Effects of an Ascophyllum nodosum-Based Biofertilizer Applied Through Different Application Methods on Growth, Yield and Nutritional Quality of Phaseolus vulgaris L. var. Opus Under a Controlled Aeroponic System

Abstract

The study evaluated the effect of an Ascophyllum nodosum-based biofertilizer applied under three treatments: foliar (FA, 0.5 g/L every 15 days), root (RA, 0.5 g/L every 30 days), and combined (F&RA, 0.5 g/L, Foliar every 15 days and Root every 30 days) compared to a control (C) in aeroponic cultivation of Phaseolus vulgaris L. var. Opus. Environmental conditions were continuously monitored using an IoE-based system, ensuring consistent microclimatic characterization throughout the experimental period. A non-parametric statistical approach was applied due to non-normal data distribution. Most growth and yield variables did not show statistically significant differences; however, significant treatment effects were observed for leaf temperature, root temperature, calcium, iron, and manganese. Significant differences among treatments (α = 0.05) were identified using Kruskal–Wallis test for calcium (p = 0.0002), iron (p = 0.0067), and manganese (p = 0.0439), while other micronutrients showed no statistical differences. Descriptive statistics indicated moderate shifts in central tendency, particularly for calcium and iron, with higher values observed in the combined treatment (F&RA). Effect size analysis using Cliff’s delta (δ) revealed moderate to large differences for calcium, iron, and manganese, although these estimates were interpreted cautiously given the unequal replication among treatments. Spearman correlation analysis showed moderate to strong associations, although none were statistically significant (p > 0.05). Overall, results indicate limited effects of the biofertilizer on growth and yield variables but treatment-associated changes in selected nutritional components, suggesting element-dependent responses to biofertilizer application.