عنوان مقاله [English]
To evaluate the effect of irrigation on seed yield and water productivity of three common canola hybrids including: Okapi (T1), Elite (T2) and Milena (T3) in the strip-plot statistical design with three repeats for 2004-2005 and 2005-2006 a field experiment was conducted in Miandoab agricultural and natural resources research center. To extract production and water productivity functions, eight treatments of different irrigation levels with IP1 to IP8 symbols including 120, 110, 100, 90, 80, 80, 70, 60 and 50% of water requirement calculated by the Penman Monteith FAO method was considered. The results showed that the production functions in T1, T2 and T3 hybrids have a correlation of 0.98, 0.98 and 0.97. By extracting the productivity functions, it was observed that the amount of water productivity decreased under severe stress conditions and increased with increasing water content. If deficit irrigation is required, IP4 treatment is recommended due to the highest seed yield (average seed yield equal to 3758.5 kg/ha for two years). The results of statistical analysis of studied parameters showed that with 10% reduction in water consumption, benefit decreased 7.83% in the first year and 3.44% in the second year. T2 and T1 hybrids had the highest yield in the first and second years, respectively, and the yield was higher in the second year than in the first year. The reason for this is the increase in temperature and more radiation received in the second year. To maximize productivity, IP4 and T2 hybrid are recommended.