• 한국환경과학회지
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• 제31권5호
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• pp.405-411
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• 2022

Production of lettuce under indoor cultivation is highly affected by light intensity. In this study, we used shade cloth (commercial black net) to examine the effect of these condition on growth without an associated yield penalty of container-grown lettuce. Four levels of shading treatments (0%, 35%, 55%, and 75% referred to as Cont., S₃₅, S₅₅, and S₇₅ with respect to Cont.) and two lettuce varieties (red and blue) were evaluated. Variety-specific growth responses were observed with respect to different levels of shading treatments. High growth of red lettuce was occurred in Cont. treatment despite plant height and leaf length being higher than Cont. However, under 35% shading treatment blue lettuce was higher than in control plants. The highest root length was observed 0% shading (Cont.) of both varieties. These results reinforce the idea that blue lettuce is the better leafy vegetable rather than red lettuce for indoor cultivation related to lower light intensity environment conditions.

• 한국환경과학회지
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• 제33권1호
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• pp.59-65
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• 2024

The objective of this study were to assess rooftop urban agriculture and analyze the differences in soil, growth, physiology, and productivity to elucidate the effect of companion planting with various plants, including lettuce (Lactuca sativa), rosemary (Salvia rosmarinus), marigold (Tagetes patula), Korean perilla (Perilla frutescens), and garlic chives (Allium senescens). Measurements were taken every other week from May to August 2023, totaling eight measurement. Regarding the characteristics of the soil planted with lettuce and aromatic plants, the combined planting of lettuce and garlic chives created a favorable soil environment for plant growth. Consequently, the best growth was observed when lettuce and garlic chives were companion planted. Companion planting of lettuce and garlic chives appears to be the most efficient concerning growth and physiology. The productivity of companion planting lettuce and aromatic plants also showed high-quality lettuce when lettuces and garlic chives were companion planted. Therefore, companion planting of lettuces and garlic chives in rooftop urban agriculture is suitable for growth, physiology, and productivity.

• Journal of Biosystems Engineering
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• 제24권1호
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• pp.25-30
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• 1999

The effectiveness of many greenhouse environment control methodologies depends on the growth information of crops. Acquisition of the growth information of crops requires a non-invasive and continuous monitoring method. Crop growth monitoring system using digital imaging technique was developed to conduct non-destructive and intact plant growth analyses. The monitoring system automatically measures crop growth information sends an appropriate control signal to the nutrient solution supplying system. To develop the monitoring system, a linear model that explains the relationship between the fresh weight and the top projected leaf area of a lettuce plant was developed from an experiment. The monitoring system was evaluated buy successive lettuce growing experiments. Results of the experiments showed that the developed system could estimate the fresh weight of lettuce from a lettuce image by using the linear model and generate an EC control signal according to the lettuce growth stage.

• 한국유기농업학회지
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• 제19권4호
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• pp.589-602
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• 2011

In this study, experiments were conducted to determine the effect of different compost teas on plant growth reponses and yield of leaf lettuce. Compost tea is a liquid extract of compost obtained by mixing compost and water for a defined period of time. The pig manure and spent mushroom compost were made by steeping compost in water. Compost tea was aerated from 24 hours and molasses and kelp were added as supplements. The four types of compost were tested growth of lettuce. EC of animal manure compost tea was higher than that of spent mushroom compost tea. Mineral nutrients were significantly higher in animal manure compost tea compared with spent mushroom compost tea. Compost tea contains nutrient and a ranges of different organisms. The beneficial fungi and actinomycetes were prominent in a spent mushroom compost tea. Compost tea from animal manure had the higher numbers of total bacteria. The actinomycetes densities were high in spent mushroom compost tea. But actinomycetes were not founded in animal manure compost tea. The growth characteristics of lettuce in animal manure compost tea were higher than those of spent mushroom compost tea. And also SPAD value in leaf was high in plot treated with animal manure compost tea. The fresh yield of lettuce in animal compost tea was higher by 181% that of control plot. The effect of compost tea on growth of lettuce was largely attributable to mineral nutrient.

