Consideration of the relative water content in the leaves is probably the most appropriate measure of plant water status for the physiological consequences of cellular water deficit. As shown in Table 2, PBZ kept relative leaf water content higher than the non-treated plants when subjected to water stress for 30 days. This is in agreement with the findings of Jungklang and Saengnil (2012) who reported that PBZ had the ability to maintain leaf water content for 30–40 days of water-deficit stress. In many plant species, relative water content in the leaves ranged from between 88% and 95% in fully turgid transpiring leaves and to about 30–40% in severely desiccated and dying leaves, depending on the species (Trouhton, 1969, Gonzalez and Gonzalez-Vilar, 2001 and Schlemmer et al., 2005). In most crop species, typical leaf RWC at around the initial wilting is at about 60–70%. PBZ kept water turgidity in our leaves during drought stress conditions and indicates that this substance enhances cell turgidity.