GROWTH PARAMETERS and MICRONUTRIENT UPTAKE RATE of SUNFLOWER CROP (Helianthus annuus L.).

The sunflower crop area has increased considerably in Brazil. The sunflower’s oil is very useful for human feed and biofuel production. Regarding it’s benefits, the sunflower`s oil is rich in polyunsaturated fatty acids as the linoleic acid, which is essential to human health. However, it is important to evaluate the growth parameters which make the sunflower an efficient plant in oil production; as well the influence of mineral nutrition with micronutrients in the oil production. Thus, this study aimed to establish curves of micronutrients accumulation in sunflower crop. The experiment was conducted in field on Typic Hapludox, located at Embrapa Soja in Londrina-PR The fertilization seeding was 300 kg/ha of 05-20-20 (N-P₂O₅-K₂O), before sowing. It was used the hybrid BRS-191 and the final plant density was 40.000 plants/ha. Plant samples were collected at each interval of 14 days after emergence and share in different parts as petioles, leaves, stems and, when applicable, chapter and achenes. It was evaluated the height, number of leaves, leaf area and the oil content in the achenes. After drying, each plant part was weighed and ground in order to determine the content of Zn, Mn, Fe, Cu and B. The curve of nutrient acculation was obtained through the nutrient content and dry mass of each plant material. In general, the estimated dry mass and achenes of the BRS 191 hybrid was 10400 kg/ha and 37.58 kg/ha showing maximum predict value of  32 leaves, 0.80 m² of leaf area and 49.53% of oil content. Iron was the micronutrient more absorbed, which accumulated more in the achenes related to the total nutrient uptake. The total accumulation of Fe, Mn, Zn, B and Cu were 38.06, 19.68, 9.20, 8.62 and 4.27 mg/plant of sunflower.