Influence of hydroponic cultivation subsystems on vegetative growth, vigour, and metabolite profiles in vanilla

Vanilla, a high-value crop, faces numerous cultivation challenges, with global demand far outpacing supply. The absence of standardised cultivation practices underscores the need for innovative solutions. This study explores the vegetative growth and metabolite changes in <i>Vanilla planifolia</i> under controlled environment conditions in a recirculating hydroponic system. This system integrates four different subsystems: nutrient film technique, deep flow technique, aeroponics, and fogponics. Over an 81‑day period, all subsystems supported biomass production, though they differed in growth performance and metabolite profiles. The deep flow technique achieved the highest fresh mass gain (27.65 g), while fogponics yielded less than half as much (12.77 g). However, no single subsystem proved clearly superior; rather, each had distinct effects on plant development and metabolism. These findings provide valuable insights into substrate-free hydroponic systems tailored to <i>Vanilla planifolia</i> and support the advancement of innovative cultivation methods to enhance and stabilise vanilla production.