• Journal of Bio-Environment Control
• /
• v.8 no.1
• /
• pp.36-41
• /
• 1999

This study was carried out to investigate the effect of root zone restriction on yield and quality of muskmelon. Three cultivation methods, isolated bench, root zone restriction sheet(RZR sheet) and conventional soil culture, were compared from April 19th to July 17th. Soil temperature was higher at isolated bench and the growth of melon was accelerated at isolated bench compared to soil culture or RZR sheet. Fruit size was bigger in order of soil culture, isolated bench and RZR sheet, while sugar content and net shape were greatest at isolated bench, and the percentage of wilted plant was 3.3% at isolated bench, 25.0% at RZR sheet and 26.7% at soil culture. Therefore, marketable yield was higher at isolated bench compared to conventional soil culture.

• Journal of Bio-Environment Control
• /
• v.7 no.4
• /
• pp.330-335
• /
• 1998

To investigate the effect of soil water control on yield and quality of musk melon in plastic film house, irrigation points were treated with -10, -20, -30, -50 and -100 kPa by 10mm dripping each time at fruit developing and ripening stage, respectively. Fresh weight of stem and leaves was not significant among irrigation points, but percentage of dry matter was highest at -100kPa and lowest at -10kPa. Marketable yield was not different among -50kPa, -100kPa, -30kPa and -20kPa and lowest at -10kPa. Sugar content of the flesh fruit at ripening stage was 15.1 $^。/Brix at -50kPa and 14.4 $^。/Brix at -10kPa Therefore, optimum irrigation point at ripening stage of fruit is -50kPa by 10mm dripping each time. time.

• Journal of Bio-Environment Control
• /
• v.5 no.1
• /
• pp.15-22
• /
• 1996

Cucumbers(Cucumis sativus L. CV. SHARP 1) were cultivated by bag culture for 5 months to investigate the effect of substrates on growth, yield, and mineral contents. The substrates used in the experiment were vermiculite + perlite +peatmoss(1:1:1=V:V:V), perlite+peatmoss(1:1=V:V), perlite+carbonized chaff(7:3=V:V), rockwool, sawdust, and chaff+chaff powder under 10 mesh (7:3=V:V). The rate of moisture content was highest at chaff powder under 10 mesh as 42.5% and was lowest at perlite+carbonized chaff as 31%. Plant height, No. of leaves, fresh and dry weight were increased in vermiculite+perlite+peatmoss(1:1:1=V:V:V). Marketable fruits and yield also showed same aspect with growth. All kinds of mineral contents except K in cucumber plants were higher at vermiculite+perlite+peatmoss(1:1:1=V:V:V), but K content was higher at perlite+ carbonized chaff(7:3=V:V) than those other substrates.

• Research in Plant Disease
• /
• v.14 no.2
• /
• pp.85-89
• /
• 2008

Clubroot of Chinese cabbage, caused by Plasmodiophora brassicae, is one of the most serious plant diseases in the world. The objectives of this study were to investigate the effect of the irrigation times on the development of club root after planting and to evaluate the effect of clubroot disease on yield of chinese cabbage in pot and field. The clubroot disease gradually increased with increasing irrigation frequency after planting. The growth characters and yield of chinese cabbage by irrigation times varied according to soil moisture and clubroot disease severity. Based on marketable yield and control value, an ideal irrigation point was at the soil matric potential of 0.06 MPa. These results suggest that the suppression on clubroot disease development could be achieved by initially reduced irrigation times after planting. Future studies on irrigation times using fungicide treatment and resistant cultivar under natural field conditions are required to improve the control effect of clubroot.

