Cassava is the main food crop grown in all provinces of the Democratic Republic of Congo. Increasing its productivity therefore comes up against multiple constraints, including diseases, in particular the endemic form of the mosaic, which occupies a prominent place. Small farmers who are the main producers remain much attached to local varieties although research regularly develops and disseminates improved varieties resistant to the African cassava mosaic. The objective of the study we conducted was, on the one hand, to assess the real yields of the resistant varieties disseminated and of the most widely cultivated local variety and, on the other hand, to determine the rate of loss of production of the variety. Local compared to varieties improved in distribution. The trial, set up with the active participation of the peasantry, included 4 repetitions in 4 different sites, near the peasants' fields. Four treatments consist of 4 varieties including 3 improved and 1 local. Cuttings taken from plants without disease symptoms are planted at 1mx1m spacing’s and harvesting took place 12 months after planting. The recovery was observed 1 month after planting, while data on diseases and pests are taken from the third month of planting until harvest at 3-month intervals. The results obtained show that the severity and incidence of the mosaic were higher on the local variety than on the improved varieties, one of which was shown to be somewhat susceptible to the disease. The loss of production of the local variety is estimated at plus or minus 50% compared to the average yield of the improved varieties.

The objective of the study was to evaluate the influence of Tithonia diversifolia in association with three hilling moments in order to identify the best moment (s) associated with Tithonia diversifolia improve soil fertility and thus give bean plants the ability to withstand the attack of bean flies and thus hope to have good yield of common beans. The experimental design was the split plot with three repetitions, with beans’ variety called Kirundo as the main plots. They were subdivided into two subplots, one of which corresponded to the application of Tithonia diversifolia and the other without Tithonia diversifolia. The main plots were nine in total and constituted six different treatments evaluated. A single fresh biomass dose of Tithonia diversifolia equivalent to 10 tons per hectare was applied in all plots with Tithonia d. two weeks before sowing beans. There were significant differences between treatments. Bean’ yield increased by an average of 212.28%, the weight of 100 seeds was improved by an average of 7.2%, the number of pupae such as the cumulative number of dead bean plants was significantly reduced by application of Tithonia diversifolia in this highly endemic study environment for bean maggot, the vigor of bean plants has been improved, there has been no interaction between Tithonia diversifolia and ridging at any given time. In conclusion, the application of Tithonia diversifolia increased bean yield in soil with many soil fertility constraints and highly endemic for bean maggot (Ophiomya spp).

The objective of this study was to evaluate five species of green manure as improved fallow on cassava yield. The trial design was a complete randomized block with three repetitions. The treatments consisted of different species of green manure and one control. Two cassava varieties Mayombe and Sawasawa were used. The yield was significantly enhanced by Tithonia diversifolia up to 343.02% for Mayombe variety compared to the control, ie 44.17 t/ha against 9.97 t/ha for the control. Also, the yield of Sawasawa variety, was high in the order of 390.4%, i.e. 38.4 t/ha against 7.83 t/ha for the control with no fertilizer. In addition, Lab lab species enhanced also the yield to 309.2% or 40.80 t/ha for the Mayombe variety against 9.97 t/ha for the control, as for Sawasawa variety, the yield was improved by 119.6% or 17.2 t/ha against 7.83 t/ha for the control. Other species, including Mucuna preta, Crotalaria grahamiana and Crotalaria ochroleuca, improved yield of the Mayombe variety in the order of 137.7%, 129.3% and 62.7%, respectively. For Sawasawa variety, only Crotalaria grahamiana improved its yield by 106.5% compared to the control.