Comparative phenological analysis of high yielding accessions of a Jatropha curcas (jatropha) germplasm bank, in Costa Rica

Abstract

The species Jatropha curcas (jatropha) is characteristic of the Mesoamerican region, with its center of origin found in Mexico. It has been adapted for use in hedgerows and is also exploited for medicinal applications, based on traditional knowledge. It is currently classified as a valuable species for the production of oils for use as biofuels or paint diluents. In Costa Rica, a germplasm bank has been created in the Universidad de Costa Rica’s Fabio Baudrit Research Station, located in La Garita, Alajuela, which contains a total of 52 accessions from Costa Rica as well as some from other parts of the world. In the annual assessment of this germplasm bank, it was determined that the most productive accessions were Turrubares JCCR36, Jacó JCCR-3, El Barro de Turrubares JCCR-43, Orotina JCCR-1, Marichal JCCR-42, Tempate 1 JCCR-6, San Vito 2 JCCR-30, México 2 JCCR-31, India JCCR-27, and Tempate 1-Guanacaste JCCR-23. Three individuals were selected from each of these accessions for weekly evaluation, in which the number of female and male flowers, the number of inflorescences, and the number of fruits were estimated. A Kruskal Wallis non-parametric analysis was carried out with the data, and the results were correlated with levels of solar radiation and rainfall. The results of this analysis showed that the accessions with the highest yields were San Vito 2 JCCR-30, México 2 JCCR-31, and Tempate 1-Guanacaste-23. The highest solar radiation rates were recorded in the months of February and March of 2014, and between May and April of 2015. Negative correlations of more than 0.40 were found between solar radiation and flower production for the years 2014 and 2015, while production of inflorescences was positively correlated with rainfall and solar radiation.