Growth Performance of Canola Grown Under Different Salinity Regimes

The comparative effects of different concentrations of saline soil and saline irrigation water were investigated on growth of canola (cv. Ganyou-5). Plants were subjected to control (non-saline), 0.2% (EC 2.5 dS.m-1), 0.4% (EC 4.5 dS.m-1) and 0.6% (EC 6.5 dS.m-1) of sea salt concentrations in soil as well as saline irrigation water. Vegetative growth parameters recorded were plant height, number of leaves and branches, fresh and dry shoot biomass, while yield components were recorded in terms of number of flowers and siliquae per plant, siliquae weight, seed number and weight per siliquae. The mean seed number and seed weight per plant were also calculated. We found that vegetative and reproductive phases of plant growth were proportionately inhibited in response to an increase in salinity in both irrigation water and soil as well. Plant yield in terms of seed weight per plant showed 86.3% reduction, when irrigated with sea salt of 0.6% dilution, while the same variety showed 34.8% reduction in soil having 0.6% of sea salt dilution. Chlorophyll “a”, “b” and total chlorophyll decreased in high salinity (0.6%) in both saline conditions. Total sugar in leaves showed increase in saline medium as compared to control when plants were irrigated with different saline solutions while showed decrease under high salinity level as compared to control when plants grown under saline soil. Protein content in leaves showed increase in high saline medium when compared with control under both salinity conditions. Plants grown in normal soil and irrigated with saline water and those grown in saline soil exhibited increase in Na+ concentration and decrease in K+ concentration in all plant parts at all salinity levels. Na+ concentration was higher in leaves at higher salinity level as compared to other plant parts, while maximum reduction in K+ concentration was observed in root at 0.6% salinity level. K+/Na+ ratio decreased in saline medium in different plant parts. Keywords— Saline soil, vegetative growth, Canola, reproductive growth, saline irrigation water, ions.