Impact of temperature variation on the productivity of beans, maize and wheat in southern Sonora, Mexico

Rising global temperatures are a major constraint on food crop production. This study evaluated thermal variability in southern Sonora, Mexico, and its effect on physiological components associated with wheat, maize, and bean yields. For this purpose, records obtained over 20 agricultural seasons of wheat under furrow irrigation and during three seasons of beans and maize under drip irrigation were used. Daytime and nighttime hourly temperatures were analyzed for the period between October and May, from the 2004-2005 season to 2024-2025. Climate risk was determined by an analysis of extreme temperature values ​​(≤ 4 °C and ≥ 33 °C), considered thresholds associated with physiological and structural damage to the plant and its reproductive organs. The results show that the average daytime temperature increased by 2.8, 2.4 and 3.0 °C during the months of October to December, respectively; while from January to May the increases were 1.5, 2.2, 2.4, 3.1 and 2.7 °C. In contrast, nighttime temperatures showed increases of 0.5, 0.1 and 0.4 °C for the months of October to December, respectively, but decreased by 1.3, 0.5, 0.4, 0.2 and 0.7 °C between January and May. An increased risk of frost was observed during January, a condition that could significantly affect bean and maize crops. Overall, this change in the temperature regime between fall and spring suggests the need to adjust sowing dates and optimize irrigation scheduling to mitigate the effects on agricultural yield.