Morphological responses of green bean (Phaseolus vulgaris L.) to growth regulators

Morphological traits although occasionally cited as outdated for scientific research remain indispensable indicators of plant performance, serving as crucial visible proxies for the interplay between genetic potential and environmental conditions in sustainable crop production. Intensified climate variability necessitates controlled environment agriculture to stabilize yields of vital horticultural crops like the green bean (Phaseolus vulgaris L.). Optimizing production requires the strategic integration of superior genetic accessions with precise chemical regulation. This study investigated the differential effects of three commercial growth regulator formulations (Formulation S, Formulation B, and Formulation N) on the morphological development and pod mass partitioning of a local indeterminate green bean accession (GB00788) under controlled greenhouse conditions. Significant treatment responses were observed. Formulation B notably enhanced root mass (2.61 g), while Formulation S significantly increased root mass (2.05 g), stem apical diameter (1.53 mm), total inflorescences (15.19), and secondary branching (5.41). Critically, Formulation S maximized pod mass on the main stem (30.86 g) but simultaneously reduced pod mass on secondary branches (7.82 g), demonstrating a strong trade-off in assimilate allocation. Furthermore, both Formulation B (2.63 ± 0.82 kg m-2) and Formulation N (2.46 ± 0.73 kg m-2) significantly improved early yield. These results reveal the complex, differential physiological effects of growth regulators on green bean development and biomass partitioning. The findings provide high-value, actionable insights for developing genotype-specific cultivation strategies, ultimately enhancing resource use efficiency and yield stability in modern greenhouse production.