• 한국환경과학회지
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• 제24권8호
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• pp.1075-1084
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• 2015

This study was conducted to investigated the changes in the nutrient components ($NO_3{^-}-N$, $NH_4{^+}-N$, $PO_4{^{3-}}P$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$) and environmental parameters (electrical conductivity, total dissolved solids and pH) on the leaf lettuce (Lactuca sativa L.) grown with hydroponics. Recirculating hydroponic cultivation system was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic. Nutrient solution was used in the standard solution for Japan vegetables experimental station and commercial hydroponic. The result showed that electrical conductivity (EC), total dissolved solids (TDS) and pH, depending on the growth of lettuce decreased continuously. With the growth of the lettuce, nitrate nitrogen, ammonia nitrogen, phosphate phosphorus were required for periodic replacement. The number of pH compensation due to the growth of lettuce are the most high. The concentration of $Ca^{2+}$ and $Mg^{2+}$ during the lettuce growth showed no significant change. However, $K^+$ concentration increased due to the replacement with nitrogen and phosphorus. Electric conductivity and total dissolved solids with total nutrient concentration showed the linear relationship and the correlation coefficient $R^2$ were 0.8601 and the 0.827, respectively.

• Journal of Biosystems Engineering
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• 제23권3호
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• pp.285-290
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• 1998

Growth information of crops is essential for efficient control of greenhouse environment. However, a few non-invasive and continuous monitoring methods of crop growth has been developed. A computer vision system with a CCD camera and a frame grabber was developed to conduct non-destructive and intact plant growth analyses. The developed system was evaluated by conducting the growth analysis of lettuce. A linear model that explains the relationship between the relative crop coverage by the crop canopy and dry weight of a lettuce was presented. It was shown that this measurement method could estimate the dry weight from the relative crop coverage by the crop canopy. The result also showed that there was a high correlation between the projected top leaf area and the dry weight of the lettuce.

• 한국자원식물학회지
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• 제32권3호
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• pp.228-236
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• 2019

This study is conducted to investigate the effects of growth characteristics (GC) and DPPH radical scavenging activity (DRSA) of the heading lettuce 'Fidel' depending on four concentrations of activated mineral groups (AMG: 1.6% active minerals and 0.03% CaO) added to basic nutrient solutions (diluted by 0, 0.05, 0.1, and 0.2%) and on four different light-emitting diodes (LED; B:R:W ratio = 0:1:12, 0:1:9, 0:5:5, and 2:3:5). Both 0.1 and 0.2% AMG showed better GC of lettuce in plant width, plant length, leaf width, leaf length, and the number of leaves than those of other AMG, while leaf thickness and chlorophyll value did not show significant difference among all AMG. Moreover, 0.1 and 0.2% AMG showed heavier shoot fresh weights than those of other AMG. As for the combinations of AMG and LED, B0:R5:W5 showed the best lettuce GC regardless of AMG compared to other AMG and LED combinations. As shown in the above results of LED, although there was a difference in lettuce growth by LED, the differences of lettuce growth by AMG were statistically significant. The DRSA was the highest at 82.8% in B2:R3:W5, followed by B0:R5:W5 at 77.8%. LED showed differences but AMG did not affect DRSA. Therefore, the optimal conditions in plant factory for GC and DRSA of the lettuce were 0.1% AMG and B0:R5:W5.

• 한국축산시설환경학회지
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• 제16권3호
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• pp.215-226
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• 2010

본 연구는 목편살수여상 pilot 장치를 설치하여 스크레파 축사에서 배출되는 뇨오수를 원수로 사용하여 가동한 후 침출액비를 공시재료로 하여 상추 양액재배 시험을 실시하였다. 처리구는 침출액비 (SL) 단독처리구, 침출 액비+어분 (SL+FM), 침출액비+골분 (SL+BM), 침출액비+게껍질 (SL+CS) 혼합처리구. 침출 액비+부산물 (SL+FM+BM+CS) 혼합처리구, 대조구로 원예연 상추양액 (NS) 처리구 등 6개 처리구를 두었다. 침출액비와 부산물 혼합처리 후 전기전도도와 pH를 조정하여 상추의 양액재배를 실시한 결과를 요약하면 다음과 같다. 1. 목편살수여상 처리 과정중 pH는 처리 시작전 7.3에서 처리 후 8.5로 상승하였다. 전기전도도 (EC)는 처리전 17.05 mS/cm에서 처리 후 30일에는 9.7 mS/cm로 낮아졌다. 2. 침출액비는 부유물질 (SS)이 낮아 수경 재배시 관배수의 막힘문제 없이 활용이 가능하였다. 침출액비는 양분조성에서 칼륨함량이 높고 인산 함량이 낮았다. 3. 침출액비시용구 (SL)의 상추수량은 원예 연 표준양액재배 대비 75%를 나타내어 25% 수량저하를 나타내었다. 침출액비을 어분. 골분. 게껍질을 혼합한 처리구는 대조구 대비 85%. 79%. 80% 수량을 나타내어 어분의 첨가 효과가 가장 높았다. 침출액비와 어분 혼합액은 침출액비 단독처리구 보다 10% 증수를 나타내어 유기양액의 대체 원료로 사용이 가능 할 것으로 보인다.

