Response of Castor Bean Plants to Different Row Spacings and Planting Seasons

Abstract

The cultivation of the castor bean plant is prominent and important because of its potential for producing vegetable oils with special properties. However, research on cultivating castor bean plants is scarce, especially in areas with altitudes of 300 m or below. Moreover, the currently available cultivars have not been widely tested in Brazil. Thus, the aim of this study was to evaluate the response of the castor bean cultivar BRS Nordestina to different spacings at low altitudes during two cropping seasons. The study was conducted in the municipality of Itaocara, in the northwest Fluminense region, Brazil, which has an altitude of 60 m. The treatments consisted of five row spacings (1.5, 2.0, 2.5, 3.0 and 3.5 m) with 1 m between plants. The plants were cultivated in the 2007/2008 spring/summer season or in the 2008 autumn/winter season. A randomised block design with four replicates was used. The following parameters were assessed: plant height, height of insertion of primary raceme, number of racemes per plant, raceme length, number of fruits per raceme and grain yield. The spacing of 2.5 m between rows had the highest yield of castor beans during the two cropping seasons. The average yield of the cultivar BRS Nordestina indicates its potential for cultivation in northern Rio de Janeiro, below an altitude of 300 m. The yield was higher during the summer cropping season. The less-dense arrangement of the plant population contributed to the cultivation of plants with more racemes in both growing seasons.