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The use of growth retardant in manipulation of growth and development with the target of increasing quanitity and quality of grain yield is extensively expanding in many countries, though this technique has not yet been fully developed in Iran
In a series of laboratory, greenhouse and field experiments the effect of chiormequat chloride on growth, development and grain yield and its components of ghods wheat was studieds. These effects were also compared between the home made chiormequat chloride and the one made by the American Cyanamid Company.
The results indicated that the two chemicals significantly reduced coleoptile and primary root lengths and also the germination percentage, when compared with the untreated controls.Both chemicals also reduced stem height due to shorter internodes. Tiller number and dry weight were increased in treated plants, however ,the rate of development of the treated plants was slowed down. The number of spikelet primordia in treared plants was significantly higher than the untreated controls. This was due to prolonged of spikelet initiation. As a result,the grain yield of treated plots was significantly higher than that of untreated controls.