Respostas do mogno africano a herbicidas fotodependentes

Abstract

African mahogany is a forest species that was introduced in Brazil in an attempt to replace the Amazonian mahogany, and because of its great acceptance in the market, is attracting more and more the interest of the Brazilian producers, but due to the recent introduction there are not many studies on the behavior of the mahogany. In response to the use of herbicides for this reason the main objective of this research was to analyse the selectivity of five herbicides in African mahogany seedlings, through visual, morphological and physiological evaluations. The herbicides used were saflufenacil, amicarbazone, clomazone, isoxaflutole and sulfentrazone at the maximum dosages recommended by AGROFIT. Visual, physiological (maximum ETR, SPAD, Yield and FV / FM protocol) and morphological (height, volume, number of leaves, leaf area and dry weight of shoot) measurements were performed up to 60 days after application (DAA). The experiment was assembled in Causalized Block Design and the averages were tested by the Tukey test at 5% with the aid of Assistat 7.7. After 24 hours of application the visuals symptoms began to occur; the herbicides saflufenacil and clomazone were the ones that presented more plants with symptoms, but all with light phytotoxicity and there was no difference between the treatments, the physiological evaluations didn't present significant difference and the herbicides didn’t inhibit the growth or issuing new sheets. All herbicides were tested and considered selective to African mahogany.