Maize responses to planting date and seasonal weather factors in Central Texas

Authors: SAPKOTA, BALA - Texas A&M Agrilife; BAATH, GURJINDER - Texas A&M Agrilife; Adhikari, Kabindra; Hajda, Chad; Flynn, Kyle; Smith, Douglas

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2026
Publication Date: 5/24/2026
Citation: Sapkota, B.R., Baath, G.S., Adhikari, K., Hajda, C.B., Flynn, K.C., Smith, D.R. 2026. Maize responses to planting date and seasonal weather factors in Central Texas. Agronomy Journal. https://doi.org/10.1002/agj2.70433.
DOI: https://doi.org/10.1002/agj2.70433

Interpretive Summary: Maize yields in Central Texas are affected by unpredictable weather, including irregular rainfall and rising temperatures. This study looked at how planting dates impact maize production over the years. We planted maize at different times from early March to late April and found that planting in the first three weeks of March consistently led to the highest yields. Planting later, especially in April, sharply reduced yields—sometimes by more than half. The study identified March 14 (73rd day of the year) as a key cutoff: planting after this date caused yields to drop by about 15 kg ha-1 each day. Weather—especially rain and cooler temperatures during the middle of the growing season—had a strong effect on the harvest. The results suggest that planting maize early in March is best to avoid heat and drought later in the season, helping farmers achieve better yields.

Technical Abstract: Maize (Zea mays L.) productivity in Central Texas is highly vulnerable to uncertain and extreme weather conditions, including erratic precipitation and rising temperatures during the growing season. Optimizing time of planting is therefore essential for maximizing grain yield under these challenging climatic conditions. This study evaluated the impact of planting date on maize grain yield across five site-years (2020 to 2023) under rainfed conditions. Maize was planted across seven-time windows, spanning from early March to late April. Results demonstrated that planting during the first three quarters of March consistently produced the highest yields, averaging above 8.1 Mg ha'¹. In contrast, delaying planting into April led to a sharp decline in yield, with late-April plantings yielding as low as 3.26 Mg ha?¹. A piecewise linear model identified the 73rd day of the year (March 14) as the breakpoint threshold planting date, after which yield declined at a rate of approximately 15 kg ha'¹ day-1. Weather variables were strongly associated with yield outcomes, particularly during the peak vegetative growth stage (31-60 days after planting), where a multivariate model explained 89% of yield variability. Growing degree days (GDD) and cumulative solar radiation were negatively correlated with yield during peak vegetative and reproductive growth stages, while both precipitation amount and frequency were positively associated. Principal component analysis further confirmed that cooler temperatures and adequate mid-season precipitation were key drivers of high grain yield. These findings highlighted the importance of timely planting in early March to avoid mid- as well as late-season heat and moisture stress in Central Texas.