Low nicosulfuron and mesotrione rates influence on various crops

Abstract

Nicosulfuron as sulfonylurea and mesotrione as triketone are some of the most used herbicides for weed control in maize. The potential off-target movement and plant injuries of these herbicides were evaluated in a bioassay under controlled conditions. Both herbicides were applied in rates of 0.005X, 0.001X, 0.05X, 0.01X, 0.1X, 0.25X, 0.5X, 1X, 2X, and 4X, where X corresponds to 60 g ai ha-1, and 120 g ai ha-1 for nicosulfuron and mesotrione, respectively. Seven species were tested: lettuce, oil pumpkin, oilseed rape, paprika, soybean, sunflower, and tomato. After applications, plants were returned to the greenhouse and grown for more 21 days and following parameters were evaluated: visual injuries, leaf area, height, and dry biomass. All data were converted into a percentage of reduction compared to untreated control. The data were subjected to a non-linear regression analysis by four-parameter log-logistic model using R statistics. According to obtained results, rates of 0.03 and 0.06 X for nicosulfruon and mesotrione, respectively influenced all measured parameters. The most sensitive species to both herbicides was lettuce. The rates of 4.8 g and 6.1g of nicosulfruon reduced biomass by 80% in tomato and oil pumpkin, while 0.2 g and 0.9 g of mesotrione reduced biomass by 80%. Since our results have reported significant injuries following low herbicide rates, herbicide drift must be mitigated in order to prevent potential negative influence on the environment.