127 J. Crop Sci. Biotech. 2010 (September) 13 (3) : 127 ~ 137 DOI No. 10.1007/s12892-010-0064-1 RESEARCH ARTICLE Development of Pongamia pinnata as an Alternative Biofuel Crop - Current Status and Scope of Plantations in India Vigya Kesari, Latha Rangan* Department of Biotechnology, Indian Institute of Technology Guwahati, Assam, India 781 039 Received: June 9, 2010 / Revised: August 10, 2010 / Accepted: September 10, 2010 Ⓒ Korean Society of Crop Science and Springer 2010 Abstract Pongamia pinnata is a leguminous tree known for its multipurpose benefits and as a potential source of biodiesel crop. Its added benefits to grow on marginal lands make it a suitable candidate in agro-forestry. These properties support the suitability of this plant for large-scale production required by a sustainable biodiesel industry. While utilizing these species as a source of biodiesel, there is a further need for research and extensive knowledge generation into various areas of production and utilization. The future success of P. pinnata as a sustainable source of biodiesel will heavily depend on an unlimited feed stock supply. This will call for large-scale plantations of clonal stocks of elite genotypes to encourage afforestation programs coordinated both at the central and state levels to cater to the needs of the biodiesel industry. The success rate will rely on the elite planting stock, propagation techniques, and plantation practices and models in making Pongamia cultivation an economically viable proposition. Key words: biodiesel crop, intercropping, mass multiplication, Pongamia Abbreviations: IAA, indole acetic acid; IBA, indole butyric acid; CPT, candidate plus tree; HSD, high species diesel; NAA, napthalene acetic acid; SHGs, self help groups; TBOs, tree-borne oil seeds Introduction The increasing price of petroleum products and concerns about oil production are likely to have serious implications for the automobile industry in the future. The answer to the above requirement is to search for an alternative to the fast-depleting reserves of fossil fuel from renewable natural resources (Martini and Shell 1998; Srivastava and Prasad 2000). The current manufacturing cost of ethanol and biodiesel in India is about US $ 0.45 L -1, roughly the same as petrol and diesel (Nigam and Agrawal 2004). This puts biofuels in a favorable position for meeting India's energy needs, especially, as the cost of petroleum is expected to continue its upward trend. India is the fourth largest ethanol producer only next to Brazil, USA, and China having its average annual ethanol output amounting to 1,900 Latha Rangan ( ) Tel: +91 (361) 2582214 Fax: +91 (361) 2582249 E-mail: latha_rangan@yahoo.com/ lrangan@iitg.ernet.in The Korean Society of Crop Science million liters with a distillation capacity of 2,900 million liters per year (Mittelbach and Remschmidt 2004). The biodiesel industry is still in its infancy in India (Mandal 2004) and currently biodiesel is being produced largely by transesterification of vegetable oil. The government has formulated an ambitious National Biodiesel Mission to meet 20% of the country's diesel requirements by 2011-2012. Since the demand for edible vegetable oil exceeds supply, the Government of India (GoI) has given a top priority for promotion and use of non-edible oils such as Jatropha curcas, Pongamia pinnata, etc., for production of biodiesel (Source: Report of the committee on development of biofuel by Planning Commission, Government of India 2003). Further, emphasis is on the use of forest and non-forest wastelands for plantation of non-edible, oil seed-bearing plants. Improper land use and population pressure over several years has resulted in extensive degradation of agricultural land that has resulted in large tracts of wasteland in India (approximately 55 million ha). On the other hand, population explosion, greater 128 Pongamia as an alternative biofuel crop in India urbanization, and land reforms have resulted in the depletion of coal and natural resources. The problem is further compounded by the fact that the demand for energy and oil is on the rise and there is a greater need to explore alternative sources of oil. This has resulted in strengthening the research and development in the areas of biodiesel. Nearly 20% of land in India can be considered largely as wasteland where little agriculture is practiced. Some of this land could be used for growing Pongamia. Pongamia pinnata (L.) Pierre (Synonyms Derris indica Lam., Bennet, Pongamia glabra Vent., & Cytisus pinnaus L.) tree belonging to the family Fabaceae, sub-family, Papilionaceae, popularly known as 'Karanj' or 'Karanja' in Hindi is known for its multipurpose benefits and as a potential source of biodiesel (Meera et al. 2003; Kesari et al. 2008; Sharma and Singh 2008; Kesari et al. 2009a). It can be propagated either by seeds or by root suckers (Duke 1983) and the yield of kernels per tree is between 8 to 24 kg (Bringi and Mukerjee 1987; Kesari et al. 2008). The seeds contain about 28 - 34% oil with a high percentage of polyunsaturated fatty acids (Sarma et al. 2005; Kesari et al. 2009a). The tree can grow on unproductive land and is adaptable to wide agro-climatic conditions. Besides the oil yielding capacity, its multipurpose benefits as a provider of green manure and medicine, and its role in agro-forestry make it a potential candidate for large-scale plantation on marginal lands (Srinivasa 1997; Scott et