Browsing by Subject "Jatropha"
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Publication Agrofuels, large-scale agricultural production, and rural development : the case of Jatropha in Madagascar(2019) Bosch, Christine; Zeller, ManfredAgrofuel production in marginal areas can contribute directly to creating employment and improving local livelihoods. Indirectly, through increasing household purchasing power and relaxing financial constraints of smallholder farmers, it can contribute to greater food production and/or food consumption and rural development. These benefits depend, however, largely on the feedstock crop and its processing, land and labour requirements, the business model, value chains and institutional frameworks. Jatropha, a feedstock crop with more benefits than first-generation energy crops like maize, experienced a spike in popularity in the early 2000s due to its value in the biofuel markets of industrialized countries. The majority of plantations and outgrower schemes could not survive what followed: disappointing yields, pests and disease, low oil prices, the 2007/2008 food price crisis, negative narratives, and inadequate funding for further research activities. Despite these challenges, large-scale land investments and new Jatropha projects continue to be undertaken. Madagascar is a country characterized by severely eroded and degraded pasturelands, low agricultural productivity, high vulnerability to climatic shocks, and overwhelming poverty and food insecurity rates. It is hypothesized that the use of marginal lands for labour-intensive agrofuel feedstock cultivation, in otherwise neglected areas, through both public and private investment, will have positive impacts through the provision of wage work in large-scale plantation schemes. Although a number of studies have investigated the rural livelihood impacts of participation in Jatropha cultivation, there is little evidence that quantifies the long-term and indirect effects on smallholder food production and household food security. Against this background, large-scale Jatropha cultivation lends itself well to studying the complex interplay between feedstock and food production, as well as the potential for agricultural and rural development. Such analysis would provide useful insights and implications for cost-effective rural development policies to target poor farmers in remote areas. Drawing on a conceptual framework that highlights the role of smallholder farmers’ livelihood strategies like off-farm employment and agricultural intensification, and livelihood outcomes like food security, this thesis explores the contribution of large-scale agrofuel feedstock cultivation on marginal land. Three important outcomes, namely household food security, information and innovation spillover effects, and agricultural input use, are studied empirically in three articles, using a comprehensive household panel data set. The data was collected in six survey rounds between 2008 and 2014, in three villages near a large-scale Jatropha project in the Haute Matsiatra region, located in Madagascar’s Southern Highlands. The first article examines the relationship between wage work for a Jatropha project and household food security. Jatropha cultivation on marginal land is labour intensive and does not compete with food production. Therefore, incomes earned can contribute to increased food security directly as well as indirectly through increased or diversified food production. Using five rounds of household panel data, results show that labour demand from the plantation declined substantially after the build-up phase and Jatropha incomes were mostly used for food and other necessities. Fixed effects models show that Jatropha work contributed significantly to an improved dietary diversity. Despite the possibility to earn income during the lean season, Jatropha work did not lead to a reduction in the more subjective lack of food and led to reduced rice stocks. Both food production and consumption were highly influenced by drought shocks and locust plagues, indicating that complementing income creation strategies with agricultural development strategies might have further positive effects on food security. To shed light on the impact pathway from Jatropha work to agricultural production, the second article explores information dissemination through social networks and through Jatropha workers who are more exposed to modern technologies than control households. In addition to institutional factors, a lack of knowledge and limited extension services for improved agricultural technologies are considered barriers to information dissemination. Using two rounds of the dataset, which contains rich information on social capital and networks as well as knowledge and innovations, determinants of production-relevant knowledge like extension services, credit and marketing opportunities are estimated. Accounting for potential endogeneity with lagged and instrumental variables, the relevance of this