Agronomic performance of cultivars sunflower in the South Part of Tocantins

The cultivation of sunflower (Helianthus annuus L.) can be conducted in various times and locations during the crop year. In state of Tocantins the culture can be explored in crop in cerrado region and in intercrop in sub-irrigated lowland. The objective of this study was to evaluate the effect of swing times in Gurupi-TO and Formoso of Araguaia-TO, with five cultivars sunflower. It was installed four times in Gurupi-TO and one in Formoso-TO. The experimental design was randomized blocks, with 25 treatments and three replications. The was five times: EP1(24/11/2008), EP2(01/12/2008), EP3(18 / 12/2008) and EP4(12/30/2008) in Gurupi-TO and Formoso (07/04/2009) in Formoso do Araguaia-TO, with five cultivars: H250, H251, H358, H360 and H884. There was significant interaction between times and cultivars for the traits: flowering, plant height, normal achene, weight of thousand achene, hectolitre weight and productivity of achenes. In Gurupi-TO, there was a negative influence for all the avaluated traits as the sowings were delayed, It accurred because of the incidence of Alternaria helianthi. Productivity close to 3000 kg ha-1 was obtained in Gurupi (EP1) and the intercrop in Formoso do Araguaia. The most productive cultivars were the H251 and H358, when cultivated in EP1 and EP5.