The effect of companion crops management on biological weed control in the seeding year of lucerne

Abstract

A 3-year experiment was conducted at the Research Station Pawłowice of the Wrocław University of Environmental and Life Sciences, Poland, to evaluate the effect of companion crops and their management on lucerne weediness and productivity. Weed density, weed structure and companion crop yield in the seeding year were evaluated. The experiment had two factors; the main factor was three harvest dates of the companion crops. The harvest date was assessed based on the barley growth stages. A subplot factor was a companion crop in which lucerne was sown: spring vetch (V), spring barley (B), mixture of spring vetch and spring barley (20%+80%, M-1) and mixture of spring vetch and spring barley (50%+50%, M-2). Lucerne without a companion crop was included as a control (L). At the companion crops harvest, spring vetch and spring barley sown alone or in mixtures significantly decreased weed density, compared with L by 53%, 70%, 78% and 83% for the companion crop V, M-2, B and M-1, respectively. Annual weed dry matter biomass ranged from 0.37 t ha− 1 in M-1 to 2.06 t ha− 1 in L. Purple deadnettle (Lamium purpureum) and lambsquarters (Chenopodium album) were the dominant weed species in the first two weed counts.