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.

This study investigated the applicability of horticultural media with recycled coir substrates the growth of Chinese cabbage (Brassica campestris L. ssp. Pekinensis) and lettuce (Lactuca sativa L.) crop. The six different types of coir based substrates were A, Coir 45: Perlite 35: Vermiculite 12: Zeolite 8 (%), B, Coir 55: Perlite 25: Vermiculite 12: Zeolite 8 (%), C, Coir 65: Perlite 15: Vermiculite 12: Zeolite 8 (%), D, Coir 75: Perlite 5: Vermiculite 12: Zeolite 8 (%), E, Coir 85: Perlite 5: Vermiculite 5: Zeolite 5 (%) and F, nursery media (control). The pH and Electric conductivity of the horticultural nursery media were 6.06–7.00 and 0.45–1.10 dS/m-1, respectively. The nursery media containing coir substrates had higher level of Total N, Ca, K, Mg and P than those without coir. Additionally, it was observed that the growth of Chinese cabbage was the best on D (containing 75% coir) while that of lettuce was the best on E (containing 85% coir). In general, when substrates containg a higher percentage of coir were used, the growth of Chinese cabbage and lettuce was ideal. Additionally, the P, Ca, and Mg content in both plants was not significantly altered by the amount of coir present in the media. However, with an increase in the amount of coir substrate, the chlorophyll, N, and K content was increased. After harvesting, there was no significant difference in the chemical properties of the horticultural nursery media of both plants. Thus, it can be suggested that, coir substrate after a single use could be recycled as horticulture nursery media.

Inflorescence, stem, and leaf samples of lettuce grown in a greenhouse in spring and autumn seasons were assayed for sesquiterpene lactones (SLs) content by high performance liquid chromatography. The concentrations of SLs were significantly higher in the inflorescences followed by upper leaf and stem compared to the other plant parts in most of the samples. SLs content (sum of lactucin and lactucopicrin) in various tissues of lettuce cultivated in spring season varied from 5.7 to 22.5 fold ranging from 27.4 ㎍/g dry weight (DW) in the upper stem (cultivar “PI 176588”) as the lowest to as high as 2,292.0 ㎍/g DW in the inflorescence (cultivar “709849-1”). During autumn cultivation, the concentration of SLs varied from 2.0 to 14.4 fold ranging from as low of 32.4 ㎍/g DW in the lower stem (cultivar “PI176588”) to as high of 838.0 ㎍/g DW in the upper leaf (cultivar “Dambaesangchu”). Higher lactucin (1.2 to 5.6 fold) and lactucopicrin (1.1 to 3.9 fold) concentration was observed during spring compared to autumn cultivation in most of the samples. SLs content in various organs of lettuce increases from the basal plant part going upwards. As lactucin and lactucopicrin are the major SLs which affects the sensory property of lettuce, their quantitative variation in the lettuce cultivars is useful for breeding new varieties with better consumer acceptance.

The purpose of this study was to evaluate the quality of fresh-cut lettuce after a washing treatment with aqueous thyme extracts of differing concentration. Four different concentrations of thyme extract were employed: 0.001% (w/v, TEA), 0.005% (w/v, TEB), 0.01% (w/v, TEC), 0.05% (w/v, TED), while distilled water was used as a control. Measurements of O2 concentration, CO2 concentration, total aerobic bacteria, CIE L*, a*, b*, browning index, total phenolic contents and enzymatic activities were investigated on day 0, 1, 3, 5, and 7 at 10 . The O2 concentration in TEB were higher than those in other samples during storage, and the CO2 concentration in TEB and TEC were significantly lower than in other samples on day 7. There was no significant difference in the total aerobic bacteria counts between treatments (p<0.05). The samples treated with TEB and TEC showed higher L* (lightness) values, but lower browning indexes, total phenolic compound levels, and enzymatic activities (polyphenol oxidase, peroxidase) than other samples during storage. Specifically, on day 7, the browning index of Cont reached 0.25, while those in the TEB and TEC were about 0.15. The L* in Cont decreased from 69.50 to 58.92, while TEB and TEC were values of 65.61 and 63.20, respectively. These results reveal that 0.005-0.01% thyme extract was effective as a washing treatment inhibited the browning of fresh-cut lettuce and is thus expected to be a useful natural extract for maintaining the quality of fresh-cut lettuce.

