Caffeine as a killing and repellent agent for snails (Acusta despecta) and slugs (Deroceras varians) on horticultural plants

Joo, Jin-Ho,Yaon, Byeong-Sung,Kim, Il-Soep,Kang, Won-Hee The Korean Society for Bio-Environment Control 2002 시설원예‧식물공장 Vol.11 No.3

Industrialization of New Varieties of Roses Under Condition in the Cordillera, Philippines

박영배,김진기,황주천,아라실지레디레드,Park, Young-Bae,Kim, Jin-Ki,Hwang, Ju-Chean,Ladilad, Araceli G. The Korean Society for Bio-Environment Control 2008 생물환경조절학회지 Vol.17 No.2

우리나라 장미산업의 국제화에 대비하여 필리핀 코르딜레라 고냉지 지역에서 생산된 장미의 품질, 수량 및 우수 품종을 연구, 소득 분석을 요약하여 아래와 같이 산업화의 기초자료를 얻기 위해 본 실험을 수행하였다. 절화 내 질적 실험에서는 대비종에 비해 특히 'Jacaranda' 품종은 개화기간 46일, 13일정도의 꽃받침 휨 정도보다 짧은 것으로 나타내므로, 광질, 조사기간 및 온도 등이 영향을 제일 많은 영향을 받는 것으로 볼 수 있었다. 절화 시 'Vicki Brown'와 'Jacaranda' 품종은(개화기간 49일, 13일 꽃 받침 휨 정도 이내) 중, 단초 절화로 분류되는 다른 품종에 비해 단축되는 경향을 보았다. 'Jacaranda', 'Vcki Brown', 'Golden Times', 'Champagne', 'Osiana' 및 'Queen Elizabeth' 품종은 전정에서 46.7일에서 50.77일까지 조기 개화되었으나 'Tineke' 품종은 전정 41일 후에 꽃 받침 휨 정도가 0.5cm에 이르게 되어 개화형성이 늦어짐이 뚜렷하였다. 여기에서 상위 10품종 장미의 순수익은 'American Orange' 품종 $77072, 'Yellow Island' 품종 $39322, 'Frosty Pink' 품종 $27130, 'Champagne' 품종 $24516, 'Coral Pink' 품종 $23992, 'Lara Pink' 품종 $22961, 'Lara Orange' 품종 $17856, 'Grand Gala' 품종 $17645, 'Golden Times' 품종 $20163 및 'Lady X' 품종 $19452 등이다. In days to calyx-flex stage test, flower development affected by light intensity, light duration and the prevailing temperature. As, 'Jacaranda' variety shorter in under 46 days of flower bud formation and 13 days of calyx-flex stage than the other variety with 'Queen Elizabeth' control variety. About cut flower only 'Grand Vicki Brown' (as within 46 days of flower formation, 13 days of calyx stage and 'Jacaranda', both with shorter plants than the other varieties produced cut flower classified as short and medium-stemmed cut flowers. 'Jacaranda', 'Vicki Brown', 'Golden Times', 'Champagne', 'Osiana', and 'Queen Elizabeth (control variety)' flowered earlier from 46.7 to 50.8 days from pruning. Flower development was likewise faster in all the above mentioned cultivars; while 'Tineke' had significantly delayed flower development reaching calyx-flex stage from 0.5 cm bud size after 51.0 days. The top ten high yielding varieties were 'American Orange', with a net income of P3,081,676.00; 'Yellow Island' with P1,572,874.00; 'Frosty Pink' with P1,085,183.00; 'Champagne' with P980,620.00; 'Coral Pink' with P959,669.00; 'Lara Pink' with P918,444.00; 'Lara Orange' with P714,252.00; 'Grand Gala' with P705,787.00; 'Golden Times' with P806,489.00; and 'Lady X' with P778,060.00 net returns.

Measurement of $\textrm{CO}_2$ Concentration and Leaf Area Index for Crop Photosynthesis Model in Sweet Pepper

Lee, Beom-Seon,Chung, Soon-Ju,Jang, Hong-Gi The Korean Society for Bio-Environment Control 1999 생물환경조절학회지 Vol.8 No.3

