DORMANCY OVERCOMING AND PRECONDITIONING IN Mimosa caesalpiniifolia Benth. SEEDS

Abstract

Seeds of ‘sabiá’ (Mimosa caesalpiniifolia Benth.) have coat dormancy, which hampers the absorption of water and oxygen, thereby delaying germination. Thus, this study aimed to evaluate methods for overcoming dormancy associated with priming on germination and vigor of seeds of ‘sabiá’, considering the efficiency, practicality and cost of treatment. The experimental design was completely randomized, in a 4 x 5 factorial scheme (four methods for overcoming dormancy x five types of priming), constituting 20 treatments with four replicates of 25 seeds. The methods for overcoming dormancy used were tip removal, seed immersion in hot water at 100 °C for three minutes, immersion in sulfuric acid for 10 minutes and intact seeds. For the determination of physiological conditioning of seeds, the imbibition curve with the different priming agents was constructed. Priming was done on filter paper moistened with solutions of mannitol at the potentials of -0.2 MPa (16 hours), -0.4 MPa (24 hours) and -0.6 MPa (36 hours) and only with distilled water for the hydropriming (12 hours) and seeds without priming. The variables analyzed were first count of germination, germination, root length, shoot length and dry weight of seedlings. The data were subjected to analysis of variance by F test and Tukey test at 5% probability. The dormancy of M. caesalpiniifolia seeds should be overcome with the use of hot water (100 °C) for three minutes, without the need for priming.

VEGETATIVE PROPAGATION OF Mimosa Caesalpiniifolia BY MINI-CUTTINGS TECHNIQUE

“…Production of Sabiá seedlings is commonly via seedlings; that they present tegumentary dormancy, hindering absorption of water and oxygen and consequently delaying germination and producing uneven seedlings (Costa et al, 2018). Methods proposed for breaking the dormancy of Mimosa caesalpiniifolia seeds involve mechanical, chemical or physical scarifi cation (Medeiros et al, 2020). Such methods require time, produce uneven seedlings, may off er risks to the operator, and may present low effi ciency.…”