Effect of Supplementation of Spirulina platensis to Enhance the Zinc Status in Plants of Amaranthus gangeticus, Phaseolus aureus and Tomato

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.