• Journal of Bio-Environment Control
• /
• v.13 no.3
• /
• pp.156-161
• /
• 2004

This study was conducted to investigate the effects of soil amendment with different characteristics on plant growth, fruit yield and quality of oriental melon for continuous cropping under protected cultivation. Humus layers in arable soil was disturbed because soil amendment from hillside to oriental melon field was continued to resolve problems for continuous cropping. Water potential and hardness of soil was decreased in sandy loam with lower clay contents compared with loam and silty clay. Leaf length and area, fresh and dry weight of plant at earlier growing stage were higher, but chlorophyll contents of leaves were dropped in sandy loam compared with silty clay soil. Fruit size and weight was higher in sandy loam, but soluble solid and color of fruit were increased in silty clay. Marketable and unmarketable yield and quantity of fermented fruit were the highest in sandy loam. Hardness and weight of fruit were decreased by longer storage period and soluble solids of fruit was peaked at 5 day after storage, but decreased by prolonged continued storage. Because of these results, soil characteristics of amendment to oriental melon field should be considered as an important factor for quality and yield of oriental melon.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.4
• /
• pp.392-402
• /
• 2021

The present study investigated the effects of tillage practices (deep cultivation [DC] and conventional tillage [CT]) and extended planting dates (mid-June to July) for maize-onion rotation in paddy fields. The silage corn (Zea mays L.) cultivar 'Kwangpyeongok' and the waxy corn cultivar 'Ilmichal' were planted on June 14, July 3, and July 15 in 2019. In both maize, the plant height of June 14 planted was up to 100 cm greater than that of July 15 planted on August 16 and up to 40 cm on August 30. At 30 Days after planting, the leaf area index (LAI) of silage corn planted on July 3 and 15 greater than that of corn planted on June 14 due to high temperature in the early season; however, there were no differences in the LAI of waxy corn according to the planting date. Despite favorable temperature, plants sown on July 3 and 15 experienced high moisture stress during the seedling stage due to consistent rainfall, and waxy corn was highly sensitive to high moisture stress. The total yield of silage corn was 1,232 (845 in TDN), 860 (598 in TDN), and 765 (508 in TDN) DW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. The fresh marketable ear yield of waxy corn was 872, 814, and 525 FW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. After the completion of maize cultivation, onion seedlings (Allium cepa L.) were transplanted on November 12, 2019, and harvested on May 27, 2020. Neither summer tillage nor maize planting date affected onion growth or yield. The marketable onion yield was 8,305 and 7,848 kg·10a^-1 with DC and CT, respectively. In conclusion, DC did not improve maize growth or yield under paddy conditions. Mid-June to early July is a practical window for maize planting for growers in this region.

• Journal of Plant Biotechnology
• /
• v.39 no.3
• /
• pp.154-162
• /
• 2012

This study was conducted to evaluate agronomic characteristics such as growth, quality, and yields of StMyb1R-1 transgenic potato and also to obtain the basic data for establishing assessment guidelines of transgenic potato. Three transgenic lines (Myb 1, Myb 2, and Myb 8) were cultivated under conventional irrigation, drought condition, and severe drought condition and were analyzed by comparing with wild type, non-transgenic cv. Superior. Myb 2 showed a different flower color from wild type and Myb 1 had much bigger secondary leaflets than wild type. Myb 1 and Myb 2 showed higher $P_2O_5$ content in both top and root zone and longer shaped tubers than wild type. In yield factors, transgenic lines had more tubers than wild type, however their yield decreases were severe because of the poor enlargement of tuber under water deficit condition. This tendency was noticeable in Myb 1 and Myb 2. In TR ratio, chlorophyll content, dry matter rate, and relative water content, there were no big differences between transgenic lines and wild type. Meanwhile, in phenotype, growth, quality, and yield factors, substantial equivalent was confirmed between Myb 8 and wild type. Then, Myb 8 showed the highest marketable tuber yield under conventional irrigation, while showed lower level than wild type under water deficit. Judged by this result, the enhancing droughttolerance by StMyb1R-1 gene might actually not mean the enhancement of photosynthesis or starch accumulation in tuber and, furthermore, not the yield improvement. More detailed research will be required to accurately understand the relationship between StMyb1R-1 and yield factors.

