Optimizing Spinach (Spinacia oleracea L.) Growth in Lead-Contaminated Environments with EDTA and GA3 Applications

Abstract Lead (Pb) contamination in soil affects plant nitrogen assimilation and reduces seed germination and plant water relations. Pb exposure also reduces carotenoid, chlorophyll, carbon dioxide, assimilation, and photosynthetic rates in plants. The use of Ethylenediaminetetraacetic acid (EDTA), and Gibberellic acid GA3 is an effective amendment to mitigate this problem. EDTA improves plant growth by increasing the bioavailability of essential ions in the soil, allowing plants to better absorb nutrients. Its efficient, environmentally friendly, and biodegradable nature makes it ideal for enhancing metal uptake and promoting healthy plant development in metal-polluted soils. GA3 improves plant growth by different mechanisms such as stem elongation, flowering and seed germination. The combined application of the GA3 and EDTA as an amendment on spinach still needs scientific justification. This study investigates the combined impact of GA3 and EDTA as an amendment on spinach growth. The 10ppmGA3, 0.5%EDTA, 10ppmGA3 + 0.5%EDTA, 1%EDTA, and 10ppmGA3 + 1%EDTA treatments were administered in four replicates using a completely randomized design (CRD), both with and without Pb stress. Results demonstrate that 10ppmGA3 + 1%EDTA exhibits a rise in spinach shoot fresh weight (97.73%), root fresh weight (89.98%), shoot dry weight (96.72%), and root dry weight (100.00%) over the control in 500Pb stress. The study found that 10ppmGA3 + 1%EDTA significantly increased spinach chlorophyll a (64.11%), chlorophyll b (98.34%), and total chlorophyll (74.37%) in 500ppmPb stress than the control. In conclusion, 10ppmGA3 + 1%EDTA is the suggested amendment for mitigating Pb stress in spinach.