본 연구는 ASKAM모델로 $CO_2$, 광 및 엽면적지수가 단고추의 동적 광합성율에 추정가능성을 평가하기 위하여 수행되었다 $CO_2$ 농도는 2구획으로 구분된 반밀폐된 생장상에서 3수준 (400, 700 or 1000$\mu$mo1 mol$^{-1}$)으로 조절하였다. 온도와 습도는 21$^{\circ}C$ 및 80-95%로 조절하였고, 양액이 순환되는 용기내에서 재배하였다. 일태양복사, 온도 및 $CO_2$농도의 단기 자료를 기초로 하여 일중 단기간격에 대한 작물 순$CO_2$흡수량를 ASKAM모델로 추정하였고, 광합성 측정 중 각 구획과 기부에서의 $CO_2$농도를 매분마다 측정하였다. 순수 $CO_2$의 구획으로의 흐름, 지상방사, 구획내의 광합성유효방사, 은도 및 상대습도를 측정하였다. 본 작물생장모델은 작물의 광합성율을 적절하게 추정할 수 있는 것으로 평가되므로 생장해석, 작물관리 및 온실관리에 광범위하게 적용될 수 있을 것으로 판단되었다. This study was aimed to introduce the measurement of $CO_2$ concentration and leaf area index in the phytotron for predicting the effect of CO.E, light and leaf area index on the instantaneous photosynthetic rate of sweet pepper with the existing ASKAM model. Measurements were made in 2 semi-closed phytotron compartments in which three different $CO_2$ concentrations were applied at random. Plants were grown on containers with circulating nutrient solution at 21$^{\circ}C$ and 80-95% relative humidity. The model estimates crop net $CO_2$ uptake for short time intervals during the day based on short-term data of daily radiation, temperature and $CO_2$ concentration. During the photosynthesis measurements, $CO_2$ concentrations in both compartments and in the basement were measured every minute. This was also done for the flow of pure $CO_2$ into the compartment, global radiation, photosynthetic active radiation inside the compartment, temperature and relative humidity. Crop growth models summarize our knowledge on crop behavior and have as such a wide range of applications in analysis, crop management and thus as a farm management tool.

Development and Validation of a Canopy Photosynthetic Rate Model of Lettuce Using Light Intensity, CO₂ Concentration, and Day after Transplanting in a Plant Factory

정대호,김태영,조영열,손정익,Jung, Dae Ho,Kim, Tae Young,Cho, Young-Yeol,Son, Jung Eek The Korean Society for Bio-Environment Control 2018 생물환경조절학회지 Vol.27 No.2

The photosynthetic rate is an indicator of the growth state and growth rate of crops and is an important factor in constructing efficient production systems. The objective of this study was to develop a canopy photosynthetic rate model of romaine lettuce using the three variables of $CO_2$ concentration, light intensity, and growth stage. The canopy photosynthetic rates of the lettuce were measured at five different $CO_2$ concentrations ($600-2,200{\mu}mol{\cdot}mol^{-1}$), five light intensities ($60-340{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$), and four growth stages (5-20 days after transplanting) in three closed acrylic chambers ($1.0{\times}0.8{\times}0.5m$). A simple multiplication model expressed by multiplying three single-variable models and the modified rectangular hyperbola model including photochemical efficiency, carboxylation conductance, and dark respiration, which vary with growth stage, were also considered. In validation, the $R^2$ value was 0.923 in the simple multiplication model, while it was 0.941 in the modified rectangular hyperbola model. The modified rectangular hyperbola model appeared to be more appropriate than the simple multiplication model in expressing canopy photosynthetic rates. The model developed in this study will contribute to the determination of an optimal $CO_2$ concentration and light intensity with the growth stage of lettuce in plant factories. 작물의 생산량은 광합성과 밀접한 관계가 있으며, 광합성 속도는 다양한 환경 요인에 의해 변화한다. 광합성 속도는 작물의 생육 상태나 생육 속도를 판단하는 지표로 사용되며, 작물 재배 시설을 구축하는 데 고려해야 하는 중요한 요인이다. 이 연구의 목적은 광도, $CO_2$ 농도 및 생육 단계에 의해 변화하는 로메인 상추의 군락 광합성 속도 모델을 개발하는 것이다. 군락 광합성 속도는 정식 후 5, 10, 15, 20 일차에서 5단계의 $CO_2$ 농도($600-2,200{\mu}mol{\cdot}mol^{-1}$)와 5단계의 광조건($60-340{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$)이 처리된 3개의 밀폐 아크릴 챔버($1.0{\times}0.8{\times}0.5m$) 내에서 측정하였다. 먼저 세 가지 환경 요인을 사용하는 식들을 곱하여 만든 단순곱 모델을 구성하였다. 이와 동시에 생육 시기에 따라 변화하는 광화학 이용효율과 카르복실화 컨덕턴스, 호흡에 의한 이산화탄소 발생 속도를 포함하는 수정 직각쌍곡선 모델을 구성하여 단순곱 모델과 비교하였다. 검증 결과, 단순곱 모델의 $R^2$는 0.923이었으며, 수정 직각쌍곡선 모델의 $R^2$는 0.941을 나타내었다. 따라서 수정 직각쌍곡선 모델이 광도, $CO_2$ 농도, 생육 단계의 3 변수에 따른 군락 광합성 속도를 표현하는 데 더욱 적합한 것으로 판단하였다. 본 연구에서 개발된 군락 광합성 모델은 식물공장에서 상추 재배를 위해 생육 단계별로 설정해야 할 최적의 광도와 $CO_2$ 농도를 결정하는 데 도움이 될 것으로 생각된다.