Light is very important for plant growth and a major limiting factor in indoor plant cultivation, such as in balconies. This study was conducted to investigate the light intensity and lettuce (Latuca sativa L.) growth in an apartment balcony affected by the direction of balcony. Photosynthetic photon flux (PPF), air temperature, and relative humidity in the east-, south-, or west-facing balcony were measured for a year. The lettuce was grown in the east-, south-, or west-facing balcony. The time and amount of light entering into the balcony differed according to the direction of the balcony window. Whereas light entered into the east-facing balcony from sunrise to noon, it entered into the west-facing balcony afternoon before sunset. The temperature and humidity in the balcony also varied according to the direction of the balcony window. Daily Light Integral (DLI) in the south-facing balcony was 20~50% of outdoor and DLI in east- or west-facing balconies was 10~20%. Also, the environmental characteristics of the balconies were affected seasonally. In the spring (from March to May), the DLI was around 10 mol･m-2･day-1 and the average temperature was around 25°C. But the DLI was below 10 mol･m-2･day-1 and the average temperature and relative humidity were around 30°C and over 60%, respectively, in the summer (from June to August). In the balcony, the average temperature was maintained around 10°C even in winter, which is a condition of freezing outdoor. Growth of the lettuce in the south-facing balcony was better than that of the other directions. This is attributed to better environmental conditions of south-facing balcony. Therefore, considering the environmental characteristics of the balcony, selection and management of crops with relatively low light demand like leafy vegetables are required. It is also recommended to cultivate crops from autumn to spring.

This study was investigated the effects of various commercial sanitizers on microbial characteristics in fresh-cut iceberg lettuce during storage. For screening sanitizer, lettuce was cut and dipped in chlorine water (0.2 ml·L-1), solution of organic acids such as ascorbic acid, citric acid, acetic acid, mixture of ascorbic acid and acetic acid (1-6%), and solutions of commercial sanitizers such as Formula 4TM (1,3,4%), Fresh produce washTM (1,3,4%), CleancolTM (1%), ChitocholTM (1%) and Natural CaTM (0.1%) for 3 min, respectively. Washing lettuce with selected sanitizers resulted in reduction of aerobic bacteria of more than 2 log CFU/g. Initial pH of lettuce was related with the pH of sanitizers. pH ranged from 4.7 to 6.1 in Formula 4 (4%, pH 1.7) and Natural Ca (0.1%, pH 12.0), respectively. Chlorine water showed consistent and significant inhibition effect in all of microorganisms except total coliform. Over 3% of Formula 4 and Fresh produce wash were found to have high bactericidal activity among sanitizers. The sanitizers of chlorine water, Fresh produce wash, Chitochol and Natural Ca were effective in reducing yeast and mould populations. As coliform and E. coli, Formula 4 (4%) showed the highest bactericidal activity. The bactericidal effect of commercial sanitizers during storage varied with the kinds and concentrations of tested sanitizers. Although inhibition effect was not showed during storage, these results suggest that commercial sanitizers could be an alternative to chlorine for washing fresh-cut produce.

