Friday, April 8, 2011
Padang jarak padang terkukur
Kiri: Buah jatropha atau jarak masak (hitam), matang (kuning); Kanan: Jarak integrasi dgn tebu.
Perumpamaan 'Seperti padang jarak padang terkukur' memberi gambaran kehancuran dimana hampir kesemua manusia mati atau tiada (lari) di arena peperangan atau mala petaka. Senjata dahulu tidak sedahsyat seperti sekarang mengunakan bom atom, peluru berpandu dsb.
Apakah jarak dimaksudkan itu 'jarak pagar (jatropha), jarak castor oil atau lain2 jenis? Kedua2 jenis jarak berasal dari Amerika Tengah/Selatan dan mengandungi minyak yang berlainan kegunaannya. Jatropha utk disel, castor oil utk pelicin (lubricant) jentera. Di Malaysia jarak castor oil yg banyak terdapat tumbuh liar dikawasan lapang dan munkin itu dimaksudkan dalam perumpamaan. Burung terkukur banyak dilihat dikawasan lapang.
Jatropha as biofuel (artikel yg saya tulis dalam Eastern Times, Sarawak, 2007)
The increasing cost of oil is much of public concern. The price shot up to more than US$80 per barrel causing many countries to hurriedly look into alternative fuel and energy sources to help ease the economic burden their populace. In this kind of situation the health and wellbeing of the lower income group will be much affected and the incidence of poverty expanded. We are perhaps staring into the reality that there may be no abatement in the rising trend of the fossil fuel because of demand due to population growth which in turn requires more energy for industrialization, transportation, utilities and just about about everything else we want to do to live. What makes it more critical is that oil is a depleting natural resource and the more conservation measures taken the longer it lasts.
The approach to exploit cleaner or green energy sources has always been on the agenda in many countries. Alternative sources or energy can be derived from hydro, solar, wind, and biomass. Many homes in parts of Europe are equipped with solar panels that generate electricity integrated to the national grid system. Plants capture the sun energy during their food making process (photosynthesis) and part of the biomass produced can in turn be exploited for energy purposes. Malaysia has developed technologies to commercially utilise palm oil, a product of processed biomass for biofuel.
Jatropha is and oil producing crop. Countries in Asia such as India, Thailand and China are ahead in research and development in the use of jatropha oil as biofuel. Malaysia has not done any concerted research on the plant although H.N. Ridley (1924) and I.H. Burkill (1966) have written notes on the plant. Perhaps we have the better choice of an oil crop to work on viz oil palm. We are more 20 years lagging behind Thailand in terms of jatropha research. Thailand has started large scale planting of jatropha at its drought stricken areas in the north east. Whereas India started massive planting (10,000 hectares) jatropha as an agroforestry crop more than two decades ago. Earlier in this century Cape Verde Islands planted 8000ha of jatropha and in 1910 exported five tonnes of the seeds to Lisbon (Portugal) and for oil extraction and soap manufacture until it stopped to do so in 1970.
Jatropha we commonly referred to is scientifically known as Jatropha curcas. It is a shrub. It can grow to 3m height under Malaysian conditions. It is a distant relative of rubber and tapioca and falls within the same family of Euphorbiaceae. Coincidently, rubber and tapioca are both of Central-South American origins. Jatropha is popularly known as ‘jarak’, and sometimes goes by the name as ‘jarak belanda’, ‘jarak pagar’, ‘jarak melaka’, ‘jarak keling’. The name jarak belanda implies that it is a non-native plant here. It was not introduced not by the Belanda (Dutch) but by the Portuguese to Malacca hence the name ‘jarak melaka’. The Portuguese also brought the plant to Africa. It was found in the Philippines before 1750.
The original home of jatropha is believed to be in Mexican-Central American region. It is drought tolerant, hardy and can be grown on marginal or poor soils, a specific niche where it does not compete for arable land. In areas threatened with desertification and soil erosion jatropha can be planted as hedge plants. In Mali, West Africa thousands of kilometers of such live hedges are found. The latex found in the leaves, stems and immature fruits deter animals to browse the plant. In Malaysia the Caringa fiery ants seems to favour the leaves to make their nests. That is another line of defense against intruders!
