(2009) Abbas Abd-Alrahman; Hafidh Abbas; Nadir Almubarak
Tow experiments were carried out to examine the application of GA3 and potassium fertilizer (K2SO4) to increase grain yield of two varieties of barley (IPA 99 and 9-12). The experiments were conducted during the winter seasons of 2004- 2005 and 2005- 2006 at the experimental farm / Diyala Agriculture Directorate. A split plot design was used in each experiment. The results of the first experiment showed that a significant increase in the number of spikes (312.6 spike / m²) and number of grain (39.0 grain / spike) with recorded increase in grain yield (3.08 ton / ha), the results of the second experiment showed that combination of GA3 + K with IPA 99 variety caused a significant increase in grain yield (4.7 ton / ha) as compared with growth regulator alone (3.74 ton / ha) or potassium fertilizer alone (3.62 ton / ha). A significant increase in the number of spikes (489.0 spikes / m²) and number of grain (42.6 grain / spike) was obtained. As a conclusion, the application of a combination of gibberellins and potassium fertilizer on barley could be used to increase the yield of grain and harvest index.