RESPONSE OF CORN TO COMBINATIONS OF ATRAZINE, PROPYL GALLATE AND OZONE

Growth chamber experiments were conducted to determine the influence of the air pollutant ozone (O3) [0.2 and 0.3 ppm (v/v)] on the growth of corn (Zea mays L.) treated with the herbicide atrazine (2.5 and 3.5 kg/ha) and the antioxidant propyl gallate (5 and 8 kg/ha). At both concentrations O3 at 0.3 ppm alone reduced dry weights of corn and chlorophyll. Chlorophyll a was more affected than chlorophyll b by O3 at 0.3 ppm alone and in combination with atrazine. Propyl gallate at both rates protected corn against O3 injury. The interaction between atrazine and O3 at 0.2 ppm was additive whereas at 0.3 ppm it was antagonistic. But combinations of atrazine and propyl gallate did not protect corn from O3 injury. © 1990.