Effect of two sources of zinc on the physiological quality of seed and nutrition of rice (Oriza sativa) seedlings

Abstract

Rice seeds coating with microparticulate zinc oxide can maximize the absorption of this micronutrient by the seedling and favor seeds vigor when compared with zinc sulfate. This work aimed to evaluate the sources and doses of zinc in seed quality and in the nutrition of rice seedlings. The experiment consisted of a completely randomized design with four replications, five doses of zinc in the form of oxide (0; 20; 40, 80 and 160 g kg(-1)), and a control treatment of zinc in the form of sulfate (40 g kg(-1)). The following parameters were evaluated: germination, accelerated aging, seedlings emergence, emergence speed index, cold test, dry matter, and zinc concentration in the root and shoot of the seedlings. Seed coating with zinc, regardless of the source, improved seed physiological quality and seedling nutrition. Zinc sources did not affect germination; however, the oxide form induced better seed vigor, except for the highest dose (160 g kg(-1)). Increasing doses of zinc oxide augmented the concentration of this nutrient in rice seedlings dry matter. Zinc coating of rice seeds in the form of microparticulate, depending on the dose, can maximize seed vigor and increase the concentration of this micronutrient in the seedlings when compared with zinc sulfate, the traditional source.