Trends and gaps in the global scientific literature about Jatropha curcas L. (Euphorbiaceae), a tropical plant of economic importance

Abstract

Jatropha curcas L., popularly known as the physic nut, is a monoecious, perennial lactiferous species belonging to the family Euphorbiaceae. Recently, interest in this species has been growing, due to its ability to flourish on degraded land and in soils with low natural fertility, the high oil content of its seeds, its rapid growth and easy propagation, and the identification of several secondary metabolites with medicinal importance. This study aims to report the main trends and gaps in the global scientific literature about J. curcas L, using a scientometric analysis. We have carried out this scientometric analysis on the global literature to identify: 1) temporal publication trends; 2) the quality of scientific production, estimated using citation numbers and journal impact factors; 3) the main journals and countries interested in this topic and the language of scientific divulgation; 4) the main research fields; 5) the use of wild or commercial cultivars; and 6) average authorship levels and international collaboration networks. Our findings have revealed a continuous increase in both quantitative and qualitative parameters in studies about J. curcas. The main trends in physic nut studies involve biofuel production and the plant's agronomic characteristics. The main knowledge gaps relating to J. curcas are in the fields of forestry, sustainability, animal nutrition, and genetic improvement. Another problem identified in this study is a lack of commercial seeds; none of the studies analyzed have used commercial seeds. India, Brazil, and China together are responsible for 55% of the knowledge about this species, obtained through scientific production. Only moderate international collaboration has been observed between countries, perhaps as consequence of conflicts of interest. Despite an increasing number of articles, some countries have stopped producing J. curcas L, and the worldwide crop production has decreased.