al. 2008; Kesari et al. 2010). Historically, Pongamia has been used as folk medicinal plant, particularly in Ayurvedha and Siddha systems of Indian medicine (Meera et al. 2003). All parts of the plant have been used as a crude drug for the treatment of tumours, piles, skin diseases, itches, abscess, painful rheumatic joints, wounds, ulcers, diarrhea, etc. (Shoba and Thomas 2001; Meera et al. 2003), and is well known for its application as animal fodder, timber and fish poison (Cribb and Cribb 1981; Bottoms 2000). It has also been recognized to possess applications in agriculture and environmental management, with antimicrobial, insecticidal, and nematicidal activity (Chopade et al. 2008; Kesari et al. 2009a). The tree itself is nitrogen fixing and so it will improve the soil where it grows (Scott et al. 2008; Uddin et al. 2009). The seeds or nuts of the tree are its most useful product. The non-edible oil extracted from seeds has traditionally been used as fuel and lubricant and in soap making. More recently, the effectiveness of Pongamia as a source of biomedicines has been reported, specifically as antimicrobial and therapeutic agents targeting host pathways and processes (Brijesh et al. 2006). It can also play a role in the rural economy by generating huge manpower employment during various stages of its cultivation as well as during downstream processing (Shrinivasa 2001). Although these species are well adapted to harsh weather conditions, there is a need to domesticate them for cultivation under different production systems on degraded lands and community wastelands (Kesari et al. 2010). Scientific information on P. pinnata has been generated by various researchers affiliated with diverse organizations in India and elsewhere even when the commercial value of this species was not recognized. While utilizing these species as a source of biodiesel, there is a further need for research into various areas Fig. 1. Pongamia plantations in India. Green shade indicates the states where Pongamia grows naturally and plantations are being carried out. Also indicated (▲) are the prominent research organizations engaged in plus tree identification and cultivation of Pongamia germplasm (Sources: NOVOD report). http://www.novodboard.com/Publications.htm http://biodiesel.nedfi.com/pages/introduction/objectives.php of production and utilization (Kesari et al. 2008; Scott et al. 2008; Mukta and Sreevalli 2010). Assessment of these resources for seed yield and oil content has not yet been done. Since the species has always been treated as an avenue tree, efforts towards domestication through identification of elite genotypes have been very limited. Selection for economically important traits such as high seed yield, high oil content, and desirable fatty acid composition is the prerequisite to make this species as an economically viable biodiesel crop (Kesari et al. 2009a). To increase the biodiesel production it's important to have unlimited feed stocks of Pongamia bearing, high oil-yielding seeds. Thus, large-scale plantation of clonal stocks of elite genotype needs to be done to encourage afforestation programs. The Indian Government has adopted a program based on biodiesel production from oil-bearing seeds of Pongamia as a high-speed diesel (HSD) substitute in India. The overall objectives of this review paper is to examine these issues involved in the raising of large-scale Pongamia plantations on various categories of land. The article also describes the various aspects of the use of an elite planting stock and appropriate propagation techniques including nursery and plantation practices and models. Such efforts are essential in making Pongamia cultivation an economically viable proposition. JCSB 2010 (September) 13 (3) : 127 ~ 137 Pongamia pinnata - Habit and habitat Species distribution and ecology The natural distribution of Pongamia is along coasts and river banks in India and Burma. It is native to humid and subtropical environments including the Asian subcontinent and lowlands in the Philippines, Malaysia, Australia, the Seychelles, the United States, and Indonesia. Natural reproduction is by seed and is common by root suckers (Duke 1983). Pongamia tree is cultivated throughout India except temperate regions (Fig. 1). A large number of trees have been planted on roadsides, railway tracks, canal banks, and open farm lands during last two decades. Pongamia can grow on most soil types ranging from stony to sandy to clayey and grows to an elevation of ca. 1,200 m (Daniel and Hegde 2007). The plant thrives well in areas having an annual rainfall from 500 - 2,500 mm, with the maximum temperature ranging from 27 to 38 ℃ and the minimum from 1 to 16 ℃. Mature trees can also withstand water logging, are resistant to high winds, drought, and salinity but are susceptible to freezing temperatures (Tomar and Gupta 1985; Misra and Singh 1987; Gilman and Watson 1994). The tree does not grow well on dry sands. Pongamia is common along waterways or seashores, with its roots in fresh or salt water and grows well in full sun or partial shade. However, maximum growth rates are observed on well-drained soils with assured moisture (Tomar and Gupta 1985; Sharma et al. 1994). Botany Pongamia is a medium-sized, hardy tree that generally attains a height of ca. 8 - 10 m and a trunk diameter of more than 50 cm (Fig. 2A). The trunk is generally short with thick branches spreading into a dense hemispherical crown