Identification of Rapeseed Limiting Factors Using Performance Comparison Analysis

Understanding the performance potential and the gap between the actual yields of crops with the achievable function is necessary to diagnose the limiting factors of performance. The present study was conducted based on the method of CPA in 50 fields of Zavkooh villi (Kalaleh, Golestan, Iran) in 2016 and 2017. In this study all information related to management practices, soil characteristics and farmer socio- economic status were measured and recorded. In the comparative performance analysis (CPA) method, using stepwise regression, the relationship between variables and yield was considered. And yield gap rate, its causes factors and it was also estimated the contribution of each of these factors to the creation of a yield gap. The results showed that between the average real yield (2308 kg ha-1) and the yieldable yield (4123 kg ha-1), there is 1818 kg per hectare of vacuum. Accordingly, the most important factors in yield gap for the region included: field size with 21.4 percent, Summer plowing with 15 percent, The time of land preparation and plowing with 14.7 percent, nitrogen fertilizer with 14.6 percent, potassium fertilizer with 14 percent, weeds density per unit area with 10.8 percent), seed treatment with 8.1 percent and Subsoiler with 1.4 percent.