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Conference abstract, 2005

Varietal variation in allelopathic activity in wheat and barley

Bertholdsson, Nils-Ove


Most breeding traits are the same in conventional and organic cereal breeding. However, a trait that is very important in organic and low-input farming, but until now been neglected in breeding is weed competitive ability. Morphological and physiological characters mainly influencing either the biomass growth or the uptake of nutrients and water could be used as potential breeding traits. However, the importance of allelopathy, i.e root exudates inhibiting weed growth, is more and more envisaged. In this paper a presentation of the genetical variation found in barely and wheat as well as how to use this in breeding of more allelopathic cultivars will be given. In both barley and wheat there is a large variation in potential allelopathic activity, measured as the root growth inhibition of ryegrass. Nordic barley landraces and old cultivars are in general more allelopathic than new breed cultivars, but there are exceptions that could be used in breeding. Hence, it may not be necessary to go back to the old landraces to find useful genetic variations and this will facilitate the breeding. New 6-row cultivars also seem to be more allelopathic than new 2-row cultivars. In wheat there is an opposite trend as Swedish landraces and old cultivars are less allelopathic than new ones. Swedish cultivars are also in general less allelopathic than cultivars from western and central Europe and North America. In a screen of 800 spring wheat cultivars and lines two cultivars from Japan and Tunisia were found to be as allelopathic as the most allelopathic barley and are now used in a conventional program to improve the allelopathic proprieties of the Swedish spring wheats. There may still be some doubts about the contribution of allelopathy to the weed competitive ability of cereals in the field. Some of the cultivars studied have also been studied in field trials and data of weed competitiveness showed that allelopathy explained depending on year 7-58 % of the variance in weed biomass in barley and 0-21 % in spring wheat


Allelopathy; barley; weed competition

Published in


WG3 workshop of COST SUSVAR 860

Authors' information

Bertholdsson, Nils-Ove
Swedish University of Agricultural Sciences, Plant breeding and Biotechnology

UKÄ Subject classification

Agricultural Science

URI (permanent link to this page)