Three field experiments were carried out, in 1980, at the National Wheat Research Center/ EMBRAPA, Passo Fundo, RS. They aimed at testnig the responses of herbicides diclofop, dicamba, the association 2,4 D with dicamba, and the mixture diclofop + (2,4 D + dicamba) in the control of rye grass (Lolium multiflorum L.) and corn spurry (Spergula arvensis L.). Simultaneously, the selectivity of these herbicides to wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and rye (Secale cereale L.) was evaluated. The results of visual evaluation of phytotoxicity showed that dicamba caused the greatest degree of injury to the three crops studied. Barley was the most sensitive crop to dicamba in the initial growth stage. Wheat, barley, and rye were tolerant to diclofop. Mixture diclofop + (2,4 D + dicamba) provided no control of rye grass in the three crops. Additionally, this mixture showed a reduction in the control of corn spurry in barley and rye crops. Dicamba caused reduction in grain yield of the three crops, showing to be little selective at the tested dosage. Rye suffered a reduction in grain yield caused by diclofop, while the mixture diclofop + (2,4 D + dicamba) was selective to all crops studied.
Control; selectivity; wheat; barley; rye