EFFECTS OF SALINITY STRESS ON GROWTH, YIELD, FRUIT QUALITY AND WATER USE EFFICIENCY OF TOMATO UNDER HYDROPONICS SYSTEM

Salt added to nutrient solution is an easy method that can improve tomato fruit quality, but plant growth and fruit production are negatively affected. Salinity reduces tomato root elongation rate and lateral root growth due to restriction of root cell growth and increased root lesion. Tomato leaf, shoot height and stem diameter reduced under salinity stress caused by photosynthesis reduction, tissues expansion reduction and cell divided inhibition. Salinity also reduces leaf chlorophyll content, stomatal resistance and photosynthetic activities. Total yield of tomato is significantly reduced at salinity equal and above 5 dS m-1, and a 7.2% yield reduction per unit increase in salinity. Salinity can decrease root water uptake through its osmotic effect, and subsequently induce water stress. Fruit quality is the only parameter which is positively affected with increased salinity.