CRESCIMENTO DE FEIJÃO CAUPI 'BRS PAJEÚ' IRRIGADO COM ÁGUA SALINA E ADUBAÇÃO NITROGENADA GROWTH OF COWPEA 'BRS PAJEÚ' IRRIGATED WITH SALINE WATER AND NITROGEN

The use of saline water in agriculture is an important alternative and a reality ever closer, in view of the reduced availability of water resources of good quality and the growing need for expansion of agricultural production. In this sense, the aim of this work was to evaluate the influence of different irrigation water salinities associated with nitrogen fertilization on the growth of cowpea cv. BRS Pajeu, in an experiment conducted in lysimeters under conditions of en-vegetation in CTRN/UFCG. We used a block randomization scheme in a 5 x 5 factorial design with three replications and the treatments consisted of a combination of five levels of electrical conductivity of irrigation water - ECw (0.9, 1.8, 2.7, 3 , 6 and 4.5 dS m -1 ) and five nitrogen rates (70, 100, 130, 160 and 190% of the recommended test in pots). The leaf number, stem diameter and the rate of absolute and relative growth in diameter and height hp. BRS Pajeu sharply reduced when subjected to ECw levels greater than 0.9 dS m -1 ; cowpea The BRS Pajeu not answered the adoption of increasing doses of nitrogen fertilizer, for interaction among salinity of irrigation water versus dose nitrogen did not affect any growth variable evaluated at 30 DAS.