Reproduction and pathogenicity of Helicotylenchus multicinctus, Meloidogyne incognita and Pratylenchus coffeae, and their interaction with Radopholus similis on Musa

Abstract The reproduction and pathogenicity of Helicotylenchus multicinctus, Meloidogyne incognita and Pratylenchus coffeae was studied on Musa AAA cv. Grande Naine pot plants and microplot plants. First, separate experiments using different inoculation numbers (between 218 and 4144) and different exposure times (between 8 and 22 weeks) were executed in pots for each nematode species. Helicotylenchus multicinctus suppressed root growth by 13%, comparing inoculated with uninoculated plants. In contrast, M. incognita stimulated root growth by 6.7%, while P. coffeae had no effect on root growth. The interaction between R. similis and each of these three nematode species was investigated in a concomitancy experiment in pots. Plants without concomitant species yielded the highest R. similis population densities but did not differ from plants previously inoculated with H. multicinctus and P. coffeae. Meloidogyne incognita was the only concomitant species that reduced R. similis population densities. Inoculation with R. similis affected the recovered numbers of P. coffeae albeit with large variability. In the microplot experiment, all four nematode species except H. multicinctus reduced the bunch weight of bananas, compared to uninoculated plants. Pratylenchus coffeae and R. similis increased root damage by 129 and 262%, respectively, while only the latter species suppressed root weight with 66%.