Qualidade Fisiológica de sementes de girassol em função da adubação boratada e tempo de armazenamento

Abstract

Boron is the micronutrient most limiting to the cultivation of sunflower, causing from slight symptoms, until the total loss of production by the fall of the chapters. On the other hand, the toxicity of this micronutrient also limits the growth, yield and quality of the seeds. The quality of the seeds used in the implantation of a crop is a fundamental factor to reach an adequate plant stand and the storage is an essential step to maintain the quality of the seeds that are produced in the field. The objective of this study was to evaluate the physiological quality of sunflower seeds, as a function of borated fertilization and storage times. The work was developed in the Laboratory of Seeds of the State University of Goiás, Câmpus-Ipameri / GO. The experimental design was completely randomized, arranged in a 6 x 6 factorial scheme, with 4 replicates. The first factor refers to the boron doses, which were used six doses (0, 1, 2, 3, 4 and 5 kg ha-1), applied manually using as boron source boric acid (17%). The second factor refers to storage times: postharvest (M0), 2 months of storage (M2), 4 months of storage (M4), 6 months of storage (M6), 8 months of storage (M8), and 10 months storage (M10). The seeds used were from plants cultivated in the safrinha of 2017 and fertilized according to the treatments with the doses of boron. After the harvest, the following evaluations were carried out at each storage time: germination test, first germination count, accelerated aging, germination speed index, electrical conductivity, weight of 1000 seeds and tetrazolium test. Based on the results obtained in the present work it can be concluded that the storage time positively influences the germination of the sunflower seeds. Seeds stored for up to ten months (M10) do not cause damage to the seed germination. And the fertilized fertilization in the sunflower crop reflects in increments in the physiological quality of the seeds.