Estimation of wheat (Triticum aestivum L.) yield limiting factors using comparative performance analysis (CPA) method in Khorramshahr region in Iran

One way to increase crop yield per unit of area is to close the gap between actual and potential yield in cropping systems. This study was conducted to determine the factors that affeced wheat yield gap in Khorramshahr, Iran during 2018-2019 growing season. In this study 60 fields of different areas under cultivation, field management practices and grain yield yield levels were surveyed based on information from agricultural services centers and continuous monitoring. Comparative performance analysis (CPA) method was used to evaluate the grain yield gap. Theaverage grain yield, attainable grain yield and wheat yield gap in Khorramshahr were 3740, 5455 and 1715 kg.ha-1, respectively. Estimated yield gap (31.5%) in this study indicated that the high importance of appropriate management practices on wheat grain yield. Most important variables affected wheat grain yield gap were included Illoxane herbicide application (579 kg.ha-1), farmers education level (292 kg.ha-1), irrigation intervals (279 kg.ha-1), potassium fertilizer application rate (256 kg.ha-1) and planting machinery and equipment (179 kg.ha-1). These factors accounted for 87.45% of the calculated grain yield gap. The results of this study showed that by improving crop management practices, the grain yield gap of wheat fields in Khorramshahr region can be reduced.