Sources and doses of nitrogen in the production of sunflower plants irrigated with saline water

ABSTRACT The cultivation of sunflower allows its use as bio-fuel and alternative forage. It is a viable alternative in the semiarid regions. Current study evaluates the effect of saline water use, sources and doses of nitrogen fertilization on the production of sunflower in the experiment conducted in drainage lysimeters between May and August 2012, under protected conditions, at Pombal - PB Brazil. The experiment consisted of a randomized block design, with a 2 x 3 x 4 factorial arrangement and three replications. The treatments consisted of two levels of electrical conductivity of water - ECw (0.3 and 3.0 dS m-1), three sources of nitrogen (urea, ammonium sulfate and calcium nitrate) and four levels of N (40, 80, 120 and 160% of recommended dose - 100 mg kg-1, for trials in pots). Dry mass of chapter (DMC), mass of achenes (MAc), the number of viable seeds (MVS), total number of seeds (TNS) and internal (DCI) and external (DCE) diameter of chapter. Irrigation with water of ECw=3.0 dS m-1 negatively affected all variable evaluated. Doses of N 104 and 160% of recommended dose for trials in pots, resulted in the highest DMC, TNS, DCE and DCI. N sources and the interaction between factors did not affect significantly any of the variable evaluated