Yield, physicochemical traits, antioxidant pattern, polyphenol oxidase activity and total visual quality of field-grown processing tomato cv. Brigade as affected by water stress in Mediterranean climate.

BACKGROUND: The 'processing tomato' is an important source of natural antioxidants whose concentration depends, along with other parameters, on water availability. In order to better understand the mechanisms that regulate the response to water stress, a study was carried out in a typically semi-arid Mediterranean environment to investigate the yield, chemical composition and visual quality of tomato cv. 'Brigade' field grown under no irrigation (V0) in comparison with those of the conventional fully irrigated crop (V100). RESULTS: The stressful conditions of V0 affected the total yield. Nevertheless, fruits exhibited an increase in firmness (+27%), total solids (+23%) and total soluble solids (+5%). The dynamic balance between the antioxidant pattern and polyphenol oxidase activity under water stress conditions resulted in fruits with increased antioxidant activity (+12%), due to a decline in enzyme activity (-48%) and a rise in vitamin C (+20%) and total phenolic (+13%) contents. CONCLUSION: It is possible to manage water stress by applying water-saving irrigation strategies in order to promote the quality and nutritional properties of tomatoes while also contributing to saving water. This is a relevant aspect in processing tomato cultivation in semi-arid environments, whereboth the cost and availability of irrigation water represent a risingproblem in agricultural activities.