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Chirahui (A. cochliacantha) is an aggressive tall-shrub which invades buffelgrass (Cenchrus ciliaris) pastures and reduces productivity. Prado herbicide (621.3 g i.a./Kg. Amynopyralid + 94.5 g i.a./Kg. Metsulfuron metil) is a new product from Dow Agrosciences in Mexico and no local data is available for its use. This study was conducted in summer of 2011 to evaluate the efficiency of Prado herbicide and manual control by machete to reduce chirahui populations. Treatments applied were: Prado herbicide one doses on 100 liters of water, manual control by machete and the untreated check. Plot 10 by 30 m were used in a randomized complete block design with three treatments and 20 replications. Data was analyzed by ANOVA. Evaluated variables were: brush mortality, grass density, plant height, basal cover and forage production. All variables were evaluated during the summers of 2011 to 2013. Prado herbicide controlled 100% of chirahui and caused no phytotoxicity problems to either buffelgrass or native grasses present. Machete treatments controlled 15% of the chirahui plants but treated plants sprouted back and reach pretreatment levels after three summer growing seasons. Chemical brush control increased (P<0.05) grass density, height, basal cover and the forage production of both buffelgrass and native grass species. Total forage production varied from 7.5 to 9.0 tons D.M./ha on chemically treated plots, from 6.5 to 6.8 tons D.M./ha on machete treated areas and from 4.3 to 4.9 tons D.M./ha on the untreated checks. Buffelgrass plots where chirahui was controlled produced additionally from 1.6 to 3.6 tons of D.M.ha/year. Manual control by machete is not recommended because forage production increases are short-lived and are economically not justified. Foliar applications of Prado herbicide are appropriated to reduce chirahui populations and increase productivity in buffelgrass pastures in the humid areas of southern Sonora, Mexico.