• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.8-13
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• 2011

This study was carried out to investigate the change of photosynthesis, leaf and fruit according to crown layers in Actinidia arguta and hybrid kiwi. Photosynthesis rate (PPFD $1,000{\mu}mol{\cdot}m^{-2}s^{-1}$) were 5.82, 7.11, $9.54{\mu}mol\;CO_2\;m^{-2}s^{-1}$ at lower, middle, and upper position, respectively in 3 layer cultivation type. The length and area of leaves collected from lower position have lager value than upper position. The fruit quality of A. arguta and hybrid kiwifruit increased with increasing crown height. A linear correlation ($R^2=0.72$, 0.89 and 0.98) was shown between fruit weight (Boeun 4, Injea 16 and HM3) and the height of crown layer(layer 1, 2, and 3). From the results, we can suppose that the tree of the upper position of crown layer in the cultivation of A. arguta and hybrid kiwifruit produce high quality fruit due to its high photosynthesis ability.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.349-355
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• 2021

The effect of night temperature was investigated on mango (Mangifera indica cv. Irwin) for setting appropriate night temperature and managing mango cultivation in a greenhouse. Different night temperatures (10, 15, and 20℃) were treated from budding to fruit development in mango trees. As night temperature increased, the initiation of flowering, full blooming, fruiting, and fruit development tended to be accelerated. There were no significant differences in the growth of shoots flushed after the fruit harvest among trees treated with different night temperatures. The lengths of the flower stalk were the shortest at 10℃ of night temperature; however, there were no significant differences between 15℃ and 20℃ of the night temperature. The length, diameter, and weight of mango fruits were higher at 15℃ and 20℃ than 10℃. Soluble solid contents and acidities showed no difference; the firmness and skin color were better as the night temperature increased. Accordingly, setting the minimum night temperatures to 15℃ or 20℃ can increase the number of fruits and produce high-quality fruits when cultivating mango in the greenhouse. Even the minimum night temperature to 15℃ can reduce heating costs in the greenhouse.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.334-342
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• 2016

In order to evaluate the modified installation methods of roof ventilation devices, derived from the previous experiment ('investigation into the optimum capacity of roof ventilation devices and their deployment'), the conventional and modified (improved) roof ventilation systems were installed in the single-span plastic greenhouse for growing oriental melons. The roof vents ($60{\varphi}$) and roof fans (maximum air capacity of $38m^3/min$) were installed in the spacing of 15m (FT, modified 'side vent+roof fan' ventilation) and 6m (TT, modified 'side vent+roof vent' ventilation) respectively on the roof of greenhouses for the modified roof ventilation treatments, and 20m (FC, conventional 'side vent+roof fan' ventilation) and 8m (TC, conventional 'side vent+roof vent' ventilation) for the conventional ones. The stem diameter, leaf blade lengh, petiole length, and leaf width were lower in the FT and TT treatments than those in the conventional treatments, FC and TC. Although the fruit weight and total yields were slightly lower in the FT and TT treatments, the marketable fruit ratio (%) were higher, as a result of increased fruiting ratio (%) in these treatments, than those of FC and TC. The marketable yields (kg/10a) in the FT and TT treatments were 8,391 kg/10a and 7,283 kg/10a, which were respectively 661 kg/10a and 487 kg/10a higher than those in the treatments of FC and TC. The modified installation methods of roof fan resulted in production of more female flowers and lower fruit drop ratio (%) compared to conventional meathods. In the treatment of the conventional ventilation with roof vent, the fruit weight, fruit length & width, and flesh thickness were higher than in other treatments, but there were no significant differences in the fruit width and flesh thickness among the treatments.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.382-391
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• 2018

The objective of this study was to determine the most effective medium condition of shoot proliferation and root formation for the efficient in vitro micropropagation of M.26 (Malus pumila Mill). Simple sequence repeat (SSR) markers were used to analyze the genetic diversity of micro-propagated and greenhouse grown M.26. Shoot proliferation was carried out in MS (Murashige and Skoog) containing benzyladenin (BA, $0.5{\sim}5.0mg{\cdot}L^{-1}$) and thidiazuron (TDZ, $0.01{\sim}0.1mg{\cdot}L^{-1}$). The highest number of shoots (10.67 shoots per explant) was induced by adding BA at a concentration $1.0mg{\cdot}L^{-1}$. TDZ treatments caused higher hyperhydricity rate in cultured explants than in BA treatments. There was no significant effect of both BA and auxin on shoot proliferation, and the optimum proliferation medium for M.26 was MS medium containing $1.0mg{\cdot}L^{-1}$ BA. To find a suitable medium composition for shoot rooting, we tested different concentrations indole-3-butyric acid (IBA) and ${\alpha}$-naphthaleneacetic acid ($0.5{\sim}5.0mg{\cdot}L^{-1}$), MS medium (1/4-1), sucrose ($0{\sim}30g{\cdot}L^{-1}$). The shoots showed good rooting on half-strength MS medium containing $1.0mg{\cdot}L^{-1}$ IBA and $15-20g{\cdot}L^{-1}$ sucrose. The rooting rate (100%), number of roots (10.45 ~ 13.60 roots per explant), root length (7.41 ~ 8.33 cm), and shoot length (4.93 ~ 5.38 cm) were good on this medium. Fifteen SSR primers were detected in a total of 30 alleles in 20 micro-propagated plantlets, all SSR profiles from micro-propagated plantlets were monomorphic and similar to greenhouse grown control plantlet M.26 plant. The results indicated that M.26 micro-propagated plantlets were genetically stable.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.459-469
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• 2015

