EFFETS OF TWO PLANTS PROPAGATION METHODS ON JATROPHA CURCAS (L.) GROWTH AND SEEDS YIELD IN TANDJILE REGION (CHAD).

Field trial was carried out in Chad to investigate the effects of two plants propagation methods on productivity of Jatropha curcas L. cultivated in four localities (Djoun, Insatal, Laï-Djoum and Tchoua) at Tandjilé region in Chad. Planting was done following a randomized block design with four replications and two treatments (plants propagation methods: cuttings of stem and seedling). Physico-chemical properties of growing soils were assessed. The growing parameters and seeds yield were evaluated. Results shown that growing parameters and seeds yield were significantly different (p˂0.05) between both plants propagation methods and four study localities. J. curcas adapted better in Tchoua locality than other three experimental sites. Cuttings of stem exhibited the highest (104±1.9 Kg/ha) seeds yield while the lowest (88±3.7 Kg/ha) is observed under seedling plants propagation method in each of four study sites. It comes out from this study that plants propagation method using cuttings of stem can be recommended to farmers of Tandjilé region (Chad) to be integrated into their agricultural systems for J. curcas growth.

Field trial was carried out in Chad to investigate the effects of two plants propagation methods on productivity of Jatropha curcas L. cultivated in four localities (Djoun, Insatal, Laï-Djoum and Tchoua) at Tandjilé region in Chad. Planting was done following a randomized block design with four replications and two treatments (plants propagation methods: cuttings of stem and seedling). Physico-chemical properties of growing soils were assessed. The growing parameters and seeds yield were evaluated. Results shown that growing parameters and seeds yield were significantly different (p˂0.05) between both plants propagation methods and four study localities. J. curcas adapted better in Tchoua locality than other three experimental sites. Cuttings of stem exhibited the highest (104±1.9 Kg/ha) seeds yield while the lowest (88±3.7 Kg/ha) is observed under seedling plants propagation method in each of four study sites. It comes out from this study that plants propagation method using cuttings of stem can be recommended to farmers of Tandjilé region (Chad) to be integrated into their agricultural systems for J. curcas growth.

…………………………………………………………………………………………………….... Introduction:-
National communities, non-governmental organizations, national and international institutions have in recent years become aware the danger posed by the emission of greenhouse gases, particularly carbon dioxide whose fossil fuel constitutes the main emission source (Minengu et al., 2014). Faced with the industries development and exponential growth of world's population, it is urgent to find a source of alternative energy to avoid energy crisis (Fall, 2007;Sall, 2007). Research focuses on bioenergy, particularly on non-edible plants that can produce oils with biofuel potentiality (Dieye, 2007;Bellefontaine, 2001;Nwaga, 2009). Jatropha curcas L., a shrub belonging to the Euphorbiaceae family, is one of the vegetable species that can solve energy problems because the oil extracted from its seeds can be used as biofuels without competing with food crops. J. Curcas growth well in intercropping with food crop (Dauriat et al., 2001, FAO, 2010. This plant is not edible for humans or livestock. It is widely used in traditional medicine. Seeds oil from J. curcas is used in the manufacture of biofuel, handmade soap, ointment and then used as insecticides and nematocides for crops protection (Hammaoui, 2006). The cake obtained after seeds oil extraction is an excellent organic fertilizer for crops (Penjit, 2012). This cake can be used as fodder for livestock after detoxification (Kasuya et al., 2013). The stem of J. curcas is used for hedgerows construction. J. curcas adapts ISSN: 2320-5407 Int. J. Adv. Res. 7(2), 795-800 796 to various soils, withstands long periods of drought and requires very little maintenance. But its optimal production requires a well-drained and fertile soil (Bellefontaine, 2001;Olivier, 2007). Many countries in the world, including America, Asia and recently some West African countries have embarked on its culture for biofuels production. The Sudanian zone of Chad offers a favorable climate for planting this shrub in order to solve the socio-economic needs of population stricken by poverty. The purpose of this work was to evaluate (1) the physico-chemical characteristics of soils from Sudanian savannah of Tandjilé (Chad), (2) plants propagation methods (seedling and cuttings of stem) as well as localities of Sudanian savannah of Tandjilé (Chad) on J. curcas growth and development. The importance and usefulness of this work follows from the fact that the plants propagation method and the Chad study area which will provide the highest seeds yield of J. curcas will be popularized.

Materials:-
Seeds and cuttings of stem of Jatropha curcas are used. They were collected locally. Fruits and cuttings were picked in november 2015 on J. curcas planted in hedge. These plants are 5 years old. Subsequently, the seeds are extracted from the fruits and they were stored in a dry place (room temperature) until the sowing day. These seeds were black in color and presented 1.86 cm length, 1.10 cm maximal diameter and 0.72 g weight at planting. Cuttings presented 2.5 cm diameter and 60 cm long and they were made at sowing day..  Methods:-Assesment of plants propagation methods on Jatropha curcas growth and yield Land preparation and experimental design:-All wild plants were cut off from the experimental sites. Thereafter each site was plowed to 50 cm depth and ridges of 10 m × 6 m (60 m 2 ) were formed. Space between two consecutive ridges was 3 m. The experimental design consisted of two treatments (plants propagation methods) lay out randomly and repeated in four blocks. The same experimental design was adopted in the four study localities (Djoun, Tchoua, Laï-Djom and Insatal). All data were statistically analyzed using the Stagraphic plus Program version 5.0. The significance of differences was determined using Duncan test.