knowledge to the adoption of innovations and the cultivation of a formerly taboo legume, as an example of diversification, is tested. The results indicate limited access to information, little knowledge on investment and marketing opportunities, and low adoption of innovations. Knowledge is relevant for both innovation performance and the cultivation of the Bambara groundnut, highlighting the need to increase and improve public extension services and information dissemination in rural Madagascar. Adoption is not only encouraged by knowledge, but also directly motivated through informal social networks. Bambara groundnut spillovers from the biofuel project can be observed, relaxing some of the constraints farmers face concerning access to information, social learning, and cultural norms. The third article explores one specific hypothesized spillover: access to and use of agricultural inputs. Given the very low use of improved inputs in rural areas in Madagascar, this study explores whether improved seed and seed information distributed to farmers encourages farmers to cultivate the seed. The analysis is based on household data gathered between 2012 and 2014 from 390 households in three villages. To investigate the adoption of improved seed, as well as the diffusion of information regarding improved seed, a randomized control trial was applied in 2013. Half of the 390 households were randomly assigned to receive the improved lima bean seed (Phaseolus lunatus), which is specifically bred for dry regions. Of the seed-receiving households, half were randomly assigned to receive information on how to store, plant, and cultivate the improved seed, as the variety was unfamiliar in the region. The control group and the two treatment groups are compared with respect to baseline characteristics, bean cultivation, information exchange with other farmers, legume consumption, and willingness to pay (WTP) for improved bean seed. To account for non-compliance, contamination, and spillover effects, local average treatment effects (LATE) are estimated. Of the seed-receiving households, 54% cultivated the seed, reaping an average yield of 6.3 kg for each kilogram of seed obtained. Seed information did not lead to higher yields. A small significant positive impact of seed distribution on legume consumption is found. WTP is 171% of the local market price for bean seed; provision of free seeds and information did not result in a higher WTP. Based on these findings, this thesis contributes empirical evidence that large-scale agrofuel feedstock production on marginal land can enhance rural livelihoods by offering alternative livelihood strategies especially for poorer households and contributing to improved livelihood outcomes. Accounting for the indirect effects shows important impact pathways on the livelihood strategies of farmers in a remote area. The provision of incentives for private investors, complemented by more public intervention in rural areas, as well as more investment in agricultural research and extension to reduce agricultural production risks, might enhance these spillovers.Publication Evaluation of suitability of non-toxic and detoxified Jatropha curcas L. meal as feed for fingerling common carp, Cyprinus carpio L., with reference to phytase application(2012) Richter, Nahid; Becker, KlausJatropha curcas L. is a hardy plant which can thrive on marginal degraded lands. Jatropha seeds contain about 300-350g kg-1 oil, which is used as fuel or in transesterified form as a substitute for diesel; they also have considerable protein quality. However, Jatropha contains antinutrients such as lectins, trypsin inhibitors and phytic acids at high levels and in toxic varities phorbolesters cause detrimental effect. Common carp fed heat-treated non-toxic Jatropha meal (JM) has been shown to have higher weight gain and protein efficiency ratio than those fish fed untreated JM. However, these parameters were significantly lower in the aforementioned trial when compared to fish fed a fish meal (FM) based diet. Reduced growth performance in fish fed non-toxic JM might be attributable to the deficiency of some essential amino acids such as lysine, to high levels of phytic acids or the presence of antinutrients. These may indicate the need for additional processing of JM for common carp. This work was therefore conducted to test various ways of further improving the nutritional quality of JM to increase the levels of inclusion in diets for common carp. In the first experiment, four diets based on 50% replacement of FM with defatted non-toxic JM were formulated, one with no further JM treatment, the second with 80% aqueous ethanol extraction before diet formulation, the third supplemented with 1% L-lysine and the fourth with 500 FTU phytase (5000G, Natuphos). These were compared to a standard, FM based diet. The results showed that diets with 500 FTU/kg phytase or 1% L-lysine could maintain common carp?s growth performance at a level comparable to fish fed a FM diet. Fish fed