Peanut Yield and Grade Response to Multiple Simulated Rainfall Events Following Inverting

Abstract

Introduction: Peanut harvesting often coincides with fluctuating weather conditions, including sudden rainfall, which can affect pods left in windrows to dry. This study aims to quantify the effects of rainfall on peanut yield, quality and aflatoxin contamination. It is the first multi-year, quantitative assessment of these impacts, providing insights for better post-harvest management and extension recommendations. Materials and Methods: Field trials were conducted over 3 years (2021–2023) at Shellman Multi-crop Irrigated Research Farm in Georgia. Peanuts were inverted at optimal maturity and exposed to simulated rainfall (0–100 mm) weekly for 3–4 weeks. Yield, quality metrics (e.g., loose-shelled kernels, splits, total sound mature kernels) and aflatoxin levels were analysed using ANOVA to assess treatment effects. Results: Increased cumulative rainfall correlated with yield loss (110 kg/ha per 10 mm of rainfall), higher percentages of loose-shelled kernels (0.45% per 10 mm), and splits (0.52% per 10 mm). Aflatoxin contamination did not significantly increase due to cooler temperatures and higher soil moisture. Results varied by year, with yield reductions ranging from 4650 kg/ha in 2021 to 2723 kg/ha in 2023 under maximum rainfall exposure. Conclusion: Prolonged rainfall and exposure in windrows have a potential to adversely affect peanut yield and quality, though aflatoxin contamination remains stable under certain conditions. These findings highlight the need for adaptive management strategies to mitigate risks associated with unpredictable rainfall during harvest seasons, ensuring sustainable peanut production in the southeastern United States.