ABSTRACT
ABSTRACT In the past decades, desert rose has become a very popular ornamental plant, especially among collectors, due to its exotic and sculptural forms. However, it has been grown on a commercial scale only recently, and little is known about how to best manage it as a container-grown plant, or even which potting medium (substrate) to recommend. Therefore, the aim of this study was to investigate the interactions between potting media and irrigation levels for growing desert rose as a potted ornamental plant. The experiment was conducted in a greenhouse using a 6 x 2 factorial arrangement with six replications, six potting media and two irrigation levels. The mixes were characterized by measuring their physical properties, specifically the density and water retention capacity (WRC), as well as chemical properties, such as the pH and electrical conductivity (EC). After 210 days, plant growth and plant water consumption were evaluated and measured. A lower dry density for the vermiculite mixes was observed in comparison to that for the sand mixes. However, WRC ranged from 428 to 528 mL L-1 among the mixes, values considered close to ideal. In general, plant growth exhibited higher increases in mixes consisting of coconut fiber + sand or vermiculite, regardless of the irrigation level. Mixes of vermiculite + coconut fiber and sand + coconut fiber can be used to grow desert rose in pots, as long as irrigation is used to maintain the moisture content of the potting medium (mix) between 60-70% and 80-90% of the WRC.
RESUMO Na última década a rosa do deserto ganhou destaque no mercado de flores, principalmente entre colecionadores, devido às suas formas exóticas e esculturais; porém, o cultivo da espécie em escala comercial é bastante recente e pouco se sabe acerca do manejo da cultura, inclusive no que diz respeito à recomendação de substratos. Assim, objetiva-se nesse trabalho estudar a interação entre substratos e níveis de irrigação no desenvolvimento de rosa do deserto em vaso. Conduziu-se o experimento em casa de vegetação em esquema fatorial 6 x 2, com seis repetições, adotando-se seis substratos e dois níveis de irrigação. As misturas foram caracterizadas mensurando-se suas propriedades físicas (densidade e capacidade de retenção de água - CRA) e químicas (pH e condutividade elétrica - CE). Aos 210 dias de cultivo avaliou-se o crescimento das plantas; além do consumo de água pela cultura. Para as misturas compostas por vermiculita verificou-se menor densidade seca em relação às compostas por areia; no entanto, a CRA variou de 428 a 528 mL L-1 entre as misturas, valores próximos aos considerados ideais. De modo geral, o crescimento das plantas teve maiores incrementos nas misturas compostas por fibra de coco mais areia ou vermiculita, independente do nível de irrigação. As misturas vermiculita + fibra de coco e areia + fibra de coco podem ser empregadas para o cultivo em vaso de rosa do deserto, quando se mantiver os níveis de irrigação entre 60-70% e 80-90% da CRA das misturas.
ABSTRACT
Aims: Adenium obesum is a known medicinal plant thereby creating the need for the evaluation of its toxicity and histopathological effects on the liver of female Wistar rats orally administered ethanol extract of the plant’s stem bark. Place and Duration of Study: Department of Veterinary Pathology, Ahmadu Bello University, Zaria, Nigeria, between January 2011 and January 2012. Methodology: Ethanol extraction of A. obesum stem bark was performed prior to screening it for its phytochemical constituents. Female rats per group were orally administered by gavage pre-defined doses (300mgkg-1, 2000mgkg-1 and 5000 mgkg-1) of the extract separatively in a stepwise procedure and observed for signs of toxicity. Control rats were administered distilled water placebo. Results: The extract contained some alkaloids, saponins, tannins, flavonoids, glycosides, steroids and triterpens with no anthraquinones. Exposed rats did not show signs of toxicity and neither was there any mortality. Changes in aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase activities were non-significant (p>0.05). Congestion and fatty degenerative changes were seen in the liver of the exposed rats, which were not significantly (p>0.05) different in exposed rats compared to the control. Conclusion: Adenium obesum did not cause major hepatic damage in the exposed rats and therefore, it is a safe oral medicinal plant within the extract dose and exposure period used in the study.