The potato is a major vegetable crop around the world, and tuberous hypertrophy is a highly complex developmental process effected by various factors that play central role in potato growth. Tuber growth under hypertrophic conditions is regulated by variations in carbohydrates and endogenous phytohormones. In the present study, we aimed to establish the basis for the enlargement of potato tubers, including changes in the chemical content of factors related to tuber formation and hypertrophy based on phytohormonal regulation, plants height and tuber biomass and other selected attributes. Our results reveal that the application of plant growth regulators such as diniconazole (Din) and prohydrojasmon (PDJ) significantly impact on potato plants growth and yield, including that of tubers. Plants treated with Din and PDJ effectively showed stunted growth and re-duced development but enhance the tuber formation and its weight. Plants treated with Din and PDJ significantly reduced the GAs and ABA accumulation and increase the sucrose level and cause significant increase in tuber development. In conclusion, a higher gibberellin content in potatoes may inhibit tuberization. Diniconazole and PDJ treatment reduced gibberellin accumulation, which in turn regu-lated abscisic acid content, demonstrating that the abscisic acid content mostly increased as gibberellin content decreased, and thereby promoting tuberization
