Formation of soursop seedlings irrigated using waters with different salinity levels and nitrogen fertilization

Abstract
Using saline waters in agriculture has become common in many regions worldwide, but some techniques have been developed to enable the use of these waters in order not to harm the crop. Thus, this study aimed to evaluate the growth of soursop seedlings, cv. ‘Morada Nova’, under interaction between salt stress and nitrogen (N) fertilization. The experiment was conducted in a greenhouse in randomized block design, in 5 x 4 factorial scheme, with 4 replicates, formed by the combination of five levels of irrigation water electrical conductivity - ECw (0.3; 1.1; 1.9; 2.4 and 3.5 dS m - ¹) and four N doses (70, 100, 130 and 160%). The dose relative to 100% corresponded to 100 mg of N dm - ³ of soil. The interaction between N doses and water salinity levels did not affect the seedling production stage of soursop, cv. ‘Morada Nova’. The growth of ‘Morada Nova’ soursop seedlings subjected to different water salinity levels was less affected in the initial stage (45 days after treatment application). Water with ECw of 2.0 dS m - ¹ can be used to produce soursop seedlings, because it leads to an acceptable mean growth reduction of 10%. N doses higher than 70 mg dm - ³ do not either attenuate salt stress or promote higher growth of soursop seedlings, cv. ‘Morada Nova’.