• Horticultural Science & Technology
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• v.32 no.2
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• pp.165-170
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• 2014

The objective of this study was to make growth and yield models of sowthistle (Ixeris dentata Nakai) by using an expolinear functional equation in a closed-type plant production system. The growth and yield of hydroponically-grown sowthistle were investigated under four different planting distances ($15{\times}10$, $15{\times}15$, $15{\times}20$, and $15{\times}25$ cm). Shoot dry weights per plant was the highest at $15{\times}25$ cm, but was the lowest at $15{\times}10$ cm. Shoot dry weights per area was the highest at $15{\times}15$ cm, but was the lowest at $15{\times}25$ cm. The optimum planting density and planting distance for yield of sowthistle were 44 plants/$m^2$ and $15{\times}15$ cm, respectively. Shoot dry weights per plant and per area were showed as an expolinear type functional equation. A linear relationship between shoot dry and fresh weights was observed to be linear regardless of the planting distance. Crop growth rate, relative growth rate and lost time in an expolinear functional equation showed quadratic function form. Radiation use efficiency of sowthistle was $4.3-6.1g{\cdot}MJ^{-1}$. The measured and estimated shoot dry weights showed a good agreement using days after transplanting as input data. It is concluded that the expolinear growth model can be a useful tool for quantifying the growth and yield of sowthistle in a closed-type plant production system.

• Korean Journal of Organic Agriculture
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• v.23 no.1
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• pp.59-66
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• 2015

Effect of seedling type and early transplanting of summer grown seedling on the growth and yield of tomato was investigated to minimize problems caused by legginess of seedling in summer. Grafted seedling, 20 days seedling (young seedling), 40 days seedling, and rooted cutting were raised from July 20 to Sept. 7 and young seedling was transplanted 20 days earlier than other seedling types. Young seedling growth was weaker than other seedling types and fresh weight was only 1/10 of 40 days seedling. Growth of young seedling at 20 days after transplanting was better than other seedling types and fresh weight was 3 times higher than 40 days seedling. Creased stem did not appear and trusses developed faster in young seedling. Total yield and commercial yield were highest in young seedling as 8,535 kg/10a, and 7,575 kg/10a. There is no significant difference among seedling types in fruit quality. This result shows that early transplanting of summer grown seedling is more effective to attain stable growth and yield in tomato.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.70-78
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• 2009

Remote sensing technique in agriculture can be used to identify chlorophyll content, biomass, and yield caused from N stress level. This study was conducted to evaluate biomass, N stress levels, and yield of tobacco (Nicotiana tabacum L.) under sand culture in a plastic film house using ground-based remote sensors. Nitrogen rates applied were 40, 60, 80, 100, 120, and 140 percent of N concentration in the Hoagland's nutrient solution. Sensor readings for reflectance indices were taken at 30, 35, 40, 45, 50 and 60 days after transplanting(DAT). Reflectance indices measured at 40th DAT were highly correlated with dry weight(DW) of tobacco leaves and N uptake by leaves. Especially, green normalized difference vegetation index(gNDVI) from spectroradiometer and aNDVI from Crop Circle passive sensor were able to explain 85% and 84% of DW variability and 85% and 92% of N uptake variability, respectively. All the reflectance indices measured at each sampling date during the growing season were significantly correlated with tobacco yield. Especially the gNDVI derived from spectroradiometer readings at the 40th DAT explained 72% of yield variability. N rates of tobacco were distinguished by sufficiency index calculated using the ratio of reflectance indices of stress to optimum plot of N treatment. Consequently results indicate that the reflectance indices by ground-based remote sensor can be used to predict tobacco yield and recommend the optimum application rate of N fertilizer for top dressing of tobacco.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.87-93
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• 2003

Growth and mineral composition of young radish in soil amended with sewage sludge (ISS) with or without liming were investigated. Levels of EC, T-N, and micronutrients were increased in the ISS treatment (50 Mg/ha) compared to the NPK treatment but those of available P and exchangeable cations were decreased. Chlorosis was appear on the young radish leaf at the ISS treatment, but this phytotoxic symptom was corrected with lime amendment (3 Mg/ha). Yields of young radish leaf and root in the combined treatment of ISS and lime were increased about 29 and 48%, respectively, compared with those in the ISS treatment. Contents of P, K, Ca, and Mg in young radish were higher in the combined treatment to ISS and lime, whereas those contents in the ISS treatment were lower than those in the NPK treatment. Contents of Cu, Zn, and Ni in soil and young radish leaf were positively correlated with total N content in young radish leaf, while contents of P, K, Ca, and Mg were negatively correlated. Contents of Cu, Zn, and Ni in leaf were negatively correlated with yield of young radish. Contents of Cu and Zn in leaf corresponding with a 5% yield reduction of young radish were 22.4 and 349 mg/kg, respectively.

