The effect of copper ions in different forms on the growth stages of pinto bean cultivars

Copper is an essential micronutrient pivotal for plant physiological processes, and its nanoformulations have garnered significant attention for their potential to enhance crop productivity. This study evaluated the comparative efficacy of different forms of copper, copper sulfate (CuSO₄), copper-EDTA chelate and copper oxide nanoparticles (CuO NPs), on the germination, vegetative growth, and yield of two pinto bean cultivars (Phaseolus vulgaris L.) (KS1191 and KS1193) using a seed priming approach. The experiment was arranged in a randomized complete block design (RCBD) with nine treatments and three replications. Treatments included CuSO₄ (0.3%), CuO NPs (0.05%, 0.1%, 0.15%), copper-EDTA (0.1%, 0.3%, 0.5%), a combination of 0.1% CuO NPs with 0.3% copper-EDTA, and an untreated control. We evaluated the impact on seed germination percentage, seedling vigor index, vegetative growth (plant height), yield components (pod number and ten seed weight), and seed copper accumulation. Analysis of variance (ANOVA) revealed significant effects of treatment on all measured parameters. In particular, seed priming with CuO NPs, particularly at the 0.1% concentration, elicited significant improvements in vegetative growth, yield, and seed copper content compared to the control and other copper forms. The findings indicate that seed priming with 0.1% CuO NPs represents an optimal strategy for enhancing growth and yield in pinto bean cultivation, highlighting the advantages of nanoformulations in micronutrient delivery.