of dark green leaves. The bark is thin gray to grayish-brown, and yellow on the inside (Daniel and Hegde 2007). The taproot is thick and long extending 10 m into the ground to extract water from far beneath the ground surface for its need without competing with other crops. The plant flourishes in dry areas where agriculture is unproductive and in poor or saline soils (Tomar and Gupta 1985). The alternate, compound pinnate leaves consist of five or seven leaflets which are arranged in two or three pairs, and a single terminal leaflet. Leaflets are 5 - 10 cm long, 4 - 6 cm wide, and pointed at the tip. The structure and biochemical features of the flower and the mechanism of pollination have been already described (Jain and Dhingra 1991; Raju and Rao 2006). Flowers, borne on racemes, are pink, light purple, or white (Fig. 2B). Pods are elliptical, 3 - 6 cm long and 2 - 3 cm wide, thick walled, and usually contain a single seed rarely two, elliptical, or reniform 1.7 - 2.0 cm long and 1.2 - 1.8 cm broad, wrinkled, with reddish brown leathery testa (Fig. 2C). Seeds are 10 - 20 cm long, fig oblong, and light brown in color (Fig. 2D). The tree starts yielding at the age of 4 - 7 years (ICRISAT 2007) and seed yield varies from 10 - 250 kg per tree. Regarding yield, there are varying estimates: 6 t ha-1 and the oil production up to 1.5 - 2.4 t ha-1, depending upon the soil and climatic conditions. Seeds contain 28 - 34% oil. The cake is non-edible; it can be used as an organic fertilizer and is rich in nitrogen and micronutrients (NOVOD 2009). The oil from the seed has provided an affordable fuel source for generators (Source: Power Pods India Feb 2004, ITDG). Propagation techniques in Pongamia The successful introduction and subsequent expansion of plantings of any new crop species is reliant on the ability to develop simple and reliable methods for the propagation of large number of plants. Propagation in Pongamia is desired from many angles. The planting season of Pongamia does not coincide with the reproductive phase (consisting of flowering and fruiting) in different eco-geographic locations and in such situations, vegetative propagation would be an ideal step towards supply of planting material round the year. Further, vast areas of wastelands could be covered with Pongamia vegetation for domestic and commercial utility. Pongamia can be successfully propagated through seeds and cuttings (Handa et al. 2005; Singh et al. 2005; Kesari et al. 2010) and the viability of the seeds is up to one year. Fig. 2. Pongamia pinnata; A. Candidate plus tree NGPP 46 occurring in North Guwahati, Assam, India (26°14'6” N, 91°41'28” E), B. Characteristic raceme inflorescence having standard petal, two identical wings and two identical keel petals. Flowering in Pongamia in Assam occur in April - May. C. Ripened pods; each pod weighs about 3 - 5 g. D. Matured seeds. Seed maturation takes roughly 9 months. Each seed weighs about 1.5 - 2.5 g. Plus tree identification Pongamia pinnata has been documented to include variable forms with a wide range of pod as well as seed size and shape (WOI 1969; Kesari et al. 2008). Characterization and selection of candidate plus trees (CPTs) is essential for the improvement of this species in addition to experiments on controlled crossing 129 130 Pongamia as an alternative biofuel crop in India among selected genotypes (Kesari et al. 2008, 2009a, b). Tree breeding consists of selection of superior germplasm followed by large-scale propagation of true-to-type plus trees in the seed orchard for the production of improved seeds, which can be used for high quality plantations (Rao et al. 2001). A plus tree is an individual tree of a species possessing superior morphological and reproductive characters than other individuals of the same species. In our early report, 10 locations with five random trees from each locations were scored for various morphological and reproductive characters viz; girth; height; number of leaves per g weight; seed germination (%); number of buds/inflorescence; number of flowers per inflorescence and number of seeds per inflorescence for two consecutive seasons in the month of April - June (2006 - 2007) from North Guwahati. Trees grown in one location are considered to be a population. To predict the performance of the candidate trees with respect to the traits studied, a combined analysis across populations (locations) was conducted using CROPSTAT. A critical minimum value (mean performance) for various vegetative and reproductive traits from different populations of Pongamia tagged from the study site was done and the tree performing above this average value for 75% of the characteristics for two seasons were designated as CPTs (Kesari et al. 2008). The data comprised of morphological (vegetative and reproductive) traits measured on 50 trees and each of the 50 trees is a different genotype (Kesari et al. 2008). Ten CPTs were identified based on the morphological markers which can be progressed further for large-scale vegetative propagation and mass multiplication. Fig. 3. Vegetative propagation of P. pinnata and the effect of IBA on the rooting of cuttings of CPT NGPP 46. IBA at a concentration of 4.92 mM induced maximum rooting. IBA at this concentration level found to enhance the number of roots by threefold, root length by two-fold as compared to control. T = Treated; C = Control A. Initial IBA treated semi-hard wood cuttings of CPT in poly