Crescimento e desenvolvimento da mamoneira (Ricinus communis L.) em diferentes ambientes.

Abstract

The castor bean tree (Ricinus communis L.) is a plant of raised tolerate to dries, it is sensitive enough to the diverse factors, among them the climatic one, generally that stressor agent takes the plant to leave the normality condition of the metabolism. Being sufficiently scarce information about the effect of the climate in the physiology of the plants. This way was it was objectified to verify and to quantify the isolated and joint effect of the factors nitrogen fertilization, and nocturnal temperature, with raised relative humidity of air, simulated in chamber of growth with ample contrai of the environment, front to the natural environment of Campina Grande - PB, the city zone ado for the culture of that oily plant in regimen of dry land on the half- barren Brazilian. The experiment was lead in conditions of natural environment and chamber of growth which belongs to the National Center of Research of Cotton - CNPA EMBRAPA, in Campina Grande - PB, among the months of July and August, in 2005. The used experiment delineation was of the sort with four repetitions and eight treatments, in factorial distribution, being the factors four nocturnal, dose of Nitrogen (0;60;120 e 180 kg of N/ha) and two temperaturas (31°C) and low (21°C). It was realized the analyzes of variance of the data of the o variable of height of the plant, the caulinar diameter, total foliar area and fitomass, dry substance of stalk, leaf with petiole, fruit and root. Based on the data of the height for two environments, the raised nocturnal temperature reduced the growth of the plants from the 35 day emergency (DAE). The caulinar diameter, of two studied factors had significance for the two times (35 and 41 DAE) and there was not significance for the two others (19 and 26 DAE), indicating independence among the factors which were studied. For the number of leaves only to the 19 DAE there was not independence of the factors. On the foliar area it was observed that it did not get independence in the 26, 35 and 41 DAE and to the 19 DAE it got dependence. On the total fitomass of the leaf with petiole and the root they had reacted in different way to the simulation of high temperature. On the parts of stalk the increase was bigger in such a way in the first shot as on the last one, and in relation to the fruit, the fructification only happens in the natural environment. The nitrogen fertilization increases the growth of the plants, almost independent of environments.