Influência de Micronutrientes na qualidade fisiológica de sementes de milho (zea mays L.)

Abstract

Practices to increase agricultural productivity include seed treatment with products that stimulate physiological potential, an effective alternative to improve early plant development. The use of micronutrients in seed treatment, an increasingly common practice, provides essential nutrients for germination and seedling development in the field. The objectives of this study were to evaluate the influence of increasing doses of boron in the treatment of maize seeds and its influence on the physiological quality of the seed, as well as the influence of different doses of a micronutrient complex. The experiments, divided into two chapters, were carried out at the Juruti University Campus of the Federal University of Western Pará, between January and May 2024. Both studies used a completely randomized design, with five treatments of different doses: the first experiment applied increasing doses of boron (0; 0.10; 0.20; 0.30 and 0.40 g.kg of boron), while the second experiment used a dose of a micronutrient complex (0; 20; 40; 60 and 80 g.kg1 of PC). The seeds were weighed and treated with their respective doses using the wet method, where the product was diluted in distilled water and then incorporated into the seeds by stirring. The variables analyzed included germination test, primary germination count, index of germination velocity, index of emergence velocity, seedling length and seedling dry mass. The data obtained were submitted to analysis of variance and analyzed by simple and quadratic linear regression, at the level of 5% of significance, in the statistical program SISVAR. In the first experiment, boron had a negative effect on the variables germination and first germination number, but it was possible to observe germination percentages that still met the parameters for marketing seeds, and in the variable first germination number there was a significant loss of vigor. The other variables analyzed showed a more obvious negative effect with the use of boron doses, compromising their quality attributes. In the second experiment, the use of increasing doses of micronutrients had a more pronounced negative effect: germination was reduced to very low percentages with the micronutrient treatment. The first germination number and the germination and emergence speed indices showed a similar behavior. There was also a decrease in the length and dry mass of the seedlings with increasing doses of the micronutrient complex, which had a negative effect on the physiological quality of the seeds and the initial development of the seedlings. The study showed that boron at high doses, as well as the use of the micronutrient complex, can severely affect seedling viability, vigor and development, indicating the need for careful moderation in the use of these nutrients for seed treatment and the importance of further studies with new dosages, sources of the elements and treatment methods.