Fontes e doses de nitrogênio e salinidade da água de irrigação no cultivo do girassol.

Abstract

Considering the water deficit, associated with quality problems, proposes, with, this paper to evaluate the viability of the use of saline water and different sources and doses of nitrogen in the sunflower production at the Semiarit Paraíba conditions of the hinterlands in order to provide economic benefits and the environmental sustainability of the activity. The experiment was realized in greenhouse condition of the Center of Science and Agrifood Technology of UFCG, Pombal, PB using the sunflower cultivation cv. Embrapa 122/V-2000 in experiment distributed in randomized block design with factorial schene ( 2 x 3 x 4) and three repetitions, being two electric conductivities of the irrigation water (CEa) ( S1 – 0.3 e S2 – 3.0 dS m-1 ) three sources of nitrogen (Urea, Ammonium Sulfate and Calcium Nitrate) and the factor doses of nitrogen from crop recommendation for the cultivation, identified as N1, N2, N3 e N4 being 40, 80, 120 and 160% of the dose indicated for the experiment. The electric conductivity of 3.0 dS m-1 change negatively growth variables such as number of leaves (LN), plants height (PH), stem diameter (SD), fresh leaves matter (FLM), dry leaves matter (DLM), and leaf area (LA), and in the growth variables of production such as external capitulum diameter (ECD), internal capitulum diameter (ICD), viable seeds matter (VSM), total seeds number (TSN), capitulum dry mass (CDM), aerial part dry matter (APDM), and achene production (AP). The doses of nitrogen promoted an increase in the SD, FLM, LA, ICD, ECD, TSN, CDM and in the APDM.The interaction between the factors studied did not promote significant effect for none of the variables studied.