Wood ash as corrective of soil pH and as fertilizer in ornamental sunflower cultivation

Wood ash, as having required nutrients by plants, can be an alternative in fertilization and soil acidity correction in agricultural crops. This study aimed to evaluate the development of the sunflower ornamental cultivar (Helianthus annuus L.) Sunflower F1 Sunbright Supreme when subjected to wood ash fertilization into of Cerrado Oxisol. The experiment was conducted in a greenhouse, in the municipality of Rondonópolis-MT, with six treatments (0, 4, 8, 12, 16 and 20 g dm -3 of wood ash) and six repetitions. The soil sample was collected from 0 to 0.20 m depth. Data were collected at 30, 37, 44 and 51 days after sowing on plant height, stem diameter, leaf number and chlorophyll index. Chapter diameter and height and disc diameter variables were assessed at 44 and 51 days after sowing, respectively. Data were subjected to analysis of variance and regression test at 5% probability through the SISVAR statistical program. Wood ash enhanced ornamental sunflower plant growth at doses between 12 and 16 g dm -3 , satisfying the commercial standards required by the flower market.