Salt Tolerance of Some Potential Low-Input Turfgrass Species.

Demand is increasing for grasses which can maintain ground cover with minimal fertilizer, irrigation, or mowing. Species best suited to these low-input uses have received relatively little attention as they lack the growth potential needed for forage grasses and the traffic tolerance and mowing quality desired in high-input turf. As part of a project to identify grasses for use on roadsides in New England PI accessions and breeding lines of red fescue, sheeps fescue, koeleria, and deschampsia were screened for salt tolerance under greenhouse conditions. A total of 59 Deschampsia cespitosa accessions, 59 Festuca accessions from the ovina group, 111 Festuca rubra accessions, and 74 Koeleria macrantha accessions have been screened. Plants were grown in sand-filled pots in an ebb-and-flow hydroponics system filled with half-strength Hoagland’s solution supplemented with sodium chloride. Salt levels were increased by 2500 ppm every two weeks to a maximum of 22,500 ppm. Data was collected every two weeks using digital imaging; plant health was evaluated by comparing the percent green pixels in treated pots relative to the control pots of the same accession. Tolerance was determined at two points, the LD50 when coverage dropped below 50% and the LD90 when coverage dropped below 10%. Salt tolerance levels (LD50) in Festuca rubra ranged from 5,000 ppm to 22,500 ppm. For the ovina group the tolerance levels ranged from 7,500 ppm to 12,500 ppm. Tolerance levels in Deschampsia cespitosa exceeded 20,000 ppm for a number of accessions. As a species Koeleria macrantha was the least tolerant with LD50 values ranging from 6,000 ppm to 9,000 ppm.