The scarcity of registered herbicides for cultivation of castor beans is still a limiting factor for its expansion. Thus, the aim of this study was to evaluate the tolerance of castor bean to trifluralin herbicide in soils of different textures. The experiment was conducted in a greenhouse in a completely randomized design with five replications in a factorial with 8 doses of the trifluralin herbicide (0; 187.5; 375; 750; 1.500; 3.000; 6.000 and 12.000 g ha-1 i.a.) applied at pre-emergence and four types of substrates (washed sand; sandy loam; sandy clay loam; and clay loam soil). At 28 days after sowing, the variables plant height, leaf area, shoot dry weight, volume and dry mass of roots were measured. It was concluded that the tolerance of castor bean to trifluralin herbicide is influenced by chemical and physical characteristics of soil. In sandy and sandy loam soils, doses of trifluralin below those commonly used for weed control are sufficient to cause the decrease in the growth of castor bean plants.
weed; selectivity; Ricinus communis
