Effect of arbuscular mycorrhizal fungi and rhizobacteria on banana growth and nutrition

Abstract - The effect of the combined inoculation of the arbuscular mycorrhizal fungus Glomus manihotis and a rhizobacteria consortium of Bacillus spp. on micropropagated banana plantlets, during the acclimatization phase under routine nursery conditions was investigated. Micropropagated banana plantlets from the 'Grande Naine' cultivar were inoculated with G. manihotis at the beginning of the nursery phase. Twenty days after fungal inoculation, a Bacillus consortium containing approximately 10⁸ CFU (colonies former units) mL^-1 was applied. Plants were harvested 4 ½ months after bacterial inoculation. Combined application of mycorrhizal fungus and rhizobacteria significantly increased plant growth and nutrition. Combined inoculated plants showed growth parameters, i.e. total fresh weight, aerial dry weight, shoot length and leaf area, significantly higher than non-treated control bananas. Leaf mineral content, i.e. N, P and K, was also significantly increased following combined application of both microorganisms. No adverse effect on mycorrhizal colonization due to Bacillus spp. inoculation could be detected. Our results demonstrate that the combined application of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria highly benefits banana plants and therefore could be considered during the acclimatization stage of micropropagated banana.