Sustainable dual-edged utilization of fly ash for growth improvement of black gram (Vigna mungo L.) and management of Meloidogyne incognita

Fly ash (FA) disposal is considered a significant challenge globally. Therefore, this study aims to examine the nematicidal activity of FA on Meloidogyne incognita and its potential as a nutritional supplement of black gram. In this study, black gram seeds were planted in pots with soil supplemented with various concentrations of FA (5%, 10%, 15%, 20%, 25%, and 30%). The elemental composition of soil and FA was determined by energy-dispersive X-ray analysis with a scanning electron microscope. The study employed morpho-molecular characterization of the root-knot nematode (Meloidogyne incognita) to examine the nematicidal features of FA. There was a substantial decrease in the black gram growth, yield, stomatal area, and biochemical components in inoculated plants as compared to control plants. All FA concentrations exhibited a negative effect against M. incognita and resulted in a significant increase in growth parameters and biochemical components compared to the inoculated plants. All the infestation parameters confirmed that FA significantly reduced nematode-juvenile invasion in black gram compared to control plants. All FA concentrations caused significant increase in the proline content and antioxidant enzymes such as superoxide dismutase, catalase, and peroxidase in inoculated plants as compared to control plants. Principal component analysis and Pearson’s correlation matrix were used to analyze all of the data. The main conclusions of this study are that 20% FA can be applied eco-friendly and safely to improve plant health and decrease M. incognita infestation in black gram.