bags containing sand and clay (1:4); B. Effect of IBA on the sprouting of cuttings of CPT, 7 weeks after insertion. C. Effect of IBA on the rooting of cuttings of CPT, 11 weeks after insertion. Vegetative propagation Vegetative propagation is a method of producing plants identical in genotype with the mother plant and forms an integral part of tree improvement programs. In this approach, the best planting stock with highest genetic quality can be obtained, which is not always possible with the sexually propagated progenies. Another advantage is that by this technique plants can be raised almost throughout the year and the plantable stock can be obtained in shorter time than those raised by seeds (Surendran et al. 2003; Kesari et al. 2009b; 2010). Thus single stock can provide large number of plants having same genetic uniformity. This technique has additional benefits in cross pollinated species like P. pinnata in producing true to type plants with shorter juvenile period leading to early productivity (Raju and Rao 2006). Propagation through cuttings Branch cuttings form the most widely used propagules for vegetative propagation through the application of synthetic and natural auxins to induce adventitious rooting. Indole-3-butyric acid (IBA) has been recommended as the best agent among different synthetic and natural auxins for root induction in cuttings of P. pinnata (Kesari et al. 2009b). However, considerable difference exists among different studies (Mishra et al. 2001; Karoshi and Hedge 2002; Kesari et al. 2009b) which may be due to the differences in experimental conditions as well as genotypic variability. Pongamia can be propagated through semi-hard wood (inter- mediate of soft wood and hard wood) and by hard wood (tertiary or secondary branches) cuttings (15 - 25 cm long and 0.5 - 1 cm diameter) comprising 3 - 4 nodes (Fig. 3A). The root initiation and sprouting of cuttings can be induced by treating the cuttings first with a fungicide and subsequently treating with auxins (IBA, IAA, and NAA) at different concentration ranging from 1.23 to 7.38 mM, respectively, for a maximum of 1 h duration. In our own studies, the performance of the cuttings was evaluated using SAS GLM software and the data were analyzed as a one-way classified data with and without sub-sampling for inferring auxin concentration that can be included in programs aimed at genetic improvement of the tree species (Kesari et al. 2009b). All auxin treatments promoted sprouting at lower concentrations (Fig. 3B) and enhanced rooting of cuttings (Kesari et al. 2009b). The effectiveness was in the order of IBA > NAA > IAA when applied singly. IBA at 4.92 mM was found to be the most effective where rooting percentage and number of roots were significantly higher (P < 0.01) than in control (Fig. 3C). However, higher concentrations of auxins above 7 mM in general inhibited the rooting of cuttings. The interaction among auxins was found to be effective in root induction and differentiation and the most stimulating effects were observed in three-component mixture. Cuttings from 2-month-old seedlings of the same mother plant, raised in nursery bed were also used as a source material for studying the effect of adventitious rooting and effect of juvenility with the JCSB 2010 (September) 13 (3) : 127 ~ 137 the scion made on root stock and kept under polyhouse for 2 months. The grafts can be then taken and placed in hardening chamber. Wedge grafting has been found to be most successful using a 3-month-old seedling raised in polybags as the stocks and semi-hardwood scions of 12 - 15 cm length (Karoshi and Hedge 2002). Direct planting of seeds in the field and in situ grafting with a scion from high yielding trees after 9 months has also been recommended (Wani and Sreedevi 2007). Multiplication of elite P. pinnata by grafting has been found to be easier than propagation by cuttings. Air layering, also called as “Chinese Layering”, is another effective method of vegetative propagation in P. pinnata, where roots are produced in small branches by applying root producing hormones and rooting media. The method can be employed to tertiary branches of Pongamia without much damage to the mother plant. Seed propagation and nursery practices Fig. 4. Propagation and plantation of P. pinnata. A & B. Seed propagation in polybags in forest nursery in April, 2007 & 2009; C. In-situ seed raising in plantation sites in June-July; D. Plantation in marginal lands in June-July. best responding concentration of auxin (Kesari et al. 2009b). The top (apical) cut ends of the treated cuttings were sealed with paraffin wax to reduce the water loss. Subsequently the cuttings were planted in poly-bags containing sand and clay at the ratio of 1:4 and kept in the mist chamber at 28 ± 2 ºC and 70 - 80% relative humidity. Light intensity was reduced to 22% of ambient sunlight and day-length was 12 ± 1 h throughout. Intermittent mist was supplied for 30 s at 15 min intervals. The results indicate that the cuttings obtained from young seedlings in nursery bed had a high rate of rooting (almost 80%) in comparison with cuttings raised from the field (66.67%). Thus rooting was more pronounced in the seedling derived material than mature cuttings (Kesari et al. 2009b). In a previous experiment (Kesari et al. 2010), it was noted that the month of collection was also found to be significant on root induction and differentiation in Pongamia. Stem cuttings collected