Comparison of the Effects of Prohexadione Calcium and Uniconazole on Sweet Potato Storage and Texture Quality

Storage quality and texture properties determine the processing quality of sweet potato (Ipomoea batatas Lam.). Prohexadione calcium (Pro-Ca) and uniconazole (UCZ) are plant growth regulators that inhibit gibberellin biosynthesis, reducing excessive sweet potato growth and improving stress resistance. This study evaluated the impact of foliar applications—applied at 37.5 g·hm−2 for both treatments—on the postharvest texture characteristics and storage performance of sweet potato storage roots. The experiments were conducted over two years (2023 and 2024) using two sweet potato cultivars, Zheshu13 (Z13) and Wanshu10 (W10). The results showed that Pro-Ca significantly improved the textural properties of sweet potatoes, including firmness, chewiness, and maximum adhesion force, especially in Z13 (p < 0.05). Pro-Ca also reduced the percentage of rotting and weight loss during storage (p < 0.05), offering a more sustainable option for sweet potato postharvest management compared to UCZ. Additionally, Pro-Ca treatment increased the soluble sugar content of Z13-2023 and W10-2024, as well as the amylose content, except for W10 (p < 0.05), which could enhance both the sweetness and texture of sweet potatoes. This study highlights the potential of Pro-Ca as an effective growth regulator for improving sweet potato storage and processing quality. Further research is needed to investigate the long-term effects and the molecular mechanisms underlying these benefits, particularly in relation to gibberellin inhibition, carbohydrate metabolism, and cell wall integrity during storage.