Salinity and calcium effects on emergence, growth and mineral composition of seedlings of eight citrus rootstocks

Abstract

Salt tolerance of several citrus rootstocks during emergence and the early seedling stage of development was studied under greenhouse conditions. Salinity delayed and depressed seedling emergence, reduced shoot and root biomasses, and altered the mineral concentration of young citrus seedlings, although the magnitude of these changes differed between rootstocks. The addition of 50 mol m'3 NaCl to a nutrient solution delayed seedling emergence by three to five days with the exception of Troyer citrange (TC). Final emergence was reduced by less than 30% in Carrizo citrange (CC), TC, and Swingle cit- rumelo (SC), and by more than 65% in Ridge pineapple (RP), Cleopatra mandarin (CM), and rough lemon (RL). In the 50 mol m~3 NaCl treatment, shoot and root biomass were reduced by over 50%. Even in the no-salt control treatment, emergence of the first seedling and time to 50% emergence varied between rootstocks. Troyer citrange seedlings emerged fastest beginning ten days after sowing. Carrizo citrange and SC eme...