Foliar potassium nitrate spray induces changes in potassium- sodium balance and biochemical mechanisms in olive (Olea europaea L. cv Chemlali) plants submitted to salt stress

Purpose: Nowadays with the precipitation scarcity induced by climate change, the use of non-conventional water resources in irrigation is needed such as saline water. The irrigation of salt tolerance species like olive could be adopted with potassium foliar spray. In this work we present how olive plants modulate sodium potassium balance and metabolism to mitigate salt stress. Research method: A pot experiment was conducted to assess how potassium nitrate modify Na/K ratio and biochemical compounds in olive plants. One-year-old olive plants (cv Chemlali) irrigated with a saline water (10g/L) were subjected to three treatments: K0, K1 and K2 (0, 1 and 2% of potassium nitrate foliar spray, respectively). Findings: Results showed differences between treatments. The mineral composition particularly the sodium and potassium content of leaves and roots revealed that the K1 and K2 treatments slightly increased K/Na in leaves and decreased in roots. Moreover, the salt stress was moderate through the osmotic adjustment. The accumulation of osmolytes (proline and soluble sugars) decreased by k1 and K2 treatments. Secondry metabolites (phenols) showed an increase by K1 and K2. Lipid peroxydation was also reduced by treatments especially in young leaves and then increased. In conclusion, potassium can be recommended in order to mitigate the harmful effects of salinity. Research limitations: No limitations were founded. Originality/Value: In the condition of current water scarcity the saline water could be used with potassium application.