A new lettuce (Lactuca sativa L.) variety ‘Sunny Red Butter’ that belongs to butter-head type has transverse broad elliptical leaf with red color. Crossbreeding of ‘Oriana’ and ‘Cardinale’ was made to obtain seeds of the F1 generation. Subsequent generations were selected using in pedigree methods until 2011, resulting in ‘Sunny Red Butter’. The new variety ‘Sunny Red Butter’ is brown in seeds and the upper part of the leaf is light red and glossy. The leaf stalk is white. It can be harvested from 30 days after planting. The average harvested leaf number is 51 leaves per plant. The average weight is 556.5g per plant, which is 44% higher than a control lettuce variety ‘Germania’. It showed that 30.9 tons/ha production was made in spring, summer, and autumn cultivations for 3 years in 6 areas (Daegwanryeong, Gyeonggi, Chungbuk, Jeonbuk, Gyeongnam, and Jeju) than the control variety ‘Germania’. The shelf-life of ‘Sunny Red Butter’ was 4 weeks for storage at 4℃. Anthocyanin amount (10.3 mg/100g) of ‘Sunny Red Butter’ was lower than that of ‘Germania’. BSL (latucin+8-deoxylactucin+lactucopicrin) amount of ‘Sunny Red Butter’, the bitter ingredients was 26.1 μg/g and higher than BSL amount of ‘Germania’. Leaf hardness of ‘Sunny Red Butter’ was 1,554 kg/cm 2 , which was thicker than ‘Germania’. ‘Sunny Red Butter’ showed better taste (more crispy and sweeter) than ‘Germania’. The new variety ‘Sunny Red Butter’ can be used as lettuce productions during spring and autumn in most area and in summer in highland of Korea.

고온기 결구상추의 선도유지 및 수급조절에 효과적인 포장조건을 구명하기 위하여 연구를 수행하였다. 수확 후 결구상추를 골판지 상자, 농산물 유통상자(P box), 개별 랩핑 등 세 가지 방법으로 포장한 후 2℃에 저장하며 품질변화를 분석하였다. 그 결과 개별 랩핑 한 결구상추의 중량감소율이 다른 처리구보다 적었고, 저장 중 색변화 및 갈변도가 가장 낮았다. 또한 다른 포장방법에 비하여 개별 랩핑 한 결구상추의 엽록소 함량 및 경도 감소가 적었다. 총 페놀함량 및 DPPH 라디컬 소거능의 경우 저장 중 개별 랩핑 한 결구상추의 값이 높았으나 포장방법에 따른 차이는 적었다. 저장 중 결구상추의 외관은 개별 랩핑 하였을 때 가장 우수하였으며 반으로 절단하여 골판지 상자에 포장한 결구 상추는 저장 14일부터 내부갈변이 발생하여 품질이 저하되기 시작하였다. 따라서 고온기 결구상추를 수확 후 개별 랩핑하여 2℃에 저장할 경우 21일간 선도유지에 효과적이며 수급조절에도 도움을 줄 수 있으리라 판단된다.

This study was conducted to investigate the effects of intermittent plasma and electrolysis treatments on lettuce (Lactuca sativa var. oak-leaf.), nutrient solution components (NO3- -N, NH4 +-N, PO4 3--P, K+, Ca2+ and Mg2+) and environmental parameters (electrical conductivity, total dissolved solids and pH). The recirculating hydroponic cultivation system consisted of planting port, LED lamp, water reservoir and circulating pump. Nutrient solution was circulated in the following order: reservoir→ filtration-plasma or filtration-electrolysis→ planting port → reservoir. The results showed that nutrient solution components and environmental parameters were changed by plasma or electrolysis treatment. Lettuce growth was not affected by the intermittent plasma or electrolysis treatment with 30 minutes or 90 minutes, respectively. The roots of the lettuce was damaged by excessive plasma and electrolysis treatment. Electrolysis treatment had greater effect on than plasma treatment because of the accumulation of high levels of TRO (Total Residual Oxidants).

