• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.701-706
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• 2014

Three highbush blueberries (Vaccinium corymbosum cvs. Bluecrop, Coville, and Northland) grown in an open field and in a rain shelter were compared to evaluate the potential benefits of rain-sheltering systems on growth and fruit quality. Shrubs grown in rain shelter flowered 5-14 days earlier and were in full bloom earlier than those in the open field. All three cultivars set fruit by nearly 90% of flowers when they were grown in the open field, but was markedly reduced when they were grown in the rain shelter, to approximately 50% for 'Bluecrop' and 'Coville'. Fruit sets ratio of 'Northland' grown in the in the rain shelter was 14.5. Fruit from greenhouse-grown 'Northland' were larger, heavier, and had more seeds per berry. Soluble sugar content (SSC) of fruits varied both with the cultivars and growing conditions. SSC of fruits grown in the greenhouse was higher in 'Bluecrop' compared to that grown in the field, but this pattern was reversed in 'Northland'. Titratable acid was significantly higher in fruits from rain shelter-grown shrubs of both 'Bluecrop' and 'Northland' than in fruits from open field-grown shrubs (P < 0.05), although there was no difference in TA with respect to growing conditions for 'Coville'. The number of seed per fruit, fruit length and diameter, weight, SSC, and TA were similar in 'Coville' shrubs grown in the open field and the rain shelter. Fruit firmness of 'Bluecrop', 'Coville', and 'Northland' was higher in the rain shelter than in the open field. 'Coville' and 'Northland' fruits harvested in the open field had higher blue chroma than those harvested in the rain shelter. However, this pattern was reversed for 'Bluecrop'. On the whole, sheltering from rain affected most fruit characteristics of the three cultivars differently. Therefore, suitable blueberry cultivars for the rain shelter should be chosen by purpose.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.393-401
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• 2017

One-year old pear (Pyrus pyrifolia L.) trees of a new commercial cultivar 'Manpungbae', recently developed in South Korea, were planted in 2001 (planting year 1) and trained to four trellis systems: Y-trellis, Y-II-trellis, pergola, and vase-pergola. To evaluate training systems in the local area (southern Korea), tree growth responses were compared for each trellis system from planting years 3 to 8. For trees trained to Y-trellis and pergola systems, a high proportion of land covered by tree canopy was maintained over the study duration, with 70-80% coverage in year 8. Eight-year cumulative yield per tree was increased in the vase-pergola system with a low planting density and an additional scaffold. Compared with other systems, cummulative yield use efficiency was greatest in Y-II-trellis and pergola systems in years 5 and 8. Compared with Y-II-trellis and vase-pergola systems, the 8-year cumulative yield per hectare was two fold greater for trees trained to the Y-trellis (103 tons) and pergola systems (101 tons). Use of the pergola system improved average fruit weight and fruit soluble solid contents, as well as net income in year 8. Given that we observed reduced fruit productivity and increased labor hours (pruning and orchard work), we consider the Y-trellis and pergola systems to be less valuable trellis systems than the others evaluated.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.258-262
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• 2011

This study was carried out to investigate the effect the water content in substrates as according to growth stage on the growth and yield of paprika in summer hydroponics. Treatments of I, II and III were composed of 55-65-60, 50-60-55 and 45-55-50 % in water contents of growth stages, respectively. Time domain reflectometry (TDR) sensors were used in a drip irrigation system. The early growth of paprika was increased by high medium water content of treatment I. Mean fruit weight was not affected by medium water content, but the fruit number per plant and yield were increased at high medium water content of treatment I. The yield of treatment I was higher than that of treatment II and III. The incidence of brown stem fruit, blossom end rot and sunburn was decreased with increasing water content of medium. Occurred in the low water content of medium. The nitrogen (N) was higher content in brown stem fruit than normal stem, but mineral contents such as potassium (K), calcium (Ca), magnesium (Mg) etc. were not affected.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.342-350
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• 2021

