Weed suppression by Canadian spring cereals: relative contribution of competition for resources and allelopathy

Integrated and more sustainable weed management practices are in great demand all around the globe. The adoption of more weed-suppressive cereal cultivars could be part of an integrated weed management strategy. Recently, a study was published analysing the relative contribution of above-ground competition and allelopathy to weed suppression of Scandinavian winter cereals at the field level. The present study used the same approach with Canadian spring wheat and triticale cultivars, and confirmed the results of the previous study. The competitive traits such as leaf area index, crop height and early vigour, and the allelochemicals belonging to the chemical group of benzoxazinoids measured in the root zone were of equal importance to explain the variance of weed biomass at the field level. In addition, a dendogram showed large genetic variability for competitive and allelopathic traits in the Canadian spring cereals, providing the genetic basis for the initiation of breeding programmes for more weed-suppressive cultivars.