Doses of boron in sunflower growing development

The objective of this study was to verify the influence of boron (B) doses on soil boron availability and sunflower characteristics in Tangará da Serra -MT. A randomized block design with four replicates, six doses of B (0; 0,5; 1,0; 1,5; 2,0 and 4,0 kg ha-1of B) was used, using boric acid. B content in soil, leaf B concentration, stem diameter, plant height, leaf diameter, mass of 1,000 achenes, shoot dry mass and yield were evaluated. All characteristics were influenced. The dose of 4 kg ha-1provided toxicity to plants with negative effects on shoot diameter and shoot dry mass.