Enraizamento de manjericão em diferentes substratos e doses de cinzas / Stem rooting of basil in different substrates and doses of ash

O trabalho teve como objetivo avaliar a influência de doses de cinzas em diferentes substratos no enraizamento de estacas de manjericão (Ocimum basilicum). O experimento foi conduzido em área do Núcleo de Capacitação e Pesquisa da Universidade Federal Rural da Amazônia, em Belém. Foi utilizado o delineamento experimental inteiramente casualizado, em esquema fatorial 2 x 5, constituído pelas combinações entre os fatores substratos (casca de arroz carbonizada e casca de castanha triturada) e acréscimo de cinzas (5 mL e 10 mL de cinza de casca de arroz, 5 mL e 10 mL de cinza de casca de castanha e sem cinza) com 4 repetições. Cada unidade experimental foi constituída por 10 estacas, num total de 400 estacas. Foram avaliadas as características percentual de enraizamento de estacas, número e comprimento de raízes. Não houve interações significativas entre os fatores avaliados (substrato e cinzas). Entre as características avaliadas o substrato casca de arroz carbonizada apresentou diferenças apenas no comprimento da raiz e no número de raízes, enquanto as dosagens de cinzas apresentaram diferenças apenas no percentual de enraizamento. O trabalho permitiu concluir que as dosagens de cinzas apresentaram efeito positivo sobre o enraizamento das estacas de manjericão, assim como o substrato a base de casca de arroz carbonizada propiciou melhores condições para o desenvolvimento das raízes. Assim, a casca de arroz é uma alternativa totalmente viável, pois além de apresentar características apropriadas para o enraizamento também possui baixo custo de aquisição, estando ao alcance de muitos produtores.

The study aimed to evaluate the influence of ash doses on different substrates on the stem rooting of basil (Ocimum basilicum). The experiment was conducted in the area of core training and research at the Universidade Federal Rural da Amazônia, in Belém, used a completely randomized design, factorial scheme 2 x 5 consisting of the combinations of the factors substrate (carbonized rice husk and bark brown ground) and increase ash (5 mL and 10 mL of rice husk ash 5 mL and 10 mL of husk ash and brown bark no gray) with four repetitions. Each experimental unit consisted of 10 cuttings, a total of 400 cuttings. Was evaluated the characteristics percentage of rooting, number and length of roots. There was no significant interaction between the factors evaluated (substrate and ash). Among the characteristics evaluated the carbonized rice showed only differences in root length and root number, while the levels of ash showed only differences in rooting percentage. The study revealed that the dosages of ash had a positive effect on rooting of cuttings of basil, as well as the substrate prepared with rice hulls provided the best conditions for root development. Thus, the rice husk is an alternative, as well as presenting features suitable for rooting also has a low cost of acquisition, being within reach of many producers.

The phenomenon of "one-trial tolerance" to the anxiolytic effect of chlordiazepoxide in the elevated plus-maze is abolished by the introduction of a motivational conflict situation.

A single exposure to the elevated plus-maze test of anxiety reduces or abolishes the anxiolytic efficacy of benzodiazepines. The present study was designed to examine whether this phenomenon of "one-trial tolerance" resulted from a motivational deficit on trial 2. We hypothesized that whereas there is a motivational conflict on trial 1 in relation to the open arms (exploration drive X natural fear of open spaces), there is no "reason" for an animal to explore it on trial 2. A motivational conflict was introduced on trial 2 by rendering the enclosed arms of the apparatus aversive on trial 1. Thus, every time rats entered the enclosed arms, an aversive situation (light and hot air blow) was produced until they left the arm. On trial 2, rats did not receive this aversive stimulation. Chlordiazepoxide significantly enhanced the percent open arm time as well as the percent open arm entries on trial 2 in rats that had been submitted to the aversive stimulation in the enclosed arms on trial 1, but was not effective in rats which had been exposed to the apparatus in the absence of the aversive stimulation on trial 1. In addition, there was no difference in the percent open arm time and entries on trial 2 between saline-treated rats submitted to the aversive or non-aversive condition on trial 1. The aversive condition on trial 1 did not modify the number of total arm entries on trial 2, either. The results suggest that the anxiolytic effect of chlordiazepoxide in the elevated plus-maze depends on the presence of a motivational conflict situation.