Variation in allelopathic tolerance of vetch cultivars to Sorghum halepense L. (Pers.) extracts

SUMMARY Using allelopathic tolerance of crops and cultivars is considered a promising supplement to weed control strategies. In order to evaluate the allelopathic tolerance of vetch cultivars to Sorghum halepense extracts in germination and initial growth of the crop, a multi-factorial lab experiment was carried out based on a completely randomized design with four replications. The experimental factors were nine vetch cultivars (‘Liya’, ‘Lorina’, ‘Moldovskaya’, ‘Obrazets 666’, ‘Asko’, ‘Violeta’, ‘Viola’, ‘Beta WP’, and ‘Panonskaya’), two aqueous extracts (of shoot and root biomass of S. halepense ) and four concentrations of the extracts (1.0%, 5.0%, 10.0% and distilled water as a control). An analysis of variance showed a significant influence of the studied factors. The results revealed variation in responses of the nine cultivars to the allelopathic effect of S. halepense . The extracts applied at different concentrations had a significant inhibitory effect on seed germination (from 2.8 to 27.3% for different cultivars), germ length (from 4.6 to 48.7%) and germ weight (from 3.6 to 34.0%). The lowest concentration (1.0%) also had a stimulating effect on growth parameters, most pronouncedly in two cultivars (‘Beta WP’ and ‘Viola’). Total effects of the weed extracts on seed germination and initial development selected ‘Beta WP’, ‘Violeta’ and ‘Obrazets 666’ as the most tolerant cultivars, as opposed to ‘Liya’ and ‘Panonskaya’, which were more sensitive. The cultivars with seeds that have greater biomass per 1000 seeds, higher seedling vigour index and protein content were found to be less sensitive to the suppressing effect of S. halepense extracts. These cultivars can be successfully used in organic fields with high density of S. halepense or in a conventional production system with a reduced use of herbicides.