Enxofre, magnésio e boro sobre a produção, qualidade e teor de lignina de sementes de soja

Abstract

Mineral nutrition has great importance in increasing productivity, and also influences the quality of seeds. Therefore, the aim of this work was to evaluate the effect of mineral nutrition on planting and seed treatment, on the production, lignin content and physiological quality of soybean seeds. For the installation of the field experiment and greenhouse, the seeds were treated with the mixed mineral fertilizer Up Seeds (cobalt 6 g L-1, molybdenum 120.6 g L-1 and nickel 12 g L-1) recommended in dose of 150 ml ha-1 and all of them were treated with Standak Top (2 ml kg-1), inoculated with Bradyrhizobium, using Masterflix liquid inoculant. The treatments used for soil fertilization were control, sulfur (Sulfururg 78 kg ha-1), sulfur and boron (Sulfururg B Max 98 kg ha-1) and sulfur, boron and magnesium (Sulfurmag 100 kg ha1; Max 51 kg ha-1; Produbor 9.8 kg ha-1). In the greenhouse the fertilization was using half of the dose of the field fertilization, to avoid phytotoxicity in the plants in the vases. Fertilization was done manually and then sowed. The evaluations carried out in the field were agronomic characteristics, productivity, classification by sieves, leaf diagnosis and chlorophyll content. The laboratory tests were germination, accelerated aging, emergency speed index, emergency, electrical conductivity, mass of one thousand seeds, tegument mass, lignin, tetrazolium, sanity, chemical composition and enzymatic analysis (esterase and isocitrate lyase). After in the greenhouse in stage R2 (full bloom), aerial part mass, number of nodules and mass of nodules were evaluated. Fertilization at planting with sulfur, boron and magnesium elements and treatment of the seeds with molybdenum, cobalt and nickel does not influence the agronomic characteristics and yield of the soybean. The physiological quality is not influenced by the nutrients applied in the planting and via the treatment of soybean seeds. These products also do not influence the lignin content in the integument of soybean seeds. Fertilization at the planting with sulfur, boron and magnesium elements and treatment of seeds with molybdenum, cobalt and nickel reduces the incidence of fungi Cladosporium sp and Cercospora Kikuchii. The treatment of seeds with molybdenum, cobalt and nickel and the fertilization in the planting with the nutrients sulfur, boron and magnesium do not interfere in the nodulation of the roots of soybean plants.