Citrus rootstocks and irrigation water salinity

During 2017-2019 at Dr. JC Bakhshi Regional Research Station Abohar, Punjab Agricultural University, an investigation evaluated the salt tolerance of various citrus rootstocks. The experiment used pot culture and exposed seedlings to different levels of saline water under net house conditions. Water soluble ions accumulated in the growing media in proportion to irrigation water concentrations. Cleopatra and Rangpur Lime showed higher Cl content in roots, while sodium content was higher in leaves and shoots. Carrizo had higher Na content in roots and lower values in leaves and shoots. Salinity led to a reduction in dry biomass ranging between 6-32% among rootstocks, with Cleopatra and Rangpur Lime showing lower reductions. Rangpur Lime exhibited higher photosynthesis, transpiration rate, stomatal conductance, water use, and antioxidant activity compared to Cleopatra, indicating better salt tolerance. Carrizo showed significantly higher leaf proline at all salinity levels. The order of salt tolerance among the citrus rootstocks was Carrizo < Volkamer Lemon = Rough Lemon < Cleopatra Mandarin < Rangpur Lime.