The biggest advantage of all cutting methods is that cuttings can be taken from well known, high yielding sources. It means that you can make many identical new plants from one parent plant or a group of selected or propagated parent plants.
In Jatropha propagation this is an issue because of the variabilty of individuel plants
Using hard cuttings in poly bags is a reliable way of setting up a Jatropha plantation. It offers flexibility at planting time and a very even stand of Jatropha because plants can be graded. It takes about 6 -10 weeks to grow a new plant from a hard cutting.
- Use branches with a diameter of maximum 3-4 cm and a length of 4-6 nodes. The colour of the wood should be greyish. Green wood is to young and can easily be attacked by fungi.Use sharp knives or scissors in order to make a clean cut.
- Do not use a machete because it will damage the cuttings. Cut the stems slightly slanted.
- After cutting, wash the cuttings in water with 1-2grams/litre carbendazim or equal to protect the cuttings from an early attack of fungi. ( This is much easier and more realistic than disinfecting your knife or scissor after every cut with ethanol as sometimes recommanded)
- Let the cuttings dry in a shady place for 1-2 hours.
- Before sticking the cutting in the pre-filled poly bag, poke a small hole with a stick in it.
- Special attention has to be paid to the soil mixture. Soil in the bags should be light and good draining. To many nutrients is not necessary and in fact will negatively influence rooting. Different local mixtures can be used to fill the bags. Coco peat turns out to be an excellent rooting medium, but might be to expensive. Mixtures of soil and sand and compost (1-1-1) are doing quit well. Make sure water and soil do not content to much salts. Farm yard manure can be very salty. Do a small trial with different mixes from local available material before you start a big nursery. The trial takes you only 4 weeks. Materials that can be used: sand, soil, compost, rice husk, peat, coco-peat, charcoal, saw dust.
- After placing the cuttings, water the poly bags slightly.
- Fresh hard cuttings do not need direct sunlight the first days (there are no leaves) so place them in a shaded area for the next 10 days and maintain a high enough humidity*, not by watering but covering them with white plastic or placing them in a greenhouse or plastic tunnel.
*Humidity is a trade off, the higher the humidity, the faster the rooting but also the development of unfavourable fungi.
In various trials longer and thicker cuttings have been used. However, once you have a selection of plants, you want to make as many cuttings as possible, so you make them as small as possible. According to the trial below (Forrest college and research institute Tamil Nadu, India) size of the cuttings does not have influence on final growth after transplanting.
The use of rooting hormones.
Various trials have been done to indentify the need and the type of rooting hormones to be used. None of these experiments however are conclusive, since the environment, the cuttings, the potting media etc. are not comparable. My experience is that when you have a good rooting media and proper environmental conditions, rooting hormones are not needed.
Hard cuttings for hedges.
Usually hedges are being planted with pretty long (60-100 cm) and thick( 2-5 cm diameter) jatropha cuttings, since the primary goal was to create a fence. Now that seed production becomes more important, cuttings should be selected from known good yielding trees.