Respuesta de cinco cultivares de cebada a la interferencia temprana de raigrás (Lolium multiflorum)

Weed interference is one of the main problems in winter crops. Among weeds, Lolium multiflorum is an important species because it can compete strongly with barley. The objective of this work was to evaluate the competitive interference between five barley cultivars (Hordeum vulgare) and ryegrass (Lolium multiflorum) during early growth stages. Two experiments were carried out: a germination test in Petri dishes and a competition experiment under semi-controlled conditions. The cultivars evaluated were INIA Arrayán, Fana, Danielle, Olimpia and Attika. In experiment 1, the germination percentage of barley was evaluated in the presence and absence of ryegrass. In experiment 2, HAUN index, plant height and shoot dry biomass were measured. The results showed that the presence of ryegrass did not affect barley germination. No differences between cultivars and no cultivar × ryegrass interaction were found for this variable. In the pot experiment, ryegrass interference appeared during early barley growth. In plant height, the effect was not observed at the beginning, but it became clear from 25 days after sowing, when plants grown without ryegrass were taller. Shoot dry biomass was the variable that showed the competitive effect more clearly, because it was significantly reduced in the presence of ryegrass. Differences between cultivars were also found in biomass accumulation, with Attika showing the highest values and Fana the lowest. HAUN index was only explained by time, with no significant effect of cultivar, ryegrass or their interaction. In general, under the conditions of this study, Lolium multiflorum did not affect barley germination, but it did affect early crop growth, mainly by reducing shoot dry biomass and, to a lesser extent, plant height.