Optimizing gibberellic acid concentration and exposure time for effective dormancy breaking and sprouting enhancement...

Tuber dormancy in Solanum tuberosum L. (potato) significantly limits early growth and yield potential, highlighting the need for effective dormancy-breaking strategies. Gibberellic acid (GA₃) is widely used to stimulate sprouting, but its optimal concentration and exposure time require further evaluation. This study, conducted in 2023 at the Department of Horticulture, University of Haripur, employed a Randomized Complete Block Design (RCBD) to investigate the effects of four GA₃ concentrations (0, 50, 100, and 150 ppm) and four dipping durations (6, 12, 18, and 24 h), totaling 20 treatment combinations. Key parameters measured included sprouting percentage, time to sprout, number of sprouts per tuber, sprout length and diameter, fresh and dry sprout weight, and relative water content. Data were analyzed using one-way ANOVA at P < 0.05. The most effective treatment-150 ppm GA₃ with a 24-hour dipping duration-achieved a 98.33% sprouting rate and the shortest sprouting time (20.45 days). This combination also resulted in the highest number of sprouts (5.63), longest sprout length (10.23 cm), maximum sprout diameter (5.7 mm), greatest fresh (1.18 g) and dry weights (0.31 g), and highest relative water content (83.31%). These findings suggest that high-concentration GA₃ treatments with extended exposure durations effectively break dormancy and enhance sprouting vigor. Future research should explore the biochemical pathways involved and evaluate economic feasibility and field performance under varied agro-climatic conditions for large-scale application.