A Vertical Stacking Approach to Rapid Generation Cycling for Indoor Growth of Tall Annual Crops—The Case of <scp> <i>Vicia faba</i> </scp> L.

ABSTRACT Accelerating breeding cycles through rapid generation turnover is a demonstrated strategy to improve the rate of genetic gain in a range of staple crops. This study presents a vertically stacked accelerated single‐seed descent (aSSD) protocol for faba bean ( Vicia faba L.), aimed at rapid generation cycling while ensuring robust plant development and seed viability. Our aim was to take a tall annual crop and grow it within a vertically stacked controlled environment, with a density of 80 plants/m 2 . Combining an LED‐extended photoperiod of 18 h, small pot size, antigibberellin to reduce plant height, and desiccation to germinate immature seed achieved 4.1 to 5.7 generations per year across phenologically diverse germplasm. Plant height was successfully reduced by up to 60% with flurprimidol without compromising flowering or seed yield. The methodology was validated by advancing 14 Australian faba bean breeding programme recombinant inbred line populations over 3 years. Beyond faba bean, this scalable, genotype‐independent platform offers applications for other tall annual species in breeding and vertical farming systems, enabling year‐round crop production and genetic improvement. The protocol's adaptability to closed‐environment agriculture presents opportunities for plant‐based life‐support systems in extreme environments, including space missions. This integrated approach to speed breeding and vertical farming represents a significant advancement in agricultural innovation.