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Herbicide promotes physiological and biochemical changes even in tolerant species. The objective of this study was to evaluate the interference of the herbicides clodinafop-propargyl and 2,4-D in the antioxidant system of wheat, and iodosulfuron-methyl in wheat and ryegrass. Two studies, divided into three experiments, were conducted in an entirely randomized design in a greenhouse and phytotron. The first study tested herbicides iodosulfuron-methyl, clodinafop-propargyl, 2,4-D, and a control without application in wheat. The second, divided into two experiments with wheat and ryegrass, tested iodosulfuron-methyl doses (0, 1.75, 3.5, and 7.0 g a.i. ha-1). The variables analyzed were the concentrations of chlorophylls a, b, carotenoids, hydrogen peroxide (H2O2), lipid peroxidation (TBARS), electrolyte leakage, and antioxidant system activity. The herbicide treatments iodosulfuron-methyl, clodinafop-propargyl, and 2,4-D decreased the concentrations of chlorophylls and carotenoids in wheat plants. The herbicides promoted oxidative stress with increased H2O2 and TBARS concentrations. Increasing the dose of iodosulfuron-methyl provided a reduction in the activity of the enzymatic antioxidant system in wheat and ryegrass. [ABSTRACT FROM AUTHOR]

Fast perishability of dragon fruit requires that strategies be adopted to extend its post-harvest shelf life, in order to reduce losses, maintain quality and increase the financial return of economic activity. The objective of this work was to evaluate the effect of storage conditions in combination with the application of 1-methylcyclopropene (1-MCP) on the quality maintenance of red dragon fruit. The treatments evaluated were cold storage (CS; 21 kPa O2 + 0.03 kPa CO2), controlled atmosphere (CA; 2 kPa O2 + 5 kPa CO2) and modified atmosphere (MA; 40 µm thick low-density polyethylene bags) combined or not with the application of 1-MCP (300 nL.L-1), with four replications per treatment. The fruits of all treatments were stored for 20 days at 13 ± 2°C and relative humidity (RH) of 90 ± 5%, followed by 3 days of exposure at ambient conditions (20 ± 3°C and RH of 70 ± 5%). After the shelf life, CA and MA maintained fruits with a higher hue angle. The treatment of 1-MPC added to CA and MA provided greater force for pulp penetration. CS, AC and MA, added to the treatment with 1-MCP, are promising technologies to be used in the storage of dragon fruit. [ABSTRACT FROM AUTHOR]