Impacts of ozone on agricultural crops in southern Africa : commentary

The potential for ozone (O3) damage to agricultural crops, trees and native plants is well documented in literature. O3 has been shown to cause a wide variety of effects to important agricultural crops including visible leaf injury, growth and yield reductions, as well as deteriorating nutritional quality in certain crops. O3-induced damage is especially an issue of concern if it threatens food supply and the economies of countries that are based strongly on agricultural production. With the availability of global chemistry transport models, global and regional estimates of crop losses can be obtained (Van Dingenen, 2009; Avnery et al., 2011; Wang and Mauzerall, 2004). Present day global relative yield losses due to O3 damage are estimated to range between 7% and 12% for wheat, 6% and 16% for soybean, 3% and 4% for rice and 3% and 5% for maize (Van Dingenen, 2009). In India it was calculated that O3 damage to wheat and rice resulted in a nationally aggregated yield loss of 9.2%, that is sufficient to feed 94 million people living below the poverty line in that country (Ghude et al., 2014).