Chemical control of species of the genus Commelina

Abstract

The objective of this work was to evaluate the control of the species Commelina benghalensis and Commelina diffusa, using post-emergent herbicides, applied separately and in mixture. Two experiments (EI and EII) were conducted, both in replicate. In the experiments, two species of Commelina were evaluated, with different number of leaves, being from 4 to 6 (EI) and from 6 to 10 leaves (EII), containing 27 treatments with post-emergent herbicides, namely: glyphosate, 2, 4-D, triclopyr, dicamba, carfentrazone, saflufenacil, flumioxazin, chlorimuron, chloransulam and diclosulam+halauxifen, applied alone or in mixture. Visual analysis of control and transient fluorescence of chlorophyll a were performed at 21 and 42 days after application (DAA), at 42 DAA plants were collected to obtain the dry mass of shoots. Data were submitted to ANOVA (p≤0.05) and compared using the Skott-Knott test. The evaluated triple mixtures were efficient in controlling both species. The triple mixtures that contained carfentrazone promoted effective and faster control when compared to the mixtures with saflufenacil and flumioxazin. Triclopyr promoted faster control for both species when compared to other auxinics. The two species respond differently to auxinic herbicides and are more difficult to control at the 6 to 10 leaf stage.