Germinative performance and initial seedling growth under the influence of plant growth regulators in agricultural crop seeds

Seed quality, particularly germination speed, uniformity, and initial seedling vigor, is a key determinant of successful crop establishment. This study evaluated the effects of a plant growth regulator (PR) in comparison to distilled water on the germination and early development of maize, rice, white sesame, and black sesame seeds. The experiment using controlled environmental conditions and standard germination protocols. While seed germination speed (GSI) was not significantly influenced by the treatments, PR application resulted in a significantly higher germination percentage (68.3 ± 0.43%) compared to water (51.0 ± 0.71%), indicating a physiological enhancement of dormancy-breaking mechanisms. PR also promoted greater shoot length (6.45 ± 1.74cm) than water (5.05 ± 1.23cm), possibly through stimulation of cell elongation and hormonal signaling. However, root length did not differ significantly between treatments, suggesting that the formulation or dosage may require refinement to achieve balanced seedling development. Among species, white sesame and rice showed superior performance in both germination metrics and seedling growth, while maize exhibited limited vigor. Strong positive correlations were observed between shoot and root growth (r= 0.87), and between germination parameters and shoot length, emphasizing the importance of synchrony between emergence and vegetative development. These findings support the potential of PRs as a strategic input for improving germination efficiency and early seedling establishment, particularly when tailored to the physiological requirements of each species.