Melhoramento da mamoneira (Ricinus communis L.) I: plano geral dos trabalhos em execução nas secções de genética e plantas oleaginosas do instituto agronômico do estado de São Paulo

In the introduction to this article data are presented to show the growing economic importance of the cultivation of Ricinus in Brasil and particularly in the State of Sao Paulo. Following general statements regarding the botany, the origin and the geographic distribution of this genus, the investigations are outlined which are carried out by the Divisions of Genetics and Oil Plants of the Instituto Agronomico of the State of Sao Paulo, Brasil, to improve this important crop plant. Summarising, these investigations deal with the following subjects : a)  Organisation of a large collection of types ; b)  Investigations concerning the variability of the genus Ricinus c)  Genetic analysis; d)  Regional variety trials ; e)  Improvement of the best varieties by individual selection and progeny trials ; f)  Regional strain tests ; g)  Breeding of improved varieties through hybridisation. In spite of the fact that these investigations have only been carried out for a few years, they are already furnishing results of economic importance, as seeds of superior varieties are already on sale to the farmers.