Abstract

Wheat in Iran is important due to increasing consumption by the population. Much of the wheat in Iran produced in irrigated farm lands, which cover about 50% of the total irrigated land. Since the irrigated land is limited, the productivity has to be increased. Wheat production is constrained by different managements, abiotic and biotic. To determine the production constraints for wheat in Moghan in the Province of Ardabil in north-west of Iran, survey was conducted in the 58 wheat fields in the region. In this survey, through identifying management factors that cause wheat yield gap to improve yield production to quantifying the highest smallholder farm yield of the study area and identifying the factors that cause yield gap in the region. The aim of this survey was to identify the large gaps between highest wheat yield on smallholder farms and average yield for five wheat cultivars. In 2015 and 2016, yield gap constraints were identified through the stepwise regression method. Management factors, including timing of planting, nitrogen and phosphorus rates, crop rotation, weeds and pest control and wheat cultivars being the main factors for the wheat yield gap in the region. Year-to-year variability in response to late planting is not unusual, but many experiments suggest that, on average, yield will peak when flowering occurs around 15 May, and will fall sharply if flowering occurs after 25 May (equivalent to a late planting i. e. after 15 December).