Gauging Turfgrass Salinity Responses in Whole‐Plant Microculture and Solution Culture

Abstract

New methods for assessing salinity responses of turfgrass lines are required to identify selections for use on marginal sites. This study was conducted to quantify whole turfgrass plant responses to salt in solution‐culture and microculture test environments, and to evaluate the latter as an alternative system for identifying salt‐resistance characteristics. Paired cultivars of bermudagrass (Cynodon spp.), creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.) Farw. syn.] and St. Augustinegrass [Stenotaphrum secundatum (Walt.) p. Kuntze] were tested in treatments ranging from control (no supplemental salt) to 32.4 dS m−1 conductivity (NaCl in the growth medium). Direct comparison between test environments of the regression slopes for osmotic adjustment revealed no significant differences for bermudagrass, and salt‐sensitive cultivars of St. Augustinegrass and creeping bentgrass. Linear or quadratic regressions characterized reductions in all shoot growth parameters with increasing salt levels in both solution and microculture environments. More severe regressions were frequently observed for relatively salt‐sensitive cultivars. Root length and area data did not exhibit consistent regressions on medium conductivity level in either test system. These results demonstrate that the small‐scale microculture environment can be used to nonintrusively monitor turfgrass plant responses to salinity.