Lettuce is an important annual leafy vegetable and bitterness is its potent flavor character. Lettuce germplasm differ their phenotypic characters and sesquiterpene lactones (SLs) contents which are important for consumer’s acceptance. This study was carried out to evaluate the phenotypic characters and SLs contents in one hundred lettuce germplasm in Jeonju, Korea. Twenty-three agro-morphological (16 qualitative and 7 quantitative) traits and two SLs (lactucin and lactucopicrin) contents were studied in these germplasm. Germplasm exhibited the variation in qualitative and quantitative characters. Average plant weight was 423.9 g with a range from 116.0 to 905.0 g. Lactucin content was varied from 19.7 (IT 294226) to 194.4 ㎍/g (IT 294298) with an average concentration of 84.7 ㎍/g. Lactucopicrin ranged from 82.5 (IT 300134) to 2228.6 ㎍/g (IT 294210) with an average concentration of 586.3 ㎍/g. Total SLs content was ranged from 120.1 (IT 300134) to 2286.6 (IT 294210) ㎍/g with the average concentration of 671.0 ㎍/g. Significant (p≤0.05) differences were found between crisp head and butter head germplasm for lactucin, lactucopicrin and total SLs content. Crisp head germplasm revealed the highest average lactucin (112.9 ㎍/g), lactucopicrin (734.8 ㎍/g) and total SLs content (847.7 ㎍/g). Crisp head and leafy type germplasm exhibited more total SLs content (847.7 and 744.7 ㎍/g, respectively) than cos (524.9 ㎍/g) and butter head type (519.4 ㎍/g). Principal component analyses of the quantitative traits indicated that the first principal component axis accounted more than 91% of the total variation. This study revealed the ample genetic variation in the agro-morphological traits and SLs contents to support the selection for improved lettuce varieties.

‘Hyesun’, a new cultivar of leaf lettuce (Lactuca sativa L.) with sharply wrinkled oval and red leaf, produced by a cross between 'Nongjeockchima’ (red leaf color) and ‘Jeockchima’ (high yield) has late bolting and high yield in the field. The cross and selection for advanced lines had been done by the pedigree method from 2002 to 2008. The ‘Hyesun’ has gray seed color and medium elliptic leaves. The yield and adaptability of the advanced lines were evaluated at several locations of Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) for 3 years (from 2009 to 2012). The type of maturity of ‘Hyesun’ is early-medium. The leaf hardness of ‘Hyesun’ is a 1,237kg/cm2, which is not thicker than ‘Yeolpungeokchima’. The anthocyanin content of 'Hyesun' is a 88.32mg/100g, which is lower than that of ‘Yeolpungeockchima’. The BSL (Bitter Sesquiterpene Lactones, latucin + 8-deoxylactucin + lactucopicrin) content of ‘Hyesun’ is a 5.0ug/g of DW, which is lower than that of ‘Yeolpungeockchima’. Compared to ‘Yeolpungeockchima’, marketable yield of ‘Hyesun’ was higher by 7% (at 381g per plant) and the bolting time of ‘Hyesun’ was remarkably delayed under high temperature cultivation in the field. The shelf-life of ‘Hyesun’ was four weeks longer than ‘Yeolpungeockchima’ at 4℃. Furthermore, because ‘Hyesun’ is more crispy and sweeter than ‘Yeolpungeockchima’, ‘Hyesun’ has the better taste. So, we recommend that the new cultivar ‘Hyesun’ can be suitable for cultivation in both spring and fall season.

Salt stress is one of major restrictions for the production of lettuce. In order to identify promising lettuce genotypes having tolerance against salt stress, effect of different sodium chloride (NaCl) concentrations (0, 100, and 200 mM) on electrolyte leakage and growth of thirty-two lettuce landraces from Korea was evaluated. Screening salt tolerant genotypes based on cluster analysis using data of electrolyte leakage discriminated 'IT105183' and 'IT195057' as the most salt tolerant landraces. More importantly, salinity significantly reduced growth of lettuce, but the reduction rates of growth caused by salt stress in salt-tolerant genotypes were much smaller than those in salt-sensitive genotypes. These results indicate that 'IT105183' and 'IT195057' have high potential for being used as parents to improve salt tolerance in other lettuce cultivars.

