Cotton Yield Losses and Ambient Ozone Concentrations in California's San Joaquin Valley

摘要

Based on controlled experiments and simulation modeling, ozone air pollution has been estimated to cause significant yield losses to cotton. The study reported here was conducted to verify losses for Acala cotton (Gossypium hirsutum SJ2) along a gradient of ambient ozone (O3) concentrations across the San Joaquin Valley in California. Cotton was grown in nonfiltered (NF) and charcoal-filtered (CF) open-top chambers at four sites during the 1988-1989 summer growing seasons. Cotton yields were reduced in NF compared to CF air in general proportion to O3 concentrations across all sites and years. Greatest cotton yield losses were at Dinuba on the east side of the San Joaquin Valley and lowest were on the west side of the valley. Ozone injury symptoms on cotton were most noticeable in areas with greatest yield losses.