Pruning, how and when and why
The four main factors to make a Jatropha bush productive are: Light, temperature, water and nutrition.
Jatropha flowers appear at the end of a branch. Ergo: A Jatropha bush should have as many branches as possible to get many flowers. Simple but not true.!!!
Apart from many branches, a Jatropha bush also needs light. With to many branches many of them will not receive enough light and the branches will stay “blind”, in other words they do not produce flowers.
Good planting material should be selected fromplants that show natural branching, even without pruning. When young Jatropha plants do not show natural branching, you might have poor planting material and/or lack of nutrients. (poor soil). Your planting distance might also be too dense. Seeds from hedges might show very poor branching so better use seeds from well branched bushes. Do not forget that between wild seeds and cuttings there can be great variability so if you are not in the position to buy selected seeds make sure that you do your own selection by picking the right seeds from the right bushes or make cuttings from well branched and well yielding trees.
Although it seems attractive for early yield (which means no pruning at all) it is recommended to prune In a very young stage (knee hight) to stimulate branching if your plants are not branching sufficiently.
HOW TO PRUNE
Pruning should take place as follows:
1e pruning: plant is knee height. This is usually 3-8 months after planting (depending on climate)
Below you will find a nice pruning sequence, executed in Mexico by JOSE INES BAZAN-MOTA
WHEN TO PRUNE
The moment of pruning is completely depending on climate conditions.
In high rainfall area's with continuous growth and flowering, pruning can be done all year round. Most of the growing locations however do have one or two periods of dormancy. Pruning should be done at the end of a dormancy period, preferably when the plant show the first signs of re-activity. Pruning at the wrong moment can result in poor branching or loss of yield
1.There are systems under development where mechanical harvesting and pruning will be combined. The method shown on this page is typical for smallholders and contract growers
2. The use of secateurs to prune is preferable.. Machetes make nasty wounds with infection risks.