Tithonia diversifolia Crop Rotation: An Efficient Cultural Practice for Control of Burrowing (Radopholus similis) and Root-Lesion (Pratylenchus coffea) Nematodes in Banana Orchards in Côte d’Ivoire

The efficiency of Tithonia diversifolia on managing burrowing ( Radopholus similis) and root-lesion ( Pratylenchus coffeae ) nematodes was examined under greenhouse and banana plantation conditions. During the greenhouse experiment, which lasted 16 weeks, 300 nematodes (150 R. similis + 150 P. coffeae ) were inoculated in pots containing two-month-old burst young plants. Eighty pots were monitored and then removed at the rate of 5 pots per week so as to assess nematode development in T. diversifolia roots. The presence rates observed in situ with respect to the initial nematode inoculum were 25%, 20%, and less than 5% individuals, respectively, at 2; 6 and 7 weeks after inoculation. From 10 weeks until the end of the experiment, no presence (0 individual) could be observed in situ . In banana plantations; 1820 T. diversifolia / ha were transplanted at a rate of one cutting/banana corm. This fallow system, carried out in banana intercropping for six months, led to a thick canopy developed by T. diversifolia above ground with a significant production of root biomass in the soil despite the vicinity to infested banana corms. Monitoring of nematode infestations has highlighted a close relationship between the duration (X) of the fallow and the reduction in parasite pressure (Y). The regression curve Y = 102.9X -3.37 fits this relationship with R 2 = 0.82. Nematode-free vitro plants implanted in the soil, 90% improved by fallow, made it possible to carry out two production cycles of bananas without nematicide application. The opportunity to involve T. diversifolia in the agrosystem for the production of “organic banana” as an alternative to the use of nematicide was discussed.