Potassium is a nutrient that positively affects achenes production within sunflower crop (Helianthus annuus L.) and its proper management is indispensable for better economical employment of this element and for a less environmental impact. Requirement nutritional between cultivars of the same species is distinct, even under the same conditions of cultivation. In order to assess production components of three sunflower cultivars submitted to different rates of potassium sidedressing an experiment was conducted in distrocohesive Yellow Latosol in the savanna of Roraima, in randomized blocks and factorial schema (3 x 5), with four replicates. Treatments consisted of the combination of three varieties (Agrobel 960, Agrobel 967 and Embrapa 122/V2000) and five rates of potassium side dressing (0; 30; 60; 90 and 120 kg ha-1). Effects of rates of K were independent from the effects of the cultivars. Hybrid Agrobel 967 presented superiority in productivity of of achenes, oil and oil content in relation to the hybrid Agrobel 960 and to the variety Embrapa 122/V2000. The most economic rate of potassium in sidedressing for productivity of achene and productivity oil was 74.5 and 80.1 kg ha-1, respectively. The maximum productions achieved by adding increasing rates of K2O as sidedressing were 2,038.3 kg ha-1 of achenes, with 52.5% of oil in seed and 1,079.3 kg ha-1 of oil yield.
Helianthus annuus L.; Achene yield; Oil teor; Savannah of Roraima
