Spatial arrangement facilitates handling and provides efficiency in light interception by the leaves, in a branching architecture adjusted to the leaf-area index and an increased profitability of the crop. The objective of the present study was to characterise the morphological and physiological behavior of the castor bean cv. BRS Energy when intercropped with cowpea cv. Marataoã, under different spatial arrangements. The experiment was conducted at the Experimental Station of Embrapa Algodão in Missão Velha, Ceará, using fertilizer (55-40-20). The experimental design was of randomised blocks in a 2³ x 3 factorial scheme. A factor combination of two spacings between rows (EL 1.5 and 1.0 m) and between castor bean plants (DM 0.5 and 1.0 m), and two densities of cowpea (DC 0,20 m, with one or two plants per hole every 0.20 m), made up the primary treatments which were distributed across the plots, with the three branching types (branches of the primary, secondary and tertiary racemes) distributed across the subplots, representing the secondary treatment. The growth of the castor bean adjusts itself to the different spacings, offset by the morphological plasticity of the crop, which presents an angle of lesser degree (54.30) in the branches of the primary racemes, and more open angles in the branches of the secondary (62.17) and tertiary (65.71) racemes. The EL with the DM and DC all interacted to produce the plasticity of the castor bean during growth. The branching angle increases with the order and height of the racemes on the plant, being influenced by crop density.
Ricinus communis; Vigna unguiculata; Spacing; Branching angle
