• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.66-71
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• 1994

In order to understand the mechanism of the wide occurrence of tipburn phenomenon in Chinese cabbage grown under protected cultivation, Chinese cabbage cultivated in two experimental plots was analyzed based on the distribution of some mineral elements by region in the plant and in the soil. The following results were obtained : 1) The occurrence of tipburn is not related to the concentration of Ca in the soil. 2) The concentration of Ca by region in the plant increased in the order such as inner leaf < middle leaf < outer leaf and inner vein < middle vein < outer vein. 3) From this results the cause of occurrence of tipburn phenomenon in Chinese cabbage which occurred at fixed times in the growth and development of the plant can be controlled by modifying environmental factors in order to prevent excessive transpiration in the inner leaf.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.42-48
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• 1999

This study was executed to see the effects of Ca : K ratios in me.L$^{-1}$ -0:9, 1.5:7.5, 3:6, 4.5:4.5, 6:3 - in the nutrient solution on the photosynthesis, transpiration, growth and incidence of tipburn in butterhead ‘Omega’and Leaf ‘Grand Rapids’lettuce (Lactuca sativa. L) grown in nutrient film technique(NFT). The photosynthesis of both lettuces showed high in the Ca : K ratios of 3:6 and 4.5:4.5 regardless of species. But stomatal resistance of Grand Rapids was higher than that of Omega. The highest transpiration rate of them was shown in the Ca : K ratio of 3:6. The transpiration rate of developing leaves was lower than that of expanded leaves. It was seemed to have relation with incidence of tipbum in the developing leaves. The nutrient solution treatment without Ca developed less growth than that of other treatments, especially growth and development of apical part were inhibited, so that in the both of them incidence of tipburn appeared 100 percent. The incidence of tipburn in Omega appeared 25 percent in the Ca/K ratio of 1.5:7.5, but Grand Rapids did not show it according to the Ca/K ratio in nutrient solution. The highest growth in two species was also shown in the Ca/K ratio of 3:6 except nutrient solution without Ca. This study suggested that the unbalanced ratio of Ca/K affected Ca transport in two species because of the increase of stomatal resistance and diffusive resistance and the decrease of photosynthesis and transpiration.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1993.10a
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• pp.9-10
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• 1993

최근의 배추 소비경향은 월동을 위한 다량의 김장을 담그는 것보다는 주년을 통해서 신선한 고품질의 배추의 요구가 매년 증가하고 있다. 따라서 종래 배추재배양식에서 벗어나 시설을 이용해 동기부터 춘기에 걸친 배추 재배면적이 매년 늘어나고 있는 것이 현실이다. 그러나 특히 배추의 시설재배에서는 동기부터 춘기에 걸쳐 칼슘결여에 기인되는 생리장애의 일종인 Tipburn이 발생해서 상품성이 떨어져 재배농가의 대단한 경제손실이 되고있다. (중략)

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.35-41
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• 1998

This experiment was conducted to find out the effect of artificial light sources(high-pressure sodium lamp, metal halide lamp and fluorescent lamp) on growth of crisphead lettuce(Lactuca sativa L.) in a plant factory. No significant differences in leaf fresh and dry weight were presented among them. Lettuce plants grown under fluorescent lamp showed the lowest growth. Considering the growth of lettuce and efficiency of lamps, it is worth using HPS(high-pressure sodium) lamp in plant factories. The leaves of lettuce plants grown under artificial light sources showed tipburn symptoms at 14th day after transplanting. The beginning of tipburn symptom have been seen on the ninth to tenth leaves from the cotyledons. It is estimated that the occurrence of tipburn was related to rapid growth and K uptake of the lettuce Plants. The Ca, Mg. Cu and Zn elements tended to be accumulated in the nutrient solutions but the T-N, P, Fe and Mn elements keep in balance in them.

• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.83-89
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• 1999

Butterhead lettuce was grown hydroponically in a plant factory during summer season. To decrease the occurrence of tipburn and increase productivity, optimum cultivars, substrates, gully slope and height, and the amount of irrigation were evaluated in this experiment. Cultivars ‘Rex’ and ‘Flandria’ showed higher productivity with less tipburn as compared to the others in spite of lower growth rates and appeared to be suitable cultivars during summer season. Cocopeat showed high productivity due to superior physio-chemical characteristics. Appropriate gully slope which makes nutrient solution easy to flow was shown to be 1 to 2%. The amount of irrigation was appropriate at 2$\ell$/gully. Higher growth of the butterhead lettuce observed when the bed was at a lower position. Low bed was thought to be good for lettuce growth with proper humidity and average temperatures.

