The effects of water stress on some compatible solutes including proline, soluble sugars and glycine betaine, the level of lipid peroxidation and membrane stability in two species of Sainfoin (Onobrychis radiate (Desf.) M.Bieb. and Onobrychis viciifolia Scop.) were investigated. The experimental plan was a basic factorial design, completely random with four replications and water stress was applied based on irrigation at 50, 60, 70 and 100% of Field Capacity (FC). Different physiological responses were observed between the species in their response to water stress. Our results showed that O. radiata possessed greater increments in soluble sugars content and glycine betaine than O. viciifolia. The Relative Water Content (RWC) in O. viciifolia was significantly lower comparing with O. radiate. The Relative Water Loss (RWL) of O. viciifolia had significantly decreased compared to control plants in all treatments and O. viciifolia was not able to withstand the 50% soil field capacity and dried out. Lipid peroxidation in O. radiata was lower than O. viciifolia and membrane of leaf cells in O. radiata was more oxidatively stable compared to O. viciifolia.

The current study was carried out to ditermine the effect of different levels of salicylic acid (SA) on yield and some physiological characteristics of sweet corn hybrids under water stress, using split plots in the base of randomized complete block design with three replications. Treatments were included water stress and salicylic acid both at three levels and three hybrids of sweet corn (pashen, basin and chalenjer) respectively as main plot, sub plot and sub sub plots. The results showed that the effects of water strees were significant on all traits. The effect of SA was significant on most traits except catalase including canned yield, forage fresh weight, forage dry weight, eair wet yield, 1000 seeds weight, a cholorophyll, b cholorophyll and peroxidase. The effect of hybrids were significant on canned yield, wet and dry forage yield and "a" chlorophyll content of leaf and were not significant on other traits. The interaction between water stress, salicylic acid and hybrids were significant on all traits. The maximum amount of canned yield, forage wet weight, weight of forage dry, fresh ear yield, were obtained  respectively 1455, 4541, 1123 and 2749.3 gr/m2 when the three following treatments, irrigation after drainage 50% available soil water, SA 0.5 ml molar and pashen hybrid were combined. In general the results showed that application of SA relatively reduced the negative effects of water deficit stress.