Acclimation of Lolium temulentum to enhanced carbon dioxide

Abstract

The recent elevation and predicted future rise in atmospheric carbon dioxide concentrations has led to greater interest in the effects of higher carbon dioxide concentrations on crop plants. Whilst there is a relatively large amount of information on the effects of increased carbon dioxide concentration on arable and glasshouse crops, relatively little is known about the responses of cool temperature forage crops to greater carbon dioxide concentrations. One of the most important forage crops is Lolium whose responses to higher carbon dioxide concentration have been de scribed at the whole crop level (Nijs, Impens & Behaeghe 1988, 1989; Hardacre, Lang & Christeller 1986). However, there is little information on the physiology behind the observed crop re sponses, particularly on how the plant acclimates to higher carbon dioxide concentrations. Thus we determined the effect of increased carbon dioxide and transfers from ‘ambient’ to ‘high’ carbon dioxide concentrations on growth and some physiological characters of Lolium temulentum.