• 생물환경조절학회지
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• 제22권4호
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• pp.392-399
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• 2013

본 연구는 식물공장에서 인공광원에 따른 서로 다른 파장이 'Seneca RZ'와 'Gaugin RZ' 반결구 상추의 광합성 특성, 생육 및 기능성물질 함량에 미치는 영향을 밝히고자 수행하였다. 본 실험에서는 FL(fluorescent lamp), 적색LED와 청색LED 및 백색LED(RBW; red : blue : white = 5 : 4 : 1)와 MH(metalhalide lamp)를 사용하였다. 두 품종 모두 생육 중기에는 RBW에서 광합성속도가 높고 생육 후기에는 'Seneca RZ' 품종은 RBW에서, 'Gaugin RZ' 품종은 MH에서 그 생육이 좋았다. 반결구 상추의 생육은 광원에 따라 생육 차이를 보였으나 각각의 광원의 영향은 품종에 따라 서로 다른 결과를 보였다. 'Seneca RZ' 품종은 생육 중기에는 MH에서, 생육 후기에는 FL에서 생육이 좋았고, 'Caugin RZ' 품종은 생육 중기와 후기 모두 MH에서 생육이 좋은 결과를 보였다. 그러나 수확시기에 'Seneca RZ' 품종은 모든 광원 처리에서, 'Gaugin RZ' 품종은 FL을 제외한 나머지 광원에서 반결구 상추의 잎끝마름증이 발생하는 결과를 보였다. 생육 단계별로 두 품종 모두 생육 중기가 후기에 비해 전반적으로 생육속도가 빠른 결과를 보였다. 'Gaugin RZ' 품종에서 생육 중기에만 광원 종류에 대한 생육속도의 차이를 보였고 생육후기에는 광원의 종류와 품종의 영향을 받지 않는 것으로 나타났다. 인공광원에 따른 두 품종의 반결구 상추의 영양학적 특성은 대부분의 성분에서 광원의 종류에 따른 통계적 유의성이 인정되어 광질이 반결구 상추의 영양학적 품질에 미치는 것으로 판단하였다. 두 품종 모두 RBW에서 4종의 비타민 함량이 높은 결과를 보였으며, 특히 ${\beta}$-Carotene의 함량이 'Gaugin RZ' 품종의 MH에서 가장 높은 결과를 보였다. 이상의 결과에서 인공광원의 종류에 따라 반결구 상추의 생육, 광합성 특성 및 영양학적 품질이 차이가 있으나 품종과 기능성 물질에 따라 각 광원의 영향이 서로 다른 결과를 보여 식물공장 내에서 재배하는 품종과 증진시키고자 하는 기능성 물질에 따라 광원의 선택을 고려해야 할 것으로 판단하였다.

• 한국환경과학회지
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• 제33권5호
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• pp.305-322
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• 2024

The aim of this study was to investigate the effects of artificial light sources on the germination and seedling vigor of lettuce, aiming to identify the optimal artificial light source for producing high-quality seedlings. Lettuce cultivar of 'Tomalin' and 'Seonpunggold' exhibited the highest seed emergence in the Metal halide(MH) lamp and High-pressure sodium(HPS) lamp treatment group, while the emergence rate parameter, T50, was the fastest in the HPS lamp treatment group. Both cultivars showed good growth characteristics such as number of leaves, root length, and stem diameter under RGB-LED, and their seedling vigor was excellent as well. The plant height was smallest in the Red + Green + Blue LED treatment, but the leaves were round and thick, resulting in higher biomass and dry weight. Single light sources of Red LED and Blue LED led to reduced growth compared with that under the mixed light treatments. Chlorophyll content in lettuce varied with the type of artificial light, with both cultivars exhibiting the highest chlorophyll content in the Red + Green + Blue LED treatment. The most suitable artificial light for lettuce seedling growth was the Red + Green + Blue LED treatment.