• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.235-242
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• 2015

The objective of this study was to determine the effects of soluble potassium silicate by soil drenching application on watermelon growth, yield, and nutrient uptake. The potassium silicate rates were control (No potassium silicate), 1.63mM, 3.25mM, 6.50mM. The potassium silicate were treated 6 times (twice before fruit forming and 4 times after fruit forming per 7 day. Soil chemical properties, such as soil pH, EC, available phosphorus and silicate, exchangeable K, nitrate-N levels were increased after potassium silicate treatment, while the concentrations of soil organic matter, exchangeable Ca and Mg were similar to control. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for increased potassium silicate treatment than the control, while number of node, and plant length were same for all treatments. With increased potassium silicate treatment, nutrient concentrations, such as P and K in the watermelon leaf at harvest were increased, N concentration in the leaf was decreased, and Ca and Mg concentrations in the leaf were same. Chlorophyll content was increased with increased potassium silicate application. The occurrence of powdery mildew was lower for the potassium silicate treatments than the control. Fresh watermelon weight for the potassium silicate treatments was 0.1 to 0.5kg per watermelon heavier than the control, sugar content was 0.5 to $0.6^{\circ}Brix$ higher than control, and merchantable watermelon was 2 to 4% increased compared to the control. These results suggest that potassium silicate application by soil drenching method in the greenhouse can improve watermelon nutrient uptake, merchantable watermelon and suppress the occurrence of powdery mildew.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.147-155
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• 1991

Effects of harvest date, number of the leaves remained on stump after flower cutting, duration of cold treatment on the growth and flowering of L. elegans 'Connecticut King' bulb were tested. Shoot emerging rate increased over 90% by delayed cold treatment, late harvesting time and more leaves remained. Flowering rate increased over 90% when conducted cold treatment of 90 days to the premature bulb at flowering date, the bulb matured for 50 days with 10 leaves and the bulb matured for over 30 days with 20 leaves, and when conducted cold treatment of 50 days to the bulb matured for over 30 days with all leaves. Delayed cold treatment duration shortened days needed to shoot emergence and flowering. Especially days to flower of the premature bulb at flowering date were the shortest of all treatments, and can be flowered within 100 days after planting. In generally, plant height, number of flowers per plant and stem diameter generally increased by longer bulb maturing period after flower cuting, and the premature bulb harvested at flowering date showed poor growing and flowering responses. But, if used the larger size bulb, it is believed that the prematured bulb can be forced to flower normally in current year without bulb maturing period.

• Journal of Bio-Environment Control
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• v.26 no.1
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• pp.7-12
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• 2017

This experiment was conducted to analyze the effect of drainage reuse rate on the growth and fruiting of summer paprika in closed hydroponic cultivation. The experiment was carried out for 25 weeks from March to September 2015 with 0, 20, 30, 50% mixing ratio of waste nutrient solution using non - recycling hydroponic cultivation as a control. As a result, stem diameter of the test was different in the groups 1 and 2, but no difference showed as the group progressed more than 3 groups. L.A.I tended to decrease with increasing drainage mixing ratio. The number of nodes in the 50% reuse test group was 1.4 compared to the control group, but there was no significant difference. The number of harvested nodes was significantly different in the control group (11.1 nodes) and the 50% reuse test group (8.7 nodes), and the harvested nodes tended to decrease as the drainage was reused. The ratio of harvest was also the same as that of the harvesting node, and the control was the highest at 33.2% and the lowest at the 50% reuse test at 27.6%. Relative yields were reduced by 30%, 35% and 45% in the control group in the first group, and this tendency was also observed in the second and fourth groups. However, in the 3 and 5 groups, the production of 50% test group increased by 13% and 5%. The ratio of unmarketable fruit was increased 2%, 4%, 4%, and 7% in 0%, 20%, 30% and 50% reuse test, respectively. In conclusion, if the decrease in yield due to the decline in early growth is carefully managed, even if the imbalance of inorganic ions occurs after the mid-term growth, the growth of the crop will enter into a stable period and the re-use will not be worried about the growth and the yield decrease.

• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.13-20
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• 2015

This study was conducted to evaluate influence of short-term application of abscisic acid (ABA) in nutrient solution on growth and drought tolerance of tomato seedlings. The treatments included four ABA concentrations (0.5, 1, 2, $3mg{\cdot}L^{-1}$) and control (non-treatment) were applied to the nutrient solution in a hydroponic system. On the $5^{th}$ and $10^{th}$ day after growing in the nutrient solution containing ABA, seedlings were transferred to -5 bars of PEG-8000 in a growth chamber to induce water stress. Except for stem diameter and fresh and dry weight of root, there were no statistical differences in other growth parameters among control, 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments. Seedlings growths were strongly inhibited in nutrient solution containing 2 and $3mg{\cdot}L^{-1}$ of ABA. The root growth such as fresh and dry weigh of root, total root surface area, and average root diameter was slightly enhanced in $1mg{\cdot}L^{-1}$ of ABA treatment. The elevation of ABA concentrations in nutrient solution resulted in the decrease in transpiration rate and increase in stomatal diffusive resistance and leaf temperature of tomato seedlings. The initiations of seedling wilting after treating in -5 bars of PEG were delayed from 10 hrs in control to 30 hrs in ABA applied treatments. Additionally, the high percentages of recovered seedlings were observed in 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments after re-irrigation. Therefore, short-term application of $1mg{\cdot}L^{-1}$ of ABA in the nutrient solution stimulated the root growth and drought tolerance of tomato seedlings by delaying the start time of wilting point and enhancing the recovery after re-irrigation.

