Micronutrient uptake in common bean (Phaseolus vulgaris L.) as affected by Rhizobium inoculation, and the supply of molybdenum and lime

Pot and field experiments were done to establish the effect of Rhizobium inoculation, Molybdenum and lime supply on the availability of micronutrients (Cu, Zn, Mn, Fe, B and Mo) in Phaseolus vulgaris L. In both field and pot experiments, Rhizobium inoculation significantly improved uptake of Mn, Fe, Cu, Zn, B and Mo in all organs (roots, shoots, pods and whole plants) except the Mo uptake in roots. Supplying Mo at 6 and 12 g.kg of seeds significantly increased Mo uptake but reduced that of Mn, Fe, Cu, Zn and B in the roots of P vulgaris compared with the zero control. In the pods harvested from the glasshouse and field, and whole plant from glasshouse experiments, the uptake of Mn and Fe were significantly reduced in treatments supplied with Mo at 6 and 12 g.kg of seeds relative to the zero control. Compared with zero-lime control, the application of 2 and 3 t.ha in the glasshouse significantly reduced the uptake of Mn, Fe, Cu, Zn and B in the root, shoot and whole plant and increased that of Mo. In the field conditions lime significantly reduced the uptake of Fe, Zn and B in the roots, Fe and Cu in the shoot and whole plant, and Mn in pods and whole plants. Lime supply between 2 3 t.ha increased the uptake of Mo in all organs both in the greenhouse and field experiment. There was a significant interactive effect between Rhizobium inoculation and Mo, Rhizobium x lime and lime and Mo supply. Interactively, the best uptake of the micronutrients was recorded in treatments involving highest rate of Mo (12 g.kg of seeds) and that of lime (3 t.ha).