Plant physiology data for the spring wheat cultivar Mulika, in response to combined ozone and drought exposure in 2015

Yield/Biomass data: This data was collected at the end of the experimental season, during August 2015. The total number of plants per pot was first counted, and all non-edge wheat plants were then cut at a level of 5cm above the soil surface. Ears were separated from the rest of the plant material, and ears were then threshed using a hand thresher to extract the wheat grains. Grain weight, ear weight and straw weight was measured before plant sampled were dried for one week in an oven at 65 degrees Celsius. Dry weight of all samples could then be measured. Data were recorded on paper data tables, and subsequently entered into Microsoft Excel. Calculation of particular harvest parameters (e.g. yield in kh/ha, harvest index) was conducted in Excel, and data was later exported as a comma separated value (csv) file for ingestion into the Environmental Information Data Centre. Calculation of certain harvest parameters (e.g. yield in kg/ha, harvest index) was carried out in Microsoft Excel following data entry.

Stomatal conductance data: This data was collected throughout the season, with measurements taken using an AP4 leaf porometer (Delta-T devices, Cambridge) over 9 separate days throughout the 2015 season. Measurements were intentionally made across a range of meteorological conditions to allow for model parameterisation at a later stage. Data were recorded on paper data tables and subsequently entered into Microsoft Excel. Each measurement of stomatal conductance was later paired with the concurrent temperature, vapour pressure deficit (VPD) and photosynthetically active radiation (PAR) as measured by on the solardome canopy computer automated monitoring system;. this data was downloaded from the computer system periodically throughout the season. The final data file was exported as a comma separated value (csv) file for ingestion into the Environmental Information Data Centre.

Chlorophyll content index data: This data was collected throughout the season, and measurements were made using a chlorophyll meter (CCM-200, Opti-sciences, Hudson, USA). Some measurements were made simultaneously with measurements of stomatal conductance, while others were not. Data were recorded on paper data tables and subsequently entered into Microsoft Excel. The final data table was later exported as a comma separated value (csv) file for ingestion into the Environmental Information Data Centre.

Growth stage assessment data: This data was collected on four days throughout the experiment: the 9th June, 30th June, 14th July and 27th July 2015. Growth stage assessment was carried out according to the decimal system described by Tottman (1987; The decimal code for the growth of cereals, with illustrations. Annals of Applied Biology 110, 441-454). Plants within each pot were examined and the maximum (i.e. most progressed) observed growth stage was recorded. Four pots per ozone and drought treatment were examined. Data were recorded on paper data tables and subsequently entered into Microsoft Excel. Data was exported as a comma separated values (csv) file for ingestion into the Environmental Information Data Centre.