Results and Discussion:-
Chemical properties of growing soils:-Growing soil presents a sand-clay texture with silt levels ranging from 1.68% to 5.05%. All soil samples have a neutral pH (6.59-7.38) (table 1), thus suggesting the optimal availability of mineral elements at different experimental sites (Kanabo and Gilkes, 1987). Organic matter and soil carbon content are relatively low (less than 1%) ( Table 1). Crops have difficulty in extracting nutrients from soil and microfauna activity is reduced when soil organic matter is less than 1% (Martin et al.. 1990). In this respect, fertilization using compost would increase the agricultural values of our growing soil, but this needs to be investigated. Phosphorus and potassium contents of growing soil range from 250 to 480 ppm and from 100 ppm to 180ppm respectively. Concerning chemical properties of growing soil. soil from four study sites presented globally a good agricultural values ; they are all likely to guarantee a good productivity of plants like Jatropha curcas L. However it would be appropriate to improve the low organic matter content of these soils by adding organic manure.

Effect of plants propagation methods on Jatropha curcas growth and development Plants height, number of leaves per plant and number of bunches per plant:-
The analysis of variance (ANOVA) shows that there is no significant difference on plant height between both plants propagation methods (seedling and cuttings of stem). However the four experimental sites influence significantly (p˂0,05) the height of Jatropha curcas plants (  Plant leaves absorb co 2 through photosynthesis, thus contributing to fight against climate change. It can also limit sunstroke, increase soil moisture content and reduce erosion (Ouédraogo, 2000;Singh and Rathod, 2002;Tchuenteu et al., 2013). Plants leaves represent a biomass that can be degraded and released nutrient necessary for improving soil fertility and plants nutrition (Bunch, 2004;Sall, 2007). In the present study, Tchoua locality exhibited the greatest foliar production, suggesting that J. curcas' cultivation in Tchoua locality would contribute effectively to fight against climate change as well as improving soil fertility compared to other three experimental sites, but this remains to be studied. In this study, plants height, foliar production and number of bunches per plant vary according to experimental area, this result does not surprise us: indeed, several authors (Reinhard and Tianasoa, 2005;Fresco, 2003 andMegueni et al., 2011) reported that plants growth parameters vary depending cultural practice and experimental area.

Dry biomass and carbon stock:-
The dry biomass, carbon stock and equivalent CO 2 sequestred depending experimental site and plants propagation method are presented in table 2. The analysis of variance (ANOVA) showed that both plants propagation methods and the four study localities influenced significantly (P <0.001) the dry biomass of plants of J. curcas, consequently carbon stock and equivalent CO2 sequestered. Plants with a high biomass correspond to those with high carbon values sequestered by photosynthesis mechanism (Tchobsala, 2016). Plants from Tchoua locality exhibited the highest (0.26±0.03 Kg) dry biomass, consequently the highest (0.13± 0.05 Kg) carbon stock compared to those from other localities. In this respect, the culture of J. curcas in Tchoua locality would contribute effectively to fight against climate change compared to Djoun, Insatal and Laï-Djoum areas.  Tchuenteu et al., 2013 andDerogoh et al., 2018) reported that plant productivity vary depending experimental area. In this study, seeds yield ranged from 55 ± 4.92 Kg/ha to 104 ± 1.90 Kg/ha. These values are lower than data found in littérature. The low seed yield obtained in this study is due to the fact that no fertilizer was applied in this work. Seeds yield can be improved if soil 799 amendment, cultural and growing conditions are improved. Indeed, Bambang et al. (2016) study the yield performance of J. curcas after pruning during five years production cycles in North Lombok dry land, Indonesia and reported that The total yield was higher (16.314.6 kg Ha-1), compared to un-pruned tree (14.800.1 kg Ha-1). In addition, Chengxin et al. (2014) study on a new J. curcas variety (JO S2) with improved seed productivity and found that this J. curcas variety produced up to 2.95 ton/ha of dry seeds in the first year and up to 4.25 ton/ha of dry seeds in the second year, much better than the local variety control. the small seed yield obtained in this study can be explained by the fact that this work was not carried out under the same experimental conditions as those of our predecessors. In addition, it was been reported that plant productivity vary according to genotype, experimental area, and year of experimentation (Koutroubass et al., 1999, Tchuenteu et al., 2013). In this study, Tchoua locality is more favorable for J. curcas growth compared to Djoun, Insalta and Lai-Djoum. Moreover, J. curcas growth and seeds yield is higher under cuttings of stem plants propagation medthod than under seeds propagation.

Conclusion:-
Soils from Sudanian savannah zone of Chad are favorable for well Jatropha curcas growing. The growing parameters of J. curcas as well as seeds yield vary depending study area and plants propagation method. J. curcas plants from Tchoua locality exhibited the highest growing parameters and seeds yield (96 ± 2.82 Kg/ha). Cuttings of stem exhibited the highest (104±1.9 Kg/ha) seeds yield while the lowest (88±3.7) is observed under seedling plants propagation method in each of four experimental areas. Cuttings of stem propagation method is recommended for J. curcas growing in Chad. Further research will then investigated the effect of organic manure on J. curcas growing in Tchad.