Publications by authors named "K Sharps"

Air quality negatively impacts agriculture, reducing the yield of staple food crops. While measured data on African ground-level ozone levels are scarce, experimental studies demonstrate the damaging impact of ozone on crops. Common beans (Phaseolus vulgaris), an ozone-sensitive crop, are widely grown in Uganda.

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We assess wheat yield losses occurring due to ozone pollution in India and its economic burden on producers, consumers, and the government. Applying an ozone flux-based risk assessment, we show that ambient ozone levels caused a mean 14.18% reduction in wheat yields during 2008 to 2012.

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Tropospheric ozone can have a detrimental effect on vegetation, including reducing the quantity of crop yield. This study uses modelled ozone flux values (PODIAM; phytotoxic ozone dose above 3 nmol m s, parameterised for integrated assessment modelling) for 2015, together with species-specific flux-effect relationships, spatial data on production and growing season dates to quantify the impact of ozone on the production of common wheat (Triticum aestivum) and common beans (Phaseolus vulgaris) across Sub-Saharan Africa (SSA). A case study for South Africa was also done using detailed data per province.

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The sensitivity of photosynthesis to temperature has been identified as a key uncertainty for projecting the magnitude of the terrestrial carbon cycle response to future climate change. Although thermal acclimation of photosynthesis under rising temperature has been reported in many tree species, whether tropospheric ozone (O ) affects the acclimation capacity remains unknown. In this study, temperature responses of photosynthesis (light-saturated rate of photosynthesis (A ), maximum rates of RuBP carboxylation (V ), and electron transport (J ) and dark respiration (R ) of Populus tremula exposed to ambient O (AO , maximum of 30 ppb) or elevated O (EO , maximum of 110 ppb) and ambient or elevated temperature (ambient +5°C) were investigated in solardomes.

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Tropospheric (ground-level) ozone is a harmful phytotoxic pollutant, and can have a negative impact on crop yield and quality in sensitive species. Ozone can also induce visible symptoms on leaves, appearing as tiny spots (stipples) between the veins on the upper leaf surface. There is little measured data on ozone concentrations in Africa and it can be labour-intensive and expensive to determine the direct impact of ozone on crop yield in the field.

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