Growth and Development of Cherry Tomato Seedlings Grown under Various Combined Ratios of Red to Blue LED Lights and Fruit Yield and Quality after Transplanting

손기호,김은영,오명민,Son, Ki-Ho,Kim, Eun-Young,Oh, Myung-Min The Korean Society for Bio-Environment Control 2018 생물환경조절학회지 Vol.27 No.1

적색과 청색광은 식물의 광합성에 효과적인 파장으로 알려져 있다. 본 연구는 다양한 조합의 적색과 청색 LED 혼합광에서 자란 방울 토마토 묘의 생장과 정식 후의 생산량과 품질에 대한 영향을 구명하였다. 파종 후 2주된 방울 토마토 묘(Solanum lycopersicum L. cv. 'Cuty')를 적색(655nm)과 청색(456nm) LED의 다양한 비율의 혼합광[red:blue = 41:59 (59B), 53:47 (47B), 65:35 (35B), 74:26 (26B), 87:13 (13B), or 100:0(0B)]과 형광등(대조구)이 설치된 생장상에 옮겨준 후 $25/20^{\circ}C$ (주/야), 광합성 광량자속 $198.6{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ (12시간)의 조건에서 27일간 육묘하였다. 그 후 방울 토마토를 벤로형 온실에 정식하여 75일동안 재배하였다. 정식 전 육묘 단계에서 27일간 LED 처리된 0B 와 59B 처리구를 제외한 모든 RB 혼합광 처리의 지상부 생체중이 대조구에 비해 높았다. 지상부 건물중과 엽면적 또한 지상부 생체중과 유사한 경향을 보였다. 줄기 신장은 13B, 26B, 35B에서 대조구와 다른 처리구들에 비해 유의적으로 가장 높았다. 특히, 26B는 59B처리에 비해 약 3.2배 높은 줄기 신장을 보였다. 정식 후 37일 째에 마딧수는 26B와 47B에서 유의적으로 가장 높았고, 식물 초장은 26B에서 대조구와 59B에 비해 유의적으로 높았다. 가장 높은 총 과실 생산량을 보였던 26B는 대조구에 비해 1.6배, 59B에 비해 1.8배 높은 총 과실 생산량을 보였다. 따라서, 본 연구는 적색과 청색 LED의 다양한 혼합 비율이 방울 토마토 묘의 생장 및 발달과 정식 후의 과실 생산량과 같은 생식생장에 영향에 중요한 요소임을 제시한다. Red and blue lights are effective wavelengths for photosynthesis in plants. In this study, we determined the effects of various combined ratios of red to blue LEDs on the quality of cherry tomato seedlings prior to transplantation, and their subsequent effects on the yield and quality of tomato fruits after transplanting. Two-week-old cherry tomato seedlings (Solanum lycopersicum cv. 'Cuty') were cultivated under various combined ratios of red (R; peak wavelength 655 nm) to blue (B; 456 nm) LEDs [red:blue = 41:59 (59B), 53:47 (47B), 65:35 (35B), 74:26 (26B), 87:13 (13B), or 100:0 (0B)] and fluorescent lamps and raised for 27 days. The cherry tomato seedlings were subsequently transplanted into a venlo-type greenhouse and cultivated for 75 days. At the seedling stage, the shoot fresh weight of seedlings in all RB combined treatments, except 0B and 59B, was higher than that of the control after 27 days of LED treatment. Shoot dry weight and leaf area also showed trends similar to that of shoot fresh weight. The stem length was significantly higher in 13B, 26B, and 35B treatments compared with the control and other treatments. In particular, the stem length of 26B plants was approximately 3.2 times longer than that of 59B plants. At 37 days after transplanting, the number of nodes was significantly higher in 26B and 47B plants, and the plant height of 26B plants was significantly higher than that of control and 59B plants. Total fruit yield in 26B plants, which was the highest, was approximately 1.6 and 1.8 times higher than that in control and 59B plants, respectively. Thus, the results of this study indicate that various combined ratios of red to blue LEDs directly affected to the growth of cherry tomato seedlings and may also affect parameters of reproductive growth such as fruit yield after transplantation.

