Phytotoxic Effects of African Mahogany Seedlings to Herbicides

Abstract

The chemical control of weed is a common practice in silviculture. However, herbicides can potentially damage the main crop and affect its growth. The lack of information about certain species such as Khaya senegalensis make it necessary to know the phytotoxic effects of herbicides. The purpose of this research was to analyze the phytotoxic effects of five herbicides on African mahogany seedlings. The used herbicides were: saflufenacil, amicarbazone, clomazone, isoxaflutole and sulfentrazone, at doses recommended by the Ministry of Agriculture for forest species. Visual, physiological (maximum ETR, SPAD, Yield protocol and F V /F M) and morphological evaluations were performed up to 60 DAA. The symptoms started after 24 hours from the application; saflufenacil and clomazone were the ones that presented more plants with symptoms such as leaf wrinkling and small necrotic spots, but all of them had low phytotoxicity. The physiological evaluations did not present significant differences and the herbicides did not inhibit the growth or the appearance of new leaves. All tested herbicides caused no phytotoxicity to African mahogany seedlings.

Herbicides selectivity on seedlings of White Leadtree (Leucaena leucocephala)

“…In pre-emergence application of clomazone in forest species such as inga-bean (I. marginata), caroba (J. puberula), and guanandi (Calophyllum brasiliensis) (Cabral et al, 2017), and pendimethalin in carcuera (P. elegans), carobinha (J. micrantha) (Marchi et al, 2018), jatoba (H. stigonocarpa), annatto (B. orellana), and dry flour (A. hasslerii) (Marques et al, 2019), the authors did not find a reduction in plant height. In postemergence application of haloxyfop-methyl in aroeira seedlings (Duarte et al, 2006), sulfentrazone in African Herbicidas pós-emergentes mahogany (Paz et al, 2018), and flumioxazin and sulfentrazone in eucalyptus (Tiburcio et al, 2012), plant height did not decrease as well. These results corroborate with the phytotoxicity analysis, thus demonstrating that there was no negative influence on plant growth.…”