This study investigated the effect of heat treatments on the quality characteristics of fresh-cut 'Romaine' lettuce by treating in hot water (45, 50, and 55℃) for 2 minutes. Sensory properties, respiration rate, ethylene production, microbial growth, browning index, total phenolics (TP), vitamin C, and antioxidant properties (DPPH, ABTS, and FRAP assays) of samples were evaluated after 5 days at 5℃. All heat treatment conditions tested in this study did not affect the change in TP after storage. Treatment at 45℃ enhanced respiration rate and ethylene production wheres decreased vitamin C content and antioxidant activities. There was no significant difference in browning index at 45℃ treatment. The rapid tissue softening occurred when treated with 55℃ hot water for 2 minutes. The 50℃ heat treatments exhibited the best quality index including texture and color, and inhibited microbial growth and browning after storage. In addition, the 50℃ heat treatment showed the highest vitamin C content and antioxidant activities (DPPH, ABTS, FRAP assay) after storage. Therefore, the 50℃ heat treatment can be used to maintain quality and antioxidant property of fresh-cut ‘Romain’ lettuce.

The present study was conducted to find a way to recycle the coir substrate by investigating changes in its physical and chemical properties based on the number of use year. Specific gravity of unused coir substrate was 0.212 g/cm3 , while it was higher for the substrate used for 2 years. Porosity was different depending on the number of use year. The porosity of unused substrate was 51.9%, but it increased to 68.6% after used for 2 years. In general, physical and chemical properties were better in the coir substrate used for 2 years than in unused one. The number of leaves, leaf area, flesh weight and dry weight of oriental cabbage and lettuce were higher in coir substrate used for 2 years than those in unused one. Whereas, no significant difference was observed between the substrates used for one year and 2 years, indicating that the one time-used wast substrate could be recycled for cultivating vegetables. Growth of the vegetables was improved when organic fertilizer composed of complex organics with different mixing ratios was provided to the coir substrate, compared to untreated plot. The optimum mixing ratio of the wast substrate and complex organics was 2:8(v/v) for fertilization using wast coir substrate. Therefore, coir substrate generally wasted after being used for one time was reuseable by supplying organic fertilizer.

최근 건강을 생각하는 먹거리의 추세 변화가 양보다 질 위주의 유기농 및 친환경 등을 이용하여 재배하는 작물에 대한 관심이 높아지고 있다. 이는 출처를 알 수 없는 불량식품 뿐만 아니라 국내 대기업 식품사들까 지 먹거리에 대한 불신을 야기 시킨 사례들로 인해 전체적인 불신으로 확대되어 사회적 관심사로 부각되고 있는 상황이다. 이러한 시점에서 먹거리에 대한 불신을 조금이나마 해소하려는 일환으로, 재배조건이 까다 롭지 않으며, 성장기간이 짧은 상추재배를 중심으로 가정용 수경식물 재배기기를 연구하였다. 식물과 식물 재배 그리고 수경식물 등을 고찰하여 이론적 배경으로 삼았으며, 식물재배에 관련된 현황과 기기에 대하여 정리 하였고, 실물 제작에 필요한 부품과 스팩에 관하여 시장조사 후 배치도 도면 및 모형을 진행 하였다. 정형화된 기기를 소비자가 직접 원하는 공간에 배치할 수 있는 심플하고 가벼운 외형과 직관적으로 사용할 수 있도록 한, 원 버튼 시스템화를 통하여 간편성을 부여하여 디자인하였다. 본 연구는 식물재배공장 형태 및 대형화의 모습을 띄고 있는 식물재배 산업을 통하여, 가정용 수경식물 재배기기의 조건을 찾아 프로토타 입 모델을 제시하였다. 이는 향 후 그 다양해 질 수 있는 연구 개발에 디자인 가이드라인으로 활용될 수 있 으며, 나아가 가정용 타 식물재배기기 디자인 개발 시 구조와 배치, 사양 등이 참고로 활용되길 기대한다.

This study was conducted to investigated the changes in the nutrient components (NO3 --N, NH4 +-N, PO4 3-P, K+, Ca2+, and Mg2+) 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 Ca2+ and Mg2+ 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 R2 were 0.8601 and the 0.827, respectively.