• 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.

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.230-238
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• 1996

The experiment was carried out to find aromatic constituent composition of Codonopsis lanceolata species grown in the native(Mt. lrwol, Youngyang, Kyungpuk Province) and the cultivated(Andong, Kyungpuk Province) areas from 1994 to 1995. The results were as follows : Air temperature and soil temperature at the native area were lower to $2{\sim}3^{\circ}C$, and to $2^{\circ}C$ than the cultivated area. Organic matter contents of plant grown at the native area higher than that of plants at the cultivated area by 4.8%. Crude protein content was higher in plant grown at native area than the plant grown in wild area but in case of crude saponin, plants grown at wild area was higher than that of native area. For inorganic element contents. K content is much higher than in the domesticated area as compared with wild area above ten over. And other elements such as Cu, Mn, Na and Mg were not remarkably different in contents. In the free amino acid compositions, argine was highest compared with other free amino acids, and Arginine content was higher in dometicated area. Recovery yield of essential oil of wild species grown at the cultivated showed 0.005%, but domesticated species was 0.004%. But both species at the native area were the same by 0.004%. Although composition of aromatic constituents in the two areas and species varied, total aromatic constituent was 21 kinds. Most aromatic constituents were aliphatic alcohols such as 1-hexanol, eis-3-hexanol, and trans-2-hexanol occupied by approximately 90% over. But three constituets as amylalcohol, furfuryl acetate, and 2-methoxy-4-vinyl phenol(MVP) were detected only in domesticated species.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.250-255
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• 2012

The effect of different source silicon ($CaSiO_3$, $K_2SiO_3$, and $NaSiO_3$) and their application methods (foliar application and subirrigation) on the growth of potted kalanchoe was investigated. Rooted terminal cuttings of Kalanchoe blossfeldiana 'Peperu' were transplanted into 10.5 cm plastic pots containing a commercial growing medium. Then, a nutrient solution, containing 0 or $50mg{\cdot}L^{-1}$ Si as $K_2SiO_3$, $Na_2SiO_3$, or $CaSiO_3$ and adjusted to EC 1.4-$1.6mS{\cdot}cm^{-1}$ and pH 6.0, was supplied through subirrigation along with the nutrient solution or by a foliar application. Plants were grown in a glasshouse under a mean temperature of $23^{\circ}C$ and RH of 70-80%. After 12 weeks of cultivation, plant growth characteristics and leaf tissue contents of P, K, Ca, Mg, Na, S, and Si were measured. Both subirrigational supply and foliar application of Si decreased the plant height and flower stem length. However, the plant condition in the foliar application resulted in disease-like soft rot on the leaf. Among three silicon sources tested, $CaSiO_3$ supplied through a subirrigation system increased shoot tissue contents of Si and chlorophyll as compared to the $Na_2SiO_3$ or $K_2SiO_3$ treatment. Shoot tissue contents of Ca, K, and Na increased when the plant was supplied with $CaSiO_3$, $K_2SiO_3$, and $Na_2SiO_3$, respectively. Subirrigational supply of $K_2SiO_3$ and $NaSiO_3$ decreased the shoot tissue contents of Ca and Mg, and K and Ca, respectively. Therefore, $CaSiO_3$ supplied through a subirrigation system could improve plant quality of kalanchoe 'Peperu' making compact potted plants.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.448-453
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• 2014