Comparison of Environmental Conditions and Insulation Effect between Air Inflated and Conventional Double Layer Greenhouse

메쓰캄카남즈사니카닐란가니자야세카라,나욱호,오우라비압둘하메드바바툰데,이종원,라쉬드아드난,김현태,이현우,Jayasekara, Shanika N.,Na, Wook H.,Owolabi, Abdulhameed B.,Lee, Jong W.,Rasheed, Adnan,Kim, Hyeon T.,Lee, Hyun W. The Korean Society for Bio-Environment Control 2018 생물환경조절학회지 Vol.27 No.1

본 연구는 공기주입 이중피복온실과 관행 이중피복온실의 생육환경과 단열성능을 비교하기 위하여 수행하였다. 두 온실의 온도, 상대습도, 포차, 이산화탄소농도, 일사량, 딸기 생산량 및 난방연료소비량을 비교하였다. 공기주입온실이 관행온실보다 야간에 상대습도가 더 높고 포차는 더 낮게 나타나 딸기의 생육에 좋지 않은 환경을 보여주었다. 이산화탄소농도는 공기주입온실이 관행온실보다 더 높게 나타났으며, 이는 공기주입온실이 더 밀폐되어 있어 환기량이 적기 때문인 것으로 판단된다. 관행온실의 광투과율이 77%로 공기주입온실의 72%보다 더 높아 관행온실의 광환경이 더 우수한 것으로 나타났다. 관행온실의 딸기 생산량이 더 높게 나타났으며, 이는 관행온실의 생육환경이 공기주입온실보다 더 우수한 결과로 판단된다. 난방연료는 공기주입온실에서 더 적게 소모되어 공기주입온실의 단열성능이 더 우수한 것으로 나타났다. This study was conducted to determine which greenhouse provided good environmental conditions for strawberry production, and performed better at conserving energy. Temperature, RH, VPD, $CO_2$, solar radiation, yield, and fuel consumption were the parameters analyzed. The temperatures of both greenhouses were well controlled in order to provide optimal day and night temperatures for strawberry production. The air inflated double layer greenhouse had higher RH values (more than 90% at night), which led to higher disease occurrence, in comparison to the conventional double layer greenhouse. Furthermore, the air inflated double layer greenhouse had lower VPD values than the conventional double layer greenhouse. Therefore, better RH and VPD were observed in the conventional double layer greenhouse. Higher $CO_2$ concentration was observed in the air inflated double layer greenhouse while the conventional double layer greenhouse ventilated better than the air inflated greenhouse, because of its side ventilators. Moreover, higher solar radiation in the conventional double layer greenhouse resulted in higher yield, in comparison to the air inflated double layer greenhouse. Thus, we can conclude that the conventional double layer greenhouse provided a better environment for crop growth, in comparison to the air inflated double layer greenhouse. Regarding fuel consumption, the air inflated double layer greenhouse had lower fuel consumption than the conventional double layer greenhouse. Therefore, from an energy consumption point of view, we can conclude that the air inflated double layer greenhouse performed better than the conventional double layer greenhouse.

Determination of the Harvest Date and Ripening Phase of 'Seolhyang' Strawberry

홍세진,엄향란,Hong, Sae Jin,Eum, Hyang Lan The Korean Society for Bio-Environment Control 2020 생물환경조절학회지 Vol.29 No.1

