Influence of sodium chloride with and without calcium chloride on growth and productivity of chilli pepper

Most chilli pepper (Capsicum annuum L.) cultivars have been classified as being moderately sensitive to NaCl salinity. Sodium and chloride ions do not depict ideal salinity ions in inland chilli pepper-producing regions of South Africa, except for coastal areas. Under inland conditions Na+ and Cl- occur in great association with Ca2+, while the opposite is true in coastal areas. The objective of this study was to investigate the effect of NaCl with and without CaCl2 on the productivity and growth of C. annuum cv. ‘Serrano’ over two seasons. Three treatments, untreated control, NaCl and NaCl + CaCl2 per m3, were arranged in a randomised complete block design, with 15 replications. At 120 days, treatments contributed 66-85% to the total treatment variation in different plant variables, without effects on fresh fruit yield, fruit number/plant and leaf number/plant. Relative to untreated control, NaCl + CaCl2 reduced dry root mass and root/shoot ratio by 9% and 12%, respectively, but increased chlorophyll content and stem diameter by 6% and 8%, respectively, without affecting other variables. In contrast, NaCl reduced plant variables by 5-35%, except for root/shoot ratio which was increased by 18%. In conclusion, cv. ‘Serrano’ was moderately sensitive to NaCl salinity, but highly tolerant to NaCl + CaCl2 salinity, suggesting that this cultivar may be suitable for production in hinterland parts of South Africa with salinity, while it may not be suitable for coastal areas.