Doses e formas de aplicação de boro em girassol

Abstract

This experiment was conducted in the experimental area of the Federal University of Fronteira Sul (UFFS), Campus Cerro Largo, at 28 ° 08 'south latitude and 54 ° 45' west longitude, in the state of Rio Grande do Sul, Brazil. The objective of evaluating the technical viability of boron doses applied at planting and foliar via, in the cultivar ADV5504 of sunflower, during the harvest period. The treatments consisted of four doses of boron at sowing (0, 2, 4 and 8 kg ha -1 ), two doses of boron via leaf (1 and 2 kg ha -1 ) and two doses of boron intercalating sowing/foliar (2 kg ha -1 at sowing and 1 kg ha -1 foliar and 2 kg ha -1 at sowing and 2 kg ha -1 foliar). Boron sources: borax (11% B) at the seeding and boric acid (17% B) were used as leaf sources. The experimental design was a randomized block design, with three replications. The growth components (plant height, stem diameters and section diameters), production components (grain yield and weight of 1.000 achenes) and lodging were evaluated. It was concluded that: the doses and forms of boron application had a significant effect on grain yield and sunflower weight of 1.000 years. Treatment with 8 kg ha -1 of B at sowing provided an average yield of 5.055 kg ha -1 and a mean weight of 1.000 achene of 63,3 g in the sunflower crop in the evaluated soil condition. The growth and lodging components were not influenced by of doses and forms of boron application.