Origin of Bel-W3, Bel-C and Bel-B tobacco varieties and their use as indicators of ozone.

Since 1962, the tobacco variety Bel-W3 (Nicotiana tabacum L.), has been used in many countries as an indicator of the presence of phytotoxic concentrations of O(3). It is super-sensitive to O(3) and may produce easily recognizable symptoms for several weeks on the new, fully expanded leaves.

Soybean root distribution, top growth and yield responses to ambient ozone and soil moisture stress when grown in soil columns in greenhouses.

Soybeans (Glycine max. cv. Williams) were grown to maturity in soil columns within polyvinyl pipe and placed in greenhouses with charcoal filtered (CF) and nonfiltered (NF) air.

Effects of ozone and soil water deficit on roots and shoots of field-grown soybeans.

Water-stressed and well-watered soybean (Glycine max cvs. Williams and Corsoy) plants were exposed to increasing seasonal doses of ozone (O(3)) using open-top field chambers and ambient air plots. Chamber O(3) treatments included charcoal filtered (CF) air, non-filtered (NF) air, NF + 0.

Photochemical oxidants potentiate yield losses in snap beans attributable to sulfur dioxide.

Field-grown snap beans (Phaseolus vulgaris) were given recurring midday exposures to sulfur dioxide in open-top field chambers containing ambient photochemical oxidants. There was a linear correlation (correlation coefficient = -.99) between increasing concentrations of sulfur dioxide and the yields of snap beans.