Select thinning and plant population in of the castor oil plant

Abstract

Crop management is composed of a set of field practices with the purpose of perfect crop yield. The present study had the objective of evaluating the selected removal of axillary buds of plant growth, on the yield components of the castor oil plant, cv. BRS 188 Paraguaçu, cultivated under two plant populations. The experiment was carried out in the Fazenda Experimental do Vale do Curu, Pentecoste, Ceará, Brazil, from June to December, 2007. The treatments were the combination of two spacing with four types of select thinning of the axillary buds and a control treatment managed according to the recommended cropping practices for the used cultivar . The experimental design was a factorial [(4 x 2) +1] arrangement in randomized blocks, with four replications and nine treatments. The treatments were the combination of four types of pruning (unpruned, prune all but the main shoot; prune all but the main and the first secondary axillary bud; prune all but the main stem and the first and the secondary buds, and two plant spacing (1.0 m x 0.50 m and 1.00 m x 0.25 m). In the control treatment the plants were unpruned and were planted in the spacing 2.0 m x 1.0 m. The pruning of the axillary buds promoted increases in the oil contend compared to the unpruned control. The pruning treatments provided a reduction in the cycle of cv. BRS 188 Paraguaçu. The higher the plant population, the higher the participation of primary racemes in the total grain yield.