• The Korean Journal of Pesticide Science
• /
• v.18 no.3
• /
• pp.175-180
• /
• 2014

This study was carried out to determine the economic injury level and economic threshold level on beet (Beta vulgaris L.) infested with Spoladea recurvalis in the plastic greenhouse condition in 2010. The second instar larvae of S. recurvalis were inoculated with 7 different density levels on the each 10 beet plants as a replication. Injury levels of beet leaves and density of S. recurvalis were increased with the inoculation density of S. recurvalis. However, yield and marketable commodity of beet were decreased. Linear relationship between the percent yield reduction (Y) of beet leaves and different infestation densities of S. recurvalis (X) was estimated by the following equation Y = 1.226x + 3.36. Based on the relationships between the densities of S. recurvalis larvae and yield index of beet leaves, the number of second instar larvae which caused 5% loss of yield, economic threshold level was estimated as 1.1 larvae/10 plants for the planting 10 days. The percent yield reduction (Y) of beet roots infested with different densities of S. recurvalis (X) estimated by the following equation Y = 1.537x + 1.4634 after inoculation for 10 days at 3rd harvesting of leaves. Based on the relationships between the densities of S. recurvalis larvae and yield index of beet roots, the number of second instar larvae which caused 5% loss of yield, economic threshold level was estimated as 6.4 larvae/10 plants for the planting 10 days.

• Korean journal of applied entomology
• /
• v.50 no.4
• /
• pp.289-293
• /
• 2011

This study was conducted to develop economic injury level (EIL) of onion thrips, Thrips tabaci, on welsh onion (Allium fistulosum L. var) in the early transplanting stage. The changes of welsh onion biomass, yield loss, and T. tabaci density were investigated according to the inoculation periods of T. tabaci. In the early transplanting stage of welsh onion, the yield loss (%) increased with increasing inoculation periods: 17.0, 53.3, 38.4, and 80.8% yield loss in 5, 10, 15, and 20 d inoculation periods, respectively. The relationship between Cumulative Insect Days (CID) of T. tabaci and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL of T. tabaci on welsh onion was estimated to 30 CID per plant based on the yield loss 12% (an empirical gain threshold 5% + marketable rate 93% of welsh onion). ET was calculated to 24 CID, which corresponds to 80% of EIL. Until a more defined EIL-model is developed, the present results should be useful for T. tabaci management in early growth stage of welsh onion. The effect of T. tabaci attack on the yield of welsh onion in late growing season (120 days after transplanting) was also examined. The yield of welsh onion increased at a low population density of T. tabaci and decreased at higher densities, showing a typical over-compensatory response.

• Korean Journal of Medicinal Crop Science
• /
• v.12 no.3
• /
• pp.226-230
• /
• 2004

Plant growth should be affected by mulching method. The study was done to examine the effect of different mulching methods on growth and yield of Atractylodes japonica Koidz. The experiment was done by six different mulching methods; no mulching, rice straw, transparent polyethylene (PE), black PE, two combined treatments of rice hull and transparent PE or black PE. Green shoot and related characters, growth and yield of early and late stages were measured on May 8, June 8 and October 26, respectively. Green shoot fresh weight was the highest in transparent PE mulching, while number of leaves, shoot and stem lengths were the greatest in rice straw mulching of the methods. In its early stage, rice straw mulching had the fewest number of leaves, roots, stems, the smallest width of leaves, and the least fresh weights of shoots and rhizomes. Combined mulching of black PE and rice hull showed the highest values in root-related characters; number of roots, fresh weights of rhizomes and roots. In its late stage, the treatment effects shown in the early stage disappeared owing to high temperature of mid-summer so that there was no significant difference between the mulching treatments. Yield per unit area and marketable yield were the highest in rice straw mulching, and combined mulching of black PE and rice hull.