Ozone injury to Bel W3 tobacco and pinto bean plants increases with increasing humidity. The degree of plant injury sustained correlates well with porometer measurements; this indicates that the size of stomatal apertures increases with increasing humidity. Humidity may therefore influence plant response to all pollutants and may account in part for the greater sensitivity of plants to ozone-type injury in the eastern United States compared with the same species of plants grown in the Southwest. with those grown in the Southwest.

No abstract

Marked differential injury by air pollution to a group of sweet corn hybrids in 2 experimental field plantings in the Los Angeles Basin occurred in 1969. At Riverside, leaf damage ranged from nearly zero in 11 hybrids to slight to severe in 23 others. Damage was clearly related to cultivar and was associated with periods of high oxidant levels and high maximum temperatures. There was only a slight relationship between the market maturity date of a cultivar and its degree of damage.

No abstract