Growth and Some Metabolic Changes in Maize Leaves as Affected By Saline-Alkaline Conditions Due to Sodium Carbonate and Sodium Bicarbonate

Summary Effect of equal concentrations of NaC₂O₃ and NaHCO₂ (3, 6 and 9 mmhos/cm) were studied, in sand culture, on growth and some metabolites in leaves of maize (Zea mays L.) cv. Vijay Composite at 30 and 60 days after sowing. Both the salts decreased length and weight of shoot and root; NaHCO₃ being more depressive than Na₂CO₃ at 30 days of growth and Na₂CO₃ becoming equally or more depressive than NaHCO₃ at 60 days sampling. Salt treatments reduced the contents of chlorophyll, RNA, DNA, protein and free amino acids significantly. The reduction was more under NaHCO₃ in comparison with Na₂CO₃ during early growth but later on their effects were comparable. No proline accummulated under salt stress due to Na₂CO₃ and NaHCO₃. The results have been discussed in the light of the published literature with special reference to specific! on effects. It has been suggested that the decreased synthesis of various maeromolecules is the major cause of salt injury to maize under saline/alkaline conditions.