본 연구는 '설향' 딸기의 수확시기에 따른 품질 특성을 확인하고, 상온(20℃)·cold-chain(10-12℃)·저온(5℃) 유통에 적합한 숙성단계를 조사하기 위하여 수행하였다. 딸기는 12월 20일부터 5월 9일까지 6번에 걸쳐서 수확하였다. 딸기를 수확할 때 적합한 숙성 정도는 3월까지는 경도 2.9-3.0 N, 당도 8.6 °Brix 이상이었으나, 4월 이후에는 당도가 감소하였다. 딸기의 숙성을 결정하는 주요 요인은 붉게 착색된 정도이고, Hunter a 값은 32-37, hue angle은 36-45℃였다. 딸기의 후숙 실험에서 숙성 정도는 딸기의 착색이 진행되는 정도에 따라서 결정되었으며, 상온에서는 10%/day, 10-12℃에서는 5%/day, 5℃에서는 3%/day씩 착색이 진행되었다. 따라서 상온에서 유통할 경우에는 80%, cold-chain·저온에서 유통하기 위해서는 90%의 착색된 과실을 수확하여야 유통하는 동안 상품성이 유지되었다. 그리고 상온에서는 70% 이하로 착색된 딸기를 유통하거나, 저온에서는 80% 이하로 착색된 딸기를 유통하는 경우에는 100% 착색이 이루어지지 않고 상품성을 잃었다. The purpose of this study was to investigate the quality characteristics of ripe fruit based on harvest date and to examine the ripening phase of 'Seolhyang' strawberry suitable for room temperature, cold-chain, and low temperature distribution. The strawberries were harvested six times between December 20 to May 9. The appropriate maturity of strawberries is characterized by the firmness of approximately 2.9-3.0 N, and SSC remained above 8.6 °Brix until March and declined after April. The quality index values that determine the maturity stage of strawberries should be red color, Hunter a value ranging from 32 to 37, and hue angle of 36-45℃. For the after-ripening experiment, the progression rate of the ripening stage determined based on strawberry color was 10%/day at room temperature, 5%/day at 10-12℃, and 3%/day at 5℃. Thus, strawberries should be harvested at 80% coloring stage for distribution at room temperature and at least 90% for low temperature storage to maintain the merchantability. Besides, strawberries harvested at 70% coloring stage at room temperature and strawberries harvested below 80% coloring stage at low temperatures below 5℃ had lost commercial value before reaching 100% coloring stage.

Comparison of Measured and Calculated Carboxylation Rate, Electron Transfer Rate and Photosynthesis Rate Response to Different Light Intensity and Leaf Temperature in Semi-closed Greenhouse with Carbon Dioxide Fertilization for Tomato Cultivation

최은영,정영애,안승현,장동철,김대현,이동수,권진경,우영회,Choi, Eun-Young,Jeong, Young-Ae,An, Seung-Hyun,Jang, Dong-Cheol,Kim, Dae-Hyun,Lee, Dong-Soo,Kwon, Jin-Kyung,Woo, Young-Hoe The Korean Society for Bio-Environment Control 2021 생물환경조절학회지 Vol.30 No.4

This study aimed to estimate the photosynthetic capacity of tomato plants grown in a semi-closed greenhouse using temperature response models of plant photosynthesis by calculating the ribulose 1,5-bisphosphate carboxylase/oxygenase maximum carboxylation rate (V_cmax), maximum electron transport rate (J_max), thermal breakdown (high-temperature inhibition), and leaf respiration to predict the optimal conditions of the CO₂-controlled greenhouse, for maximizing the photosynthetic rate. Gas exchange measurements for the A-C_i curve response to CO₂ level with different light intensities {PAR (Photosynthetically Active Radiation) 200µmol·m^-2·s^-1 to 1500µmol·m^-2·s^-1} and leaf temperatures (20℃ to 35℃) were conducted with a portable infrared gas analyzer system. Arrhenius function, net CO₂ assimilation (A_n), thermal breakdown, and daylight leaf respiration (R_d) were also calculated using the modeling equation. Estimated J_max, A_n, Arrhenius function value, and thermal breakdown decreased in response to increased leaf temperature (> 30℃), and the optimum leaf temperature for the estimated J_max was 30℃. The CO₂ saturation point of the fifth leaf from the apical region was reached at 600ppm for 200 and 400µmol·m^-2·s^-1 of PAR, at 800ppm for 600 and 800µmol·m^-2·s^-1 of PAR, at 1000ppm for 1000µmol of PAR, and at 1500ppm for 1200 and 1500µmol·m^-2·s^-1 of PAR levels. The results suggest that the optimal conditions of CO₂ concentration can be determined, using the photosynthetic model equation, to improve the photosynthetic rates of fruit vegetables grown in greenhouses. 본 연구는 반밀폐형 토마토 재배 온실에서 광합성율 극대화를 위한 적정 탄산가스 시비 농도를 구명하고자 광합성 모델을 이용하여 잎의 최대 카복실화율(V_cmax), 최대 전자전달속도(J_max), 열파괴, 잎 호흡 등을 계산하고 실제 측정값과 비교하였다. 다양한 광도(PAR 200µmol·m^-2·s^-1 to 1500µmol·m^-2·s^-1)와 온도(20℃ to 35℃) 조건에서 CO₂ 농도에 대한 A-C_i curve는 광합성 측정 기기를 사용하여 측정하였고, 모델링 방정식으로 아레니우스 함수값(Arrhenius function), 순광합성율(net CO₂ assimilation, A_n), 열파괴(thermal breakdown), R_d(주간의 잎호흡)를 계산하였다. 엽온이 30℃ 이상으로 상승하였을 때 J_max, An 및 thermal breakdown 예측치가 모두 감소하였고, 예측 J_max의 가장 최고점은 엽온 30℃였으며 그 이상의 온도에서는 감소하였다. 생장점 아래 5번째 잎의 광합성율은 PAR 200-400µmol·m^-2·s^-1 수준에서는 CO₂ 600ppm, PAR 600-800µmol·m^-2·s^-1 수준에서는 CO₂ 800ppm, PAR 1000µmol·m^-2·s^-1 수준에서는 CO₂ 1000ppm, PAR 1200-1500µmol·m^-2·s^-1 수준에서는 CO₂ 1500ppm을 공급했을 때 포화점에 도달하였다. 앞으로 광합성 모델식을 활용하여 과채류 온실 재배 시 광합성을 높일 수 있는 탄산시비 농도를 추정할 수 있을 것으로 판단된다.