Anthocyanin is known for positive health beneficial effects that including reduces age related oxidative stress and inflammatory responses. It was produced by vegetable crops and a lettuce is one of the crops. The general pathway of anthocyanin expression is well defined but it is not clear how environments effects on anthocyanin accumulation in a lettuce. Therefore we initiated to study interaction between anthocyanin expression and environment factors. Frist, we applied RGB leaf images in a lettuce to calculate anthocyanin areas in a leaflet with two different cultivars, different developmental stages, and different environments. Later, we attempted to capture RNA expression level with next generation sequence (NGS) RNA sequencing method called RNA-seq. As a result, combined two technologies showed that quantitate phenotypic data help to understand the gene expression of anthocyanin in lettuce cultivars.

A new lettuce cultivar ‘Misun’ (Lactuca sativa L.) with wrinkled traverse narrow elliptic and deep red leaf, which has late bolting and high yield. It was developed from a cross between ‘Yeoreum Jeocgchima’ (deep red leaf color) and ‘Yeoreumdukseomjeokchukmyeon’ (high yield). The cross and selection for advanced lines had been done by the pedigree method from 2001 to 2008. The advanced lines were evaluated for yield and adaptability at several locations in Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) from 2009 to 2011 year. The ‘Misun’ has gray seed color and traverse narrow elliptic leaves. The shelf-life of ‘Misun’ was four weeks longer than ‘Dukseomjeokchukmyeon’at 4℃. The anthocyanin content of ‘Misun’ (88.32 mg/100 g) was higher than that of ‘Dukseomjeokchukmyeon’(74.78 mg/100g). The BSL (latucin+8-deoxylactucin+lactucopicrin) content of ‘Misun’ (5.0 ug/g, DW) is lower than that of ‘Dukseomjeokchukmyeon’(12.0 ug/g, DW). Compared to ‘Dukseomjeokchukmyeon’, marketable yield of ‘Misun’(289 g per plant) was 11% higher than that of it, showed good yield in fall season cultivation and has particularly improved expression of red leaf color at high temperature cultivation in the field. Furthermore, its taste is better, more crispy, and sweeter than those of ‘Dukseomjeokchukmyeon’. Thus, this new cultivar ‘Misun’ can be suitable for cultivation in low temperature during spring and fall season season.

비소 함유 골재를 토양개량제로 사용하였을 경우 광미에 포함된 유효태 또는 광물로 존재하는 비소가 용출되어 식물 생육에 미치는 영향을 조사하기 위해 실험 한 결과를 요약 하면 다음과 같다. 1. 중세사에서 자갈크기의 유비철석 입자시료에서는 비 소가 약 95.28 mg kg-1 정도 함유된 있으나 밭토양 시 료에서는 비소가 없는 것으로 조사되었다. 2. 상추 재배토양에 함유된 양을 기준으로 생물학적 이용 가능 비소와 그리고 상추로 전이된 비소의 양의 비율 을 비교한 결과 토양으로부터 생물학적 이용 가능 비 소 형태로 전환된 비소의 비율은 최저 2.20%에서 최 대 3.31%로 조사되었다. 3. 상대적 생물학적 이용가능 비소와 상추내 비소 지수는 정의 상관관계를 보이고 있는 반면 이의 비소 지수가 증가함에 따라 상추의 엽장, 엽폭, 엽수, 생체중과 건 물중 모두 반비례로 감소하는 것으로 조사되었다. 4. 입자직경이 토양보다 큰 모래 또는 자갈크기의 비소를 포함한 자갈이 혼합량이 증가됨에 따라 식물가용수분 함량이 감소될 뿐만 아니라 상추가 자라는 동안 비소 를 포함된 유비철석입자부터 비소가 토양내로 용존되 어 작물체내로 전이기 증가되어 상추 엽장, 엽폭 엽수, 생체중, 그리고 건물중에 영향을 준 것으로 판단한다.