Is mixture cultivation of Musa varieties a pertinent agroecological strategy for nematode management?

Varietal mixtures is a cultural technique based on the introduction of genetic and functional diversity to manage pests and diseases commonly used on some grass crops to mitigate wind- and soil-borne pathogens. Reports of effect of varietal mixture still remain very scarce in other crops. In a field experiment conducted in Martinique, we evaluated the ability of the varietal mixture of bananas to manage plant-feeding nematodes. Three cultivars of banana (a Cavendish dessert banana, a new synthetic hybrid FB924 and a plantain French Horn) having different levels of susceptibility to nematodes were planted two by two forming six couples of both mono- and mixed varieties. As a result, banana varietal mixtures had significant effects both on nematodes abundance and community compositions. However, special attention has to be paid in the choice of varieties in plant mixtures. The introduction of the synthetic hybrid FB924 contrary to the plantain increased the relative abundance of the spiral nematode Helicotylenchus multicinctus while that of the most damaging burrowing nematode Radopholus similis decreased. This study provides the first discussion on the way to combine genotypes for an agroecological management of plant-feeding nematodes to increase profitability and yield stability.