The effects of elevated spring temperatures on the growth and fruit quality of the mandarin hybrid 'Shiranuhi' [(Citrus unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulata] were investigated in plastic greenhouses, to develop a cropping system to improve the quality of the fruit and increase the income of growers on Jeju Island, South Korea. Under conditions of elevated temperature I ($25/15^{\circ}C$, day/night) and elevated temperature II ($28/18^{\circ}C$, day/night) during early spring, budburst was advanced by 11 and 15 d, and full bloom by 22 and 45 d, respectively, compared to those of the plants grown at ambient air temperature in a plastic greenhouse. Elevated temperatures decreased the number of spring shoots but increased mean spring shoot length and leaf area. Growing 'Shiranuhi' trees at elevated temperatures resulted in increases in mean fruit weight and fruit L/D ratio (> 1.0). In addition, fruit color development was significantly advanced in trees grown under elevated temperatures during early spring, which allowed the fruit to be harvested 1-2 months earlier than trees grown under ambient air temperature. Fruit soluble solids content (SSC) and titratable acidity (TA) at harvest were similar between elevated temperature I and ambient air temperature, but were significantly higher than at elevated temperature II. Considering fruit quality, harvest time, and yield, the elevated temperature treatment regime of $25/15^{\circ}C$ (day/night) during early spring could be useful for cultivation of the mandarin hybrid 'Shiranuhi' to increase the income of growers.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.297-310
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• 2023

M.7 rootstock is moderately resistant to fire blight. However, M.7 is generally too vigorous for high-density apple systems, but it can be grafted onto cultivars that exhibit weak tree growth, such as 'Sansa'. This study investigated the vegetative growth, yield, and fruit quality of 'Sansa' apple trees grafted on M.7 or M.9 rootstocks to assess the feasibility of establishing domestic high-density apple systems using M.7 and to determine the optimum exposure length for rootstocks. Trees were planted with exposed rootstock lengths of 5, 10, and 15 cm. The vegetative growth of apple trees grafted onto M.7 was greater than that of M.9 and vegetative growth tended to decrease as the exposed length of rootstock increased. However, the differences in yield per tree, average weights, soluble solids contents, and titratable acidity due to the rootstock and its exposure length varied. The accumulated yield over a 10 year period and the yield efficiency of M.7 were lower than that of M.9 and the yield efficiency tended to decrease as the exposed length of rootstock increased. When apple trees were grafted onto M.9, biennial bearing and tree vigor weakening occurred if the exposed length of the rootstock was over 10 cm. Conversely, when apple trees were grafted onto M.7, vegetative growth was excessive if the exposed length of rootstock was below 10 cm. Based on the results from this study, the optimum M.7 and M.9 exposure lengths for 'Sansa' were 15 cm and 5 cm, respectively.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.188-195
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• 2021

This study was conducted to investigate the growth and quality characteristics of melon (Cucumis melo L.) cultivars and the irrigation requirements for cultivars. In our previous study in 2019, twelve melon cultivars including 'Dalgona' were examined for their cultivar characteristics under the same irrigation condition for all cultivars, and sorted into several groups based on different growth condition; for the internode length (from 0 to 20th node), leaf area, and fruit weight, 'Kingstar' belonged to the largest group, 'Worldstar' the middle group, and 'Dalgona' the smallest group. After analyzing the results of the previous experiment, 'Dalgona', 'Worldstar', 'Kingstar', and 'Rubyball' were selected as test cultivars for the growth group in 2020, and irrigated according to different irrigation levels for each cultivar. The control of the irrigation volume for each melon cultivar by monitoring the drainage rate during the cultivation periods showed that all four cultivars required a similar amount of irrigation in the 'early growth' stage where crops grew at about the same rate. From 'flowering time', however, the change in irrigation requirements showed a similar tendency for 'Worldstar' and 'Kingstar' and for 'Rubyball' and 'Dalgona' respectively. A sudden change in each irrigation volume was observed from the fruit set; 'Dalgona' began first to decline and 'Rubyball' was second, followed by 'Worldstar' and 'Kingstar'. In conclusion, the irrigation volume was the largest in 'Kingstar', followed by 'Worldstar', 'Rubyball', and 'Dalgona' in the same order as the growing amount of plant length, leaf area, and fruit weight. Therefore, it is necessary to control exactly the irrigation volume by reflecting the unique growth characteristics of each cultivar for the production of high-quality fruit in melon hydroponics, and especially to use great care when different cultivars are cultivated together.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.49-56
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• 2003

