Influência de retardantes de crescimento e da luminosidade na produção de crisântemo de vaso

• Autor(a) principal: Matiello, Hediberto Nei
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1125
• topic: Dendranthema grandiflora; Cromatografia; Daminozide; Paclobutrazol; Clormequat; Dendranthema grandiflora; Chromatography; Daminozide; Paclobutrazol; Clormequat; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

This work evaluated the effects of concentration, frequency of application and kind of growth retardants, light, type and number of long days in the plant parameters of potted chrysanthemum (Dendranthema grandiflora Tzvelev). The distribution and permanence of the growth retardants in the plant organs were also verified. Three experiments were realized. In the first one, the chrysanthemum varieties Indianápolis and White Mega Time were submitted to combinations of different factors like light in the long days (150 and 160 lux), long day's period (15 and 20 days), kind (daminozide and clormequat), concentration (0 and 4000 mgL-1) and frequency of application (9 and 21 days) of growth retardants. The experimental design was the randomized block with three replications in a 26 factorial way. In the second experiment, the Indianapolis variety was treated with different concentrations of daminozid and clormequat (0 to 4000 mgL-1), and paclobutrazol (0 to 80 mgL-1). The frequency of application was 9 to 21 days. The experimental design was the central composite with five replications of the central point. In the third experiment, methanolic extracts of roots, stems and leaves of the Indianapolis variety were submitted to high performance liquid chromatography (HPLC) analyses after application of 4000 mgL-1 of daminozide, 4000 mgL-1 of clormequat and 80 mg L-1 of paclobutrazol. The experimental design was completely randomized with three replications for each concentration. The results of the first experiment showed many two-factors interactions, mainly in the plant height, number of floral stems and the cultivation cycle. The intensity and frequency of light affected few plant characteristics. Plants of the White Mega Time variety treated with daminozide showed the lower height, smaller diameter and greater number of flower buds. The second experiment showed the effect of concentration of daminozide in the plant height. The commercial height was obtained with only one application of 2065 mgL-1. The concentration and frequency of application of clormequat affected only the dry weight of the plant and showed a phytotoxic effect. Plant commercial height was obtained with one application of 42.85 mgL-1 of paclobutrazol. The third experiment showed that the HPLC was efficient to detect and quantify the daminozide and paclobutrazol in the root, stem and leaf. The clomerquat was not detected. The leaves showed the highest concentration of daminozide and paclobutrazol, followed by stem and root. The daminozide was most persistent in the stem, while the paclobutrazol was in the leaves.