Albert Ngakou

Cowpea Quality Seed Indicators as Influenced by Field Application of Selected Biofertilizers and Mycoinsecticide in Three Agroecological Zones of Cameroon

Inoculation of cowpea with biofertilizers (rhizobia + mycorrhiza), and spraying them with the mycoinsecticide Metarhizium anisoplae has been shown to improve growth and grain yield. However, the treatment may impair the technological properties of the grains, which have not yet been investigated. This study is a followup to our recent study on the effect of selected biofertilizers and mycoinsecticide in three agroecological zones of Cameroon, aimed at evaluating the physical properties and the protein content of cowpea seeds as affected by these bio-inoculants. Spraying cowpea plants at flowering with the mycoinsecticide M. anisopliae and/or inoculating cowpea seeds at sowing with biofertilizers (rhizobia, mycorrhizae) had no significant effect on the protein content, water absorption capacity, and the percentage of seed coat. They instead significantly affected the physical properties of seeds, such as the seed weight, length, geometric diameter, and sphericity, but this varied from one agroecological zone to another. Whereas the seed weight was increased in agroecological zone V, a significant decrease was observed in zones I and II. The changes in weight reflected those of diameter and volume as confirmed by the correlation analysis. Application of biofertilizers had no significant effect on the water absorption capacity, protein, and coating percentage of cowpea seeds, suggesting that the main qualities of cowpea seeds for industrial utilization remained the same. The increased yield generally associated with these treatments may result from changes in the geometric size, which depends on the agroecological zone.

Assessment of biofuel potential of dead neem leaves ( Azadirachta indica ) biomass in Maroua town, Cameroon

Dead leaves of neem trees in the Sahelian urban zone are among the wastes that are underutilized, since it is either buried or burnt, and thus, contribute to increased environmental pollution. Unfortunately, the lack of information on the biomass and energy potentials of these wastes empedes any initiative for its industrial biomethanization. This study was investigated with the aim of evaluating the biofuel potentials of dead neem leaves in Maroua town. The number of neem trees, as well as biomass produced by their dead leaves in the town was estimated. Different possible forms of energy which could be generated from biomass were determined. Results revealed the presence of 45500 neem trees in the whole town. In addition, averagely 1.2 kg of dead neem leaves was daily produced per tree. All the neem trees were able to generate 53.7 tons biomass/day, which can supply 756.538 m3 of biogas in 7 months of defoliation. This biogas volume was assimilated to 5.674 MWh/day of electrical energy, sufficient enough to support the need of 7565 householders. The biogas produced could be used as cooking energy source, or substitute the firewood demand of 3926 householders for 7 months, leading to the preservation of 567.45 ha land /year from destruction as the result of uncontrolled firewood collection in the sahelian zone. Key words: Biomethanization, biogas, biofuel, dead neem leaves, energy, Maroua town.