during the month of January rooted better in terms of percentage response, average root number, and average root length than those collected during October. This variation in seasonal rooting response may be attributed to the physiological condition of the plant cuttings. Air layering and grafting Grafting is an effective technique to overcome the problem of long juvenile period as well as assurance of good productivity owing to elite scions. In grafting, one-year-old seedlings of Pongamia can be used as root stock. The scions can be collected from an elite genotype with the same dimensions as that of the root stock. A wedge-shaped cutting can be made and inserted in Plant propagation by seed is the most commonly known method for producing new plants in large numbers and in less time. Though seed propagation is not difficult, it involves careful management of germinating conditions as well as knowledge of seed requirements of the species (Hartmann and Kester 1986). Maintenance of seed quality requires concerted effort when seeds are required in bulk as in the case of tree nurseries. Pongamia is easily propagated through seeds either by direct sowing in the nursery bed/ polybags during July-August or in situ sowing of seeds in the plantation field (Figs. 4A and B). Potting mixtures consisting of sand, soil, and manure in the ratio of 1:1:1 have been found to yield good results for large scale production of quality planting material of P. pinnata (Arjunan et al. 1994; Handa et al. 2005). Sowing of fresh seeds is recommended as germination rate decreases on storage. The germination of Pongamia is hypogeal i.e. in normal seedling; the cotyledons remain beneath the germination medium while the plumule pushes upwards and emerges above. Seedlings attain a height of 25 - 30 cm in their first growing season and transplanting to the field occurs at the onset of rainy season when seedlings are 60 cm in height (Daniel and Hegde 2007). Bold and cleaned seeds are sown in advanced, well-prepared seedbeds. The seeds are dibbled in the nursery beds at the spacing of 7.5 x 15 cm during the onset of hot weather. Mulching of beds is also found helpful for moisture conservation. Germination takes almost a week and up to 85% seed germinates in properly managed nursery (author personal communication). However, the knowledge of germination and pre-treatment is essential for reproducibility of uniform results. The most commonly used pre-treatment are soaking of seeds in hot water, growth regulators, or salt solutions (Ramamoorthy et al. 1989; Kumar et al. 2007). Soaking of seeds in IBA (0.15 mM) or GA3 (0.06 mM) for 24 h enhances germination (NOVOD 2008) and seedlings develop large root systems. P. pinnata produces root suckers profusely. This characteristic makes it unsuitable for agro-forestery. It has the potential to become a weed if not managed properly. Therefore, this 131 132 Pongamia as an alternative biofuel crop in India species can be regenerated by coppice management (Misra and Singh 1989). Plantation practices and models Scientific literature and case-studies have suggested various plantation models for large-scale Pongamia plantations (Misra and Singh 1987; Naidu and Swamy 1993). These range from blocks of monoculture plantations in community lands and less productive wastelands, with intercropping in agro-forestry models on productive lands to boundary, row plantations along the agricultural fields, and strip plantations along rail, road, and canals. Whatever be the model adopted, a large array of spacing between plants is recommended apart from considering locale specific factors to maximize the yield output (Bhojvaid 2008). While selecting the site, it is important to ensure that the land is available for a relatively long duration. Each site can be spread over an area of 1.5 ha out of which 1 ha can be brought under plantation (500 plants ha-1 at a spacing of 5 x 4 m). This will cover on average at least 25 genotypes collected from various locations. The remaining 0.5 ha can be used to develop a small nursery for multiplication of plants by conventional methods. Pits of 60 x 60 x 60 cm3 are dug for planting, with rows spaced 5 m apart and plants spaced 4 m apart within row for a total of 500 plants ha-1. Each pit is then filled with soil + 5 kg farm yard manure. One-year-old healthy seedlings (height ca. 60 cm), are selected and uprooted with the ball of earth for transplanting in the field (Fig. 4). The onset of the monsoon in JuneJuly is the appropriate time for plantation. Three irrigations may be given in a year when required for better growth and development of the plants. The spacing adopted in avenue plantings is about 8 m between plants. In block plantings, the spacing can range from 2 x 2 to 5 x 5 m. Pongamia seedlings withstand shade very well and can be interplanted in existing tree stands. Information on management practices to maximize seed or biomass production is not available and should be investigated. Because it tolerates moderate levels of salinity, Pongamia is an ideal candidate for saline soil reclamation (Singh 1990). Existing plantations and initiatives on Pongamia in India Many State Governments, NGOs, and multinationals have shown great interest in Pongamia plantations in the last decade. However, there is no systematic study to record the extent of Pongamia plantations in India. The President of India's address at the Banker's Conference 2004 (New Delhi) stated