Influence of foliar applied chlormequat on radiation attenuation by winter barley canopies

Abstract
Biomass production in barley is determined by the amount of solar radiation absorbed by the foliage (Gallagher & Biscoe, 1978). As incident irradiance per unit area varies little between neighbouring sites and seasons in the cereal growing areas of the U.K. (Monteith, 1978), biomass production will largely be governed by the size of the canopy, the orientation of canopy constituents and the efficiency of conversion of absorbed radiation into dry matter (Green, 1984). Reviewing the literature, Monteith & Elston (1983) have highlighted the constancy of mean seasonal efficiency, concluding that growth is limited by the ability of the stand to absorb radiation.