The Effects of Ozone on the Growth, Yield, and Partitioning of Dry Matter in Cotton

Abstract

Cotton (Gossypium hirsutum L.) Alcala SJ‐2 was grown in an activated carbon‐filtered greenhouse and exposed to biweekly 6‐hour ozone fumigations at a concentration of 490 µg m−3. Two ozone treatments were used, differing in age at initial exposure and total ozone dose. Sacrificial harvests were taken from all treatments at 14‐day intervals to monitor plant response and to provide the basis for growth analysis techniques.Ozone reduced the vegetative growth and boll production in both ozone treatments. The dry weights of all partitioned plant parts were reduced with the largest reductions occurring in roots and bolls. Fumigated plants initially produced fewer leaves with significantly less leaf area. A period of stimulated leaf and branch production followed the initial growth depression. Boll production was depressed 48% in both ozone treatments. Mean relative growth rates of partitioned plant parts were extremely good predictors of absolute responses. Mean net assimilation rates of ozone‐stressed plants were reduced throughout growth. The ozone‐treated plants were characterized by larger mean leaf area ratios, which accounted for elevated plant mean relative growth rates at 64 days of age.

Diel trends in stomatal response to ozone and water deficit: a unique relationship of midday values to growth and allometry in Pima cotton?

“…These observations are consistent with previous evidence in upland and Pima cottons (Oshima et al . ; Miller ; Temple et al . ; Temple ; Grantz & Yang ) and in other species (McLaughlin et al .…”

Effect of O3 on Hydraulic Architecture in Pima Cotton (Biomass Allocation and Water Transport Capacity of Roots and Shoots)

“…Numerous studies indicate that O, exposure of plants (McLaughlin and McConathy, 1983;Heggestad et al, 1988;Temple et al, 1988a;Heggestad and Lee, 1990;Kostka-Rick et al, 1993;Pell et al, 1994), specifically including upland cotton (Gossypium hirsutum L.; Oshima et al, 1979;Miller, 1988;Temple et al, 198813;Temple, 1990b), reduces plant size and commercial yield. Effects typically include reductions in leaf area, height, biomass production, and relative allocation of biomass below ground.…”

Effects of SO2 and O3 on Allocation of 14C-Labeled Photosynthate in Phaseolus vulgaris

“…'4CO2labeled plants but no There is good evidence that air pollutants may exert significant impacts on plant productivity by altering the partitioning of dry matter between plant parts (10,19,24,25). In addition to altered partitioning of carbohydrates between plant parts, the costs of repair from air pollution as well as disease-related stress may reduce carbohydrates available for growth by increasing the costs of repair of damage to cellular or metabolic systems (11).…”