This study was conducted to investigate the effect of time of hand-thinning on vegetative growth, bitter pit incidence, fruit quality, and return bloom in 'Gamhong'/M.9 apple trees. The time of hand-thinning were 3, 5, 7 and 9 weeks after full bloom, and the primary thinning (leaving only the king fruit on cluster) and secondary thinning (adjusting crop load) were conducted at the same time. The time of hand-thinning was correlated to the vegetative growth, average fruit wight, yield, soluble solids content, bitter pit incidence, and return bloom, negatively, and to the yield of middle grade fruits (fruit weight was 250-299g and none pit on fruit surface) per tree, calcium contents of leaves, and fruit red color, positively. There was no significant effect of time of hand-thinning on fruit firmness, titratable acidity, and total incomes per tree. In conclusion, if the time of hand-thinning of 'Gamhong'/M.9 apple tree was completed at 9 weeks after full bloom, it could produce about 300g of high-quality fruit without bitter pit.

• Korean Journal of Plant Resources
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• v.29 no.6
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• pp.704-711
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• 2016

Tomatoes are considered as one of the main components of daily meals in most households. Thus, it is important to invest in studies enhancing their yield and nutritional value. The study evaluated the effect of wood vinegar (WV) on tomato under greenhouse conditions. Data on fruit number, fruit weight, and plant height were recorded. Total phenolic content (TPC) and antioxidant activity of tomato were determined using the Folin-Ciocalteu reagent and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, respectively. FRR-CF+500x-WV significantly increased the fruit number (86.11%) and fruit weight (81.78%) over the control. Results were comparable to HRR-CF+250x-WV, indicating that conventional fertilizer and WV may have synergistic effect on each other. TPC and scavenging effect on DPPH radical was improved by 250x-WV application. The increase in the phenolic compounds can be attributed to WV as a direct source or as a factor triggering the plants to produce more secondary metabolites with the purpose of increasing natural defenses. The significant effect obtained by applying the full recommended rate of conventional fertilizer on the carotenoid content was due to the availability of the major nutrients needed by the plant. Correlation analysis showed that carotenoids have negative correlation with TPC and DPPH. However, TPC and DPPH showed that these are positively correlated with each other. Tomatoes are excellent source of antioxidants associated with the reduction of some human diseases and improved health. The results provided evidence that WV alone and/or its combination with conventional fertilizers has favorable effects on the quality of tomato.

• Korean Journal of Plant Resources
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• v.9 no.1
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• pp.71-75
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• 1996

Experiments were conducted to investigate the proper stem number and the propagation method of Lycium Chinense Mill. from 1993 to 1994.The results obtained were summerized as follows. The most effective propagation method was stem cutting 20cm in which flowering time was 15days earlier and dry fruit weight was 30 percent heavier(91kg/10a) than in seed propagation. The optimal diameter of cutting was 0.9cm of which dry fruit weight was 227kg/10a and 28 percent heavier compared with that of 0.5cm. stem number 5 had the best top growth and the heaviest 100 fruit weight as 13.4g. Fruit number per plant was increased as 864 in stem number 5. Dry fruit yield of stem number 5 was 104kg/10a and 16 percent increased compared with that of control.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.265-274
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• 1999

This experiment was carried out to investigate the effect of container size and substrate volume on the growth and fruit yield of hydroponically grown cucumber(Cucumis sativus L.) plants. Seeds were sown in plug tray filled with coir dust on Feb. 13, 1998. Seedlings with 5 to 6 true leaves were transplanted in $2{\ell},\;4{\ell},\;6{\ell},\;8{\ell}\;and\;10{\ell}$ plastic pots filled with perlite. Cucumber fruits were harvested with 1 to 2 days interval, and fresh weight, number of normal and malformed fruit were recorded. Plant height, stem diameter, number of leaves and leaf area were highly depended on the container size. Total fresh weight and the number of fruit were increased with increasing container size. NAR(net assimilation rate) and CGR(crop growth rate) increased also with increasing the container size. Optimum container size for hydroponically grown cucumber plant using perlite was recommended as $8{\ell}$ per plant.

