment Control
• /
• v.22 no.1
• /
• pp.55-59
• /
• 2013

This study was evaluated that seasonal change of the hesperidin content was in relation to the skin color and weight of fruit in outer or inner side of the canopy, for determine the optimum time and the index of most abundant hesperidin content in lemon fruits juice. The hesperidin content was different with fruit growth and on fruit bearing site of the tree. The fruits of the either side contained the highest hesperidin value at 162 and 176 days after anthesis just after de-greening and the value was highest in the fruits of outer side of the canopy. This time also corresponded to the time just before the cessation of fruit growth. These results suggested that the optimum harvesting period for more hesperidin content was the stage just after de-greening and just before fruit growth cessation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.1
• /
• pp.59-65
• /
• 2012

Plant growth-promoting effects of rhizobacterial inoculation obtained in pot experiments cannot always be dependably reproduced in fields. In this study, we investigated the effect of inoculation with Azospirillum brasilense and Methylobacterium oryzae, which have displayed growth promoting effects in several pot experiments, on growth and fruit yield of red pepper under field condition in a plastic-film house. Four rows spaced 90 cm apart were prepared after application of compost ($10Mg\;ha^{-1}$), and red pepper seedlings (Capsicum annum L., Nocgwang) were transplanted in each row with 40-cm space. Experimental treatments were consisted of A. brasilense CW903 inoculation, M. oryzae CBMB20 inoculation, and uninoculated control. Twelve plots, 10 plants per plot, were allotted to the three treatments with four replicates in a completely randomized design. At the time of transplanting, 50 mL of each inoculum ($1{\times}10^8cells\;mL^{-1}$) was introduced into root zone soil of each plant, and re-inoculated at 7 and 14 days after transplant. Plant growth and fruit yield were measured during the experiment. Both A. brasilense CW903 and M. oryzae CBMB20 could not promote growth of red pepper plants. All growth parameters measured were not significantly different among treatments. There were large variations in fruit yield recorded on plot basis, and no statistically significant differences were found among treatments. The failure to demonstrate the expected plant growth promoting effect of the inoculants is possibly due to various environmental factors, including weather and soil characteristics, reducing the possibility to express the potential of the inoculated bacterial strains.