Morphophysiology of Eggplant Irrigated With Wastewater and Nitrogen and Phosphorus Doses in the Semi-arid Region of Brazil

Water is a scarce resource in semi-arid regions, therefore, the correct water management is an essential practice. In this research we evaluated the use of nitrogen, phosphorus and treated wastewater on the growth and morphophysiology of eggplants (Solanum melongena L.) in the semi-arid region of Brazil. The experiment was conducted in Pombal, Paraíba, Brazil, using a randomized block design, in a 4 × 4 + 1 factorial scheme: wastewater with four nitrogen doses (N1 = 0.22; N2 = 0.39; N3 = 0.56; and N4 = 0.73 g N dm-3) and four doses of phosphorus (P1 = 0.96; P2 = 1.68; P3 = 2.40; and P4 = 3.12 g P dm-3), and the controls - distilled water fertilized with 0.56 g of N dm-3 and distilled water fertilized with 2.40 g of P dm-3. Each treatment was replicated 4 times. The nitrogen and phosphorous interaction did not influence the growth and physiological aspects of eggplant plants. Excess growing media nitrogen significantly decreased gaseous exchanges of eggplant plants, being found decreased of 4.4 μmol m-2 s-1 the CO2 assimilation.