Growth of castor bean plant under different types of wastewaters and soil water levels

Abstract

This work evaluated the effect of different levels of water into the soil and types of treated wastewaters from industries of Campina Grande city, Paraíba state, on the growth of castor bean plant, variety BRS Nordestina. The experiment was conducted in greenhouse of the National Center of Research of Cotton. The experimental design was in entirely randomized blocks with 15 treatments in scheme of additional factorial analysis [(4 x 3) + 3] with three replications, having the following factors: three types of treated wastewaters and water of provisioning (A1 = IPELSA - Industry of Cellulose and Paper of Paraíba S/A; A2 = COTEMINAS - Industry of improvement of cotton fiber S/A; A3 = ILCASA - Industry of dairy products of Grande S/A (LEBOM); A4 = Water of the network of public provisioning of Campina Grande city, three levels of available soil water (AW) (N1 = 100%, N2 = 80% and N3 = 70%) and three controls, one for each AW with water of provisioning and with inorganic fertilizer in the foundation (A4C). In order to evaluate the growth of the castor bean plant during a period of 135 days, biweekly measures of the plant height, diameter of the stem and total foliar area variables were accomplished. For all growth variables there were significant interactions among the studied factors, denoting the interdependence among them, what was reflected on the growth of the plants. The castor bean plant, variety BRS Nordestina, responded well to irrigation with treated wastewater, especially from COTEMINAS industry mainly when associated to the level of 100% of the available soil water.