Influences of shading and irrigation in summer hot pepper cultivation on the plant growth and mesophyll tissue were investigated. Hot pepper plants were exposed to three shade levels (0, $30{\pm}5$ and $80{\pm}5%$) and irrigated or non-irrigated in greenhouse condition. Plant height and leaf area were highest in 30% shading and stem diameter and fresh and dry weights were highest in no shading. Plant growth was better in rain shelters with irrigation than in those without irrigation. The numbers of hot pepper fruits in the beginning of harvest were 49 in rain shelters without irrigation and shading, 22 in those with irrigation and without shading, 5 in those without irrigation with 30% shading, and 1 in those with irrigation and 30% shading. However, 80% shading showed lowest flower number and flower abscission, resulting in no fruit set, regardless of irritation. This is because carbohydrate translocation from leaves to reproductive organs may be not enough for developing fruits due to the lack of sunlight. The yield of hot pepper tended to be higher in rain shelter with irrigation than in those without irrigation. In optical microscopy observation, the thickness and development of mesophyll tissues decreased as increasing the degree of shading but no effect of irrigation on mesophyll tissues was observed. When stomata were observed with scanning electron microscope (SEM), the shape of stomata was normal but tissues surrounding stomata were slightly wrinkled in plants grown under 30% shading. The large number of abnormal stomata and wrinkled leaves was observed among plants grown in rain shelters with 80% shading. In plants grown in rain shelters without irrigation, tissues surrounding stomata were wrinkled and 10-20% decrease in the number of stomata was observed. Therefore, in hot pepper cultivation in summer with high temperature, shading was not effective for fruit yield and mesophyll tissue development; if shading is unavoidable, high degree of shading is not advisable. Further studies are needed for appropriate cultivar selection and environment-control techniques in hot pepper cultivation in summer with high temperature.

• Research in Plant Disease
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• v.19 no.2
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• pp.108-113
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• 2013

Wilt damage on tomato plants caused by Ralstonia solanacearum has been increased as the areas of tomato cultivation increased during the warm seasons. Also, the tomato rootstocks used to prevent the disease occurrence are not effective in the highly prevailing regions. Therefore, bacterial wilt resistant eggplant rootstock EG203, collected from AVRDC, was tested for its effect to deter the Ralstonia solanacearum wilt disease in the greenhouses at Buyeo Tomato Experiment Station from 2003 to 2005, and at Gumi, Kyungpook province from 2009-2011. Planting of eggplant rootstock EG203 should be done three weeks before the planting of tomato scions so that they can have similar stem diameter (2.5-3.0 mm) and can be easily grafted. Both insertion and inarching grafting showed 93-96% success rates. In the greenhouse tests at Buyeo Tomato Experiment Station from 2003 to 2005, eggplant rootstock EG203-grafted tomatoes showed the disease occurrence of 4.3%. On the other hand, non-grafted or other commercial rootstock-grafted tomatoes showed disease occurrence of 58.0% and 25.0-36.7%, respectively. In the greenhouse tests at Gumi, Kyungpook province in 2009, the disease occurrence on the EG203-grafted and non-grafted tomatoes was 2-5% and 20-80%, respectively. In 2010, at Gumi, Kyungpook province, when the wilt disease occurred slightly, the tomatoes grafted with tomato rootstocks B-blocking and Chung-gang, and eggplant rootstock EG203 showed similar disease severities, but EG203-grafted tomatoes formed lately cluster, resulting in the reduction of yield compared to tomato-grafted tomatoes. In 2011, at Gumi, Kyungpook province, when the wilt disease occurred severely, the tomato rootstocks 'B-blocking' and Chung-gang and eggplant rootstock EG203-grafted tomatoes showed disease occurrences of 60-85% and 0-1%, respectively. Therefore, it was concluded that tomato rootstocks 'B-blocking' and 'Chung-gang' are more useful in the areas contaminated with low levels of pathogen and eggplant rootstock EG203 is more useful in the areas contaminated with high levels of pathogen.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.781-796
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• 2015

This study was carried out to investigate the effect of no-tillage and split irrigation on the growth of pepper plant under green house condition in Jeonnam province. Moisture content of soil at whole quantity irrigation in tillage was increased rapidly regardless of soil depth for initial irrigation and then was decreased continuously until next irrigation. Deviation of moisture content in soil was decreased with increasing depth of soil. Moisture contents of top soil and subsoil (20 cm) at whole quantity irrigation in no-tillage were increased with sunrise, and then decreased with sunset. Moisture contents of top soil in tillage, and top soil and subsoil (20 cm) in no-tillage at half quantity irrigation indicated a cyclic diurnal variation by evapotranspiration. Salinity of soil was increased after initial irrigation and then was decreased continuously until next irrigation. With increasing depth of soil, increases of salinity in soil was delayed. Salinity of top soil in no-tillage was increased between AM 11:00 and AM 12:00, and then showed the highest level between PM 2:00 and PM 6:00 on a cyclic diurnal variation by evapotranspiration. Salinity of subsoil (30 cm) in no-tillage was not measured a cyclic diurnal variation. Moisture content and salinity of soil was positive correlation regardless of tillage and no-tillage cultivation. Growth of pepper in no-tillage cultivation was higher than that in tillage cultivation. Main branch Length and stem diameter of half quantity irrigation plot was higher than that of whole quantity irrigation plot regardless of tillage and no-tillage cultivation. After harvesting, the number of pepper fruits of half quantity irrigation plot was increased remarkably by 49% and 47%, in tillage and no-tillage cultivation, respectively. Pepper yield of no-tillage cultivation plot was higher by 8% than that of tillage cultivation plot. Pepper yield of half quantity irrigation plot was increased remarkably by 36% and 39%, in tillage and no-tillage cultivation, respectively.