Abstract

TOLOZANO, B; PISANI, J.M  and  PURICELLI, E.C. Control mecánico y químico de Tessaria dodoneifolia (Hook. et Arn.) Cabrera (chilca dulce). RIA. Rev. investig. agropecu. [online]. 2017, vol.43, n.2, pp.128-134. ISSN 1669-2314.

The encroachment of native or exotic woody species in rangelands results not only in cover changes of some species, but also in changes of the amount and availability of forages for livestock. Tessaria dodoneifolia (Hook. et Arn.) Cabrera (sweet chilca) is a native shrub species in Argentina, which in recent years has been mentioned as an invader of north-eastern Argentinean rangelands. The objectives of this research were to study in sweet chilca: 1) the efficacy of mechanical (shoot cutting up to 30 cm high) and chemical control treatments (picloram+triclopyr and picloram+2,4D) and the combination of both types of control, 2) the optimal control timing (onset o end of the weed season growth), 3) the optimum dose of picloram+2,4D on plants of different sizes, and 4) the emergence of new seedlings of sweet chilca one year after herbicide application. Chemical treatments alone or in combination with with mechanical control showed a very good control. Picloram+2,4D was the most effective treatment at applied at the beginning of active growth, while other treatments did not differ between application times. Sweet chilca plants did not survive the recommended dose for other shrub species. No differences in control on seedling establishment one year after herbicide application was observed.

Keywords : Herbicides; Optimal dose; Rangelands; Argentina.