This work aimed to assess the effect of different water tensions in soil over the development and production of two onion cultivars irrigated by drip system. The experiment was carried in the experimental area of the DAG/UFLA, from June to October 2008. The experimental was conducted in randomized block design in 2 x 6 factorial scheme, with four repetitions. The treatments were two onion cultivars, the hybrid Optima F1 and the non hybrid Alfa Tropical and six soil water tensions, i.e., 15, 25, 35, 45, 60 and 75 kPa. It was verified that the hybrid Optima F1 presented the best responses regarding the following analyzed characteristics: total bulb yield, commercial bulb yield and average mass of commercial bulbs. The plant height and the hypocotyl diameter presented linear decreasing response as the soil water tensions were increased, for both cultivars. In both cultivars, in order to achieve taller plants, higher bulb yields (total and commercial) and higher average mass of commercial bulbs, the irrigation should be applied when the soil water tensions is around 15 kPa at 0.15 m depth.
Allium cepa L.; trickle irrigation; soil water tension
