A filed experiment was carried-out during the winter season of 2010-2011 and 2011-2012 at the experimental farm
of Baghdad University. The main objectives were to asses the role of irrigation blocking and ethephon spraying on growth
of wheat cultivars. Two bread wheat cultivars were included. These were IPA-99 and Abu-ghraib-3. Ethephon foliar
application and irrigation blocking was applied at elongation and booting developmental stages. A split-plot design with
four replicates was used. Main plots were assigned to irrigation blocking-ethephon spraying treatment, whereas, cultivars
assigned to sub-plots. Data presented as an average of the two seasons since the interaction of season treatments was not
significant. over irrigation blocking-ethephon spr aying treatment the wheat cultivar IPA-99 was significantly superior to
Abu-Ghraib-3 in plant height, flag leaf area, dry weight of flag leaf, specific weight of flag leaf, chlorophyll content,
tillers number and dry weight of above ground plant parts after 95 and 155 days of sowing. Meanwhile, the difference
between the two cultivars had not reached the level of significance in crop growth rate and relative growth rate. Irrigation
blocking and ethephon spraying at elongation stage, although significantly increased plant height, flag leaf area, dry
weight of flag leaf, specific weight of flag leaf, chlorophyll content, tillers number/plant and dry weight of plant after 95
and 155 days, the difference in crop growth rate and relative growth rate between elongation and booting stages was
insignificant. It might be concluded that ethephon foliar application might compensate the suppressing effect of irrigation
blocking through modifying plant physiology and regulate the transmission of auxins that lead to reduction in water need
and an increase in wheat plant growth.