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Although Russian wild ryegrass (Psathyrostachys juncea) is recommended for saline lands, adequate plant stands can be difficult to establish. 'Swift' and 'Tetracan' are two varieties specifically bred for easy establishment. Plants from each variety were tested for their inherent ability to emerge and survive in saline seedbeds maintained at solution electrical conductivities of 2, 10, 20, 30, 40, and 50 dS/m. Canada's Salt Tolerance Testing Facility provided the necessary controls for the tests. By applying the Gompertz function in a non-linear regression fit to the test results, three equation parameters, four derived indices, and a related variable could be evaluated in comparing the two wildrye varieties. The best statistically discriminating indices for between 'Swift' and 'Tetracan' were the rate of emergence and survival at the Gompertz inflection, the asymptotic maximum attained in each test (Emax), the time to reach 0.99Emax, the emergence occurring at the Gompertz inflection point, the Gompertz shape parameter, and the Gompertz time constant. They indicated that 'Tetracan' plants emerging from very severely, severely, and moderately saline seedbeds showed better salinity tolerance than 'Swift' wildrye plants.
H. Sleppuhn. H. Wang and Y. Gan 1998. EVALUATING RUSSIAN WILD RYEGRASS EMERGENCE FROM SALINE SEEDBEDS USING THE GOMPERTZ FUNCTION. Canadian Agricultural Engineering 40(4):241-247.
Canadian Society for Bioengineering