Effect of growing systems and cultivar on yield and water use efficiency of greenhouse-grown tomato.

The aim of this research was to compare the cultivation of tomato (Solanum lycopersicum L.) plants in soil with two hydroponic systems: the Nutrient Film Technique (NFT; closed cycle), and rockwool (open cycle), in terms of yield and water-use efficiency (WUE).Two trials were carried out, one in Winter-Spring (WS), and the other in Autumn-Winter (AW). In both trials, four tomato cultivars were used: two of the beefsteak fruit-type ('Diana F1' and 'Jama F1'), and two of the cherry fruit-type ('Naomi F1' and 'Conchita F1').The two hydroponic systems showed greater earliness; on average, 10 d and 8 d earlier than in soil, in the WS and AW trials, respectively.Total fruit yield was influenced by the growing system. In the hydroponic systems, total yields were 11% and 7% higher in the WS and AW trials, respectively, than in the soil system. Cultivation in soil gave good results in terms of WUE in both trials, due to the use of tensiometers, suitable watering volumes, and mulching. Between the two hydroponic systems, NFT gave a higher yield, with lower water and fertiliser use, and a greatly reduced environmental impact.