ARS | Publication request: Assessing uniformity in soil plant atmosphere chambers

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 14, 2008
Publication Date: N/A

Technical Abstract: Growth chambers provide precisely controlled environments in which to grow plants and evaluate the effects of one or more controllable parameters on plant responses. Because of this precise control, it is arguable that less plant replication is required in growth chamber versus field studies. However, when evaluating treatment effects in studies using multiple growth chambers, lack of uniformity of the controlled conditions between and within each chamber can bias experimental results if not accounted for. SPAR (soil-plant-atmosphere research) growth chambers are semi-closed outdoor naturally sunlit growth chambers that control temperature, humidity, and carbon dioxide concentration. SPAR chambers continuously monitor and record environmental conditions and whole plant photosynthesis at 5 minute, and evapotranspiration at 15 minute, intervals. Spring wheat (cv. Apogee) was grown in 12 SPAR chambers in the summer of 2006 at USDA-ARS facilities in Beltsville, MD USA to evaluate variability between, and within, the chambers. Chambers were maintained at the same environmental conditions (e.g. 16 h 23/18°C 16 h day/night thermoperiod, 740 ppm daytime atmospheric CO2 concentration) over the 70 day experiment. Periodic measurements of leaf and tiller numbers, stem length, organ dry weights as well as whole-season environmental and gas exchange data were used to evaluate the uniformity of the chambers.