Saraswat, ShwetaPrajapati, Nandini2021-08-092021-08-092021-02https://krishikosh.egranth.ac.in/handle/1/5810171595The present study was conducted to assess the effect of humic acid on Zn and Cr absorption by Allium cepa from mixed industrial waste water. The plant growth parameters as root length, shoot height, and their dry weight were also investigated at varying concentration of humic acid and mixed industrial effluent after 14 days of treatment. The application of humic acid influenced the root length, shoot height and their dry wt. The maximum root length (22.34 cm), shoot height (29.03 cm), root dry wt. (0.89 g) and shoot dry wt. (1.05 g) was observed at 50 ppm humic acid exposure. However, in case of mixed industrial effluent, there was substantial decrease in plant growth as compared to control. Although, the exposure of both 50 ppm humic acid and 50% mixed industrial effluent did not adversely affected the plant growth. The maximum root length (18.73 cm), shoot height (26.43 cm), root dry wt. (0.76 g) and shoot dry wt. (0.95 g) were recorded in combination of both 50 ppm humic acid and 50% mixed industrial effluent after 14 days of treatment. In general, Zn and Cr accumulation was higher in roots than shoots at different exposure of mixed industrial effluent either individually or in combination of humic acid. Although humic acid application reduced the metal uptake into the plant parts substantially at both 50% and 100% mixed industrial effluent exposure. At 50ppm humic acid and 50% mixed industrial effluent the Zn uptake in roots (0.29 mg g-1) and shoots (0.006 mg g-1) was minimum. Likewise, the Cr uptake in roots (0.10 mg g-1) and shoots (0.005 mg g-1) was also observed minimum. The Bioconcentration factors for Zn and Cr uptake were <1 in all the treatments. Similarly, Translocation factors were also calculated < 1 indicated the low mobility of metals in aerial plant parts. Results revealed that higher doses of humic acid application decreased Zn and Cr uptake in plant parts and also promoted the growth of Allium cepa plant. The study further suggested that Allium cepa could be grown in moderately metal contaminated environments by adopting optimum humic acid conditioning which could decrease the hazardous effects of heavy metals on plant growth and their further transport to various food chains.EnglishThesis