Sodium chloride salinity in fruit vegetable crops in soilless culture.

Tomatoes, cucumbers and sweet peppers (capsicums) were grown in hydroponic systems in which the nutrient solutions were recirculated. The EC of the nutrient solution was maintained at values of 2.5, 3.7 or 5.2 dS m-1 (25 degrees C) in the different treatments. In some of the treatments, the EC values mentioned were achieved by addition of nutrients, and in others by addition of a combination of nutrients and NaCl. Yields of all 3 crops were adversely affected by increased EC values. Most fruit quality characteristics, on the contrary, were favourably affected. However, the incidence of blossom-end rot in tomatoes and capsicums increased at higher EC values. For capsicums, this was especially the case with NaCl addition. Apart from that, only slight specific NaCl effects were noticed. Salinity threshold values for the different crops lay between 2.3 and 3.5 dS m-1 and salinity yield decrease values ranged from 2.3 to 7.6% for each dS m-1. The absorption of Na and Cl differed with crop and with the Na and Cl concentration. (Abstract retrieved from CAB Abstracts by CABI’s permission)