diets containing JM and ethanol treated JM had significantly lower growth performance than the control. The addition of 1% L-lysine or 500 FTU phytase enhanced percent body weight gain, food conversion efficiency and specific growth rate to a level comparable to those of the control. Furthermore, the addition of 500 FTU phytase significantly increased whole body Mg, P and K to the levels of those fish fed Diet Control. When the level of JM replacement was increased from 50% to 75% while at the same time supplementing the diets with inorganic phosphorus (Experiment 2), however, a significant decrease in body weight gain of common carp was observed both with and without 500 FTU phytase. In a third experiment, the effect of JM diets with added phytase but without phosphorous supplementation was therefore investigated in more detail. At the end of the eight week trial, phytase supplementation had not affected body mass gain (BMG), food conversion ratio (FCR) and specific growth rate (SGR) of fish. However, whole body phosphorous (P), P gain and P retention were significantly improved in fish fed JM with phytase supplementation when this was compared to the fish fed JM without phytase. Moreover, fish fed JM diets indicated higher O2 consumption per gramme body mass gain than carp fed FM diets. Energy expenditure per gramme protein retained was significantly higher for fish fed JM with or without phytase addition, indicating that the utilisation of JM was associated with higher energy costs for the fish. In the final experiment, the nutritional quality of non-toxic JM was compared to that of the toxic variety once appropriate measures had been taken to detoxify the latter. FM was replaced with either of the two at 75% of total dietary protein, for each Jatropha variety once without further supplementation and once supplemented with 500 FTU phytase and 1% lysine. The results of this experiment indicated that there was no significant differences in final body mass (FBM), % BMG, feed intake (FI), FCR and specific growth rate (SGR) of fish fed diets Control and non-toxic, supplemented JM. However, fish fed diets based on detoxified or non-toxic, unsupplemented Jatropha showed significantly inferior growth parameters when compared to carp fed the first two diets (p<0.05). Whole body P was significantly higher in fish fed the Control and non-toxic JM diets (with/without phytase and lysine) than fish fed either of the two detoxified JM diets (p<0.05). The depressed growth performance in the group fed detoxified JM could imply that the detoxification process was not complete and traces of phorbolesters may still be present in the diets. This work has shown that, given proper treatment, JM can act as a suitable replacement for FM at high levels in diets for common carp. The results of this work suggest that phytase addition to enhance phosphorous availability and lysine supplementation to correct the essential amino acid imbalance are two factors that have significant effects in improving JM suitability for common carp.Publication Isolation, characterization and potential agro-pharmaceutical applications of phorbol esters from Jatropha curcas oil(2012) Devappa, Rakshit K.; Becker, KlausBiodiesel is generally prepared from renewable biological sources such as vegetable oils by transesterification. Jatropha curcas seed oil is a promising feedstock for biodiesel production. During biodiesel production from Jatropha oil, many co-products such as glycerol, fatty acid dis-tillate and seed cake, among others, are obtained. The efficient use of these co-products would enhance the economic viability of the Jatropha based biofuel industry. However, the possible presence of phorbol esters (PEs) in these co-products restricts their efficient utilization. During biodiesel production, Jatropha oil is subjected to many treatments (stripping, degumming and esterification) wherein PEs present in the oil undergo partial or complete destruction depending on the treatment conditions. One of aims of this study was to develop and integrate methodolo-gies for using the PEs as a value added product instead of simply allowing them to be destroyed during biodiesel production. Potential uses of the phorbol ester enriched fraction (PEEF), ob-tained from Jatropha oil in agro-pharmaceutical applications were also investigated. The reason for choosing this group of compounds (PEs) was that they are highly bioactive both in vitro and in vivo, but they are currently considered to be merely toxic, unwanted biomaterial in the Jatro-pha biodiesel production chain. The recent increase in the cultivation of Jatropha cultivation means that there are potentially huge quantities of PEs that could be used for many purposes. This study revealed that a large proportion (85.7%) of PEs was localized in the endosperm portion of the Jatropha seed. Interestingly, the kernel coat contained PEs in high concentration. The endosperm portion of the kernel also contained antinutritional factors such as phytate (96.5%) and