Effects of Different Viscosity Mechanical OilAdjuvants on Herbicides Activity

Several experiments were conducted in greenhouse to evaluate the effects of 10 mechanical oil concentrates on the efficacies of cyanazine and nicosulfuron for the control of barnyardgrass ( Echinochloa crusgalli (L.) Beauv.) and velvetleaf ( Abutilon theophrasti Medic.). Results showed that all the mechanical oil concentrates enhanced the activity differently with different viscosity. Of 10 adjuvants, the one with viscosity of 46 mm 2/s (40℃) (MOC 46 ) was most effective and that with 32 mm 2/s (40℃) followed. The enhancement to cyanazine is better than to nicosulfuron. The order of enhancement of MOC 46 on different herbicides was: atrazine and cyanazineatrazine+cyanazine and atrazine+ nicosulfuron cyanazine+ nicosulfuron nicosulfuron. All the treatments above, the order of safety to maize seedlings was: atrazine/nicosulfuron/atrazine+ nicosulfuron cyanazine+atrazine and cyanazine+nicosulfuroncyanazine. Cyanazine with the addition of MOC 46 had detrimental effects on maize seedlings.