Responses of Cool-Season Turfgrasses to Salt and Drought Stresses In the Intermountain West.

Salinity and drought both cause desiccation stress in plants, therefore various species may have mechanisms in common to cope with both stresses. The objectives of this investigation was to study responses of two cool-season turfgrasses under salt and drought stress and to determine whether salt and drought tolerant species have similar tolerance mechanisms. In the salinity stress experiment, seedlings of three Kentucky bluegrass (KBG) (Poa pratensis L.)(‘Midnight’, accessions ‘S-107’ and ‘67-126’) and one tall fescue (TF) [Schedonorus phoenix (Scop.) Holub] (‘Matador’) were subjected to 0, 6, 12, 18, and 30 dS/m for 2 weeks. In a separate drought stress experiment, seedlings were subjected to—well-watered conditions and a gradual dry down. Turf quality, stomatal conductance, xylem water potential, and photosynthesis rate were measured in both experiments. Based on turf quality, shoot and root dry weight, and stomatal conductance, ‘67-126’KBG was more susceptible to salt, while TF and ‘S-107’ and ‘Midnight’ KBG were clearly more salt tolerant. The water potential of ‘67-126’KBG did not decrease even at high salt concentrations, making it difficult to absorb water from the soil and resulting plant death. In the drought experiment, KBG maintained turf quality longer than TF during the dry-down treatment. TF also used the most water based on measurements of volumetric water content.  Among KBG varieties, ‘67-126’ extracted water from the soil faster than ‘S-107’ and ‘Midnight’. In conclusion, ‘67-126’KBG was the least salinity tolerant entry but exhibited drought tolerance while ‘S-107’ and ‘Midnight’ KBG were both salt and drought tolerant based on turf quality and water potential. TF was salt tolerant but the least drought tolerant in our study.