the significance of biodiesel plantations especially in wastelands that accounts for nearly 55 million hectares in India. A significant portion of wasteland (approximately 11 million hectares) can be used for raising biodiesel producing plants that can yield a revenue of approximately Rs 20,000 crore (approx US$ 5 billion) per year and also provide employment to over 12 million people both for plantation and for running the extraction plants. The mission on biodiesel plantations to sustain energy security in India has triggered many initiatives both at the central and state levels. The Ministry of Rural Development (MoRD) has provided financial support to nine States in 2005-06 for raising 18 crore seedlings of Pongamia and to 18 States in 2006-07 for raising of approximately another 18 crore seedlings of this plant. The Ministry of Agriculture through National oil seeds and vegetable oils development board (NOVOD) is promoting Pongamia under the scheme of Integrated Development of treeborne oil seeds (TBOs). The NOVOD Board has undertaken the plantation model of Pongamia in an area of approximately 1,400 hectares for producing parent material for large-scale plantation. The board has also identified elite planting material of Pongamia under their R&D program and has preserved the germplasm. The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patencheru, Andhra Pradesh, India is supporting innovative research on the Pongamia 'Journey from Forest to Micro-enterprise' for improving rural livelihoods and empowerment. The objectives of the organization are to rehabilitate the degraded lands and protect the environment, to asses and develop sustainable crop management practices, and to assess the enhancement of income of self-help groups (SHGs) by planting Pongamia. The program also aims at value addition of its byproducts after oil extraction. Two National Networks working under the aegis of NOVOD Board are promoting research on TBOs mainly on Jatropha and Pongamia in close liaison with state agricultural universities, institutions of Council of Scientific and Industrial Research (CSIR), Indian Council of Forestry Research and Organization (ICFRE), Indian Council of Agricultural Research (ICAR), Central Food Technological Research Institute (CFTRI), The Energy and Research Institute Institute (TERI), and the Indian Institute of Technology, New Delhi (IIT). About 28 institutions are involved in this Network for undertaking joint research on issues such as the identification of elite planting material, seed resource assessment, collection and storage, phenological and chemical evaluation for characterization, tree improvement to get quality and reliable seed source, multilocation trials of elite planting material, techniques for mass multiplication of quality planting material, and model plantation including agro-forestry models for evolving good intercropping system of TBOs. Plantations costs and economics Quick economics of seed production to demand for diesel requirement for India is shown in Table 1 (Source: NOVOD Table 1. Quick economics for biodiesel production from P. pinnata (Source: ICRISAT 2007; NOVOD Report 2009) Parameters Value Seed production Seeds produced per plant No. of plants ha-1 Total yield of seeds ha-1 14 - 18 kg per year 500 (5 x 4m) 5000-8000 kg ha-1 (Average ~ 6000 kg ha-1) Oil production 100 tonnes of seeds Oil production ha-1 Demand for diesel Land required to produce 36 million tonnes oil 30 tonnes of oil 1800 kg ha-1 36 million tonnes per year 20 million ha JCSB 2010 (September) 13 (3) : 127 ~ 137 Table 2. Cost of plantation model (US$) of P. pinnata in one hectare land in Indian condition (Source: NOVOD Report, 2009) S.No 1 2 3 4 5 6 7 8 9 10 11 12 Particulars Site preparation (cleaning and levelling of field) - 10 FW Alignment and staking - 2 FW Digging of pits (500 Numbers) of 60 cm3 size @ 25 pits per FW - 20 FW Cost of FYM (including carriage) 10 kg per pits digging 1st year (5 MT) 2 kg. per plant from second year onward up to 5th year @ US$ 8.9 per MT Cost of fertilizers @US$ 0.13 per kg (500 g per plant during 1st year and 250 g per plant from 2nd year onward and 2 FW for each application. Mixing of FYM, insecticides fertilizers and refilling of pits @ 40 pits per FW 13 FW Cost of plants (including carriage) 500 Numbers during first year and 50 Numbers of plants during second year for replanting @ US$ 0.12 per plant. Planting and replanting cost 100 plants per FW - 5 FW and 1 FW, respectively. Irrigation - 3 irrigation 1st and 2nd year and 1 irrigation during 3rd year onward @ US$ 11.11 per irrigation. Weeding and soil working 4 FW x 2 times Plant protection measures Harvesting of fruits per seeds FW per 100 kg Sub total : Contingency (10% of the above) Grand Total : 1 2 Year 7th 8th Total 1st 2nd 3rd 4th 5th 6th 9th 10th 11th 12th 13th 14th 13.3 2.7 26.7 - - - - - - - - - - - - - 13.3 2.7 26.7 44.4 8.9 8.9 8.9 - - - - - - - - - - 71.1 33.8 19.3 19.3 19.3 - - - - - - - - - - 91.8 17.3 - - - - - - - - - - - - - 17.3 61.1 6.1 - - - - - - - - - - - - 67.2 6.7 1.3 - - - - - - - - - - - - 8.0 33.3 33.3 11.1 11.1 - - - - - - - - - - 88.9 10.7 10.7 4.4 8.9 - 10.7 8.9 - 10.7 8.9 - 53.3 85.3 42.7 31.1 128.0 170.7 213.3 234.7 256.0 256.0 256.0 256.0 1909.3 254.4 88.6 25.4 8.9 279.8 97.5 58.9 5.9 64.8 58.9 5.9 64.8 53.3 5.3 58.6 85.3 8.5 93.8 128.0 170.7 213.3 234.7 256.0 256.0 256.0 256.0 2370.1 12.8 17.1 21.3 23.5 25.6 25.6 25.6 25.6 237.0 140.8 