Journal of Al-qadisiya in arts and educational sciences

Temperature extremes are a feature inherent in the climates that are located within the arid and semi-arid regions, including the study area, and it is also among the most important climatic factors that negatively affect the cultivation of the wheat crop, because the thermal anomalies that occur as a result of temperature rates moving away from their rates often reach To levels that exceed the upper thermal limits that the crop can bear, which directly affects the productivity of the wheat crop. In order to reveal the effect of thermal extremism on crop productivity, monthly data for the agricultural season for a period of 30 years were used at the level of three climatic stations (Al Hayy, Aziziyah, and Al Kut). Analyzing the data statistically to monitor the state of fluctuation and thermal extremism and its trends during that period with the help of a number of statistical methods, and for the purpose of coming up with an analytical vision based on digital analysis of temperatures and their impact on the productivity of the wheat crop by making thermal models that describe the conditions of the climate (moderate and extreme) and trying to link those Models and yield yield based on simple correlation coefficient (Pearson). The study reached a number of results that support its hypothesis that there is a direct effect of thermal extremism on the productivity of the wheat crop, and this was demonstrated through the strength of the positive correlation between the high productivity rate and the frequency of the (moderate) thermal model, as well as the existence of a negative correlation between the repetition of the extreme thermal model ( Too cold, too hot) and low productivity.
The study also revealed that there was a rise in the average temperature during the study period, especially in the last decade of it compared to the first decade because the study area was affected by global climate changes, which negatively affected the cultivation of the wheat crop in several directions, the most important of which is the failure of the crop to obtain adequate thermal requirements for each A stage of its growth, as well as the change in the dates of planting the crop from its predecessors, which resulted in the shortening of the season of growth necessary for the crop from (197 days) in the first decade of study to (180 days) in the second decade and to (164 days) in the third decade, which is This negatively affects the productivity of the crop because it is not able to meet the necessary time to complete its physiological processes.