• Title/Summary/Keyword: 결구상추

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Effects of Ca : K Ratios in Nutrient Solution on Photosynthesis, Transpiration, Growth and Incidence of Tipburn in Butterhead and Leaf Lettuce. (배양액내 Ca : K 비율이 상추의 광합성, 증산, 생육 및 tipburn 발생에 미치는 영향)

  • 배종향;이용범;최기영
    • 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.

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Effect of Artificial Light Sources on the Growth of Crisphead Lettuce in Plant Factory (식물공장에서 인공광원이 결구상추의 생육에 미치는 영향)

  • 조영렬;한동욱;이용범
    • 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.

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Effect of Sodium Selenate Supplied Condition by Fertigation on the Growth and Content of Minerals, Ascorbic acid, Nitrate, and Selenium of Some Western Vegetables (Sodium selenate의 토양관주 처리방법에 따른 서양채소의 생육과 무기성분, ascorbic acid, nitrate 및 셀레늄 함량에 미치는 영향)

  • Lee, Sung-Jin;Kang, Ho-Min;Kim, Il-Seop
    • Journal of Bio-Environment Control
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    • v.17 no.1
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    • pp.43-50
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    • 2008
  • This study was conducted to investigate the proper supplied conditions of sodium selenate supplied by fertigation to improve functionality of major western vegetables; beet, broccoli, cabbage lettuce, celery, and parsley in highland. In this work, the growth and content of minerals, ascorbic acid, nitrate, and selenium were measured in western vegetables that treated sodium selenate by different concentration, treatment time and treatment frequency. While there was not different in early growth of some western vegetables among different concentration of sodium selenate; 1,2, 5 and $20\;mg{\cdot}L^{-1}$, at 20 days after treatment, the fresh weight was reduced 33% at cabbage lettuce,47% at broccoli, and 74% at parsley compared control in $5\;mg{\cdot}L^{-1}$ treatment. But the fresh weight of beet and celery reduced just 20% and 15% compared control in even $20\;mg{\cdot}L^{-1}$. The ascorbic acid of cabbage lettuce, celery, and beet increased as sodium selenate concentration increased, so that of cabbage lettuce showed 1.2 times compared control in $20\;mg{\cdot}L^{-1}$ treatment and also that of beet and celery increased 10%. But the ascorbic acid of broccoli and parsley was not influenced by treated sodium selenate. As the concentration of sodium selenate increased, the nitrate contents decreased regardless of crops compared control. This reduced effect of nitrate was highest in cabbage lettuce, followed by beet and celery. The mineral contents, such as K, Ca, and Mg, decreased in all crops, as the concentration of sodium selenate increased. The potassium content showed an obvious negative correlationship with the concentrations of sodium selenate regardless of crops, but the magnesium and calcium content did not show significant difference between treatments. The selenium content increased in proportion as increasing sodium selenate concentrations. The broccoli, celery and parsley treated $20\;mg{\cdot}L^{-1}$ sodium selenate showed 24.4 times, 76.4 times, and 560 times higher than control, respectively. When the sodium selenate supplied to some western vegetables in different growth stage, the selenium content increased 1.3 times and 1.4 times higher in early stage than in late stage in cabbage lettuce and broccoli, respectively. However in parsley and celery, the selenium content showed the highest in middle stage. The selenium content increased in proportion as increasing the sodium selenate treatment frequency, but in above 10 times treatment, the increased effect alleviated in parsley, celery, and cabbage lettuce. On the contrary, the selenium content of broccoli increased constantly as treatment frequency increased.

Optimizing Planting Distance and Labor-Saving Efficiency for Head Lettuce Using a Transplanter for Summer Season Cultivation in the Alpine Area (고랭지 결구상추의 기계정식시 적정 재식거리 및 노력절감효과)

  • Jang, Suk-Woo;Kim, Won-Bae;Kim, Jin-Young
    • Horticultural Science & Technology
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    • v.18 no.6
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    • pp.787-791
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    • 2000
  • Lettuce seedlings used in this investigation of planting distance and labor-saving efficiency were first grown in 100-hole paper trays for 30 days. Seedling height for transplanting ranged from 3 cm to 6 cm and plants had 3 to 5 leaves. The beds prepared for transplanting were of the arched type and were 35-40 cm in width, 15-20 cm in bed height, and between-bed furrow width was 20 30 cm. Typical seedling planting depth with the transplanter was 4-5 cm, although depth was quite variable because of the irregularities of the ground. Total transplanting time with the transplanter varied from 2.6 to 2.7 hours per 10a, while it took 38.1 hours per 10a with conventional planting. It was critical that the condition of both the seedlings and the bed be adjusted to the transplanter before planting. Considering yield and inter-plant distance, optimal transplanter performance resulted with $60{\times}20cm$ or $60{\times}25cm$spacing, and the labor-saving efficiency using the transplanter was improved by over 93% of that of conventional planting by hand.

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Effects of Cutting Methods on Qualities of Fresh-Cut Apples and Leafy Vegetables (절단방법이 신선절단 사과와 엽채류의 품질에 미치는 영향)

  • Chung, Hun-Sik;Jeong, Moon-Cheol;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.19 no.2
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    • pp.173-177
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    • 2012
  • Whole apples were cut with a sharp or dull knife, and whole cabbages and crisp lettuce heads were cut into salad or thin strips with a knife or by hand. The fresh-cut apples, cabbages, and lettuce were packed in low-density polyethylene bags and kept at $4^{\circ}C$, and their qualities were investigated. Browning and softening of the apples that were cut with a sharp knife were more delayed than those of the apples that were cut with a dull knife. The soluble solids and pH of the fresh-cut apples were not affected by the sharpness of the cutting blade. The browning indexes of the fresh-cut cabbages and lettuce were significantly lower in the samples that were cut with a knife than by hand and in the samples that were cut into large pieces. The results suggest that the cutting blade sharpness, cutting tools, and cut types affected the quality of the fresh-cut apples and leafy vegetables, and that the cutting methods which minimized the cutting damage should be used to retard the browning and softening of the produce.

Effect of Nitrogen Starvation on Quality of Crisp Lettuce in Deep Flow Culture (결구상추의 수경재배시 수확전 질소중단이 품질에 미치는 영향)

  • 김혜진;김영식
    • Journal of Bio-Environment Control
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    • v.7 no.3
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    • pp.253-258
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    • 1998
  • Lettuce plants(Lactuca sativa var. capitata L.) were subjected to nitrogen starvation for 18, 14, 11, 7, and 0 days before harvest. The nitrate content of lettuce was decreased greatly by nitrogen starvation and also its fresh weight. The nitrate content of the middle part of leaves was lowest at the treatment of 18 days before harvest. In the inner part it was lowest at the treatment of 11 and 14 days before harvest. The longer the period of nitrogen starvation was, the more were decreased the absorption rates of cations at harvest. During the experiment, the pH was decreased except the treatment of 7 days before harvest. The EC was continuously increased regardless of treatments.

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Effects of Cultivars and Cultural Conditions on the Growth, Quality and Occurence of Tipburn of Butterhead Lettuce during Summer Season (품종과 재배조건이 여름철 양액재배 반결구 상추의 생육, 품질 및 잎끝마름증 발생에 미치는 영향)

  • 유성오;배종향
    • 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.

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