Growth effects of microorganisms based commercial products inoculated to tissue cultured banana cultivated in three different soils in Kenya

The effect of inoculation of microorganisms-based commercial products on post-flask management and field establishment of tissue cultured (TC) banana plantlets was investigated. TC banana cv. Gros Michel plantlets were inoculated with Bacillus, mycorrhizal and Trichoderma based products in a Vertisol, Humic Nitisol, Rhodic Ferralsol and conventional nursery media. Initial inoculation of plants with products was done at the acclimatization phase and subsequently at the potting phase. Survival of inoculated plantlets was recorded at the end of the acclimatization phase, 8 weeks after deflasking. Effect of products on growth was evaluated as ability to enhance height and girth of pseudostem, leaf length, leaf width, number of functional leaves and root and shoot biomass yield. The efficacy of products on survival of plants at hardening was variable and dependent on soil type. Inoculation with Bacillus enhanced survival of plants in the Vertisol, mycorrhiza and Trichoderma inoculation in the Rhodic Ferralsol and mycorrhiza in the Humic Nitisol and conventional media. Performance of inoculated plants was dependent on soil type. Application of Bacillus based products significantly increased plant growth (leaf length, leaf width, plant height, shoot dry weights) in the Vertisol and Rhodic Ferralsol in the nursery phase. Application of multiple species mycorrhiza and Trichoderma under field conditions significantly increased plant growth (apparent volume and leaf surface area) in the Vertisol by over 100% and 25% compared to the control and conventional practice respectively. Mycorrhizal colonization was not significantly affected by product inoculation. However, higher percentages of colonization were observed with Bacillus inoculation in the Vertisol and by mycorrhizae and Trichoderma in the Rhodic Ferralsol compared to the non-inoculated controls. Results demonstrate that tissue cultured bananas can benefit from application of arbuscular mycorrhizal fungi, Trichoderma and Bacillus to improve survival and growth during the nursery phase as well as enhance plant performance under field conditions. The effect of microorganisms-based commercial inoculants is however dependent on soil type and the stage of plant development.