Growth Response in Spinach to Sequential and Simultaneous Exposure to NO2 and SO2

Abstract

Spinach (Spinacia oleracea L.) was exposed intermittently to NO2 and SO2 (2 hours/week; 0.8 or 1.5 ppm) in a simultaneous or sequential fashion over the 42-day growth period. Nighttime simultaneous exposure to NO2 and SO2 reduced growth and altered assimilate partitioning to the root. The relative growth rate of total plant and root was reduced significantly below controls early in the growth period. In contrast, neither daytime exposure to the pollutant mixture nor sequential exposure to the 2 pollutants affected growth.