Emergence, height, and yield of canola and barley grown in saline root zones

Abstract

The salinity tolerance of a crop relates to its inherent ability to yield economic product as root-zone salinity increases. Barley (Hordeum vulgare L.) ranks as one of the more salt-tolerant of the annual cereal grain crops, but producers seek a salt-resistant, non-cereal grain crop as an agronomic alternative for saline fields. Could canola (Brassica napus L.) serve as this alternative? Two greenhouse tests were conducted to determine the inherent crop responses of three canola cultivars (Quantum, Hyola 401, InVigor 2573) to saline rooting media compared with that of Harrington barley. These crops were grown in sand tanks flushed four times daily with solutions dominated either by chlorides with salt concentrations measuring from 1.4 to 32 dS m-1 or by sulphates from 1.6 to 27 dS m-1 . In the Cl-test, the rate of emergence and the emergence time of the Quantum plants lagged those for Hyola and Harrington. In the SO4-test, these measures for the InVigor plants equalled those for the Hyola, but lagged those for Harrington. Relative crop height at harvest did not differ among the test crops in either test. Crop grain yields relative to the salt-free production analysed by the modified-discount equation resulted in Cl-solution tolerance indices of 11.0, 14.3, and 12.6 for Harrington, Hyola, and Quantum and SO4-solution indices of 11.4, 15.6, and 16.7 for Harrington, Hyola, and InVigor, respectively. Covariance analyses based on paired t-tests confirmed the conclusion that the salinity tolerance of the canola cultivars equalled that of Harrington barley. Key words: Salt tolerance, salt resistance, salinity, canola, barley, abiotic crop-stress