Interference and economic damage level of alexandergrass on carioca type beans

Determining the competitive ability of bean cultivars and the economic damage level (EDL) caused by alexandergrass is important for the implementation of integrated weed management. This work aimed to evaluate the interference of alexandergrass and determine the level of economic damage when it competes with seven carioca-type bean cultivars. The experiment was conducted in a completely randomized experimental design, with treatments consisting of the carioca bean varieties IAC Imperador, IPR Curió, ANFC9, IAC Milênio, IPR Tangará, IPR Sabiá, and BRS Pérola and 12 alexandergrass densities for each cultivar, ranging from 0 to 560 plants m−2. Plant density, leaf area, soil cover, and shoot dry matter of alexandergrass were evaluated 35 d after emergence. The variables alexandergrass plant density, grain productivity, control costs, bean price, and herbicide efficiency were used to estimate EDL. The cultivars ANFC9, IAC Milênio, and IPR Tangará were the most competitive, and IAC Imperador, IPR Curió, IPR Sabiá, and BRS Pérola the least competitive against alexandergrass. The highest EDL values were observed in the cultivars ANFC9, IAC Milênio and IPR Tangará, which ranged between 3.80 and 15.70 plants m−2 of alexandergrass. The cultivars IAC Imperador, IPR Curió, IPR Sabiá, and BRS Pérola showed the lowest economic damage with 1.10 to 5.60 plants m−2 of alexandergrass.