Propagation of Cestrum corymbosum by seeds and cuttings

Cestrum corymbosum é um arbusto ornamental nativo do Brasil. A pesquisa visou estudar sua propagação sexuada e vegetativa, avaliando a germinação e o crescimento e testando o efeito do tamanho das estacas e do ácido indolbutírico (AIB) no seu enraizamento e desenvolvimento. Para avaliar a germinação, foram utilizadas seis repetições de 100 sementes. Em seguida, 200 plântulas foram transferidas para embalagens individuais mantidas em canteiro. O experimento de propagação vegetativa, com delineamento inteiramente casualizado em arranjo fatorial 3 x 2, constituiu-se na combinação de três concentrações de AIB (0, 1000 e 2000 mg.L-1) e dois tamanhos de estacas (8 e 15 cm). As estacas foram plantadas em substrato comercial Plantmax HA®. No experimento de propagação sexuada, verificou-se elevada germinação (92%), assim como alta taxa de sobrevivência após repicagem para recipientes individuais (99,5%). Para o experimento de propagação vegetativa, foi detectada influência significativa do tamanho das estacas em relação à sobrevivência, enraizamento (P < 0,01) e número de folhas (P < 0,05). Estacas de 8 cm apresentaram melhor sobrevivência (93,3%) e enraizamento (91,3%). A aplicação de concentrações de AIB não resultou em diferenças significativas (P < 0,01), demonstrando não ser necessária para o enraizamento dessa espécie.Palavras-chave: Germinação; enraizamento; ácido indolbutírico; espécie nativa; Solanaceae.AbstractPropagation of Cestrum corymbosum by seeds and cuttings. Cestrum corymbosum is an ornamental bush native from Brazil. This research aimed to study the sexual and vegetative propagation of this species, evaluating germination and growth of the seedlings, and testing the influence of indolebutyric acid (IBA) and cuttings size on its rooting and development. In order to evaluate germination, six repetitions of 100 seeds were considered. After that, 200 seedlings have been transplanted to individual packages kept in a bed. The vegetative propagation experiment has been arranged in a 3 x 2 factorial completely randomized design that comprised the combination of three IBA concentrations (0, 1000 and 2000 mg.L-1) for two cuttings sizes (8 and 15 cm). The cuttings were planted in commercial substrate Plantmax HA®. A high germination (92%) has been verified. The survival after transplantation was very high (99.5%). It was detected statistically significant influence of the cuttings size on plants survival, rooting (P<0.01) and leaves number (P<0.05). The cuttings of 8 cm presented better survival (93.3%) and rooting (91.3%) rates. The treatment with IBA in distinct concentrations did not produce results with significant differences (P<0.01).Keywords: Germination; rooting; indolebutyric acid; native species; Solanaceae. AbstractCestrum corymbosum is an ornamental bush native from Brazil. This research aimed to study the sexual and vegetative propagation of this species, evaluating germination and growth of the seedlings, and testing the influence of indolebutyric acid (IBA) and cuttings size on its rooting and development. In order to evaluate germination, six repetitions of 100 seeds were considered. After that, 200 seedlings have been transplanted to individual packages kept in a bed. The vegetative propagation experiment has been arranged in a 3 x 2 factorial completely randomized design that comprised the combination of three IBA concentrations (0, 1000 and 2000 mg.L-1) for two cuttings sizes (8 and 15 cm). The cuttings were planted in commercial substrate Plantmax HA®. A high germination (92%) has been verified. The survival after transplantation was very high (99.5%). It was detected statistically significant influence of the cuttings size on plants survival, rooting (P<0.01) and leaves number (P<0.05). The cuttings of 8 cm presented better survival (93.3%) and rooting (91.3%) rates. The treatment with IBA in distinct concentrations did not produce results with significant differences (P