Inoculante microbiológico e desenvolvimento inicial de plantas de milho sob déficit hídrico.

Abstract

Maize development is strongly influenced by water availability, with water deficiency posing a significant challenge to seed germination, plant development, and yield. This study aimed to evaluate the effect of microbial inoculants on the early growth of maize plants under water deficit conditions. Seeds of the MG580 hybrid were used, and the experiment was conducted in Uruçuí, Piauí, in October 2023. A randomized block design was used, in a 4 × 4 factorial scheme, with four replications. Seeds were treated with three inoculants Bioasis®, Auras®, and Azotrop® along with a control, and subjected to four water potential levels: 80, 70, 60, and 50% of water retention capacity, totaling 16 treatments. The seed moisture content after inoculant treatment was evaluated using a completely randomized design with four replications and four treatments. Early plant maize development was assessed under different combinations of inoculants and water potentials. The emergence speed index (ESI), plant height, fresh and dry biomass, and root volume were measured. Maize seed treatment with the microbial inoculant Auras® reduced the seedling emergence speed index at the 50% water potential, compared to untreated seeds and those treated with Azotrop® and Bioasis®. The inoculants promoted root development under water stress conditions (50% water retention capacity) but did not influence the percentage of normal seedlings, plant height, or fresh and dry biomass. Inoculating maize seeds with microbial products may be a promising strategy to mitigate the effects of water stress during the emergence and early development stages. However, it is important to consider the specific effects of each inoculant, as well as environmental conditions, to maximize the benefits of this practice in agriculture. The MG580 maize seeds demonstrated good resistance to water deficit under the evaluated conditions, with satisfactory results in most variables.