Produtividade do melão (Cucumis melo L.) irrigado por gotejamento com água de diferentes níveis salinos

Abstract

This work was conduct at the experimental field in the "Laboratório de Hidráulica e Irrigação do Departamento de Engenharia Agrícola do Centro de Ciências Agrárias da Universidade Federal do Ceará", Brazil. The objective of this research was to study the effect of irrigation with marginal quality waters (salinity) on melon yield and fruit weight, conducted by a drip irrigation system. Randomized blocks design were use with four replications. For the treatments were use apply 6 differences levels of salinity (EC = 0.46; 1.50; 3.00; 4.50; 6.00; 7.50 dS.m-1), artificially obtained by salt (NaC1) addition. Results showed that water with EC ≤ 3.00 dS.m-1 (threshold salinity) did not affect the yield and fruit weight. However, waters with EC above 4.50 dS.m-1 decreased the fruit weight and yield significantly, with maximum diminution at 56,63% to EC = 7.50 dS.m-1. Constant addition of salt in irrigation water increase the EC (electrical conductivity), SAR (sodium adsorption ratio) and ISP (interchangeable sodium percentage) in the soil profile. Permeability and sodicity problems may appear later as a result of continuous irrigation.