Germinação e produção de girassol em condições de estresse

• Ano de defesa: 2015
• Autor(a) principal: Nunes, Renato Leandro Costa
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Fitotecnia; Germinação; Estresses; Girassol; Seed germination; Helianthus annuus
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/19119

Currently one of the largest interests in the case of physiological seed quality, is to determine a more normal seedlings germinated in less time possible. The objective of this study was to evaluate the germination behavior, physiological and production of sunflower cultivars under conditions of abiotic and biotic stress, and to determine the periods of weed interference in this culture. First, the effects of abiotic factor (temperature) in a completely randomized design in a factorial 5 x 20, five temperature regimes 25.0; 27.5; 30.0; 32.5 and 35,0º C and 20 cultivars. With the result obtained in the first experiment was carried out experiments with salt and water stress. Both were held in DIC in a factorial 4 x 5, four cultivars that had germination behavior highlighted submitted to five water potentials (0.0, -0.3, -0.6, -0.9 and -1.2 MPa ). Both experiments were conducted in a growth chamber at 30 ° C, the best temperature for germination, and that this temperature is similar to Ceará coastal micro having low altitude and latitude. The experiments were conducted with four replications and evaluated the germination percentage, germination rate index, mean germination time, average fresh and dry weight of seedlings. Besides these, was determined to productivity and periods of weed interference in sunflower cultivation in the field, and for that used a randomized block design with four replications in a factorial 2 x 5 being, that is, two types of competition (presence or absence) combined with periods of coexistence and weed control being 20, 40, 60, 80 and 100 days after emergence of sunflower. The temperature of 30 ° C was the most suitable for conducting the cultivars germination test. The cv. Olissun showed the highest physiological quality under different conditions of temperature, while maintaining acceptable values for the thermal stresses, water and salt. Coexistence intervals in Olissun Sunflower cultivation affected periods of weed interference in culture. For achenes productivity, the period before interference was 27 days after emergence (DAE) of culture, the total period of interference prevention was 37 DAE and the critical period of interference covered 10 days of crop cycle