• Journal of Bio-Environment Control
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• v.3 no.2
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• pp.145-150
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• 1994

This study was carried out with different nitrogen fertilization levels for the purpose of basic information of culture of chicory (Cichorium intybus L. var. foliosum) in Korea. Treatment level of nitrogen fertilization was separated as 0, 10, 20, and 30kgN/10a. Though the apparent growth of chicory was increased as the increasing level of nitrogen fertilization, the deterous effects such as tipburn and bolting were increased. The treatment of 15-25kgN/10a was suitable for the production of chicory having high quality and commercial value.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.146-150
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• 2017

This research investigated the effect of photo/dark period and relative humidity during dark period on the growth and quality of water dropwort in a closed-type plant factory system. At 30 days after planting, the shoot fresh weight of water dropwort under relative humidity of 60/90%(light/dark) treatment significantly higher than that under relative humidity of 60/60% treatment. The shoot fresh weight of water dropwort increased by extending light period under relative humidity of 60/60% treatment, but 16/8h photo/dark period showed the best shoot fresh weight, followed by 20/4h and 22/2h under relative humidity of 60/90% treatment. In the relative humidity of 60/90% treatment, the tipburn occurrence was reduced under 16/8h photo/dark period condition as 1.4%, whereas it was significantly increased under 20/4h and 22/2h of relatively long light time duration as 15.5% and 30.3%, respectively. In the relative humidity of 60/60% treatment, the tipburn occurrence was 15.5% under 16/8h photo/dark period condition and those under 20/4h and 22/2h photo/dark period condition were higher than 25%. The stem hardness of water dropwort was lowest in relative humidity of 60/90% and 16/8h photo/dark period treatment. The mineral contents of leaves were decreased by extending light period, but the contents of Ca were not different significantly among the treatments except the 60/60% and 22/2h treatment.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.126-128
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• 1998

토양의 완충능이 없는 양액재배에서 Ca 흡수는 양이온과의 길항작용, 온도, 습도 및 염류농도 등에 의해 변화된다. 배양액내 무기 양이온 중 Ca 과 K, Mg의 복합비율 조성에 따른 상추의 광합성, 기공저항, 수분이용효율 및 증산량을 측정하여 상추 tipburn에 관여하는 Ca 흡수를 알아보고자 본 실험을 수행하였다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.04a
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• pp.66-67
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• 1995

상추는 세계에서 가장 많이 재배되는 샐러드용 채소이다. 특히 반결구상추는 유럽을 중심으로 재배되고 있고, 최근에 독특한 향기와 샐러드로서 품질이 우수하여 수경재배 또는 식물공장에서 재배가 급속히 늘고 있다. 반결구상추는 서늘한 기후를 좋아하는 채소로서 고온기 재배는 품질이 떨어지고 tipburn과 같은 생리장해가 많이 나타난다고 알려져 있다. 특히 수경재배에서는 토양재배보다 생육이 다른 관계로 Ca결핍과 같은 장해가 많이 나타나 상품화율이 현저히 떨어지게 된다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.111-114
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• 1998

상추의 Ca 결핍으로 인한 생리 장해인 tipburn은 \circled1 배지 중의 Ca이 부족했을 때 \circled2 배지 중 Ca 은 충분하나 여러 원인에 의해서 Ca 흡수가 억제될 때, 또는 \circled3흡수 및 지상부로의 이동은 어느 정도 이루어지나 필요한 부위로의 충분한 공급이 이루어지지 않을 때 또는 필요량이 많아 공급이 부족할 때 등이다. 본 실험은 지상부로의 Ca 이동에 영향을 미치는 인자 중 습도 조건을 달리 했을 때의 막투과성의 변화와 기공반응 및 생육에 미치는 영향을 살펴봄으로써 상추의 Ttpburn 발생에 미치는 습도의 영향을 알아보고자 실시하였다. (중략)