Effect of Exogenous Application of Different Concentrations of Indole-3-Acetic Acid as a Biostimulant on Onion (Allium cepa) Cultivation

Abstract

Indole-3-acetic acid (IAA) is a key vegetative hormone that plays crucial roles in plant growth and development. In this study, the effect of the exogenous application of IAA as a biostimulant in the cultivation of onions (Allium cepa) was investigated. Different IAA concentrations were evaluated to determine their effects on onion growth and chemical parameters. Various physical and chemical parameters such as total fresh weight, plant height, chlorophyll content, nitrates, total phenols, and antioxidant capacity (DPPH) were analyzed. The results revealed that exogenous application of IAA had a significant impact on onion growth and quality. Specifically, it was found that certain concentrations of IAA fostered a greater fresh weight of the bulb, an increase in the levels of phenolic compounds and a greater DPPH. However, the onion response to IAA was dependent on the concentration. In conclusion, the present study provides evidence that the exogenous application of IAA as a biostimulant can improve onion growth and quality. These results are relevant for the development of sustainable agricultural practices and could be oriented towards crop improvement.