Potencial fisiológico e sanidade de sementes de milho revestidas com quitosana

Abstract

Several harmful effects to the environment can be attributed to indiscriminate use and disposal of non-renewable and non-biodegradable products. Chitosan is a biopolymer with excellent film forming properties that has been studied on seed coating. The objective was to evaluate the effect of chitosan coating formulations (0.6-3.4% w/v chitosan and 0-0.6 g glycerol/g chitosan) on the quality of corn seeds (Zea mays L.) through the analysis of physical aspects (visual analysis of the coating, water content and 1,000-seed mass), physiological potential (germination test, germination speed index, seedling length, cold test, seedling emergence, seedling emergence speed index, seedling height and root and shoot dry matter mass) and health quality (Blotter test). Two coating methods were also tested (1 – drying the seeds immersed in the polymeric solution and 2 – drying after immersion and immediate withdraw of the seeds from the solution). In application method 1 there was no germination, therefore the results referred to application method 2. Chitosan coating solution associated with glycerol did not interfere in water content, 1,000-seed mass, germination and emergence percentage, cold test and root dry matter mass, but higher concentrations can reduce germination speed index, emergence speed index, seedling height and shoot dry matter mass. Coating in the selected condition (chitosan 2% and 0.3 g glycerol/g chitosan) reduced the occurrence of Penicillium spp. The potential use of chitosan as a coating on corn seeds was confirmed considering the physical aspects and without compromising the physiological potential.