AUXIN-MEDIATED MODULATION OF VEGETATIVE AND REPRODUCTIVE TRAITS IN SWEET PEAS

Abstract

This study investigated the influence of foliar-applied indole-3-acetic acid (IAA), a common auxin, on the vegetative and reproductive performance of sweet peas (Lathyrus odoratus L.). The experiment comprised five treatments with IAA applications of 0-100 mg L⁻¹. Results revealed significant improvements in growth and yield traits with accumulative IAA levels up to 75 mg L⁻¹. The 75 mg L⁻¹ treatment recorded the highest plant height (85.6 cm), number of branches (7.4), and leaf area (65.3 cm²), along with early flowering (42.3 days), maximum number of flowers (21.2), and pods per plant (11.6). In contrast, the highest concentration (100 mg L⁻¹) caused slight reductions in most traits, suggesting a possible inhibitory effect beyond the optimal auxin threshold. The control treatment consistently produced the lowest values across parameters. The findings confirm that moderate auxin doses can enhance sweet pea growth, flowering, and pod development, potentially benefiting ornamental and seed production.