effects of the irrigation cut-off time in different growth stages on grain and oil yield components of autumn’s canola cultivars in isfahan region

abstract to evaluate the effects of the irrigation termination in different growth stages on yield and its components of autumn’s canola cultivars in isfahan region. an experiment was conducted in 2005-2006 in kabotar abad research station. a split plot layout within a randomized complete block design with tree replication was used. main plots were seven level of the irrigation cut-off time (d1:control irrigation or irrigation after 80 millimeter vaporize from class a basin to physiological maturity, d2: the irrigation cut-off time from stem elongation stage and then on , d3:the irrigation cut-off time from flowering stage and then on, d4: the irrigation cut-off time from pod stage and then on, d5: the irrigation cut-off time in stem elongation and flowering stages, d6: the irrigation cut-off time in stem elongation and pod stages, d7: the irrigation cut-off time in flowering and pod stages) and sub plot were two canola cultivar(zarfam and okapi) great autumn’s product. the results showed that the effect of the irrigation cut-off time treatments on plant height, number of pod per plant, number of grain in pod, thousand grains weight, grain and oil yield were significant. after control irrigation treatment, maximum grain yield and oil yield were obtained by d5, d6 and d7 treatments respectively but there is significant between these treatment and other treatments. minimum grain and oil yield were produced by the irrigation cut-off time from stem elongation stage treatment. zarfam was significant as compared to okapi superior for plant height, number of pod per plant, thousand grains weight, oil percentage and oil yield. on the basis of the results obtained, d5, d6 and d7 treatments and zarfam cultivar might be suitable for obtained maximum grain and oil yield under the irrigation cut-off time condition to the present study.