The stem is soft and thus easy to cutback to maintain hedge height. New branches are formed and bore fruits at the terminals. Propagation by stem cuttings is easily done to obviate the juvenility period and hence faster harvest. Seeds germinate within 10 days but plants take a longer time to get to the harvesting stage. In a small scale test planting as hedge using 0.5m cuttings direct onto very sandy, infertile used tin mining soil carried out the author, the survival rate was less than 50%. Short branches that grew from the growing produced few fruits within several months.
An enterprising concern announced in the papers a few days ago to go into commercial planting of jatropha in the West Indies to produce the seed oil for biofuel and other downstream activities. The pressed cake left after the oil extraction has about 3.5% nitrogen content and can be used as organic manure. It is toxic (mainly due to curcin, a chemical close to that of ricin of castor oil) for animal feed unless further treatment is done. Apart for the plant has insecticidal and medicinal properties - the oil as a purgative, the leaves as antiseptic, and latex to arrest bleeding. Children in villages used to blow bubbles using the latex froths from the stems and leaves. The author can testify to some of these properties after having had first hand experience in using or being treated with the leaves and latex.
The jatropha seeds when pressed hydraulically produce about 35% oil. The kernel within the shell of the seed contains much of the oil yielding to more than 50%. Report of a yield trial comparing several cultivars in India (1996) indicated that jatropha can yield 1800kg of seeds/hectare which is equivalent to about 60kg of oil produced. A recent visit by a group from Sarawak led by the Land Development Minister to China says that research yield of 3 tonnes of oil per hectare can be obtained. There is a wide difference between the two yield reports. This be due to many factors such as differences in soil and climatic conditions and are the technological applications - varieties, cultural practices, oil extraction methods (via chemical means for example) etc.
As of now our information on jatropha are based from outside or secondhand sources – reports, visits, literatures, internet and media. As a guide a publication entitled ‘ Physic Nut, Jatropha curcas L. published by the International Plant Genetic Resources Institute, Rome in 1996 can be a good source of information to start with. As advised by the Chief Minister it is appropriate to conduct scientific and plot trials before going into larger scale planting in Sarawak. Factors such as suitability to the soil and climatic conditions, yielding capacity, the planting density, pruning regime, fertilizer requirement, oil extraction are some of the unknowns to be settled and conjectures to be verified.
In the many years I have been in Sarawak I have not come across a single plant of jatropha. In Sabah a few hedge plants were observed along the roadside close to Lahad Datu. Jatropha plants found in Sabah are likely from the Philippines initially . Rainfall averages indicate that areas around Tawau and Kota Kinabalu have drier months from January to April (93 – 129mm/month) whereas Kuching, Bintulu and Miri do not have that marked tendency meaning that their rainfall patterns are fairly uniform through the year. For higher seed yield, the 3-4 months of dry period is necessary to restrict vegetative growth and allow food partitioning for fruit development. This is also the case with mango fruiting. Apart from the dry period treatment, pruning and cutback can also be an effective cultural practice to reduce vegetative growth and stimulate flowering. In rainy, low lying areas or the wetland/peatland the jatropha roots being quite tender may not be able withstand the soaky grounds.
As a plant breeder, the first step I would take towards crop development is to collect many representative types/varieties of jatropha within and outside the country and put them to field trials to determine seed yield and oil quality. From there pick the top few ones and further test their performance at several sites of varied soil and climatic conditions. The initial selection process for high yield may take at least five years. It must be remembered that the variety that yield well in China for example may perform dismally here. A strategy to reduce risk in getting into a new crop like jatropha is to incorporate it in an agroforestry multi-tiered cropping system in combination with profitable annual and perennial crops, food and non-food types. Although the plant is shade tolerant sufficient sunlight must be given to obtain the desired seed yield.