Saturation Levels by Bases and Time of Incubation in the Development and Growth of Ornamental Sunflower

摘要

Floriculture is a promising segment of Brazilian agriculture. The ornamental sunflower (Helianthus annuus L. cv. Folded Sungold), also known as dwarf sunflower, in addition to being used in gardens can be marketed as cut flower or vase. The sunflower represents a great alternative for small producers because it requires little space, has easy handling and short cycle, besides providing greater economic return. In this context, we aimed to evaluate the development of this culture submitted to different levels of saturation per base, combined with the incubation time of the limestone. The experiment was carried out in a greenhouse at the Federal University of Mato Grosso-University Campus of Rondonópolis. A randomized block design with factorial scheme 6 × 2 was used, with six levels of saturation per base: 0, 20%, 40%, 60%, 80%, 100%;and two incubation times: 0 and 30 days, resulting in 12 treatments with four replicates, totaling 48 experimental units. Each plot consisted of a plastic polyethylene vessel with a capacity of 1.2 dm−3. The following variables were analyzed: Height of the floral stem;number of leaves, diameter of chapters;root volume;fresh mass of leaves;fresh mass of floral stems;fresh mass of chapters;fresh root mass and chlorophyll index (SPAD). Data were submitted to analysis of variance by the test F at 5% probability of error. The qualitative factors were submitted to the Tukey test and quantitative factors to the regression test, both with a 5% probability of error. Basal saturation levels of 80% and 100%, in the treatment with incubated soil, provided higher quality of inflorescence for commercialization purposes.