187.8 234.6 258.2 281.6 281.6 281.6 281.6 2607.1 Mortality/casuality replacement: 10%; Survival percentage: 90%; Wage rate per field worker (FW): US$ 1.33; Gestation periods (Years): 4; US$ 1= INR Rs. 45; 1 MT = 1000 kg Report, 2009). The planting density (number of plants per hectare) in different models, soil type, and intensity of postplanting operations such as irrigation will determine planting costs. Resultantly, the reported/published plantation cost is approximately US$ 555.55 per ha on a yearly basis (NOVOD 2009) (http://www.tn.gov.in/policynotes/agriculture). A wide array of subsidies on plants, plantations, and other related activities has been announced by NOVOD and many state governments (Table 2). The table shows that total money spent in the plantation of P. pinnata in 1 ha land was ca. US$ 2607.13. Once the harvesting of fruits starts from the 5th year, the money spent was ca. US$ 53.33, and in the successive years i.e. 6th, 7th, 8th, 9th, 10th, 11th, it increases to 60, 50, 40, 30, 20, and 10%, respectively, of the previous year. Management and future aspects Intercropping Pongamia is widely used as an intercrop particularly with legumes and pulses (Chaukiyal et al. 2000). The dwarf and short duration oilseed and pulse crops such as mustard, groundnut, chickpea, cowpea, horse-gram, and millets like bajra, etc., can be grown successfully as intercrops up to 4 - 5 years after planting without affecting the growth of Pongamia plants. This practice increases the economic feasibility of Pongamia plantation and generates avenues during gestation period from the same land (Pokhriyal et al. 1996). The intercrops selected by various institutions in India for agri-silvicultural trial in Pongamia suggests that there are no significant differences between pure cropping and intercropping on plant height, collar diameter, number of branches, and grain yield. From the results of intercropping plantation of Pongamia with other crops, it is evident that all morphological parameters are not significant within the tree species and survival rate is about 80 - 100%. Cultivation/silvicultural research issues Pongamia can be grown as block plantations, row fences, or in combination with the agricultural crops, fodder, and medicinal plants. Such plantation models have to be tested in field to optimize yields for adaptation by the farmers and entrepreneurs. Standardization of spacing between plants is essential to avoid competition to facilitate higher yield. Irrigation schedule is vital to maximize yields under agro-forestry models and pruning schedules to optimize seed production. Standardization of mass production of clonal material and selection of species for intercropping to increase financial viability of Pongamia plantations has been suggested by Bhojvaid (2008). Extension activities-training of trainers and farmers Unless the value of plant genetic resources is known among 133 134 Pongamia as an alternative biofuel crop in India local communities, there may not be much interest in management. Therefore, value addition to a plant, thereby strengthening the livelihoods of the local communities, would be an effective mode for propagation and management in Pongamia. Field-level workers involved in extension activities of Pongamia cultivation within the project area should be trained on the various aspects of Pongamia plant cultivations such as importance of elite planting materials, its procurement, nursery raising, plantation establishment, and post-planting care. These trained persons can act as a potential source of imparting training to farmers that includes extension activities. Besides, farmers can be given literature/booklets in local languages on various aspects of management of Pongamia plantations. Our own experience where the results of the lab-based experiments were consolidated and made available to the local people through an awareness program by display of charts and posters prepared in the local language (Assamesse) brought interesting facts to our understanding. The response of this program and the uses of these plants by the local people were also recorded. As an added extension of this activity, field demonstrations can be done to show the economic viability and feasibility of cultivation as an alternative option on degraded lands and community wastelands with the help of forest officials. Clonal cuttings of the superior or CPT materials can be supplied to forest officials to replicate the process on larger scales and to promote cultivation of Pongamia on more marginal and wastelands. State forest departments can also be approached for the allocation of marginal lands and better management. Plant breeding methods of enhancing production potential in Pongamia could be targeted towards development of early-bearing Pongamia varieties to reduce the gestation period from 7 to 4 years, higher oil content (74%) with desirable oil quality characteristics especially monounsaturated fatty acid from the point of view of using it as biofuel. Selection of day-neutral varieties so that seed production takes place throughout the year leading to the development of high yield Pongamia varieties that are produced in the “off season” could also be attempted for strategies towards development of dwarf high-yielding varieties that can reduce collection as well as management cost could be developed. Further, development of site-specific genotypes those are tolerant to adverse growing