Journal of Agriculture & Life Sciences

Light-Response Curves for Jatropha Curcas Provenances under Field Conditions in Costa Rica
Elemer Briceño Elizondo, Elizabeth Arnaez-Serrano, Ileana Moreira-Gonzalez, Arias Aguilar, Jesus Hernandez-Lopez

Abstract
Widespread consideration on the potential for Jatropha curcas to produce biodiesel has recently brought attention on the species. However little solid information on key physiological and management aspects exist on the species for Central America. A gene bank, established at the Experimental Station Fabio Baudrit, located in La Garita de Alajuela, Costa Rica, comprised of a number of 52 accessions from around the country and abroad, identified 10 potential provenances of importance. Through annual monitoring, the provenances Turrubares, Cruce Jaco, Barro Turrubares, Orotina, Marichal, Tempate 1, San Vito, Mexico, India, Tempate, were identified as the most productive. Data gathering was made during the same hours of the morning from 8 am to 11 am, through the beginning of the rainy season (June-August). A characterization of the quantum yield of individuals from these provenances was performed. The light saturation point ranged from 154 μmol (photon) m–2 s–1 (eq.1, Provenance Orotina) to 988 μmol(photon) m–2 s–1(eq. 1 Provenance San Vito). The maximum assimilation rate was exhibit by San Vito provenance (16.6 μmol (CO2m–2 s–1), which is consistent with other variables such as respiration and its light compensation point. Respiration ranged from 1 μmol (CO2) m–2 s–1(Tempate) to 5 μmol(CO2) m–2 s–1(Turrubares). The data from Turrubares exhibited inconsistencies and the curve did not adjust well; fluctuations in cloud cover and stomatal closure affected data from this site, signaling the sensitivity of the species but also its quick adaptation to changing conditions.

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