• Journal of Bio-Environment Control
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• v.10 no.1
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• pp.30-35
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• 2001

This experiment was undertaken to investigate the effect of root zone temperature during the night on absorption of mineral nutrients, growth, and fruit yield of the truss-limited hydroponic tomatoes in winter. The root zone temperature was either controlled to 10, 15, 20, $25^{\circ}C$, or left uncontrolled at ambient temperatures. Temperature of the covered beds rose as root zone temperature was raised, but it in all treatments was less than 3$^{\circ}C$ higher than that in the control. Raising root zone temperature, except $25^{\circ}C$, showed positive effect on plant height, leaf length, stem diameter, and plant fresh and dry weight, but not on T/R ratio which was the greatest in the control. Root activity in all treatments except $25^{\circ}C$ increased as compared to the control. Mean fruit weight, fruit count per plant, and fruit yield were the greatest in 2$0^{\circ}C$ treatment. Root zone temperature did not significantly affect the contents of total nitrate and magnesium in leaves, stems and roots. Concentrations of phosphate and calcium increased in leaves and stems, but decreased in roots as root zone temperature increased. Overall, 2$0^{\circ}C$ treatment gave the greatest growth and energy efficiency.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.69-69
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• 2020

소엽(Perilla frutescens var. acuta)은 흔히 차조기, 자소엽 등으로 불리며, 식재료나 약재로 이용된다. 최근 들어 자소엽을 향장 원료로 활용하고자 하는 시도가 이루어지고 있다. 따라서 유기자재 처리를 통해 향장원료 자소엽의 고품질 생산을 위하여 본 시험을 실시하였다. 전북 농업기술원 허브산채시험장에서 육묘한 종묘를 2020년 5월 노지 포장에 주간 간격 50cm 한줄 재배로 정식하였다. 처리는 규산염(성분량 20%), 키토산(성분량 5%)가 함유된 자재를 각각 500배, 1,000배 희석하여 6월 21일, 8월 3일, 8월 23일 총 3회에 걸쳐 압축 분무기를 이용해 작물이 충분히 적셔지도록 살포하였으며, 무처리구는 물을 살포하였다. 초장, 초폭, SPAD, 생체중, 건물중을 조사하였으며 잎과 꽃의 총 폴리페놀 함량, 총 플라보노이드 함량, FRAP(철환원 항산화력) 활성 ABTS+ 라디칼 저해활성을 측정하였다. 생육특성 중 초장과 초폭은 처리간 유의성은 없었으나 무처리, 규산염 500배, 키토산 1,000배 처리에서 대체로 높았으며, SPAD는 키토산 1,000배가 가장 양호하였다. 수량성은 모든 자재 처리구가 무처리구보다 많았으며, 지상부 생체중은 무처리 대비 키토산 1,000배는 14.1%, 건물중은 무처리 대비 11.9%로 키토산 1,000배 처리가 수량성이 가장 많았다. 총 폴리페놀 함량은 꽃보다 잎에서 더 높은 수치로 나타났으며, 잎의 폴리페놀 함량은 규산염 500배 처리에서 가장 많았다. 꽃은 1,000배 처리에서 가장 높았다. 총 플라보노이드 함량은 꽃이 잎보다 높았으며, 잎은 규산염 500배 처리, 꽃은 키토산 1,000배 처리에서 함량이 가장 많았다. FRAP 활성은 잎의 경우 규산염 500배 처리에서 높았으며, 꽃의 FRAP 활성은 키토산 1,000배에서 좋았으나 처리 간의 차이는 크지 않았다. 자소엽 잎의 ABTS+ 라디칼 저해 활성은 규산염 500배 처리에서 가장 높았으며, 꽃은 경우 무처리에 비하여 자재 처리가 높았으며, 500배보다 1,000배 처리에서 높은 라디칼 저해 활성을 보였다. 이상의 결과, 자소엽 유기자재 처리는 무처리보다 대체로 수량성과 항산화 활성이 높았으나 추가적으로 적정농도 구명 후 경제성 분석이 필요할 것으로 판단된다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.3
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• pp.237-246
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• 2010

