Condicionamento fisiológico de sementes de beterraba com reguladores de crescimento

Abstract

Seed priming is a technique used for the controlled imbibition of seeds, allowing the activation of metabolic processes of germination, though without the radicle protrusion. The use of growth regulators with the priming may favor the physiological processes of seed germination and accelerated. The objective of this study to evaluate the effect of physiological conditioning of beet seeds with growth regulators. three cultivars were used: Early Wonder, Maravilha and Itapuã and five types of constraints: control (unconditioned seed) standard hydropriming (water), priming with salicylic acid, gibberellic acid and ascorbic acid. To define the treatments initially were tested doses in the range of 0; 1; 2; 4 mmol L-¹ ascorbic acid, gibberellic acid and salicylic acid. Prior to etching, the curves were imbibition of seeds, determining the optimum time for conditioning. After conditioning, the seeds were evaluated for germination, speed of germination, seedling length and seedling dry weight. The experimental design was completely randomized with four replications, in the first step, separately for each cultivar, in order to determine the appropriate dosage for conditioning. In the third stage, a factorial design was adopted 3 x 5 (cultivars x type of conditioning). The results were submitted to variance analysis and when this was significant proceeded to regression analysis, the second step. In the third stage of the work was performed mean comparison with Tukey test at 5% probability of error. The physiological conditioning of beet seed alters the potential of germination and seed vigor and the answer is related to the cultivar and the type of conditioning adopted. Doses of between 1 and 2 mMol L-¹ ascorbic acid, gibberellic or salicylic promote germination of beet seeds and doses between 1 and 3 mMol L-¹ ascorbic acid, gibberellic or salicylic promote the growth of roots and shoots of beet seedlings. Priming with water, salicylic acid or gibberellic acid techniques are the best among the tested, to promote germination and growth of sugar beet seedlings. The priming procedures for the cultivar Early Wonder proved inefficient, however for Maravilha and Itapuã cultivars hydropriming and conditioning with ascorbic acid respectively, showed efficiency to improve the physiological potential of seeds.