Tratamento de sementes com o micronutriente níquel em plântulas de genótipos de soja

Abstract

Nutritional management practices are essential to ensure the sustainability of agriculture in tropical agroecosystems. In the soybean cultivation system, modern genotypes are becoming more productive and more demanding in terms of nutrients, thus, there is concern regarding the current fertilizer recommendation to attend the nutritional plants demand. In this scenario, the application of emerging nutrients, such as nickel (Ni), can play a key role. This micronutrient is a cofactor of the enzymes urease and hydrogenase, which act in the nitrogen (N) metabolism in plants, in addition to acting in seed germination. However, studies on methods of application for this micronutrient, especially seed treatment, are incipient. The research project aims to evaluate the response of seedlings of modern soybean genotypes to fertilization with micronutrient Ni supplied in seed treatment. Furthermore, the project aims to determine the agronomic dose of this micronutrient, as well as evaluate the symptoms of its phytotoxicity. In the laboratory, six doses of Ni will be tested on six modern genotypes cultivated in tropical conditions. For this purpose, the experiment was implemented on germination paper and conducted in an incubator under controlled conditions. After seven days of implantation, the height of the aerial part and length of the root system were evaluated. The experimental design was completely randomized, with four replicates. The results were analyzed by analysis of variance and, when significant were analyzed by regression test, and the means were compared by the Tukey test (p < 0.05).Cultivars respond differently to Ni doses. For responsive cultivars, Ni application via seed treatment was beneficial up to a Ni dose of 66 mg kg-1 of seeds. Ni doses greater than 66 mg kg-1 of seeds increased the percentages of seedlings abnormal and dead seeds, and reduced the root and shoot lengths of seedlings.