Abstract:
Fertilizer induced salinity adversely affects plant growth through its ionic and osmotic effects as in ordinary
salinity caused by toxic ions (Na, Cl, etc.). In this study, to determine the ionic and osmotic effects of fertilizer
induced salinity and NaCl salinity on growth, ascorbic acid, proline and hydrogen peroxide (H2O2) accumulation
and stomatal resistance (SR), relative water content (RWC), malondialdehyde (MDA) contents of tomato and
pepper plants subjected to different treatments (i.e. control, 40 mM NaCl salinity and excess fertilizer salinity)
were investigated under greenhouse condition. The results of this study indicated that similar to NaCl salinity,
fertilizer induced salinity significantly reduced the fresh and dry weights of tomato and pepper plants. Relative
water content of the plants was decreased by NaCl salinity. Both NaCl and fertilizer induced salinity caused
significant increases in proline, MDA, ascorbic acid and H2O2 accumulation, and stomatal resistance of the
plants. Salinity achieved by NaCl and fertilizer altered plant growth and plant physiological processes ionically
and osmotically in a similar manner.
