At present, vegetatively propagated crops are susceptible to virus infection, and cassava (Manihot esculenta Crantz) is no exception to this generalization. It is in this context that the major concern in Africa has turned to the virus that induces African mosaic. Indeed, African Cassava Mosaic is a major constraint to cassava production due to its implications in dramatically increasing yield losses. In the perspective of setting up strategies to fight against this pandemic, the objective of this research is to study the influence of cropping systems on the degree of susceptibility of Cassava to African Mosaic (MAM) in the locality of Kivira. To achieve this objective, 90 fields were chosen randomly and this because of 30 monoculture fields based on cassava, 30 fields based on cropping associations and 30 fields where cassava is integrated with trees of species forests. The incidence, severity and Symptom Severity Index (SGI) of African Cassava Mosaic were observed in each field. In total, 7820 cassava plants (Manihot esculenta Crantz) were evaluated on all the fields studied. At the end of this study, the results show a very highly significant difference in the number of diseased plants, the incidence and the severity of MAM depending on the cropping systems and cultivars (p-value < 0.05). In the monoculture, we observe a high number of diseased plants with an average of 7.8 plants against 3.9 plants for the association and 2 for the agroforests. The average incidence of African cassava mosaic is 39.52% in monoculture, 22.36% in crop associations and 12.10% in agroforestry systems. The severity values ​​are respectively 20.79% for monoculture, 10.4% for association and 5.73% for agroforestry systems. In view of the results of this study, the extension as well as the adoption by farmers of approaches based on agroforestry can constitute an important pillar for the diversification of production while reducing the effects of African mosaic on cassava cultivation in tropical Africa.

A phenologic study of the gases agroforeteries and sylvan was done in Beni-Butembo rea with the objective to determine the cash wood agroforesteries and sylvan in Beni-Butembo area.To achieve this, we identified the agroforestry and forestry species found in peasant fields in order to establish the optimal periods for their flowering, fruiting and seed production.After analysis, 19 species were identified, most of which are atmospheric nitrogen fixing legumes and the other agroforestry for the amount of their biomass which contributes to the improvement of soil structure.Most agroforestry species flower and give fruit once or twice a year such as Grevillea robusta, Markhamia lutea, Calliandra calothyrsus, Leucaena leucocephala, while Eucalyptus sp flowers all year round hence the permanent availability of its seed and Cedrella does not fruit in high altitudes. However, all of the inventoried species bear fruit during cropping periods, which implies that there is the possibility of producing the seed twice a year, and others throughout the year. Thus, the phenology depends on local climatic and ecological conditions and from one species to another.