Viability and vigor of Moringa oleifera Lam. seeds by means of rapid tests

Abstract

Moringa oleifera Lam. is an arboreal forest species of great economic potential, adapted to the climatic conditions of the Brazilian semi-arid region, whose multiplication is mainly by seeds. Rapid viability and vigor tests help in the choice of lots. Thus, the objective of this study was to assess the efficiency of the pH of exudate and primary root protrusion tests in the evaluation of viability and vigor, respectively. Two seed lots were initially evaluated for moisture content, germination, first count, germination speed index, seedling length, seedling dry mass and electrical conductivity. For the pH of exudate test, phenolphthalein (1%) and sodium carbonate (2 and 4 g L^-1) solutions were prepared, with three soaking periods (1, 3 and 5 h) and three temperatures (25, 30 and 35 °C). Exudate solution in strong to light pink color indicated viable seeds, whereas very light pink color to colorless indicated non-viable seeds. The primary root protrusion test was performed under 25, 30 and 35 °C, evaluating the primary root protrusion of at least 2 mm, every 12 h until 196 h. The experimental design was completely randomized, with four replicates. pH of exudate test with 1 h of soaking at 25 or 30 °C with 2 g L^-1 sodium carbonate solution was promising, but further studies are needed before it is indicated as routine use for the species. Primary root protrusion test is efficient and can be conducted at 35 °C with evaluation after 48 h.