Extrato pirolenhoso na redução de doses de 2,4-d e picloram no controle de Senna obtusifolia

Abstract

The aim of this study was to evaluate the reduction in doses of 2,4-D and picloram using pyroligneous extract and mineral oil adjuvant to control Senna obtusifolia. The experiment was carried out in a greenhouse at the Campus of Engineering and Agrarian Sciences of the Federal University of Alagoas. The statistical design adopted was entirely randomized in a 2x4 factorial scheme, with four pyroligneous extractions. The treatments consisted of a combination of two types of adjuvant (with and without mineral oil) and four mixtures of herbicide and pyroligneous extract (no herbicide, 0.5 L ha-1 of herbicide + 1 L of pyroligneous extract, 1 L ha-1 of herbicide + 0.5 L of pyroligneous extract and 1.5 L ha-1 of herbicide). The data obtained was submitted to analysis of variance and the means were compared using the Tukey test at 5% probability. It was found that the mean relative dry mass (%) and phytointoxication of the 1 L dose of 2.4-D and Picloram with 0.5 L of pyroligneous extract did not differ significantly from the commercial dose (1.5 L of 2.4-D and Picloram), in both treatments with and without mineral oil. In this way, similar to phytointoxication, reducing the herbicide mixture by 0.5L with the addition of 0.5L of pyroligneous extract can be effective in controlling Senna obtusifolia. The reduction of 0.5 L of the herbicide based on 2.4-D and Picloram, with the addition of the pyroligneous extract showed efficiency equal to the commercial dose.