Effect of weather variability in sweet corn production under subtropical environment of the Southeastern U.S.

Abstract

The main goals of this study were to evaluate the performance of commercial sweet corn cultivars in southeastern U.S. and to identify the effect weather variability on cultivar development; to find best practices for nitrogen (N) management and to identify the effect of weather in N management; lastly, to use the CSM-CERES-Sweetcorn model to analyze sweet corn production under different N fertilizer rates and application timing in different weather scenarios. Field trials for this study were conducted in three locations of the State of Georgia, and two locations of the State of Alabama, in 2020, 2021, and 2022. Heavy rainfall events, unpredictable heat and drought stresses, and frequent high-temperature fluctuation create challenges during crop growing seasons. Results indicated that cultivar performance was rather impacted by season rather location, and yields were higher in the spring compared to fall. Affection, GSS1170, Passion, and SCI336 had best performance for most locations in both season and showed high potential against environmental stresses. Higher total soil N was found in treatments with high N rate; however, it was not translated to yield. Moreover, yield did not show a significant difference among treatments, which may be explained by the same amount of N uptake by the plant in all treatments. Nitrogen use efficiency (NUE) was higher in lower N fertilizer treatments, and it was positively correlated to yield. Therefore, there is no need to increase N fertilization to achieve higher yields, instead, it will increase N leaching and waste. The CSM-CERES-Sweetcorn model was able to simulate sweet corn growth and development under different N fertilizer rates across two years with different weather patterns. However, the model was not sensitive enough to detect differences in the N fertilizer rates applied, which requires further research to improve the model and allow better predictions among the different N fertilizer rates.