Turfgrass Responses and Rootzone Media Characteristics as Affected by Salinity

Abstract

Utilization of salt-tolerant species or cultivars is one the most effective methods to address salinity problems in turfgrass management. The relative salt tolerance in 26 commercial creeping bentgrass (Agrostis stolonifera) cultivars during germination was studied. Final germination rate (FGR) and daily germination rate (DGR) decreased as salinity levels increased; however, DGR was more sensitive to salinity stress. Substantial differences in salt tolerance were observed in bentgrass cultivars, with 'Declaration', 'Seaside II', 'T-1 ', and 'Bengal' being the most salt-tolerant (averaged predicted salinity level causing 50% reduction of DGR [PSLD] = 8.2 g L -1 NaCl) and 'Tyee', 'Kingpin'. and 'SRI 150' being the most salt-sensitive (averaged PLSD = 6.5 g L -1 NaCl). Relative salinity tolerance in four populations of prairie junegrass (Koeleriu macrantha) collected from Colorado, Minnesota, Nebraska, and North Dakota and two improved turf-type cultivars from Europe ('Barleria' and 'Barkoel') was determined and compared to Kentucky bluegrass (Poa pratensis), perennial ryegrass (Lolium perenne), sheep fescue (Festuca ovina), hard fescue (F. brevipila), and tall fescue (F. arundinacea). All populations of prairie junegrass showed similar salt tolerance with an average of PSLF and PSLD being 7.1 and 5.3 g L -1 NaCl, respectively, comparable to Kentucky bluegrass and hard and sheep fescue but lower than tall fescue and perennial rye grass. In junegrasses, larger variations were observed in visual quality (VQ) than in electrolyte leakage (EL) and dry weight (OW) at vegetative growth stage. 'Barleria' junegrass showed the highest VQ, following two salt-tolerant grasses, tall fescue and sheep fescue. Junegrass - Nebraska population was the least salt-tolerant within the species, but still exhibited similar or higher tolerance than Kentucky bluegrass and perennial ryegrass cv. Arctic Green. Overall, junegrass was more salt sensitive during germination but more tolerant to salinity when mature.