Response of Chlorophyll, Relative Water Content and Protein Percentage of Safflower Leaves to Salinity and Foliar Calcium, Potassium and Magnesium Applications

To study the effect of Ca, K, and Mn foliar spray on chlorophyll and relative water contents of safflower (cv. Padideh) leaves under salinity condition a factorial experiment based on randomized complete block design with three replications was conducted at Vali-e-Asr University Greenhouse in 2011. Factors were salinity with four levels: 0, 500, 1000, and 1500 mg NaCl kg -1, and foliar spraying of plants with four levels: distilled water, 10 mM CaNo3, 10 mM K2HPO4 and 1 mM MnSo4. Spraying were applied two weeks after emergence and continued every 2 weeks. Results showed that 1500 mg NaCl reduced SPAD value, leaf chlorophyll fluorescence and relative water content. However, increasing salinity induced higher leaf water saturation. Foliar spraying of plants with MnSO4, K2HPO4 and CaNo3 nutrients, also reduced SPAD value. Foliar application of plants with Ca(NO3)2 increased leaf protein in 500 mg NaCl and without salinity. Application of MnSo4 increased chlorophyll b, a and also chlorophyll a (in 500 mg NaCl). Thus, in respect to the positive role of calcium and manganese in the production and preservation of chlorophyll and protein, foliar spray application can be a suitable strategy to reduce crop losses under salinity conditions.