Hormonal Regulation of Tillering in Sorgum (Sorghum Bicolor (L.) Moench) and its Influence on Grain Yield and its Components 1. Growth Characteristices
Alowan, A. L.; Jaddoa, K. A.
Iraqi Journal of Agricultural Sciences 46(4): 494-502
A field experiment was carried out at the Experimental Farm, Department of Field Crop Sciences, College of Agriculture - University of Baghdad during the spring and fall seasons of 2013. The aim was to investigate the possibility of hormonal regulation of tillering in sorghum and its relationship with grain yield and its components. R.C.B.D design with Split-plot arrangement was used with three replicates where three sorghum cultivars (Inqath, Rabeh and Abu al sabeen) occupied the main plots and seed soaking treatments with Gibberellic acid and Ethephon occupied the sub- plots. Seed soaking treatments were (T2=300, T3=600 and T4=900 mg. l-1) of gibberellic acid and (T5=500, T6=1000 and T7=500 ppm) of ethephon besides two control treatments : un-soaked seeds (T0) and seeds soaked with only water (T1). Results indicated that there were Significant differences between varieties in growth characteristics in both seasons. there were significant difference in the field emergence due to the varieties, seed soaking and their interactions. T4 treatment gave the highest values of field emergence (77.78 and 92.00%) in both seasons, respectively compared with (60.00 and 81.67 %) for (T7) treatment. KH70 gave the highest values of plant height (88.7 and 175.00 cm) in the last two weeks of sampling in spring and fall season, for ankath and rabihno significant differences in both seasons. Concerning seed soaking, T4 tretment gave the two weeks of sampling compared with (60.83 and 141.00 cm) for (T7) treatment. For leaves number no significant differences were found for both varieties and seed soaking However, for flag leaf area, flag leaf dry weight and chlorophyll content of these characters with the increasing of GA3 concentration in both seasons, respectively, while ethephon treatments decreased these characters.