FACILITY FOR STUDYING THE EFFECTS OF ELEVATED CARBON-DIOXIDE CONCENTRATION AND INCREASED TEMPERATURE ON CROPS

The requirements for the experimental study of the effects of global c limate change conditions on plants are outlined. A semi-controlled pla nt growth facility is described which allows the study of elevated CO2 and temperature, and their interaction on the growth of plants under radiation and temperature conditions similar to the field. During an e xperiment on winter wheat (cv. Mercia), which ran from December 1990 t hrough to August 1991, the facility maintained mean daytime CO2 concen trations of 363 and 692 cm3 m-3 for targets of 350 and 700 cm3 m-3 res pectively. Temperatures were set to follow outside ambient or outside ambient +4-degrees-C, and hourly means were within 0.5-degrees-C of th e target for 92% of the time for target temperatures greater than 6-de grees-C. Total photosynthetically active radiation incident on the cro p (solar radiation supplemented by artifical light with natural photop eriod) was 2% greater than the total measured outside over the same pe riod.