Relationship of leaf elongation rate of young wheat leaves, gross primary productivity and environmental variables in the field with hourly and daily temporal resolution

Plant growth is controlled by an interplay of internal and external factors. The production biomass via photosynthesis dependent on the plant response to environmental variables such as temperature, vapour pressure deficit light intensity. Short-term responses these at fine temporal scales hours are not well investigated, especially under field conditions. present study explores relationship between leaf elongation rate (LER) young wheat leaves in very high resolution (minutes). Turbulent fluxes CO2 were measured with eddy covariance technique used derive GPP, air soil short wave radiation simultaneously measured. analysis revealed importance different (hourly, daily). On hourly scale, GPP shortwave explain most variance LER, however a daily temperature main driver. A cross-correlation confirmed that strongest immediate can be found LER incoming radiation; determining photosynthesis. In principal, also shows same diurnal patterns lag behind LER. Multivariate models show combinations or perform best. These results indicate term processes mainly radiation, while magnitude temperature.