Results of spacing trials for a dwarf variety of castor beanA dwarf variety of castor bean, I. A. 38, is becoming increasingly popular among growers of this crop in the state of São Paulo. It is a good yielder and is easy to be harvested because of the short size of the plants. A total of 16 spacing trials for this variety have been carried out in six different experiment stations from 1948/1949 through 1952/1953. The spacings tested ranged from 1.00 to 2.50 m between rows, and from 0.45 to 2.00 m between plants in the row. The best yields under the conditions of the experiments were obtained when the rows were set 1.00 m apart and plants in the row spaced at distances from 0.45 to 0.90m. A close spacing of plants in the row is preferred and recommended for general use because it helps to check the weeds.