Variation between barley cultivars in early response to weed competition

An experiment was conducted with three spring barley (Hordeum vulgare ssp. vulgare L.) cultivars of contrasting, competitiveness to identify variations in their early competitive response to weed competition and to study canopy architecture and growth development at the early stages of cultivar growth. The aim was also to investigate whether differences in shoot morphology, growth development and competitive response could explain the differences in competitive ability against weeds. The barley cultivars were grown outdoors in boxes either in monoculture or in a mixture with white mustard (Sinapis alba L.) as a model weed. The experiment was run until the barley cultivars were in the stem elongation stage. The varieties with strong to medium competitive ability against weeds shortened the time of emergence in the presence of S. alba in contrast to the least competitive cultivar. The results also indicated that spring barley cultivars with strong competitive ability against weeds have an early stem extension as a response to weed competition and a low competitive response. Morphological traits, namely large length of the two first internodes, long main shoot in the tillering stage and a small leaf angle, may be important traits in competition for light.