Assessing the Climatic Suitability for Olive Tree Cultivation in Iraq Based on Spatiotemporal Variations in the Growing Season Duration.

Abstract

Abstract

This research aims to assess the spatial suitability for olive cultivation in Iraq by analyzing influential climatic elements. Specifically, it seeks to determine the commencement, termination, and duration of the growing season using statistical methods to delineate optimal cultivation zones . The study employs a range of quantitative and statistical techniques to define the growing season. The Third-Degree Polynomial function was identified as the most efficient method for achieving high-precision results aligned with the research objectives. This analytical approach is based on identifying the lower and upper thermal thresholds for olive growth, followed by an analysis of daily minimum and maximum temperature data across seven climatic stations representing Iraq’s diverse topographical regions. The data spans a 45-year time series (1980–2025), ensuring a realistic representation of climatic variations . Findings indicate that the primary growing season for olives in northern and western Iraq begins in April. Conversely, in central and southern regions, the season starts earlier in March, while in Basra, it commences in February—a variation attributed to the diurnal temperature gradients between the north and south. The total duration of the growing season in Sulaymaniyah is 183 days per annum, and 182 days in Ar-Rutba. These two stations recorded the highest values among the studied sites, categorizing them as "Highly Suitable" for olive growth. Meanwhile, Al-Hayy and Basra stations are categorized as "Suitable," with an annual growing season totaling 141 days each.