Beet seed priming with growth regulators

Seed priming is a technique used to induce metabolic germination processes. Use of growth regulators in seed priming may facilitate increments in physiological processes during seed germination. The objective of this study was to evaluate the effect of priming and growth regulators on beet seed germination. The treatments were cultivar type (Early Wonder, Itapua and Maravilha) and seed priming technique, which included a control (unconditioned seed) standard hydropriming (water) and a conditioning with salicylic, gibberellic and ascorbic acids, respectively. The treatments were defined by initially testing 0, 1, 2 and 4 mM ascorbic, gibberellic and salicylic acids. Before seed priming, imbibition seed curves were established to determine the optimal conditioning time. After conditioning, the germination, rate of germination, seedling length and seedling dry weight were evaluated. First, the appropriate dosage for conditioning was determined by using a completely randomized experimental design, with four replications per cultivar. Then, a 3 x 5 (cultivar x conditioning technique) factorial design was adopted. Whenever the results were significant by variance analysis, regression analysis was performed. Finally, Tukey's test was used to compare the means at P=0.05. Beet seed priming alters the potential of germination and is influenced by the cultivar and conditioning technique. Pretreatment with 1-2 mM ascorbic, gibberellic or salicylic acids, respectively, promotes beet seed germination, whereas at 1-3 mM, the growth of roots and shoots of beet seedlings is promoted. The most effective techniques to promote germination and growth of sugar beet seedlings were priming with water, salicylic acid or gibberellic acid.