Adequacy of methodology for germination of diaspores of barauna, Schinopsis brasiliensis (Anacardiaceae)

Abstract

Schinopsis brasiliensis Engl. (Anacardiaceae) is a typical "Caatinga" (savanna) tree, whose seed germination occurs in a slow and irregular. The ideal conditions for seed germination of many tree species are still unknown. The present study objective was to evaluate different temperatures and substrates to establish a protocol for seed germination Schinopsis brasiliensis, conducted at the Federal University of Paraiba, Areia, Paraiba State (PB), Brazil. Therefore, different temperatures (25, 30, 35 and 20-30 ºC) and substrates (including sand, vermiculite between, on paper, between paper and paper roll) were used. To assess the effect of treatments for germination (%), first germination count (%), germination velocity index (GSI), lengths of the principal root and of the aerial portion of the seedlings and dry weights of the root system and of the aerial portion of the seedlings. The experimental design was completely randomized with treatments arranged in a 4 x 5 factorial arrangement (temperature and substrate), four replicates of 25 diaspores for each treatment. The means were compared by Tukey test at 1% probability and orthogonal contrasts between temperatures (35 vs 30 º C, 30 vs 25 º C and 20-30 vs 30 º C). The germination tests of S. brasiliensis should analyze the numbers of seedlings germinated 10 (first count) and 20 days (final evaluation) after sowing; The combination of a vermiculite substrate and alternating temperature (20-30 ºC) was best for stimulating the germination of S. brasiliensis diaspores.