Effects of Abscisic Acid (ABA) and Benzylaminopurine (BAP) Derived Minitubers on Germination and Yield of Two Potato Cultivars (Solanum tuberosum L.)

Potato, the world’s fourth most important food crop, is primarily vegetatively propagated, necessitating high-quality, virus-free seed tubers. This two-stage experiment was conducted at the University of Jiroft (2022–2023). In Stage 1, plantlets were subjected to foliar application of growth regulators—Abscisic Acid (ABA), Benzylaminopurine (BAP), and BAP+ABA—during stolon induction and tuberization stages under controlled conditions. In Stage 2, the resulting tubers were evaluated for germination, seedling establishment, and field performance. Measured traits included sprout number and length, days to emergence, emergence percentage, stems per plant, morphology, and yield. Results showed that BAP application during tuberization increased sprout length by 41% (cv. Santé) and 52% (cv. Colomba) versus controls, and also resulted in the shortest time to seedling emergence. The highest seedling emergence percentage (40% above control) was recorded with ABA during stolon induction. cv. Colomba showed 10% higher emergence than cv. Santé. In cv. Santé, BAP+ABA during tuberization increased sprout number by 50% over control. In cv. Colomba, BAP alone during tuberization gave the greatest sprout number (33% increase). In both cultivars, BAP+ABA applied during tuberization produced the highest number of tubers per plant. These findings highlight the potential of targeted growth regulator applications to improve seed tuber quality, sprouting, emergence, and ultimately yield in potato.