Hormonal Regulation of Tillering in Sorghum

The present study, which is implemented for the first time in Iraq and maybe in the world, aims at regulating tillering in various classes of sorghum by using the third strategy: Using some of plant growth regulators such as gibberellin (growth promoter) and ethephon (growth retardant) to promote branch contribution in grain harvesting with a rate close to primary stem contribution through regulating competition principle between primary stem and tillers by soaking the seeds of tree classes of sorghum at different concentrations from these two regulators in comparison with dry seeds (non-soaked) and other soaked in water in order to know the performance of these classes specially that concern the tillering feature and its relation with grain harvesting. These classes were planted by plant density (53300 plant\hectare.-1) to provide space for its plant to produce more tillers, then regulating them harmonically by using growth regulators.