Leaf-to-air vapor pressure deficit differently affects barley depending on soil water availability

Abstract

Plant response to drought may be altered by the variation in air temperature and humidity and these interactions may be more frequent and intense with expected climate changes. The study examines impact of temporal changes in air temperature and air humidity on spring barley grown in dry and wet soil.The impact of two hours long changes in air temperature and relative humidity (RH) was evaluated on spring barley grown in soil of optimum and limited soil water availability. The alterations in stomatal conductance, transpiration photosynthesis, leaf temperature in response of air humidity and air temperature were analyzed.Air RH strongly differentiated leaf stomatal conductance in plants grown in well-watered soil. Despite the low impact of air RH on leaf conductance in plants grown in dry soil, a significant decline in transpiration with an increase in air RH occurred. The increase in air RH induced significant increase in leaf temperature in well-watered plants. Changes in leaf vapor pressure deficit (LVPD) differently affected stomatal conductance (gH2O) in plants grown in soil with optimum and limited water availability.Temporal changes in air humidity and temperature differently affected barley grown under optimum and limited water availability.