Revestimento de sementes de milho com quitosana e biomassa microalgal

Abstract

Microalgae has been studied as a biostimulant or biofertilizer in the development of agricultural crops, however its application is still incipient. In this work, the objective was to evaluate the potential use of chitosan associated with the cyanobacteria Aphanothece microscopica Nägeli in the coating of corn seeds (Zea mays L.) and its effect on the physiological potential and health quality of the seeds. A chitosan solution (2% m/v) containing biomass of the cyanobacteria Aphanothece microscopica Nägeli (0.1% m/v) was used, incorporated in two ways: fresh biomass (QBF) and biomass submitted to 4 freeze/thaw cycles (QBC). Seeds coated with chitosan without biomass (Q) and without coating (Control) were also analyzed. All treatments were evaluated for water content, 1,000-seed mass, germination, germination speed index, seedling length (root, shoot and total), cold test, seedling emergence, seedling emergence speed index, seedling height, root and shoot dry matter mass and health quality. The treatments QBF, QBC and Q did not significantly affect the 1,000-seed mass, germination, shoot length, cold test, emergence, height and root dry matter mass, but reduced the emergence speed index and shoot dry matter mass. QBC treatment tended to reduce the occurrence of Fusarium spp. and treatments Q, QBF and QBC the occurrence of Penicillium spp. in the seeds. The results indicate an antimicrobial potential of the coatings with minimal impact on the physiological potential of the seeds.