An Experiment To Determine the Yield of Jatropha
Grown Under Varying Conditions In Central Haiti

Jatropha is an oil-rich plant that is reported to grow in poor soil in semi-arid conditions without irrigation.  (Note: Some of the literature claims that poor soil and lack of irrigation will reduce the yield of Jatropha but that the plant remains a valuable source of oil.)  In small quantities, the oil from Jatropha can be extracted through a hand press.  The remaining seedcake makes a rich fertilizer for the Jatropha fields and other crops. Soap is another by-product of the process.

The oil from Jatropha can be used as cooking oil, lamp oil, and diesel fuel.  (Note: The use of the oil in diesel engines requires a slight modification of the engine to increase the size of the jets.)

Together, these uses of Jatropha hold promise for the people of Haiti - fuel, fertilizer, soap, and new sources of income.

Research Opportunity

The climate is consistent throughout Central Haiti (i.e., the area around Hinche and Thomassique) - about six months of dry period (approximately November through April) and six months of rainy season (approximately May through October).  However, the soil conditions vary substantially.  Cerca La Source has rich soil whereas in Thomassique the soil is dry and rocky.  The area outside of Hinche tends to be more like Cerca La Source but can also be rocky.  By planting Jatropha in three locations in this region, the impact of soil condition on the yield of the crop can be measured.

The Research Design

This experiment will involve planting Jatropha on approximately 4.5 acres of land at three sites in Central Haiti.  Because the focus of the experiment will be on the importance of soil condition, every effort will be made to keep the following conditions consistent at all of the sites:

• Source of the seeds (a single source will be used)
• Germination of the seeds (all seeds will be started in germination bags in a single nursery at the same time)
• Time of planting (the seeds will be planted at the three sites at the same time)
• Planting technique (the same planting technique will be used at all three sites, i.e., all the seeds will be placed in the ground in the same manner)
• Care and pruning (the plants will be inspected and pruned the same way and at the same times at all sites)
• Absence of fertilizer (none of the sites will fertilize the fields during this experiment)
  

The following variations are expected at the sites:

• The soil conditions (as described above and shown in the chart below)
• Planting style (two of the sites will follow a 3mx3m design; the third site will use a hedging approach)
• Irrigation (half of two sites will be irrigated on a regular schedule; the other half of those two sites and the third site will not be irrigated)

Sketch of the Design

The research design can be illustrated as follows:

Timeline

This experiment will begin in January 2009 and extend for five years until December 2013.  The Jatropha plant is not expected to yield enough seeds to press oil until the third year and beyond.  A tentative timeline for the experiment is:

• October 2008 - Commitment from the land owners (Done)
• November 2008 - Order seeds
• January 2009 - Start seeds in the nursery
• May 2009 - Plant seeds in the three sites (note how many failed to germinate in the nursery)
• November 2009 (after the rainy season) - Measure growth of the plants (including notation of how many failed to survive the first year)
• January 2010 - Irrigate according to plan
• March 2010 - Irrigate according to plan
• May 2010 - Irrigate according to plan
• May 2010 - Measure growth of plants (including notation of any that failed, and noting number and weight of any seeds that might be harvested)
• November 2010 - Measure growth, failure, seeds; prune as appropriate
• January 2011 - Irrigate according to plan
• March 2011 - Irrigate according to plan
• May 2011 - Irrigate according to plan
• May 2011 - Measure growth and failure; prune as appropriate; harvest seeds (possibly first measurable harvest); press oil from seeds, noting the weight and volume of oil and its appearances; preserve small quantity to test shelf-life
• November 2011 - Measure growth and failure; prune as appropriate; harvest seeds (gathering data on number and weight); press oil from seeds, noting the weight and volume of oil and its appearances; preserve small quantity to test shelf-life; check on shelf-life of seeds pressed in May 2011
• January 2012 - Irrigate according to plan
• March 2012 - Irrigate according to plan
• May 2012 - Irrigate according to plan
• May 2012 - Measure growth and failure; prune as appropriate; harvest seeds (gathering data on number and weight); press oil from seeds, noting the weight and volume of oil and its appearances; preserve small quantity to test shelf-life; check on shelf-life of samples saved in previous rounds
• November 2012 - Measure growth and failure; prune as appropriate; harvest seeds (gathering data on number and weight); press oil from seeds, noting the weight and volume of oil and its appearances; preserve small quantity to test shelf-life; check on shelf life of samples saved in previous rounds
• January 2013 - Irrigate according to plan
• March 2013 - Irrigate according to plan
• May 2013 - Irrigate according to plan
• May 2013 - Measure growth and failure; prune as appropriate; harvest seeds (gathering data on number and weight); press oil from seeds, noting the weight and volume of oil and its appearances; preserve small quantity to test shelf-life; check on shelf-life of samples collected in previous rounds
• November 2013 - Measure growth and failure; prune as appropriate; harvest seeds (gathering data on number and weight); press oil from seeds, noting the weight and volume of oil and its appearances; preserve small quantity to test shelf-life; check on shelf-life of samples collected in previous years
• December 2013 - Analyze data from all four years; prepare report; disseminate report to all participants and stakeholders

Parallel studies will be designed for 2012 and 2013 (Years 4 and 5) to document the effectiveness of the Jatropha oil in various applications (for cooking oil, for lighting, for running generators).

This experiment is intended to assess the potential for growing Jatropha in Central Haiti and the conditions under which it is most likely to thrive.  The metrics that will be used to evaluate the potential include:

• The percentage of seeds that germinate when started in the nursery
• The percentage of plants that survive throughout Year 1, 2, 3, 4, 5
• The growth rate (measured by plant height and number and size of branches) in Years 1, 2, 3, 4, 5
• The seed yield (number and weight of the seeds gathered in Years 1, 2, 3, 4, 5)
• The oil produced (weight and volume)
• The shelf-life of oil produced (measured in months that it is usable)
• Residual products produced in the process (list of products such as soap and fertilizer; descriptions of quantity and quality and applications of each product)

For further information about this study, please contact Peter Dirr at: peterdirr@gmail.com