Changes in Photosynthesis and Oxidative Stress in Wheat Plants Submmited to Herbicides Application

Abstract

-The use of herbicides, even in tolerant crops, can cause stress evidenced by increase phytotoxicity affecting growth and development. The objectives of this study were to evaluate herbicides effect from different mechanisms of action in photosynthetic and oxidative stress parameters, as well visual phytotoxicity and wild radish control in wheat crop, cultivar Quartzo. Two trials were conducted where the first one evaluated the photosynthetic parameters on wheat plants in two seasons collection, following the application of herbicides bentazon, clodinafop, iodosulfuron, metribuzin, metsulfuron and 2,4-D; and the second one evaluated wild radish (Raphanus sativus) control, wheat phytotoxicity and yield due to bentazon, iodosulfuron, metribuzin, metsulfuron and 2,4-D herbicides application. Photosynthetic rate, stomatal conductance and transpiration were negatively affected by metribuzin, metsulfuron and 2,4-D herbicides at 24 and 120 HAS (hours after spraying) compared to control. Oxidative stress was similar or lower to control, when herbicide was applied and, in general, there was no difference between application times. Lipid peroxidation, catalase activity and phenols were higher in the first collection time. The application of herbicides iodosulfuron and 2,4-D reduces chlorophylls and carotenoids in wheat. Herbicides bentazon, iodosulfuron, metribuzin, metsulfuron and 2,4-D are selective to wheat, cultivar Quartzo and do not affect wheat yield. 2,4-D, metribuzin and iodosulfuron are more efficient for wild radish control. Keywords

Differential Tolerance of Clones of Eucalyptus grandis Exposed to Drift of the Herbicides Carfentrazone-Ethyl and Glyphosate

“…photosynthetic rate, as observed in our study, has also been reported in the literature on plant species exposed to glyphosate (Ding et al, 2011;Yanniccari et al, 2012;Agostinetto et al, 2016;Gomes et al, 2016;Radwan and Fayez, 2016). Means ± standard error of the mean followed by the same uppercase letters in the columns and lowercase letters in the rows do not differ significantly from each other by the Tukey's test (p≤0.05).…”

Effect of herbicides in the oxidative stress in crop winter species

“…Lipid peroxidation shows no difference between herbicides. MDA accumulation in absolute values was observed in the treatments with metsulfuron and 2,4-D (Agostinetto et al 2016).…”

“…CAT has one of the highest turnover rates for all enzymes: one molecule of CAT can convert 6 million molecules of H 2 O 2 to H 2 O and O 2 per minute. CAT is important in the removal of H 2 O 2 generated in peroxisomes by oxidases involved in β-oxidation of fatty acids, photorespiration and purine (Agostinetto et al 2016). After fomesafen exposure, outcomes show a decrease in the CAT enzyme activity, which directly related to the increase in the lipid peroxidation.…”

Seed Pre-Treatment and Planting Geometry Positively Influence Herbicide Efficacy in Wheat (Triticum aestivum)

“…Chemical means are used to control weeds as they allow quick, easy and economical solutions to a number of weed problems (Lagator, 2013). The efficacy of different herbicides varies according to crop management practices, and there is often a dose-dependent response of herbicides under varying agro-management practices (Agostinetto et al, 2016;Singh et al, 2016). Pyroxsulam (PALLAS TM 45 OD, Dow AgroSciences LLC.)…”