Resumo

PINEDA-PINEDA, J. et al. Efluents and substrates on poinsettia development. Rev. Chapingo Ser.Hortic [online]. 2008, vol.14, n.2, pp.131-137. ISSN 2007-4034.

In order to improve quality and plant production in poinsettia cv. Supjibi Red by using organic fertilization with lower detrimental impact on the environment, this research was designed to assess the effect of foliar sprays of two effluents from vermicompost [one obtained in 2003 (1) and another in 2004 (2)] and the substrates: 1) volcanic rock, 2) mix 1 (peat + vermiculite, 1:1 v/v), and 3) mix 2 (leaf mould + volcanic rock + peat + perlite, 3:1:0.75:0.75 v/v). Foliar sprays were aplied every 10 days at 0.05% concentration. Irrigation with complete nutrient solution was applied daily in plants grown in volcanic rock, twice a weekin in plants grown in mix 1, and once a week in plants grown using mix 2. Plants grown in volcanic rock and sprayed with effluent 1 showed highest plant height (50.2 cm), chyatia number (64), bracts area (3884 cm²), total dry weight (39.6 g), and leaves dry weight (13.6 g). There was no significant effects on shoots and flowers number, specific leaf weight, anthocyanin concentration, and bract color. Effluents did not have any significant effect in leaf nutrient concentration. Effluents effectiveness varied depending on the substrate used. The best treatment was volcanic rock plus foliar sprays of effluent 1, this treatment could be used in the poinsettia stock plants hydroponic culture.

Palavras-chave : Euphorbia pulcherrima Willd. ex Klotzch; foliar fertilization; vegetative growth; chyatia; nutrition.