ABSTRACT
Trace elements or micronutrients play a major role in the metabolism of both plants and humans.
Zinc has a major specific role in metabolism when compared with other elements. The microbial
biofertilizers are applied in the form of seaweed liquid extracts, microbial inoculants, biostimulators
and biofortification agents. All these categories of microbial biofertilizers are involved in the
enhancement of plant nutrient uptake. In the present study, Spirulina platensis is used as a biofortification
agent to enhance zinc levels in cultivars of Amaranthus gangeticus, Phaseolus aureus and
Tomato. Different experimental methods were followed including soaking seeds in different concentrations
of Spirulina (5, 10, 15, 20, 25 and 30 g in 100 ml of water); soaking seeds in Spirulina
hydrolysate at different time intervals (1, 2, 3, 4, 5 hrs and overnight); Spirulina in combination
with biofertilizers, chemical fertilizer, organic fertilizer and vermicompost in various proportions
(25:75; 50:50; 75:25) and foliar spray with different concentrations of Spirulina (25, 50, 75, and
100g in 5 litres of water) respectively. The zinc content of the yield of the cultivars was estimated
and the study results indicated that there was a significant increase in zinc levels with p-value
0.015, 0.003 and 0.035 for Amaranthus gangeticus, Phaseolus aureus and Tomato respectively
when compared with the control and between the set-ups, with biofortification of Spirulina platensis.
The obtained results emphasize the application of Spirulina platensis to enhance the mineral
nutrient in plants which are non-polluting, inexpensive, utilizable renewable resource to
maintain the soil fertility.