Lettuce Production Using a Commercial Scale Recirculated Capillary Hydroponic System
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Accession number;05A0364409
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| Title;Lettuce Production Using a Commercial Scale Recirculated Capillary Hydroponic System |
| Author;
ZARZA-SILVA HUGO A.
(Chiba Univ., Chiba, Jpn)
MARUO TORU
(Chiba Univ., Chiba, Jpn)
TAKAGAKI MICHIKO
(Chiba Univ., Chiba, Jpn)
HOHJO MASAKI
(Chiba Univ., Chiba, Jpn)
SHINOHARA YUTAKA
(Chiba Univ., Chiba, Jpn)
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Journal Title;Japanese Journal of Tropical Agriculture
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Journal Code:F0874A
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ISSN:0021-5260
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VOL.49;NO.1;PAGE.45-52(2005)
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| Figure&Table&Reference;TBL.12, REF.19 |
| Pub. Country;Japan |
| Language;English |
| Abstract;Three experiments were carried out sequentially in spring, summer and fall to study the possibility of producing butterhead lettuce (Lactuca sativa L.) using a capillary hydroponic system (CHS) on a commercial scale under tropical environmental conditions. In all the experiments, two temperature regimes combined with two flow rates of nutrient solution were applied. The air temperature was controlled in the ranges of 25-30.DEG.C. and 30-35.DEG.C. and the solution flow rates were 50 or 80ml min'-1' m'-1'. For all the three growing seasons, better plant growth was associated with the lower temperature regime. Higher water flow rate stimulated plant growth only in the summer growing period under the higher temperature regime, due to the larger amount of dissolved oxygen in the nutrient solution. Although the plant quality parameters and leaf color remained unaffected under most of the temperature regimes and flow rates, they differed according to the seasons. In general, higher SPAD values and nitrate concentrations were observed in the spring and fall growing seasons as well. Lower SPAD values and higher vitamin C concentrations were recorded in the summer growing season. The estimated cost of the required-materials for constructing a 1000m'2' CHS in Paraguay and Thailand amounted to .YEN.665,950 and .YEN.659,100 respectively, based on the price of the materials in each country. Estimated cost of the materials in Japan was threefold higher than that in the tropical countries. All the year round lettuce production under tropical conditions using CHS was considered to be fairly possible, since the microclimatic conditions in the greenhouses were similar to those of outdoor tropical conditions. (author abst.) |
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