Características fitotécnicas e fisiológicas do gladíolo Amsterdam cultivado sob diferentes tipos de telas

• Autor(a) principal: Santos, Raimundo Luiz Laurinho dos
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1237
• topic: Gladíolo (Amsterdam); Gladíolo - Cultivo; Fluorescência da clorofila; Sombreamento - Telas coloridas; Gladiolus (Amsterdam); Gladiolus - Cultivation; Chlorophyll fluorescence; Shading - Colorful fabrics; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

The objective of this study was to evaluate physiological and phytotechnical characters of gladiolus Amsterdam , as well as monitor its development through growth analysis. The gladiolus was grown in four different light environments: full sunlight (control) and under three screens − aluminized, red and blue −, which restricted in 50% the overall brightness. Bulbs with circumference between 12 and 14 cm were planted in pots with capacity of 11 L containing appropriate substrate. To monitor the temperature and humidity throughout the entire plant cycle, miniloggers (HT-500) were installed. The experiments were conducted in a completely randomized design with 60 pots in each light environment, of which five were used for the phytotechnical characters measurement, five were left in the environment after stem harvest to complete the ripening of the bulbs and 32 were employed in growth analysis, the rest was used in the border. When plants exhibited two true leaves, photosynthesis measurements were made in relation to light intensity and time of day, light intensity in relation to time of day and spectrum quality curves in the four culture environments. Spot measurements of gas exchange and chlorophyll fluorescence were initiated 36 days after planting and repeated every 10 days, four in spring and five in autumn. Growth analysis started 21 days after planting, when the plants presented the first pair of leaves. There were eight samples in each growing season. There was no significant effect between treatment averages in the end of each growing season regarding leaf gas exchange. The stomatal conductance, transpiration, and internal carbon dioxide concentration in the substomatal chambers were lower during spring, but not limiting the quality of the flower stem. The chlorophyll fluorescence parameters indicated no presence of stress in gladiolus in two cropping seasons. In treatments with screens, the number of flowers in floral spike was higher during spring. The gladiolus showed a superior average in the length of the aerial part than the ones of control, being greater in autumn. In both evaluated periods, the gladiolus under blue screen did not reach the best commercial classification (10 mm) as for the stem diameter, and flower diameter was smaller in autumn. Only in the treatments with aluminized and red screens the plants achieved the best commercial standard (≥ 110 cm) as for the length of the flower stem. The average dry matter of the flower stem of the gladiolus grown under red and aluminized screens and full sunlight were greater than the gladiolus under blue screen. The total dry matter (TDM) and leaf area (LA) showed growth pattern of a sigmoidal curve, and gladiolus grown under blue screen had lower TDM. Specific leaf area (SLA) of gladiolus under blue screen was greater than the others in the two growing seasons. The leaf area duration (LAD), both in spring and autumn, had strong growth. While the plants had accelerated vegetative growth, they began to be stable at 63 DAP. The leaf area ratio (LAR) and leaf weight ratio (LWR) were elevated in the first samplings, indicating strong investment in leaves. The bulb weight ratio (BWR) in full sunlight was greater than in treatments with screens. In the full sunlight treatment, the averages of plant height were lower in the two growing seasons. The gladiolus grown under red and aluminized screens presented vigorous growth and greater number of commercially desirable characteristics.