EMERGENCE OF Megathyrsus maximus SEEDLINGS GROWN UNDER SALT STRESS

Abstract

The aim was to evaluate the effect of salt stress on the percentage and speed of emergence of seedlings in forage cultivars of the species Megathyrsus maximus (Jacq.). The study was conducted in a completely randomized design in a 3×4 factorial scheme, with three forage cultivars (Mombaça, Tanzânia and MG12-Paredão) and four salinity levels (0, 1.5, 3.0, and 4.5 dS/m), with six replications. Stress was induced by irrigating the pots with saline solution. The percentage of seedling emergence was evaluated at seven days after sowing (DAS), and the emergence speed index (ESI) until 15 DAS was evaluated. Analysis of variance for the percentage of emergence and ESI showed significant effect (P<0.01) for cultivars and salt stress and non-significant effect for the interaction between factors. The percentage of emergence was higher in the Mombaça cultivar (39.4%) and did not differ between the Tanzânia (30.5%) and MG12-Paredão (25.0%) cultivars. ESI was similar between the Mombaça and Tanzânia cultivars and higher than the MG12-Paredão cultivar. Salt stress reduces the percentage and speed of seedling emergence of the Mombaça, Tanzânia and MG12-Paredão cultivars of Megathyrsus maximus. The Mombaça, Tanzânia and MG12-Paredão cultivars show the same behavior regarding seedling emergence performance when subjected to different levels of salt stress.