Effect of the salinity on the organoleptic quality and yield of early-grown soilless grafted tomatoes under heated glasshouses in the south of France

The effect of two salinity levels in the nutrient solution on the organoleptic quality and yields of tomatoes was studied in an early crop. Two hybrids, one a "long shelf-life" type, the other a "short shelf-life" type, were grown in a glasshouse with a soilless system recycling the drainage solutions. Production was monitored quantitatively and qualitatively. The fruits were assessed at two periods by a panel of consumers. Overall, high salinity levels affected the total soluble solid contents (TSS) and the titrable acidity. Both increased significantly no matter what the season or hybrid tested, with the exception of the titrable acidity for the short shelf-life hybrid in the spring. Firmness was affected little by an increase in salinity levels; in contrast, there was a significant varietal effect. At the same time, consumers detected differences and preferred fruits produced at high salinity levels whatever the hybrid tested. When salinity increases, the number of fruits produced does not change but their average weight and size decrease significantly. In conclusion, it is possible to improve the intrinsic quality of soilless-tomatoes plants grown under heated glasshouses in the Mediterranean region by increasing salinity levels, for both long and short shelf-life hybrids. This type of crop management is possible by recycling drainage but it reduces yield by about 20%.