Qualidade sanitária e fisiológica de sementes de milho inoculadas com microrganismos eficientes

Abstract

Corn is a very versatile cereal, being a crop of great importance in agriculture. The use of microbiological products, such as bacteria, fungi and viruses, can be a viable alternative to improve the health, germination and vigor of these seeds. Thus, this work aimed to evaluate the effect of different doses of efficient microorganisms on health, germination and seed vigor of three maize cultivars. For that, five different doses of efficient microorganisms (0, 25, 50, 75 and 100%) and three maize cultivars (Amarelão, Pixurum and AG9025 PRO3), composed the treatments in a bifactorial way, following a completely randomized design. Before each test, seeds of different maize cultivars were inoculated with five different doses of efficient microorganisms. Seed health was determined by the percentage of infection by Fusarium spp., Penicillium spp. and Aspergillus spp.. In the germination test, the percentage of normal and abnormal seedlings and the percentage of dead, hard and dormant seeds were obtained. And seed vigor was measured by the germination speed index and the first germination count. Statistical analyzes comprised analysis of variance, followed by regression or Tukey's mean test, depending on the analyzed variable. Efficient cultivar x microorganism interaction was verified for fungal infection (Fusarium spp., Penicillium spp. and Alternaria spp.), germination and first germination count. For the germination speed index there was only a significant effect of cultivar. The lowest rate of Fusarium spp. was verified at a dose of 75% for the Amarelão and Pixurum cultivars and for the hybrid cultivar the dose of 50% was the one that obtained the best response, with less infection. For Penicillium spp. the 100% dose reduced the infection in relation to the control for the hybrid cultivar and Pixurum. Efficient microorganism inoculation enhances Aspergillus spp. and Penicillium spp. in the Amarelão variety. For the hybrid cultivar at a dose of 75%, there was the lowest infection rate of Aspergillus spp., while the Pixurum variety did not adjust the equation, maintaining a low average of infection. In the average percentage of germination, in the doses of the control treatment (dose 0%) and 25%, the best average of germination was obtained, for both cultivars. As the seeds of the three cultivars were subjected to higher doses of efficient microorganisms, there was a negative impact on germination, increasing the percentage of abnormal seedlings. For dead and hard seeds, no significant difference was verified between the evaluated treatments. Higher IVG was obtained by the hybrid (16), followed by Amarelão with (12) and Pixurum with a value equal to 11, higher IVG, means greater vigor. For the Pixurum and hybrid cultivars, the best result in the first count was in the control treatment (dose 0%) and in the Amarelão cultivar, the highest vigor was at the 100% dose, therefore, in order to increase seed vigor in the Amarelão cultivar, the use of efficient microorganisms is a great alternative. With this, the use of efficient microorganisms for use in the treatment of corn seeds can become something viable, in order to reduce fungal infection at higher doses, but it can affect the germination and vigor of the seeds.