Effect of Water Salinity on Germination of Different Crops in Arid and Semi-Arid Regions: Assessing Seed Tolerance to Irrigation Salinity

Water salinity is the most critical factor limiting the yield and production of different crops in arid and semi-arid areas. Salt tolerance during germination is generally reflected in further growth and salinization of soils by low water quality affects crop yield worldwide. This work tries to tackle different seed varieties against high salinity since its early ontogeny stages. The effect of various water salinity levels, 0.685, 1.89, 1.95, 2.33, 3.97, and 6.40 dS/m, on germination of tomato, squash, wheat, and barley, was investigated. As salinity indices, the following parameters were determined: EC, pH, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), sodium salinity potential (SSP), and potential salinity (PS). In addition, germination indexes were taken into account, such as the coefficient of velocity of germination (CVG), germination rate index (GRI), and mean germination time (MGT). Results showed that lower levels of salinity (0.685, 1.89 and 1.95 dS/m) improved the germination rates for all studied seeds without great affecting the percentages of increase when compared with the control (freshwater). The high salinity at 6.4 ds/m significantly reduced the germination attributes, particularly in the case of CVG, GRI, and MGT. A partial salinity tolerance was observed in squash and tomato. Most significantly, a negative correlation of the different germination attributes to a salinity of 3.97 dS/m was detected, indicating that such water was not suitable for irrigation, especially for tomato, wheat, squash, and barley. Conclusion: All the studied seedling attributes may serve as proper indicators for the evaluation of the suitability of saline water for irrigation purposes. The ascending order of saline water irrigation potential was arranged as follow: canal water (0.685) > 1.95 > 2.33 > 3.97 dS/m. Higher salinity is injurious in seedling was attained after 6.40 followed by 3.97 dS/m.