Morphophysiological and Biochemical Responses of Peltophorum Dubium Under Glyphosate Drift

The object of this research was to determine the sensitivity and bioindicator potential of the plant species Peltophorum dubium to glyphosate drift contamination by monitoring the effects of this herbicide in forests adjoining agricultural areas where it was applied. Sub dose glyphosate concentrations of 2%, 4%, 8%, 16%, and 32% of the recommended commercial dose of 1440 g ha^-1 in simulated drift exposure tests revealed P. dubium intoxication to be very low (<4%) at doses lower than 115.2 g ha^-1 and reached 40% when exposed to 460.8 g ha^-1. In plants exposed to a dose of 460.8 g ha^-1 there was a reduction in photosynthetic rate, transpiration, and stomatal conductance of 22.7%, 18.1%, and 33%, respectively, contrasted to the control dose. The morphophysiological responses of P. dubium indicate low sensitivity to glyphosate drift at lower exposure doses as well as the species’ survival capacity in areas contaminated by this herbicide.

Keywords:
leaves; stomatal conductance; underdose; aerial part; root; bioindicator