The low availability of boron (B) in the soil is one of the limiting factors for the production of sunflower, which is an oleaginous plant characterized by broad climatic adaptability. The objective of this study was to evaluate the influence of boron rates applied in different soil classes on the development of sunflower cultivar Helium 863. The samples were collected in the layer 0-20 cm of the soil classes Gray Argisol - GL, Red Yellow Argisol -RYA, Litholic Neosol -LN, Eutrophic Red Argisol - ERA, Fluvic Neosol -FN and Haplic Vertisol - HV. The experiment was arranged in a randomized block 4 x 6 factorial (soils x doses) design, with four replications. The experimental unit was represented by one plant per pot. The soils showed significant effect (p <0.01) for all growth parameters studied. The sunflower plants grown in the soils FN, HV, GL and LN showed the highest leaf area, the largest inflorescence diameter, the highest levels of foliar boron, largest number of leaves and highest plant height, respectively. Fertilization with boron did not influence the production of dry matter of sunflower cv. Helium 863.
mineral nutrition; Helianthus annuus L.; micronutrient; azomethine-H; leaf area
