Documentation of production process and determination of limiting factors of wheat yield by CPA method in Kalaleh County

This study was conducted to evaluate the factors limiting wheat yield in Kalaleh County using the Comparative Performance Analysis (CPA) method in 2015-16. Collection of the required information was done by fieldwork, and personal interviews with farmers. To this aim, 60 wheat fields in dry land areas of Kalaleh were selected to have sufficient diversity in all crop management, planting, crop protection and harvesting. The amount of grain delivered to the wheat shopping centers was recorded after determining the amount of drop as the final yield of the farm. The CPA was used to determine the yield gap and identify the factors that caused it. The results of yield model showed that there was a difference of 4071.7 kg between achievable (7248 kg/ha) and actual yield (377.4 kg/ha). Among studied variable, the farmer experience, seeding rate, the amount of phosphorus in soil, frequency of use of fungicide, organic matter of soil, amount of potassium absorbed in soil and amount of applied nitrogen had the most influence on wheat yield gap in the study area, which were 19.4, 16.8, 14.9, 14.3, 12.7, 11.7 and 10.3 percent of the achievable yield. By amending these factors, it seems that it could reduce the difference between achievable yield and actual yield.