As a part of agricultural utilization of charcoal and pyroligneous acid, the effect of wood carbonization products on the growth of red pepper and soil microorganisms was investigated. The treatment of charcoal and pyroligneous acid provided good growth conditions to microorganisms through neutralizing soil acidity and improving the physicochemical properties of soil. Therefore the density of useful microorganism in the soil has been increased. In the growth of red pepper, the length, diameter, and the fruit numbers of red pepper have been increased by treating with wood carbonization products. It was especially shown that yield has increased about 50% in the fruit number, by treating charcoal 1kg, 1000 time-diluted solution of pyroligneous acid and bacteria, compared with the control. It was estimated that increasing the length of seedling and the diameter of red pepper stem contributed to the resistance against the prerequisites of various environmental changes in open field. Therefore, the final yield would be increased. In the antagonism experiment of red pepper mold (Colletotrichum gloeosporioides), the mold became extinct in the 2- and 10-time diluted solution of pyroligneous acid, compared with the control. On the other hand, their growth speed was delayed in the 100- and 1000 time-diluted solution.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.248-253
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• 2015

This study was conducted to determine the impact of temperature elevated based on climate change scenario on growth and fruit quality of red pepper (Capsicum annuum L.) in walk-in plant growth chambers. The intraday temperatures of climate normal years (IT) were determined using intraday mean temperatures of climatic normal years (1971~2000) in the Andong Province during the growing season (May 1~July 30). Red pepper plants were cultivated under different temperatures (starting at IT rise by up to $6^{\circ}C$, $2^{\circ}C$ increment). Plant height, stem diameter, branch number, leaf number, fresh weight and dry weight increased under the temperatures higher than IT. The number of flower was the greatest under IT+$2^{\circ}C$ (mean temperature at $22.8^{\circ}C$). The total number and the weight of fruits were the highest under IT+$2^{\circ}C$. While the fruit weight, fruit length and fruit diameter decreased more than IT+$2^{\circ}C$ as the temperature increased gradually. These results concluded that in condition that the current diurnal temperature change cycle is maintained in Andong area, in accordance with climate change scenarios, when the temperature rise $2^{\circ}C$ higher than intraday temperature of Andong area the quantity of pepper fruits will increase while maintaining quality, but increases more than that degree yields are expected to decrease significantly. This result suggests that the fruit yield could increase under IT+$2^{\circ}C$ and fruit quality could maintain great, but the fruit yield could decrease under the temperatures higher than IT+$2^{\circ}C$.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.17-24
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• 2012

Soil types for cultivated crops are approximately compose of volcanic ash soils for black(21%) and dark brown soils(41%), and non-volcanic ash soil of red-yellow soil(17%) in Jeju Island. The effects of these soils on fruit qualities of kiwifruit 'Jecy Gold'(Actinidia chinensis cv. Jecy Gold) were investigated in non-heating plastic house. Soil moisture potential was the lowest in the red-yellow soil during fruit growth. However, transverse diameter of fruit in the red-yellow soil was tends to be smaller than in volcanic ash soils, but longitudinal length of fruit was not shown difference by soil types during fruit maturation. Soluble solids in fruit was not differed by soil types until 140 days after of anthesis, after that the red-yellow soil was the highest. No difference on acid contents and hardness of fruit by soil types. Fructose, glucose and sucrose contents in harvested fruit were $4.45{\pm}2.08$, $5.43{\pm}1.13$, and $2.40{\pm}0.40%$ for the red-yellow soil, $2.51{\pm}0.55$, $3.52{\pm}0.86$, and $0.79{\pm}0.33%$ for the black soil and $2.54{\pm}0.47$, $3.52{\pm}0.73$, and $0.73{\pm}0.38%$ for the dark brown soil, respectively. These results show that soluble solid and free sugars in fruit were affected by soil types. It is estimated that soil moisture was rapidly drought in the red-yellow soil of non-volcanic ash soil than in the black and dark brown soils of volcanic ash soil.