Effect of plant density and Earthing up process on yield triats and components of sorghum cultivar (Bihawth 70)
Abstract
A field experiment was conducted at the experimental farm belong to Rabban A-Safiya company- Aureij site located in south of Baghdad to study the effects of plant densities and four dates of Earthing up after emergence on lodging percent, growth traits and grain yield and its components of sorghum crop (Bihawth 70 cultivar). The layout of the experiment was a split-plot in a Randomized Complete Block Design (RCBD) with three replicates. The main plots included four treatments of plant densities (53333, 66666, 80000 and 100000 plant ha-1) while sub plots were four dates of Earthing up (control, 4 weeks, 5 weeks and 6 weeks) after emergence, sowing took place in the first half of August 2018. The results showed that the plants density 100000 plant ha-1 showed the highest grain yield (8.715-ton ha-1) and biomass (27.583-ton ha-1), While the plant grown at low density (53333 plant ha-1) gave the highest number of grains per head (4332), weight of 1000 grain (27.600 g) and plant yield (119.540 g plant -1). The date of four week Earthing up after emergence gave the lowest number of grains per head (4043 head-1), weight of 1000 grain (26.875 g), grain yield (7.950-ton ha-1) and biomass (20.517 ton ha-1). There was a significant interaction between plant densities and earthing up, of the most studied traits except for 1000 grain weight and grain yield per unit area. Plant density 100000 plant ha-1 with date of four week earthing up after emergence gave grain yield (9.166 ton ha-1) biomass (28.567 ton ha-1), while the plant density of 53333 plant ha-1 with earthing up date of four weeks after emergence gave the highest average, number of grains in the head (4422 head-1) and yield per plant (124.280 g) .It is clear from this study that the date of four week Earthing up after emergence of sorghum crop (Bihawth 70 cultivar) resulted in a reduction in the number of increased the yield per plant. Also, the increase of plant density led to increased competition among plants for growth factors, especially light, which led to an increase in some of vegetative growth traits resulting in an increase in grain yield per unit area, despite of the decrease in some grain yield components.
