Control of Problematic Weeds in Mediterranean Vineyards with the Bioherbicide Pelargonic Acid

Abstract

[EN] Pelargonic acid (PA) is the only natural herbicide authorized for professional use in Spain. Incorporating PA into an integrated weed management strategy in vineyards may enable a more sustainable production method for grapes. In this work, PA of 55% concentration, formulated by a commercial company (PSEI), was evaluated and applied at 8, 10, 12, and 15 L/ha for weed control in Mediterranean vineyards during 2020 and 2021. A total of 22 different weed species, 16 dicotyledonous and 6 monocotyledonous, were identified in the experimental areas. Previously, greenhouse assays were performed against Avena fatua L. and Chenopodium album L. to determine the dose/response curves. PSEI proved to be a viable post-emergence herbicide with an efficacy of 40.79¿80.90%, depending on the applied dose (higher doses were the most effective). Broader herbicidal activity (20% or more) was obtained against dicotyledonous weeds compared with monocotyledonous. The PA formulation was remarkable in achieving PSEI-similar effects as compared to the market reference but at lower concentrations (around 13% less PA) and doses (1¿8 less L/ha). PA has proved to be a good candidate to control weeds in Mediterranean vineyards when used as a post-emergence broad-spectrum herbicide in the first stages of weed development.