trypsin inhibitor (95.3%). The presence of high levels of antinutritional/toxic com-ponents in the kernel was presumed to be one of the factors that protect Jatropha seeds against predatory organisms during post harvest storage. Based on the presence or absence of PEs, a qualitative method was developed to differentiate between toxic/nontoxic Jatropha genotypes. In this method the methanol extract of seeds is passed through a solid phase extraction (SPE) column and the absorption (280 nm) of the result-ing eluate is measured. After screening Jatropha seeds collected from different parts of the world for toxic and non-toxic genotypes using the pre-established HPLC method for PEs, a cut off value of the absorbance was set up to differentiate toxic and nontoxic genotypes. Raw kernels whose SPE eluates had an absorbance ≥0.056 were considered as toxic and ≤0.032 as nontoxic. Corresponding absorbances for the SPE eluates of defatted kernel meal were ≥0.059 (toxic) and ≤0.043 (nontoxic). However, confirmation of the presence of PEs especially in Jatropha products for food applications should be carried out using the pre-established and validated HPLC method. The developed qualitative method could find its applications for screening the toxicity of products and co-products obtained from the Jatropha biodiesel industry. Conditions were optimized for the extraction of PEs as a phorbol ester enriched fraction (PEEF) from Jatropha oil using methanol as a solvent and a magnetic stirrer/Ultra-turrax as ex-traction tools. The extent of PE reduction in Jatropha oil was >99.4% using methanol as the sol-vent. The PEEF obtained (48.4 mg PEs/g) was 14 fold higher in PEs than in the original oil and this fraction was highly bioactive as determined by the most sensitive snail bioassay (LC100, 1 ppm) (see below). As the removal of PEs from oil took 60 min, which might be considered a long time in an industrial process, further conditions were optimized to extract maximum PEs in the shortest possible time with minimum solvent. The tools used for PE extraction (Ultra-turrax and magnetic stirrer) were effective with a treatment time of 2 and 5 min, resulting in 80 and 78% extraction of PEs, respectively. The biodiesel prepared from both the residual oils met European (EN 14214:2008) and American biodiesel standard (ASTM D6751-09) specifications. It was evident from the study that PEs could be easily extracted by either of the two methods with a high yield and the residual oil could be processed to produce high quality biodiesel. Also the residual oil with a lower PE content is expected neither to harm the environment nor the workers who had to handle it. The extracted PEEF was evaluated for its agricultural potential as a bio control agent. The PEEF had a high biological activity in aquatic bioassays using snails (Physa fontinalis), brine shrimp (Artemeia salina) and daphnia (Daphnia magna), when compared with microorganisms. The EC50 (48 h) of the PEEF was 0.33, 26.48 and 0.95 ppm PEs for snail, brine shrimp and daphnia respectively. High MIC (minimum inhibitory concentration) values (≥215 ppm) and EC50 values (≥58 ppm) were obtained for both the bacterial and fungal species. Among the bio-assays tested, the snail bioassay was the most sensitive, producing LC100 at 1 μg of PEs/ml. The snail bioassay could be used to monitor the presence of PEs in various Jatropha derived products, contaminated soil and other matrices in the ecosystem that might be involved in the production or use of Jatropha and its products. The study also demonstrated that the PEs exhibit molus-cicidal, antifungal and antibacterial activities. The shelf life of the PEEF was investigated. The PEEF was more susceptible to degradation when stored at room temperature (50% degradation after 132 days) than when stored at 4 °C or -80 °C (8% and 4% degradation respectively). Similarly, the PEEF lost biological activity (the snail bioassay) more rapidly at room temperature becoming ineffective after 260 days; while at 4 °C and -80 °C, only 27.5% and 32.5% activity was lost after 870 days. The degradation of PEs was due to auto-oxidation. Changes in fatty acid composition, increase in peroxide value and decrease in free radical scavenging activity of the PEEF reflected the auto-oxidation. Inclusion of antioxidants as additives (butylated hydroxyanisole (BHA), Baynox and α-tocopherol) pro-tected the PEs against degradation. The study demonstrated that the PEEF was susceptible to oxidation and addition of antioxidant stabilised the PEs during storage. In soil, PEs present in both the PEEF (2.6 mg/g soil mixture) (silica was used to adsorb PEs) and Jatropha seed cake (0.37 mg/g soil mixture) were completely degraded as the temperature and moisture content of the soil increased. PEs from silica-bound PEEF were completely de-graded after 19, 12, 12 days (at 13% moisture) and after 17, 9, 9 days (at 23% moisture) at room temperature (22 −23°C), 32 °C and 42 °C respectively. Similarly, at these temperatures, PEs from