Cabbage yield response to salinity of trickle irrigation water

The objective of this work was to study the effect of saline water on the yield of cabbage (Brassica oleracea, cv. capitata), under two plant population density treatments (2 and 4 plants for each dripping point), applying an experimental design known as double emitter source DES. A saline water gradient was created, shown by an electrical conductivity from 0.89 up to 10.98 dS.m(-1) Experiments were carried out in the Campus of Gambelas, University of Algarve, Fare, South Portugal. The results showed: 1 - For lower water salinity levels (from 1 up to 3 dS.m(-1)), cabbage yield decreased about 40 % at the higher plant population density; on the other hand, for the lower plant density, cabbage yield decreased only about 20 %; 2 - Yield decreased almost linearly with the increase of salinity; however between 1 and 6 dS.m(-1), yield reduction was higher, as well as from 9.6 up to 11 dS.m(-1) 3 - It was also shown that the salinity threshold value was lower than 2 dS.m(-1). Regression lines had r(2) values not lower than 0.80.