Abstract

The potential weed suppressive ability of a variety mixture is essential for the yield and yield stability of the crop. Opinions differ on what constitutes the perfect mixture, but one theory is that it is important to have niche differentiation or complementarity between varieties in a mixture. Niche differentiation is predicted to result in reduced levels of intraspecific competition, increasing the opportunities for individuals to perform well and to compete better as a plant stand against weeds. Detailed information about how mixtures influence the weed competitive ability is currently lacking, but in some studies fewer weeds have been found in mixtures than in pure lines. A greenhouse trial was performed to investigate whether mixtures of barley varieties could suppress weeds better than barley grown in pure stands, and whether the weed suppressive effect differed between the various mixtures. The barley varieties used differed in three specific characteristics, namely allelopathic activity, root length development and shoot length in the first growth stages. Two weed species, Brassica rapa and Lolium perenne, were chosen as the model weed flora. The results indicate that the competitive effect on weed biomass was dependent on the composition of the barley variety mixture. There was also a tendency for mixtures to have a better competitive effect on weeds than pure stands of barley varieties, but this effect depended on the varieties contained in the mixture. Contrasting allelopathic activity and shoot development characteristics between the varieties in the mixture increased the competitive effect. The weed suppressive effect was lowest in a mixture containing varieties differing in root development but with low shoot development and high allelopathic activity

Published in

Conference

5th Workshop of the EWRS Working Group: Crop-Weed Interaction In collaboration with SUSVAR Cost action 860 Working Group Plant-plant Interactions

SLU Authors

• Didon, Ulla

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science


Permanent link to this page (URI)

https://res.slu.se/id/publ/23776