seed cake were degraded after 21, 17 and 17 days (at 13% moisture) and after 23, 17, and 15 days (at 23% moisture). The toxicity of PE-amended soil extracts when tested using the snail bioassay decreased with the decrease in PE concentration. The study demonstrated that PEs pre-sent in the PEEF or Jatropha seed cake are completely biodegradable in soil and the degraded products are innocuous. In preliminary studies, the PEEF exhibited potent insecticidal activity against Spodoptera frugiperda, which is a common pest in corn fields damaging maize crop across the tropi-cal/subtropical countries such as Mexico and Brazil. The PEEF produced contact toxicity with an LC50 of 0.83 mg/ml (w/v). The PEEF at higher concentration (0.25 mg/ml, w/v) also reduced food consumption, relative growth rate and food conversion efficiency (FCE) by 33%, 42% and 38% respectively. The study demonstrated that the PEEF has a potential to be used as a bio-control agent. Further in-depth field experiments on the effects of the PEEF on S. frugiperda will pave the way for its use under field conditions. The pharmaceutical potential of Jatropha PEs was also investigated. The PEs from Jatropha oil were purified. At least six purified PEs (designated as factors C1 to C6) were present in Jatropha oil. The identities of the purified PEs (factors C1 and C2) were confirmed by NMR. Whereas, factor C3 and factors (C4 + C5) were both obtained as mixtures. However, comparison of peak areas for phorbol 12-myristate 13-acetate (PMA) and Jatropha factor C1 in the HPLC method showed a difference in sensitivity of absorption at 280 nm of 41.3 fold. All the individual purified Jatropha PEs (factors C1, C2, C3mixture and (C4+C5)) and PEs-rich extract (factors C1 to (C4 + C5)) were biologically active when tested in the snail and brine shrimp bioassays. In ad-dition, all the Jatropha PEs produced platelet aggregation in vitro with an effective order of (based on ED50 (μM)): Jatropha factor C2 < factor C3mixture < factor C1 < factor (C4+C5). The PEs-rich extract (contains factor C1 to C6) was toxic to mice upon intra gastric administration, with an LD50 of 27.34 mg/kg body mass as PMA equivalent or 0.66 mg/kg body mass as factor C1 equivalent. The prominent histopathological symptoms were observed in lung and kidney. The Jatropha purified PEs-rich extract, purified PEs (factor C1, factor C2, factor C3mixture and factors (C4+C5)) and toxic Jatropha oil produced severe cellular alterations/disintegration of the epithelium and also increased the inflammatory response (interleukin-1α and prostaglandin E2 release) when applied topically to reconstituted human epithelium (RHE) and human corneal epithelium (HCE). In RHE, the nontoxic oil (equivalent to the volume used for toxic oil) pro-duced a lower cellular and inflammatory response than the toxic oil and the response increased with an increase in concentration of the PEs. In HCE, nontoxic oil (equivalent to the volume used for toxic oil) produced marked cellular alterations. The study demonstrated that the pres-ence of PEs in Jatropha oil increased the toxicity, both towards RHE and HCE. In addition, all the purified Jatropha PEs gave positive responses in the tumour promotion assay and negative responses in the tumour initiation assay in vitro (the assay was based on foci formation in Bhas 42 cells). In the tumour promotion assay, the order of transformed foci/well formation was: PEs-rich extract > factor (C4+C5) > factor C3mixture > factor C1 > factor C2. The tumour promotion ac-tivity was mediated by the hyper activation of protein kinase C (PKC). The aforementioned studies demonstrated that Jatropha PEs are toxic when administered orally or when applied topically to the skin or eye tissues. The data obtained should help in establishing safety measures for people working with Jatropha PEs. The potential of Jatropha PEs as a feedstock intermediate for the synthesis of Prostratin, a promising adjuvant in anti HIV therapy, was evaluated. The studies demonstrated that the Jatro-pha PEs could be synthesized sequentially by converting them first to crotophorbolone and then to prostratin. As analyzed by Nano-LC-ESI-MS/MSR, the prostratin synthesized from Jatropha PEs had similar mass and peak retention time to the reference prostratin (Sigma, St. Louis), The study showed that prostratin could be synthesized from Jatropha PEs. However, further optimi-zation studies are required to ascertain the synthesis reactions and yield of prostratin synthesized from Jatropha PEs. Some of the preliminary requirements for any successful bio-control agent are that it should have a high bioactivity on the target organism, a long shelf-life and a high biodegradability in soil. In addition, the bioactive phytochemical should be available in large quantities, it should be easily extractable and continuously available. The PEEF potentially satisfies these aforesaid re-quirements. The abundance and novelty of PEs present in Jatropha species could form a new ?stock? for the