Productivity of castor bean plants intercropped at different plant densities with Urochloa ruziziensis

ABSTRACT Castor bean is an important raw material to produce biofuel in Brazil and can be grown in several regions of the country due to its good adaptation and tolerance to high temperatures and water deficit. The objective of this study was to evaluate the productivity of castor bean plants intercropped at different plant densities with Urochloa ruziziensis. The experiment was conducted in a randomized block design with four replications, using a 4 × 2 factorial arrangement, consisting of four plant densities (13,574, 24,512, 36,816, and 40,723 plants ha-1) of castor bean and two crop systems (single crop, and intercrop with Urochloa ruziziensis). The data were subjected to analyses of variance and regression, and means were compared by the Tukey’s test (p