SODIUM CHLORIDE AND SILICON AFFECT YIELD AND QUALITY OF TOMATO FRUITS

Abstract

Tomato (Solanum lycopersicum L.) is a glycophyte species with medium sensitivity to salts, tolerating electrical conductivity values in the soil solution of up to 2.5 dS m-1. Silicon (Si) is a beneficial element that can act as an inorganic biostimulant in plants subjected to salinity. In this research, the main effects of two study factors were evaluated: a) salinity by NaCl (0, 50, and 100 mM) in the nutrient solution and b) biostimulation by Si, applied to the leaves (0, 75, and 150 mg L-1), as well as the interaction of both factors on yield and quality in fruits of the second cluster of tomato plants cv. Río Supremo grown hydroponically under greenhouse conditions. Yield was significantly reduced in the saline treatments, and was not affected by the application of silicon. Compared with the control, the NaCl concentrations evaluated reduced the fruit pH value by 6.2 %, but increased titratable acidity (TA) by 64.8 %, electrical conductivity (EC) by 72.9 %, and total soluble solids (TSS) by 80 %. Consequently, the NaCl treatments increased the TSS/TA ratio, compared to the control. The application of 75 mg Si L-1 through the leaves reduced the pH of the fruit by 0.6 %, while the dose of 150 mg Si L-1 increased the EC and the TSS/TA ratio in fruits. In plants treated with 50 mM NaCl and with both doses of Si, an increase in fruit pH was recorded, while treatments with 100 mM NaCl with both doses of Si significantly reduced the TA values. The TSS/TA ratio increased with both doses of Si in the treatments with 100 mM NaCl. It is concluded that the combination of saline treatments with silicon can improve some quality attributes of tomato cv. Río Supremo fruits.