agro-pharmaceutical industries. Considering the projected oil yield of 26 million tons/annum by 2015 (GEXSI, 2008), huge amount of raw materials will be available for both biodiesel and pharmaceutical industries. PEs in the form of the PEEF could be used either as in-sect controlling agents in agricultural applications or as a ?stock? biomaterial for synthesizing prostratin in pharmaceutical applications.Publication Jatropha meal and protein isolate as a protein source in aquafeed(2011) Kumar, Vikas; Becker, KlausAs aquaculture continues to develop, there will be an increasing need to use alternative plant proteins in aquaculture diets so that aqua eco-systems will be sustainable. Jatropha (DJKM, H-JPKM and DJPI) can be used as protein rich sources in the diets of fish and shrimp. There is a high potential for the safe use of DJKM, H-JPKM and DJPI in diets for fish and shrimp without compromising performance, provided that these ingredients are free of toxic factors. The detoxification process developed in Hohenheim is simple and robust and produces products that are safe and of good quality. Their addition to fish and shrimp diets gave excellent performance responses without any ill effects on animal health or safety. Effects on growth and nutrient utilization: ? Detoxified Jatropha kernel meal, H-JPKM and DJPI could replace 50%, 62.5% and 75% fish meal protein respectively without compromising growth performance and nutrient utilization in fish. In addition, DJKM could also replace 50% fish meal protein with no adverse effects on growth and nutrient utilization in shrimp. If the replacement levels are exceeded, the producer must examine the nutrient profile of the feeds carefully to ensure that desired production levels can be achieved and fish and shrimp health maintained. ? High inclusion (>50% fish meal protein replacement) of DJKM decreased the efficiency of conversion of feed to body mass. This could be explained partly by the increased mean feed intake which was possibly a reaction to the reduced protein retention, measured as protein efficiency ratio and protein productive value. No such effects were seen with the use of DJPI in common carp diets. ? Increased DJKM inclusion in diets caused a significant lowering of protein, lipid and energy digestibilities. No such effects were seen when DJPI was used in common carp diets. Effects on energy budget: ? Feeding DJKM and H-JPKM to common carp and Nile tilapia respectively did not change the major components of the energy budget (routine metabolic rate, heat released and metabolisable energy) compared to fish meal and soybean meal fed groups. These results revealed that dietary protein sources DJKM and H-JPKM can be efficiently utilized for growth by common carp and Nile tilapia respectively, as well as soybean meal and fish meal. Effects on expression of growth hormone and insulin-like growth factor-1 encoding genes ? As the level of DJKM inclusion increased in the common carp diet, growth rate decreased. The expression of Insulin-like growth factor-1 (IGF-1) in liver also decreased with increase of DJKM in the diet and that of the growth hormone in liver decreased. Effects on clinical health parameters and gut health: ? No mortality and unaffected haematological values suggested the fish were all in normal health. Alkaline phosphatase and ALT activities; urea nitrogen, bilirubin and creatinine concentration in blood were in the normal ranges which showed that there was no liver or kidney dysfunction. ? The measured plasma nutrient levels gave no indications of stress, but increasing the level of plant protein in the diet decreased plasma cholesterol. This may be related to high NSP content or reduced dietary intake of cholesterol. Decrease in muscle cholesterol level is also expected which could be considered good for human health. ? Histopathological evaluation of organs showed no damage to the stomach, intestine or liver of common carp or rainbow trout. Effects of Jatropha-phytate in Nile tilapia The defatted Jatropha kernel meal obtained after oil extraction is rich in protein (58−66%) and phytate (9 −11%). The phytate rich fraction was isolated from defatted kernel meal using organic solvents (acetone and carbon tetrachloride). It had 66% phytate and 22% crude protein and its inclusion in fish diets showed the following: ? Negative effects on growth performance, nutrient utilization and digestive physiology (nutrient digestibility and digestive enzymes). ? Adverse influences on biochemical entities such as metabolic enzymes (alkaline phosphatase and alanine transaminase) and electrolytes/metabolites. Salient changes include decreased red blood cell count and hematocrit content, decreased cholesterol and triglyceride concentrations in plasma and decreased blood glucose levels. The adverse effects observed may be due to the interaction of phytate with minerals and enzymes in the gastro intestinal tract, resulting in poor bioavailability of minerals and lower nutrient digestibility. The level of