Pepper response to mild conditions of combined soil-water and salinity stress

Three soil matric water potentials (-0.03, -0.1 and -0.3 MPa) and three saline treatments were factorially combined to investigate their possible additive and interactive effects on the growth, f1owering, yield, net photosynthesis and water use efficiency of pot grown pepper in greenhouse. Matric potential was indirectly monitored by frequent pot weighing. Rewatering to field capacity was made when the desired thresholds were reached. Saline solutions, with a relative ionic ratio as in the fresh irrigation water composition, were used to establish the osmotic treatments. Periodic leachings were made to overcome salt accumulation and suction was applied after watering to the bottom of the pots to avoid the formation of a water table. Substantial differences in plant response were noticed among matric treatments. The wellirrigated treatment proved to be more responsive than the others for ali the tested parameters. No statistically appreciable differences were found among the osmotic treatments for most of the traits, with a mean response equivalent to the intermediate matric treatment. The intermediate saline treatment showed consistently higher values than the other treatments in ali the traits under observation. No significant interaction between matric and osmotic treatments were detected. In most circumstances the lowest saline treatment proved to be less detrimental than the corresponding matric treatment.