Crescimento de mudas de gravioleira irrigada com água de diferentes salinidades sob adubação nitrogenada.

Abstract

Considering the limitation of water resources in the semi-arid region of Northeast Brazil, it is necessary to carry out studies of techniques that allow the use of inferior quality water in irrigated fruit production. Thus, the objective of this research was to evaluate the initial growth of soursop irrigated with waters of different salinities and nitrogen fertilization. The experiment was carried out in a protected environment of the Federal University of Campina Grande at the Agro - Food Science and Technology Center, Campus Pombal - PB, adopting a randomized complete block design in a 5 x 4 factorial scheme with four replications and two plants per plot. The treatments corresponded to five levels of electrical conductivity of the irrigation water - ECa (0,3; 1,1; 1,9; 2,7 and 3,5 dS m-¹) associated to four nitrogen doses (70; 100; 130 and 160 mg of N per dm-3 of soil), whose dose of 100% corresponds to 100 mg of N dm-3. Electrical conductivity water of 1,5 dS m-1 can be used in irrigation of soursop seedlings cv. New residence during growth up to 75 days after application of treatments. The initial growth of soursop seedlings is favored with nitrogen fertilization dose of 70 mg N per dm-³. Nitrogen fertilization, especially at a dose of 130 mg of N dm-3 of soil, reduces the effect of irrigation water salinity up to 1,9 dS m-1 on the number of leaves of soursop cv. Morada Nova, at 75 days after application of treatments.