phytate used in the present study (1.5 and 3.0%) corresponds to 16.5% and 33.0% of DJKM in the fish diet. The DJKM at levels > 16.5% in the diet would exhibit adverse effects in Nile tilapia. Addition of phytase to the phytate containing diets would mitigate the adverse effects of at least up to 3% Jatropha phytate (or 33% DJKM) in the diet. Addition of phytase (1500 FTU/kg) in diets containing DJKM is recommended to maximize their utilization by Nile tilapia.Publication Opportunities and constraints for agrofuels in developing countries : case studies on economic viability and employment effects of Jatropha production(2010) Grass, Martin; Zeller, ManfredThis dissertation was motivated by controversial statements of politicians and lobby groups for and against first-generation agrofuel production. Therefore this thesis contributes to a more realistic view on opportunities and constraints for agrofuel production based on first-generation technologies. The findings are based on an intensive literature review covering the following topics: current production trends of ethanol and agrodiesel, their potential for fossil energy substitution and greenhouse gas reduction including related costs, rural development and poverty alleviation. This more general overview on agrofuels was deepened by own research on Jatropha seed production in India and Madagascar. In this context the economic viability of Jatropha seed production and possible income effects for households living in the vicinity of a Jatropha plantation were analyzed. For this special agrofuel feedstock the findings allowed shedding some light on important aspects of the much broader topic concerning the production of agrofuels. To cover the above mentioned topics this dissertation is structured around three research papers. The first paper identifies and discusses the opportunities and constraints of first-generation agrofuel production in developed and developing countries and is based on an intensive literature review. Therefore this paper contrasts arguments used by politicians to justify agrofuel support measures like energy security, greenhouse gas reduction potential, income generation and possible rural development with new scientific findings on each argument. Furthermore data on worldwide trends in ethanol and agrodiesel production were presented. The second paper focuses on one possible option to lower competition between food and agrofuel production at least partially. This option is seen in the production of Jatropha seeds on marginal land not suitable for food production. In this context an Indian case study revealed the economic viability of Jatropha seed production on marginal land. The database for this study includes data derived from literature as well as experimental field data provided by the ?International Crops Research Institute for the Semi-Arid Tropics?. The third paper addresses possible income effects for rural households offering their labour force to a Jatropha plantation in central Madagascar. The econometric impact assessment is based on a socio-economic household survey undertaken by the author in 2009. To account for possible selection bias the propensity score matching approach was used to estimate the average treatment effect on the treated by comparing the average income of Jatropha plantation households and control households. The findings for 336 households reveal positive income effects for households working at the Jatropha plantation. The dissertation concludes that more investments in research are needed to gain a potential win-win situation for rural households, investors and the environment especially for the case of developing countries. The results lead to the conclusion, that smallholder based Jatropha seed production should not be promoted in developing countries. Therefore this dissertation concludes further that it would be far better for developing countries to let international investors set up Jatropha plantations, hence in this case the economic risk is borne by the foreign investors. Furthermore abundant labour in rural areas could find employment opportunities with such plantations and therefore would be able to generate some income for their families. Nevertheless the implementation of Jatropha projects financed by international investor?s needs regulations set up by national governments. Those regulations should cover each aspect within the entire value chain of Jatropha agrofuel production and should be embedded in a national energy and rural development policy. Furthermore institutional frameworks such as land tenure security and labour rights have to be enforced. Setting up aforementioned regulations and institutional frameworks can prevent possible constraints such as, land grabbing, exploitation of rural labourers, loss of biodiversity and competition between Jatropha seed and food production e.g. for scarce water, which could occur due to foreign investment in local Jatropha (and other agrofuel feedstocks) cultivation in the worst case.