The Role of Salicylic acid and Salinity of Irrigation Water on Growth and yield and Activity of Peroxidase, Catalase, Nitrate Reductase and Nitrates contents in Spinach (Spinacia oleracea L.)

Soil salinity reduces water availability of plant roots via negative (low) osmosis potential, as well as decrease of germination dynamics of plant seeds by ionic toxicity of Na and Cl, Significant differences in fruit-set, yield, photo synthetic rates, stomata conductance, total chlorophyll content, proline, In general, salinity affects almost every aspect of the physiology and biochemistry of plants. This experiment was conducted on a private farm in Babylon Governorate at the period from 1/10/ 2012 to 15/5/ 2013, to study effect of Salicylic acid application with three concentrations (0, 20 & 40 mg /liter ) and the quality of irrigation water in three levels ( 1.3 , 5 & 10) dS.m-1, Results showed that the Salicylic acid increased the plant tolerance of salt water stress significantly in the average of leaf area, total chlorophyll in the leaves, nitrate content of leaves, nitrate reductase of leaves, proline content, the water salinity increased electrical conductivity of the soil ,POX and CAT activity , Sodium and proline contents in leaves, resulting in decreased growth and leaf contents of NPK, The poultry and Salicylic acid applications was alleviated negative effects of saline water by increasing dry weights of shoots and NPK contents in leaves with a reduction of POX and CAT, reduction of sodium and proline contents in leaves.

Keywords:

Spinach , Oxidative stress , Salinity , Salicylic acid , POX , CAT , Nitrate reductase ,