This study was conducted to evaluate growth characteristics and yield of silage corn hybrids by different planting dates at paddy and upland field. Days to silking by different planting dates at paddy field were 81 days at planting on April 22, 70 days on May 20 and 62 days on June 10, respectively, and they were getting shorter as planting date delayed. There was no significant difference in days to silking between paddy and upland field. Plant height in paddy field was no significant difference between at planting on April 22 and on May 20, and it was shortened sharply at planting on June 10. There was no significant difference in plant height between paddy and upland field. There was no significant difference in lodging by different planting dates in paddy field. There was significant difference in lodging between paddy and upland field (P<0.05). There was no significant difference in stay-green by different planting dates in paddy field, and no significant difference between paddy and upland field. Ear ratios to total dry matter in paddy field were 43% at planting on April 22, 41% on May 20 and 28% on June 10, respectively, and it was lower as planting date delayed. There was no significant difference in ear ratios to total dry matter between paddy and upland field. Fresh yields in paddy field were lower with 14% at planting on May 20 and 32% on June 10 compared to on April 22 as planting date delayed. There was no significant difference in fresh yield between paddy and upland field. Dry matter yields in paddy field were higher with 9% at planting on May 20 and lower with 24% on June 10 compared to at planting on April 22 as planting date delayed. Dry matter yield in paddy field was lower with 9% compared to 1,931 kg/10a at planting on April 22. TDN (Total digestible nutrients) yields in paddy field were higher with 5% at planting on May 20 and lower with 28% on June 10 compared to at planting on April 22 as planting date delayed. TDN yield in paddy field was lower with 11% compared to 1,340kg/10a at planting on April 22.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.407-411
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• 2008

This study was conducted to estimate the economic injury level (EIL) and economic threshold (ET) of the green peach aphid, Myzus persicae, on Chinese cabbage (Brassica campestris var). The changes of biomass of Chinese cabbage and M. persicae density were investigated after introduction of M. persicae at different density (0, 2, 5, 10, 15, and 20 per plant; inoculated at 10d after planting). The densities of M. persicae largely increased from the above initial densities to 0, 92.3, 177.4, 406.9, 440.4, and 471.3 aphids per plant at 18d after the initial inoculation, respectively. The biomass of Chinese cabbage significantly decreased with increasing the initial inoculated density of M. persicae: 602.0, 264.2, 262.0, 109.3, 151.0, and 67.3 g in above plots with different initial densities, respectively. The relationship between cumulative aphid days (CAD) and yield loss (%) of Chinese cabbage was well described by a nonlinear logistic equation. Using the estimated equation, EIL of M. persicae on Chinese cabbage was estimated 25 CAD per plant based on the yield loss 13%, which take into account of an empirical gain threshold 5% and marketable rate 92% of spring Chinese cabbage. Also, ET was calculated at 80% of EIL: 20 aphids per plant. Until a more elaborate EIL-model is developed, the present result may be useful for M. persicae management at early growth stage of Chinese cabbage.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.160-165
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• 2005

Since the growth and quality of oak mushrooms are sensitively affected by environmental conditions, an adequate environmental control is very essential to improve the yield and quality under protected cultivation. In this study, the diameter, thickness, length and hardness of cap and stipe, the dry weight, fresh weight and moisture content of the mushrooms were analyzed under the environmental conditions such as night air temperatures (control, $5{\~}11^{\circ}C$ and $12{\~}18^{\circ}C$), relative humidities in the daytime (control, humidifying for 6 h and 12 h), and wind velocities (control, fan-operation for 6 h and 12 h). At a lower night temperature, the quality of the mushrooms was improved, and considered to be optimum at $3{\~}8^{\circ}C$ in terms of fresh weight and quality. At $70{\~}80{\%}$ of relative humidity in the daytime, the fresh weight was increased, but the quality decreased. Considering the quality, the relative humidity in the daytime is adequate at around $50{\%}$. At 6 h of maintaining the wind velocity at $1{\~}2\;my{\cdot}s^{-1}$, the growth and quality were better, but the lightness became higher at 12 h although the fresh weight was reduced by evaporation. It is concluded that even though both of the yield and quality are not easily improved at a same time, optimum approaches should be required by using the relationship among environmental factors and the growth and quality.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.320-324
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• 2001

This study was conducted to investigate the effects of mechanical stimulation and growth regulators known to control overgrowth in hot temperature tomato transplants on the seedling quality and the growth and yield after planting. Brushing and impedance were applied as mechanical stimulation, and diniconazole and hexaconazole as chemical growth regulator were used in various ways at different concentrations and treatment times. Diniconazole treatment regardless of concentration and treatment times reduced plant height, leaf area and fresh weight of young plant. Though treatments of high concentration and many times reduced the yield of tomato after planting, these of proper amount and proper times maintained the level of control. Hexaconazole treatment controlled less plant height of transplants than diniconazole, and its effect also didn't support continuously after planting. However, hexaconazole treatment reduced the yield due to little fruit number and malformed plants, and also delayed the harvesting time as compared to the control. Both brushing and impedance controlled plant height of transplants. However, impedance treatment reduced the yield due to malformed plants after planting, and also delayed the harvesting time, while brushing treatment didn't reduced growth and yield as compared to the control. From the above results, it was thought that proper application of brushing and diniconazole can control excessive overgrowth without reducing yield.