Effectiveness of glycinebetaine foliar application in relieving salt stress symptoms in two turf-grasses

Salinity is one of the problems that has to be dealt with in turf-grass management, due both to restrictions in freshwater use for landscape irrigation and exposition to salt stress in coastal areas. This has led to the need to select salinity tolerant genotypes and test management practices, such as the application of osmoprotectants, in order to maintain turf quality at acceptable costs. We compared the effects of irrigation with 600 mM NaCl and glycinebetaine (GB) application for 8 weeks on pot-grown weeping alkaligrass (Puccinellia distans (L.) Parl.) and tall fescue (Festuca arundinacea Schreb.). We selected two easily assessable parameters, total clippings fresh weight and chlorophyll content, to evaluate the response to different treatments. Leaf sap solute potential was measured to estimate the effect of treatments on osmoregulation. Salinity treatment resulted in a 70% reduction in total clippings fresh weight in weeping alkaligrass, while the reduction was only 20% in tall fescue. GB treatment had no effect on salt-stressed plants of weeping alkaligrass, while in tall fescue total clippings fresh weight was the same as that of the control. We conclude that in our experimental conditions, weeping alkaligrass was more sensitive to salinity than tall fescue and that foliar application of GB relieved salt stress symptoms in tall fescue, but had no significant effect on weeping alkaligrass.