Development of biodegradable coatings for maize seeds and their application for Azospirillum brasilense immobilization.

The objective of this study was to develop biodegradable coatings for agriculture crop seeds based on starch, gelatin, and polyvinyl alcohol (PVA). Developed materials were characterized according to their microstructures, barrier properties, influence on germination of maize seeds, and ability to sustain Azospirillum brasilense Ab-V5 viability in coated maize seeds. The coatings were obtained employing different proportions of starch, gelatin, and PVA, ranging from 0 to 3.0 g/100 g of each material, respectively. Samples formulated with the pure polymers showed the highest values of water absorption capacity, solubility, and water vapor permeability, and the ternary mixtures showed the lowest values. Single polymer formulations and the binary starch-gelatin mixture (CS50GL50) favored maize seeds germination compared to the uncoated maize seeds. In addition, seed coating obtained from CS50GL50 formulation resulted in A. brasilense Ab-V5 viability in coated seeds up to 15 days after bacterial immobilization, being considered a promising low-cost, biodegradable, and renewable source material to be used in agriculture.