Techniques of Domestication and Carbon Sequestration of Jatropha curcas Associated with Vigna unguiculata in Marginal Soil of Garoua Region, Cameroon

In order to reduce the increase of fuel prices, and improve the living conditions of the population, a study was carried out by Convention No. 1/IRAD/PCS ESA2-SDCC in the region of Garoua in Cameroon. The study aimed to characterize the behaviour ofJ. curcas associated with V. unguiculata in marginal soils in the Sahel region in order to improve the livelihoods of the farmers and promote its domestication in rural areas. It also aimed at pointing out the influence of two implantation techniques of d. curcas on the germination, the different quantities of NPK and cow dung, planting techniques and association with V. unguiculata var. lori on growth parameters of development and yield of J. curcas on the degraded marginal soils in the region. The experimental design was a completely randomized block with five levels of fertilization （F0： control; FI： 50 g; F2：100 g of NPK 15-20-15; F3：1 kg and 2 kg of cow dung） per plant. Two types of establishment propagator （Ge） and direct seedling （Se） with three replications were used. Data were analysed by Stratigraphic ＋ and XLSTAT. Results showed that the propagator germination was higher than the direct seeding, 95% and 40% respectively. The Principal Component Analysis （PCA） of the parameters of growths and yield of J. curcas showed high correlation between the production of the leaves and the length of the leaves （R = 0.861; P 〈 0.001）. These parameters were correlated with the Biplot （F1 and F2） to 53.24%. It was opposed to the positives and imperfect correlation between the height and the recover parameters （R = 0.486; P 〈 0.05）. The treatments 100 g of NPK per plant and 2 kg of cow dung per plant induced strongly the development and yield ofJ. curcas and V. unguiculata adapted to marginal soils.

Influence of Agricultural Inputs on Growth and Yield of Jatropha curcas （L.） in Cameroon

A study was carried out in the Northern region of Cameroon to assess the influence of fertilizers （chemical fertilizer NPK （15-20-15 w/w/w） or cow dung） on the growth and yield ofJatropha curcas from four origins namely Cameroon, Senegal, Tanzania and Mozambique. The experimental design was factorial with 4 origins×3 fertilizers×8 month durations. After planting, growth parameters and dendrometric measurements were carried out monthly during eight months. Data were analyzed using a Statgraphics program and Duncan test. The results showed that plant of Tanzania and Mozambique origin had higher germination rate in field 75% and 69.5%, respectively. The survival rate of transplants was 100% for Cameroon origin and 98.48% for Senegal origin. NPK and cow dung significantly （P 〈 0.05） increased the growth parameters height, diameter, number of ramifications, leaves and fruits of Jatropha curcas. In addition Jatropha from Cameroon origin exhibited the highest growing conditions and high fruit yield, then highlighting its potential for the biofuel program of the country. But significant improvement needs to be done, particularly on the level of fertilizer needed.