Condicionamento fisiológico na qualidade de sementes de milho

Abstract

It was aimed to evaluate different methodologies and water potential for priming corn seeds and; to evaluate plant growth regulators application, in different doses, through priming in stored corn seeds so, two experiments were conduct. In the first, four water potential were used (0.0, -0.4, -0.8 and -1.2 MPa) and three conditioning methods (soaked in non-aerated solution, soaked in aerated solution and paper roll) with a control. The seeds were primed for 24 hours, in polyethylene glycol 6000 solution, and posteriorly dried and evaluated for moisture content, percentage and first count of germination, emergence in sand, emergence speed index, length and dry mass of seedlings, cold test and vigor index. In the second experiment, two evaluation periods were use, after priming and after 30 days of storage, and ten treatments. The treatments were seeds primed in water (0.0 MPa) or polyethylene glycol 6000 (0.4 MPa), with or without plant growth regulator addition, at different doses. The plant growth regulator employed was composed of gibberellic acid, cytokinin and auxin. In the first experiment, for water potential, -0.4 MPa was superior in percentage and first count of germination, length and seedling dry mass, germination after cold test and vigor index. So, priming in polyethylene glycol 6000 solution at -0.4 MPa can improve vigor on corn seeds. For the priming methods, the germitest paper roll raised the length and seedling dry mass and vigor index however, for large scale priming the soaked in non-aerated solution is recommend. In the second experiment, was observed that addition of plant growth regulator in priming do not improve the quality of corn seeds. The priming in water, independently of plant growth regulator addition, generated reduction on seeds storage capacity.