Seasonal evolution of the quality of fresh glasshouse tomatoes under Mediterranean conditions, as affected by air vapour pressure deficit and plant fruit load

Abstract Changes in yield and quality of fresh tomatoes in response to air vapour pressure deficit (VPD) and plant fruit load were studied under Mediterranean summer conditions. Plants thinned to three or six fruits per truss were grown in two compartments, one at a VPD below 1.5 kPa, the other without VPD control. The seasonal trend in fruit yield and quality was assessed from April to September by weekly measurement of number, fresh weight and dry matter content of harvested fruits, together with the occurrence of blossom-end-rot (BER) and cracking. On two occasions, in July and September, sugar and acid content was measured at three ripening stages. The seasonal decrease in fresh yield w…