Susceptibility of banana intercrops for rhizobacteria, arbuscular mycorrhizal fungi and the burrowing nematode Radopholus similis

The susceptibility of 7 non-leguminous and 7 leguminous banana intercrops (and rotation crops) for rhizobacteria, mycorrhizal fungi and the burrowing nematode Radopholus similis was investigated and compared with the host response of banana cv. Grande Naine (Musa AAA group). In 50% of the tested combinations, the bacteria elicited nodules but these nodules were effective in fixing nitrogen only in about 11% of the tested combinations. Of the non-leguminous intercrops tested, wormseed, sweet potato cv. Tapato and cotton showed a poor mycorrhizal compatibility, based on the frequency (F%) and intensity (I%) of mycorrhizal colonisation. Of the leguminous intercrops tested, soybean, Grant's rattlebox, common bean, pigeon pea and sunn hemp showed a moderate mycorrhizal compatibility. Overall, F% and I% were higher in the leguminous intercrops compared with the non-leguminous intercrops. The susceptibility for R. similis differed among the intercrops tested. In the non-leguminous intercrops, marigold, sweet potato cv. Tapato, cotton and sesame were non-hosts, sweet potato cv. Inzovu, sorghum were intermediate hosts and sorgho-sudangrass was a good host. In the leguminous intercrops, hairy indigo was a non-host, Grant's rattlebox, soybean and sunn hemp were poor hosts and cowpea, common bean and pigeon pea were intermediate hosts.