Composition of Optimal Nutrient Solution for Single-stemmed Rose 'Red velvet' in a Closed Aeroponic System

Kang Mu Jang,Lee Joo Hyun,Lee Yong-Beom The Korean Society for Bio-Environment Control 2005 생물환경조절학회지 Vol.14 No.3

Experiments were carried out to develop an optimal nutrient solution for the single-stemmed rose (Rosa hybrida L.) 'Red velvet' in a closed aeroponic system. Plants were grown in 1/3, 1/2, 1, or 3/2 strength of the nutrient solution of National Horticultural Research Station in Japan (NHRS). Significantly less changes of pH and EC ($dS{\cdot}m^{-1}$) in the drainage were observed in 1/2 strength treatment as compared to other treatments. The $NO_3-N$, K, Ca, and Mg concentrations in the drainage solution of 1/2 strength treatment were maintained at optimal levels. These results indicated that the rose uptakes of both nutrients and water was more stable than those in other concentration. The concentration of macronutrients in nutrient solution were adjusted based on the ratio of nutrient:water (n/w) taken up by plants grown in the 1/2 strength solution. The composition of the new solution (classified the University of Seoul (UOS) solution) was as follow; $NO_3-N$ 8.8, $NH_4-N$ 0.67, P 2.0, K 4.8, Ca 4.0, Mg 2.0 $me{\cdot}L^{-1}$. To further evaluate new solution on crop growth, the rose 'Red Velvet' was grown again in l/2, 1, and 2 strength UOS solution to compare with 1.0 strength PBG (proefstion voor bloemisterij en glasgroenpe) solution. Overall the plant growth, including the stem length and number of five-leaflet leaves was higher in 1.0 strength of UOS solution than other treatments. Results presented in this study indicate that the nutrients in the UOS solution are well balanced for the single-stemmed rose in the closed aeroponic system.

Effect of Root Zone Cooling on Growth Responses and Tuberization of Hydroponically Grown 'Superior' Potato (Solanum tuberosum) in Summer

Chang, Dong-Chil,Jeong, Jin-Cheol,Lee, Yong-Beom The Korean Society for Bio-Environment Control 2006 시설원예‧식물공장 Vol.15 No.4

A potato (Solanum tuberosum L. cv. Superior) cultivar was grown in aeroponic cultivation system to investigate the effect of root zone cooling in summer. Based on their nutrient uptake, growth responses, and tuberization, the possibilities for potato seed production were determined. Although shoot growth and early tuberization increased in the conventional non-cooling root zone system (root zone temperature of $25\pm2^{\circ}C$), stolen growth, photosynthesis, transpiration rate and number of tubers produced were higher in the cooling root zone system ($20\pm2^{\circ}C$) than in the non-cooling system. Increasing root zone temperature above $25^{\circ}C$ stimulated absorption of K more than T-N, P, Ca, Fe and Mn. On the other hand, root zone temperatures in the range of $20^{\circ}C$ to $25^{\circ}C$ did not affect Mg contents. The lower uptake and supply to leaves of T-N, Fe and Mn at the high root zone temperature promoted early tuberization and advanced haulm senescence. The results stress the importance of keeping root zone temperature to as low as below 20, particularly in summer under temperate Bone.