FRUIT-QUALITY AND PARTITIONING OF MINERAL ELEMENTS IN PROCESSING TOMATO IN RESPONSE TO SALINE NUTRIENTS

A sand culture experiment was conducted to study the effect of saline water on the growth and fruit quality of processing tomato (Lycopersic on esculentum Mill.) Seedlings of five tomato cultivars were transplan ted in quartz-sand pots in a greenhouse at the Agricultural Experiment Station of Sultan Qaboos University. There were four saline nutrient solutions and a control consisting of half-strength Hoagland solution. Salinity treatments were: 50 mM NaCl + 3 mM K2SO4 (EC 6.75), 50 mM Na Cl + 1.5 mM orthophosphoric acid (EC = 7.18), 50 mM NaCl + 1.5 mM orth ophosphoric acid + 3 mM K2SO4 (EC 7.29), and 50 mM NaCL (EC = 5.6). Tr eatments were applied daily commencing two weeks after transplanting. Data were collected on growth, and fruit yield and quality. Partitioni ng of mineral elements was determined in the vegetative tissue. The re sults obtained clearly show that concentrations of total soluble solid s were increased in fruits treated with saline nutrients. Dry matter c ontent of fruits exposed to salinity were higher than those from the c ontrol plants. Fruit acidity was increased with salinity, possibly due to a lower water content and increased organic acid accumulation. In the saline treatments, sodium (Na) content was decreased when potassiu m (K) was applied with NaCL but Na was higher in stems followed by roo t and leaf tissues. The partitioning of K followed a trend opposite to that for Na but with higher content in leaves. A similar situation wa s observed for calcium (Ca) and magnesium (Mg). Accumulation of phosph orus (P) was the lowest among all the ions. These results indicated th at survival under saline conditions was accompanied by high ion accumu lation. The study confirmed that saline nutrients are important for im proving fruit quality of processing tomatoes.