Author ORCID Identifier:
Date of Graduation
7-2026
Document Type
Thesis
Degree Name
Master of Science in Crop, Soil & Environmental Sciences (MS)
Degree Level
Graduate
Department
Crop, Soil & Environmental Sciences
Advisor/Mentor
Elli, Elvis
Committee Member
Kelley, Jason
Second Committee Member
Fernandes, Samuel
Third Committee Member
Roberts, Trenton
Keywords
Mid-South Region, Planting, Hybrid Maturity, Environmental Impacts, United States
Abstract
Deepening the understanding of the impact of environmental conditions on maize yields is critical in the Mid-South US, where crop land for maize production has significantly increased over the past decades, while productivity is constrained by typical mid-season heat stress. Actionable management practices, such as planting date and hybrid relative maturity, play a key role in determining maize final grain yields and above-ground biomass, and can serve as a tool to minimize the impacts of heat and drought stresses. Currently, no multi-environmental study in Arkansas investigating the combined effect of weather variables and management practices on maize yields and biomass exists. Our research objectives were to i) identify key weather variables driving maize grain yields in Arkansas and investigate impacts of increased power of the variables on yields in simulated scenarios, ii) quantify the combined effect of planting date and relative maturity on grain yields, above-ground biomass production, harvest index, and yield components. A comprehensive yield database collected across multiple environments across 15 years (64 site-years) in Arkansas was used to quantify the effect of weather predictors on yields through the use of mixed effects models. A sensitivity analysis evaluating the effects of increasing night-time temperatures on maize yields was conducted. High-resolution field studies were conducted across 5 locations in Arkansas during the 2024 and 2025 growing seasons (9 site-years), testing contrasting planting dates (From March 27th to June 4th) and hybrids of diverse relative maturity. Maize was planted on raised beds and furrow irrigated. At maturity (R6), final grain yields, above-ground biomass, harvest index, kernel number, and kernel weight were determined. Mixed-effects models identified minimum temperature, a proxy of night-time temperature, as being the most relevant weather variable driving yields. In simulated scenarios, for each 1°C increase in night-time temperature, yields decreased by 3.7% or 500 kg ha-1. Delaying planting decreased both grain yields (-33 kg ha-1 day-1) and above-ground biomass (-73 kg ha-1 day-1), with no clear effects on harvest index. Short-season hybrids consistently yielded less than full-season hybrids. Yield and above-ground biomass responses to planting date varied across relative maturity groups, with greater penalties observed for full-season hybrids compared to short-season hybrids. Both kernel number and kernel weight decreased when planting was delayed, with more pronounced penalties in kernel weight. These findings bring region-specific insights into the impact of weather variables and help refine management practices to minimize agricultural risk and maximize grain yields in the Mid-South US.
Citation
Nores Allende, M. (2026). Drivers of Maize Productivity in the Mid-South U.S.: Planting date, Hybrid Maturity, and Environmental Impacts. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6360
