Effect of Deficit Irrigation and Storage on Physicochemical Quality of Tomato (Lycopersicon esculentum Mill. Var. Pechtomech)

Abstract

Deficit irrigation is a water saving strategy used to make economic use of water for agricultural activities in order to save water for other purposes. This water deficit may have some negative effects on the quality and postharvest life of the food produced. The aim of this study was to determine the effects of deficit irrigation and postharvest storage on some physicochemical qualities of tomatoes. Tomato fruits (Pectomech variety) cultivated under different irrigation treatments (100% ETc, 90% ETc, 80% ETc and 70% ETc) were harvested and analyzed for firmness, total soluble solids (TSS), titratable acidity (TA) and pH. Firmness was determined by a penetrometer, TSS by hand refractometer, TA by titrating the juice with a standard base (NaOH) and pH by pH meter. Results indicated that firmness, total soluble solids, titratable acidity increased with increasing deficit irrigation while pH decreased. However, these increases and decreases in the parameters with the various water applications were not significant. Titratable acidity of the tomato fruits decreased significantly (p<0.05) as storage progressed. Firmness of the fruits decreased while total soluble solids and pH increased with increasing storage period. Considering the percentage increases and decreases in the physicochemical qualities of the tomatoes in this study, it can be concluded that a 10% reduction in the amount or volume of water applied in the cultivation of the Pectomech tomato variety would produce tomato with optimum quality that would compensate for yield losses.

Keywords: Deficit irrigation, firmness, Pectomech, titratable acidity, total soluble solids