Climate-responsive optimization of transplanting and harvest schedules for 'Sodammi' sweet potato (Ipomoea batatas L.)

Abstract

Climate change has generally advanced the transplanting dates for sweet potatoes due to rising temperatures. However, the increased climatic variability accompanying climate change may pose risks to early transplanting. Nevertheless, research on the optimal transplanting and harvesting dates under such conditions remains limited. Therefore, this study aims to evaluate the optimal transplanting and harvesting dates for the stable cultivation of the sweet potato cultivar "Sodammi" in Yeoju, South Korea. The field experiment was conducted over two consecutive years (2023 and 2024). Transplanting was performed on five dates: April 15 (T1), April 20 (T2), April 25 (T3), April 30 (T4), and May 5 (T5), while harvesting was conducted at 110, 120, and 130 days after transplanting. In 2023, low early-season temperatures caused chilling injury in T3 and adversely affected T1 and T2. In contrast, no chilling damage was observed in 2024 due to comparatively warmer early-season conditions. In 2023, T4 demonstrated the highest storage root yield (2799.6 kg 10a(-1)), while T3 recorded the lowest (1512.9 kg 10a(-1)), with significant differences (p < 0.05). In 2024, T1 yielded the highest (2448.5 kg 10a(-1)), while T3 and T4 yielded lower amounts (1,970.6 and 2096.5 kg 10a(-1), respectively), showing statistically significant differences. These findings indicate that the effectiveness of transplanting and harvesting schedules varies depending on yearly climate conditions. With increasing interannual climate variability, determining the optimal transplanting and harvesting schedule has become more challenging. This study provides a scientific basis for flexibly adjusting cultivation timing in response to such uncertainty.