Smog damage to cotton in the San Joaquin Valley

Abstract

Photochemical air pollution (smog) is harmful to California agriculture, as has been widely recognized since the 1940s, when growers in the Los Angeles Basin reported silvering, bronzing, and other discolorations on leafy crops such as lettuce, spinach, and Swiss chard. Severe smog injury on these crops rendered the produce unmarketable or greatly reduced its value.