Chlorophyll fluorescence in guanandi tree (Calophyllum brasiliense) after herbicide application

Abstract

-Chlorophyll fluorescence is currently used as a rapid diagnostic and nondestructive method to detect and quantify damage on the photosynthetic apparatus of leaves on weeds, crops and ornamental/coniferous trees in response to both environmental stress and herbicides. This study aimed to evaluate chlorophyll fluorescence in guanandi plants (Calophyllum brasiliense) after application of different postemergence herbicides. The experiment was performed in a completely randomized design, with six treatments (control, bentazon, sulfentrazone, isoxaflutole, atrazine and glyphosate) and five replications. The herbicide treatments were applied with a stationary sprayer, and electron transport rate (ETR) was subsequently analyzed with OS5p Multi-Mode Chlorophyll Fluorometer. In the monitored period, guanandi plants subjected to atrazine showed higher sensitivity to chlorophyll fluorescence than the other treatments. Although bentazon is a photosystem II inhibitor, it showed no major changes in electron transport for the studied species and in the monitored period. In summary, ETR is a good parameter to evaluate the effect of some herbicides on Calophyllum brasiliense plants.Keywords: electron transport rate, bentazon, sulfentrazone, isoxaflutole, atrazine, glyphosate. RESUMO -A fluorescência da clorofila tem sido utilizada como um método diagnóstico rápido e não destrutivo para detectar e quantificar danos no aparato fotossintético das folhas em plantas daninhas

Ammonium Glufosinate Associated with Post-Emergence Herbicides in Corn with the cp4-epsps and Pat Genes

“…In the experiments conducted in Botucatu and São Manoel (Figure 3), ETR was significantly affected by the association of ammonium glufosinate + bentazon (9) 3 h after application, differing significantly from the other treatments. The herbicide bentazon inhibits the transport of electrons in photosystem II (Nimbal et al, 1996), leading to a rapid decrease in ETR, which is also reported in other species (Macedo et al, 2008;Araldi et al 2015). A rapid recovery in ETR levels was observed in this association (ammonium glufosinate + bentazon) and, at 1 DAA, these levels were close to the other treatments ( Figure 3B) since the herbicide bentazon did not cause a substantial damage to thylakoids (Macedo et al, 2008) and the PAT enzyme rapidly degraded the ammonium glufosinate.…”

Phytotoxic Effects of African Mahogany Seedlings to Herbicides

“…As for the species K. senegalensis, the herbicide was not considered phytotoxic, and did not differ from the control treatment in any of the analyzed variables. Araldi et al (2015) evaluated the effect of isoxaflutole and sulfentrazone In Guanandi seedlings and reported a 25% reduction in ETR 48 hours after the application of isoxaflutole. That result differed from the present study, where no significant differences were detected with the use of this herbicide.…”

Effect of pre-emergent graminicide herbicides on germination and early development of native species

“…Aiming to improve weed control methods in reforestation, herbicides selective for some agricultural crops have been used empirically (Araldi et al, 2015). Notwithstanding, the impacts of these herbicides on the diversity of the native plant community have been demonstrated in only a limited number of studies and therefore deserve more attention on risk assessment (Boutin et al, 2012).…”