conditions such as salinity, drought, alkalinity, and water logging can be taken as future research so as to increase the range of growth/cultivation of Pongamia. Biodiesel production system for Pongamia The most important trait influencing the overall commercial success of P. pinnata as a promising energy crop is its high seed yield coupled with high oil content. In addition to these parameters, the oil quality aspect should receive due attention with more efficient values for biodiesel standards adding to the overall efficacy of the biofuels. Importantly, the successful adoption of biodiesel is reliant on the supply of feedstock from non-food crops with the capacity to grow on marginal land and not destined to be used for the cultivation of food crops (Hill et al. 2006). P. pinnata is a strong candidate to contribute significant amounts of fuel feedstock, meeting both of these criteria. The seeds of P. pinnata contain 30 - 40% oil, which can be converted to biodiesel (fatty acid methyl esters; FAMEs) by transesterification with methanol in the presence of KOH. The role of Pongamia as a feed stock for biodiesel production was well defined and confirmed. The naturally occurring Pongamia oils are tri-esters of the tri-alcohol and glycerol known as triglycerides. However, the direct use of Pongamia oils and/or blends is generally considered to be unsatisfactory for diesel engines. The reason is high viscosity; free fatty acids content as well as gum formation due to oxidation and polymerization during storage and combustion. Carbon deposits and lubricating oil thickening are some other obvious problems (Srivastava and Prasad 2000). To overcome these drawbacks, considerable effort has gone into developing vegetable oil derivatives that approximate the properties and performance of petroleum-based diesel fuels. Some of the processes that have been investigated are pyrolysis, microemulsification, and transesterification. Attempts have been made for the conversion of Karanja oil to fatty acid methyl esters (De and Bhattacharyya 1999; Vivek and Gupta 2004; Karmee and Chadha 2005). Meher et al. (2006) investigated the optimal reaction conditions to increase the yield of methyl esters by transesterification of Karanja oil with methanol. The reaction parameters such as catalyst concentration, alcohol/oil molar ratio, temperature, and rate of mixing were optimized for production of Karanja oil methyl ester (KOME). Azam et al. (2005) reported that fatty acid methyl ester (FAMEs) of oil of P. pinnata was found most suitable for use as a biodiesel since it meets the major specification of biodiesel standards of the USA, Germany, and European Standard Organization. Extensive studies have shown that Pongamia triglycerides hold promise as alternative diesel engine fuels (Shrinivasa 2001; Sarma et al. 2005; Scott et al. 2008; Sharma and Singh 2008; Mukta et al. 2009; Kesari et al. 2009a). The studies by Vivek and Gupta (2004) revealed the maximum yield of FAMEs up to 89% with molar ratio of MeOH per oil 8 - 10, KOH 1.5% w/w of oil as catalyst when the reaction was conducted for 40 min at 68 - 70 °C. Karmee and Chadha (2005) reported that conversion of crude Pongamia oil to biodiesel is 92% at 60 °C with 1:10 molar ratio (oil:methanol) for KOH (1% w/w) catalyzed transesterification. Whereas Meher et al. (2006) demonstrated that the yield of FAMEs from Karanja oil is 97 - 98% under the optimal condition of 1% KOH as catalyst, MeOH/oil molar ratio 6:1, reaction temperature 65 °C, and rate of mixing 360 rpm for a period of 3 h. Conclusions It has been opined that Pongamia cultivation will add vegetative cover, control soil erosion, and generate biodiesel, thus helping reducing carbon dioxide emissions from fossil fuels. The proposed biodiesel production system also has the potential to address several other important national priorities, the most important being rural development and poverty alleviation. A JCSB 2010 (September) 13 (3) : 127 ~ 137 biodiesel program will open up a large number of employment opportunities by way of plantations, collection of oil seeds, and production of biodiesel. It is estimated that raising a plantation of Pongamia over one hectare of land will generate employment for 300 - 320 persons-days (NOVOD 2008). Furthermore, wasteland can be effectively used for cultivation and subsequent rehabilitation under agronomic/silvicultural aspects (Shrinivasa 2001). Appropriate planting models for different agro-climatic zones and land-uses, and post-planting care and interventions to enhance yields, leading to economic viability are of prime importance in Pongamia plantations In view of the limited supply of natural fossil fuel, Pongamia is undoubtedly one of the key source-species and a potential source of viable biodiesel. Standardization of the vegetative propagation techniques and establishment of PGRC (Pongamia Genetic Resources Center) can be a timely step in this direction for large-scale production of genetically superior saplings throughout the year. The results of our current study on adventitious rooting from CPT varying different natural and synthetic auxins could also encourage tree breeding and its commercialization in areas suitable for its growth. It also has important implications for germplasm utilization and may establish a case study of genetic enhancement of biodiesel species (Rangan, personal communication). 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