The Effect of Salinity Levels of irrigation water and Mechanical Damage of Seeds on the Germination and Growth Characteristics of Seedlings of Two Varieties of Bread Wheat ) Triticum aestivum L.(

"A factorial experiment with completely randomized design (CRD)with three replicates was carried out at agronomy laboratory of the Directorate of seed testing and certification / Branch of Salahaldeen to study the effect of salinity levels of irrigation water )0 ،1.75 and 2 Mm ) and grains affected by the use of mechanical seeds in seed germination and seedling growth for two varieties of wheat bread(IPA99 and Sham 6). The characteristics of germination percentage ،speed germination ،length of plumule and radical ،pure live seed percentage and seed vigor studied. The observed results are as follows: Significant differences are found between cultivars. (IPA99) cultivar gave the highest tolerance to water salinity and seed fracture. However ،salinity levels and seed fracture caused a significant decrease in all features. As for interactions ،cultivars and seed mechanical damage interactions were significant in all characteristics. While the interactions of varieties and levels of salinity were significant in the characteristics of the speed of germination and length of plumule . Interactions of salinity levels and seed mechanical damage did not reach the significant limit except for the characteristic of the plumule’s length, which reached the highest value at 7.697 cm . At the same time, the triple interactions (cultivars ،seed mechanical damage and levels of salinity) were significant except for both germination percentage and pure live seed percentage. The best triple interaction was (IPA99) with 1.75 Mm and undamaged seed, which gave the best values in: germination percentage ،length of plumule and radical ،pure live seed percentage and seed vigor. The values of the above were as follows: 98.67% ،8.707 cm ،10.01 cm ،94.72 ،18.45 respectively."