Inherent responses to root-zone salinity in nine alfalfa populations

Steppuhn, H., Acharya, S. N., Iwaasa, A. D., Gruber, M. and Miller, D. R. 2012. Inherent responses to root-zone salinity in nine alfalfa populations. Can. J. Plant Sci. 92: 235–248. Alfalfa productivity can be enhanced by growing crops from cultivars tolerant of root-zone salinity. Rangelander, Keho, Bridgeview, Halo, CW054038, CW064027, Rugged, Bullseye and TS4002 alfalfa plants (respectively designated Ra, Ke, Br, Ha, C8, C7, Ru, Bu and T4) were grown in sand tanks irrigated with nutrient-sulphate solutions averaging 1.53 (nutrients only), 8.03 and 15.61 dS m−1 in electrical conductivity. Except for Br and C7, seedlings emerged equally under the 1.5 and 8.0 dS m−1 treatments, but decreased in the 15.6 dS m−1 treatment by percentages ranging from 3.1 through 29.5. Average shoot biomass among the populations respectively decreased by 49.6, 43.6 and 37.6% in the 1st, 1st+2nd, and 1st+2nd+3rd harvest-cuts as salinity increased from 1.5 to 8.0 dS m−1 and by 80.1, 73.2 and 67.1% from 1.5 to 15.6 dS m−1. At 1....