Nutrição e fertilização de orquídeas in vitro e em vasos

• Autor(a) principal: Rodrigues, Donizetti Tomaz
• Data de Publicação: 2005
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5433
• topic: Orquídea; Meio de cultura; Água sanitária; Contaminação; Orchid; Culture medium; Bleach; Contamination; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

The nutrition of ornamental plants plays an important role in the production of quality seedlings and flowers. In general, studies focusing on nutrition of such plants are rare, particularly for orchids, which represent a wide field for new research. On this background, our study investigated mainly: the performance of in vitro-grown orchid plants in different chemical media compositions; the effect of the addition of organic and/or chemical fertilizers; and lime addition to the growth medium. In vitro cultivation was evaluated regarding the plant response to different mineral doses and compositions in the medium. The Knudson C medium and that of Novais or NPK fertilizers were used as nutrient sources for this purpose. Two studies were realized in the experiments in pots: one tested different organic fertilizers (a commercial and another homemade one, the latter composed of castor bean meal, bonemeal and ashes) or mineral fertilizers (Peter s or Ca nitrate), applied individually or jointly. The second tested the application of lime doses to the growth medium of plants of the genus Epidendrum. Results obtained in vitro showed that the simple use of NPK fertilizers in culture medium for orchids is feasible; maximal seedling growth was achieved with doses of 5 g L -1 . The simultaneous application of homemade organic and Peter s fertilizers led to a significant increase in plant growth, while separate applications of the two fertilizers did not result in significant differences between them. The commercial organic fertilizer provoked B toxicity symptoms in the plants, as demonstrated in the tissue analysis. Lime application resulted in a higher total dry matter yield and number of leaves per plant. There was however no significant difference in plant height, resulting in plants with shorter internodes, which indicates a probable Zn deficiency.