• Food Science and Preservation
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• v.19 no.5
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• pp.665-671
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• 2012

The effects of pretreatment by pulsed electric fields (PEFs) on the juice expression characteristics of the Malus pumila fruit were investigated. Fresh fruits were divided into quarters, were produced on a laboratory scale (100 g apples per lot) by pretreatment with electric fields at two different field intensities (1, 2 kV/cm; n=50, 100, 200, and 400 pulses), and were then pressed at room temperature. Relative to the control samples, the juice yield increased with increasing field intensities. The total phenolics and antioxidant activity were higher in the juice from the PEF-treated fruit than in the juice from the untreated fruit. There was no significant difference in soluble-solid and reducing sugar contents between the PEF-treated and untreated fruits. These results suggest that PEF pretreatment may be useful for increasing the juice yield, total phenolics, and antioxidant activity of the Malus pumila fruit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.68-75
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• 2000

Optimum processing conditions for vinegar fermentation using fig, pear and persimmon were determined. Alcohol contents in the fermentatio broth of crushed fruits of fig, pear and persimmon were 7.5%, 5.1% and 6.8%, respectively. Alcohol contents increased up to 14.3~15.1% by adding 24% of sugar to the fruit juices. The total acidity of 7.04%, 3.30% and 3.66% were obtained for fig, pear and persimmon, respectively, through acetic acid fermentation of fruit juices containing 8% ethanol. Acetic acid yield increased by shaking during fermentation for pear and persimmon broth. Acetic acid yield increased 1.80~1.92 times by adding 0.5% of yeast extract to the fermentation broth of pear and persimmon. After fermentation, each fruit vinegar was clarified up to 93.1~97.4 of light transmittance by using 0.6% of kaki shibu for 4 days at 1$0^{\circ}C$. After aging for 60 days at 1$0^{\circ}C$, the acidity of fruit vinegar decreased slightly. Tannin content of persimmon vineger was remarkably higher than the other, while light absorbance of pear vinegar was higher than the other vinegars. Acetic acid was identified as the main volatile organic acid in the fruit vinegars, while propionic, isobutyric and isovaleric acids were identified as the minors. The content of non-volatile organic acids in the pear vinegar was higher than that in the persimmon vinegar. Sensory evaluation results indicate that the fig vinegar was preferred to the pear vinegar in the aspects of color, flavor and overall acceptability, but the fig vinegar had a strong background taste. Sensory scores of the persimmon vinegar increased significantly by pasteurization, but those of the fig and pear vinegars did not by pasteurization.

• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.245-251
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• 2022

BACKGROUND: Selection an suitable light source is essential in the year-round production of horticultural crops in closed production systems such as plant factory with controlled environments. This study was investigated to confirm the effects of artificial light sources on growth of cherry tomato'CF Jelly'(Lycopersicon esculentum var.) under high-pressure sodium lamps (HPS), metal-halide lamps (MH), and LEDs. METHODS AND RESULTS: Light intensity of the light sources was controlled at 220±30 µmol/m²/s with 12 hrs of photoperiod for a day. Flower development was significantly faster in HPS and MH treatments compared to the LEDs. There was no significant difference between the leaf number and leaf shape under the HPS and MH treatments. Reproductive growth of cherry tomato was significantly promoted by the LEDs treatment of blue plus red lights. Fruit yield per plant also increased under the LEDs compared to the others. CONCLUSION(S): Growth, flowering, and fruit setting of the cherry tomato were accomplished by the artificial lights under plant factory conditions. The HPS treatment showed negative effect on fruit quality in terms of blossom-end rot incidence compared to the LEDs or MH treatment. Effect of the LEDs on promotion of fruit weight and yield was also proved. Additional research should be carried out for improving sugar metabolism or decreasing disease in the fruits under plant factory system using only artificial lights.