INITIAL GROWTH OF Enterolobium contortisiliquum (Vell.) Morong UNDER ABIOTIC STRESSES
dry forests, growth, salinity, water deficit.
Enterolobium contortisiliquum plants when exposed to high stress are little adapted to growing in these environments. The objective of this study was to evaluate the effect of water and salt stress on the growth of Enterolobium contortisiliquum (Vell.) Morong seedlings. The experiment was carried out in a protected environment located at the Academic Unit Specialized in Agricultural Sciences (UAECIA), belonging to the Federal University of Rio Grande do Norte (UFRN), Macaíba / RN, from February to April 2019. The design was in blocks randomized (DBC), with five treatments, four repetitions in which the experimental unit consisted of twenty plants. The experimentation of the different stresses occurred independently. The first under water deficit in the periods: 0; 4; 8; 12; 16 days the second under the effect of salt in the irrigation water, measured in the electrical conductivities (EC): 2; 4; 6 and 8 dS.m-1 and (0.1 dS.m-1) defined as control. Before sowing, pre-germinative treatment was applied, using sandpaper. For the composition of the substrate, common sand and tanned cattle manure were used, in the proportion 1: 1. The treatment evaluation was started with established seedlings, 30 days after sowing. The evaluated characters were: plant height, leaf number, leaf area, stem diameter, Dickson's quality index, stem length, main root length, shoot dry matter and total dry mass, in addition to biochemical tests (amino acids, proline, total soluble sugars, starch). The results were subjected to analysis of variance by the F test at 5% probability and, in case of significance, submitted to regression analysis, considering the response with the best biological expression. Lesser performance was observed in the growth of monkfish from the control treatment, being affected drastically under the highest limit, in both stresses.