Effect of Plant Density and Spraying with Ethephon on Yield and its Components of Sorghum (Var. Bohooth .70)

A field experiment was carried out during the spring and autumn season 2021 in Al-Kut region - Wasit Governorate, to study the effect of plant densities and ethephon spraying on the yield and yield component of Sorghum (var. Bohooth 70). The experiment was applied according to a randomized complete block design (RCBD) in a split split plots design with three replications. The main plots included three plant densities (80000, 66666 and 50000 plants.ha-1), while the sub plots included three stages of ethephon spraying (4, 8 and 12 leaf per plant). Sub-sub plots included three concentrations of ethephon (0, 800, 1600 ppm). The results showed that the lower plant density (50,000 plants.ha-1) led to a significant decrease in plant height and the rate of lying, and a significant increase in yield per plant, weight of 1000 grains, and number of grains per head. Spraying ethephon increased the yield per plant, weight of 1000 grains, number of grains per head and yield of grain (t.ha-1). On the other hand, there was a significant relationship between the concentration of ethephon and the decrease by plant height and the rate of lying when sprayed at the stage of 4 and 8 leaves. It can be concluded from this study that plant height and lying ratio can be reduced when using low density with ethephon spray during early growth stages for economical grain production.