Effect of different banana (Musa spp.) cultivars combinations on root infection of the "Orishele" cultivar by plant parasitic nematodes in southern Côte D’Ivoire

Background and Objective: Varietal mixture is a cultural technique in which the genetic and functional diversities of varieties are used to manage pests and diseases. However, the effects of varietal mixtures on the number and communities structures of pests, including plant-feeding nematodes, have rarely been studied. Plant parasitic nematodes Radopholus similis, Pratylenchus coffeae and Helicotylenchus multicinctus are threats to the sustainable production of plantain. In these experiments conducted in southern Côte d'Ivoire, the effect of varietal mixtures of bananas on plant-feeding nematodes communities have been evaluated. Methodology: Local banana varieties (Corne 1, Figue Sucrée and Orishele) and hybrids varieties (FHIA 21 and PITA 3) were used for this study. Effects of the prototype or combination modalities of banana varieties (D 25, D 50 and D 75) and effects of banana varieties combined with the Orishele variety (Corne 1, Figue Sucrée, FHIA 21 and PITA 3) were tested in a split-plot design. Root infestation by nematodes in field conditions were evaluated at the flowering stage of each banana variety. Results: Banana varietal mixtures significantly affected both nematode densities and community composition. The results obtained show that in the prototype P3, the relative abundance of nematodes the most damaging species on bananas, decreased. The use of a varietal mixture in which one variety supports a low nematodes multiplication rate appears to have practical relevance, especially in systems based on very susceptible cultivars of plantains. Conclusion: varietal mixtures allowed a decrease of pest pressure on the susceptible Orishele cultivar.