اثر آبياري و كود نيتروژن بر صفات زراعي و فيزيولوژيكي دو رقم كانولا

Effect of irrigation and nitrogen fertilizer on agronomical and physiological traits of two canola (Brassica napus L.) cultivars.

In order to investigate the effect of irrigation and nitrogen fertilizer on agronomical and physiological traits of two canola cultivars, an experiment was established in randomized complete block design as split-plot factorial arrangement with four replications in 2005-2006 at Agricultural Research Station of Khorramabad Iran. Irrigation was as main-plot factor consisted of four levels 60, 90, 120 and 150 based on accumulative evaporation from class A evaporation pan (abbreviated as I60, I90, 1120 and I,so). Sub-plot factors were included nitrogen fertilizer in four levels 0, 70, 140 and 210 kg ha"1 (abbreviated as No, N70, N^o and N:i0) and two cultivars, Zarfam (V() and SLM046 (V2). According to simple analysis results, irrigation and irrigation x cultivar interaction had significant (P0.05) effects on Thousand Seed Weight (TSW) in the 2006. At both I6o and I)2o treatments, Zarfam showed higher TSW compared with SLM046.As nitrogen rate increased, and Oil Yield (OY) increased in the 2006 significantly (P<0.05).The irrigationxnitrogen and irrigationxcultivar interactions were significant on OY in the 2006 at P<0.05 and P<0.01 Level, respectively. Zarfam had a higher TSW and Oil Percentage (OP) in both years, but on basis OY was superior Zarfam in the 2005 and SLM046 in the 2006. The irrigationx nitrogenxcultivar interaction had a significant effect on OP in both 2005 (P<0.05) and the 2006 (P<0.01) years. This interaction showed that in both cultivars in every irrigation level, the highest OP was obtained from no nitrogen application and OP decreased with nitrogen application. According to the results of combined analysis, both Water Use Efficiency (WUE) and Dry Matter Remobilization Efficiency (DMRE) were increased by decreasing water supply in I90 to F1S0 treatments. N0 and N210 treatments resulted in the lowest WUE and DMRE, respectively. Considering all traits, the first year of experiment was better than second year. The irrigation x cultivar interaction had a significant (P<0.01) effect on Seed Yield and WUE. Zarfam had more adaptation to water-limited conditions. Generally, Ii5oN70Vi combination is recommended in the study region due to appropriate performance in oil production.