IMPACT OF CLIMATE CHANGE ON MAIZE (Zea mays L.) PLANTING DATES IN THE EASTERN REGION OF PUEBLA, MEXICO

Climate change affects crop production, resulting in economic losses. One of the most significant changes caused by this phenomenon is a shift in the optimal planting date, so it is important to identify the optimal planting dates under the new climatic patterns, or at least appropriate ones that allow the selection of the indicated maize (Zea mays L.) variety (for example, short, intermediate, or late cycle genotype) that would be best to plant in order to obtain higher yields. Therefore, this research hypothesized that climate change would lead to shifts in the planting dates of rainfed maize. The objective was to assess the impact of climate change on planting dates in the eastern region of Puebla, Mexico. For this purpose, daily precipitation (PCP), as well as maximum and minimum temperature data from 13 climatological stations covering the period 1961–2020, were analyzed. Data quality was assessed using RClimDex software, and reference evapotranspiration (ETo) was estimated using the Penman–Monteith method. The optimal planting date was defined as the point when PCP ≥ 0.5 ETo, indicating sufficient water availability for seed germination. Results revealed that climate change increased variability in planting dates during the 1991–2020 period compared to 1961–1990. A spatially differentiated impact of climate change on planting dates was observed. In the 1991–2020 period, the earliest planting dates shifted toward the northwest, while the latest remained in the southern part of the region. These differentiated effects highlight the need for localized climate change adaptation strategies to support agricultural planning.