A Versatile Plant Growth System With Wide Range Environmental Control
ABSTRACT A controlled-environment facility is described that can be used as a general purpose plant growth room (9.3 m3 total volume) or a dual chamber unit (0.97 m3 each) for studying photosynthesis, respiration and transpira-tion. Temperature for either application can be main-tained with average fluctuations of less than ±1.5 °C for the range of 15 to 35 °C. Humidity and carbon dioxide control is possible over ranges of 30 to 95 percent relative humidity and 300 to 1400 ppm C02 with maximum fluc-tuations of ±8.2 percent RH and ±10 percent of full operational scale, respectively. Continuous measurement of evapotranspiration and carbon dioxide exchange is provided. Photosynthetically active radiation (400 - 700 nm) up to 1150 JLIE nr2 s'1 (81 klux illuminance) is pro-vided by a combination of fluorescent and high pressure sodium lamps. The internally located chambers are detachable and mobile and assembled of structural subunits for simple interchange of cultivation type and/or separation of aerial and root environments.