Programme National Légumineuse, Section Défense des Végétaux, Laboratoire de Phytopathologie, Institut National pour l'Etude et la Recherche Agronomique de Mulungu, Sud-Kivu, Bukavu, RD Congo
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).
With the aim of finding biodegradable organic substances that are not harmful to humans and that do not pollute the environment, that are effective against the fly and alternatives to synthetic pesticides polluting the environment, a test of the insecticidal activity of Tephrosia vogelii, Tetradenia ruparia and Tithonia diversifolia was carried out in the presence of the synthetic pesticides (Thiodan) and the control. Indeed, the results obtained are as follows: During the two cropping seasons, at stages V3-V4 and r6, the variety V2 / Rwr2254 is the most susceptible to attack by the common bean fly; When treated with insecticide plants and the synthetic insecticide, thiodan, we found that there were fewer pupae on common bean plants treated with the insecticide plant Tephrosia vogelii and thiodan, followed by the lethal dose (Dl 90) of each insecticide plant. For the 2 cropping seasons, the plot yield in gram shows that the variety V1 / HM 21-7 gave the high yield; the plant Tephrosia vogelii yielded a high yield and compared to treatments, thiodan provided high yield and The extrapolated yield in kilograms per hectare still shows that the variety V1 / HM21-7 is the one that gave a high yield, the insecticide plant Tephrosia vogelii is the one that gave a high yield and the thiodan is the treatment that gave high efficiency. Thus, the use of these insecticidal plants is an alternative for managing the bean fly for improving common bean productivity.
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.