Floração de Helianthus annuus L. com adubação NPK e conteúdo de água disponível no solo

The production of flowers and ornamental plants is an activity that has achieved great economic importance in several Brazilian states however in Paraiba State is little explored, which is intended to leverage with fertilization and water management. A trial was carried out in a greenhouse located at the Federal University of Campina Grande, in Campina Grande, Paraiba State, Brazil, with sunflower, cv Embrapa 122 V2000, in order to evaluate the effects of nitrogen, phosphorus, potassium and available soil water on the flowering this oil crop. A completely randomized design with 11 treatments originated from a baconian matrix was adopted. Reference doses were 60:80:80 kg ha-1 of N:P 2 O 5 :K 2 O, respectively and four available soil water (55, 70, 85 and 100% AW) in triplicate. Stem growth, head external and internal diameter and number of petals were measured when the flowers were fully open. While not affecting the number of petals, the highest percentage of available soil water promoted better benefit to the inflorescence of sunflower. Doses of 60 kg ha -1 N; 80 kg ha -1 P 2 O 5 e 80 kg ha -1 K 2 O provided better quality inflorescences.