Effect of tillage and plant management on the productivity of different provenances of Jatropha curcasL
By: Dr Lamine Barro
Laboratory of Ecology & Eco-hydrology
Department of Plant Biology
Faculty of Sciences & Techniques
Cheikh Anta Diop University of Dakar,
BP. 5005 Fann, Dakar Senegal
Jatropha curcas L. belongs to the Euphorbiaceae and is one potential crop to supply the essential raw material for the production of biofuel. This research aimed to study the effects of sub soiling and tree management on the performances of different JCL provenances but also the effect of fruits maturity stage on the oil content and oil quality of their seeds. Four factors (sub soiling, tree management intensity, fruit maturity stage and seeds origins or provenances) were studied. The study area belongs to the Sudano-Sahelian climate. It is located at an average altitude of 20 m with a deep water table from 12 to 36 m. Results showed a significant effect of the factors (p < 0.05) on growth and branching of plants and on the quantity and quality of JCL seed oil. Growth variables (collar diameter of the main stem, crown diameter) have not varied significantly under the influence of tillage 3 years after planting except for plant height that significantly varied as a result of the interaction of factors. Similarly, branching and functional features have not varied significantly as a result of factors (provenance and subsoiling). Furthermore, subsoiling had a significant effect on flowering with a higher rate in the worked plot (average 69.38) than in the control (average 43.17). Fruiting branches recorded under the effect of tillage (p = 0.0205) were higher in the control (5.2 ± 5.6) than in the prepared plot (0.1 ± 5,6). Tree management favored the production of several branches resulting in better fruit production. Seeds harvested on yellow fruits (after 7 days of drying) gave a higher oil content (30,21g) and viscosity (35.37 ± 0.10 cSt) than those obtained from black (23,45g respectively; 35.285 ± 0.10 cSt) or green fruits (17,771g; 35.08 ± 0.10 cSt). These results mean that the stimulation of branching by managing JCL plants can increase fruit production in one hand and that the yellow fruit stage is the optimal one for a higher oil content. This study revealed other avenues of research, in particular the effect of subsoiling, provenance, tree management intensity on the development but also the productivity of Jatropha curcas plants in Bargny (Senegal).
Key words: Jatropha curcas L., Development, Productivity, Provenance, Tillage, tree management, growth, branching, oil content, oil quality.