Effect of plant density and earthing up process on growth triats of sorghum cultivar

تأثير الكثافة النباتية وعملية التتريب على صفات النمو لمحصول الذرة البيضاء

Abstract

This experiment was carried out in the experimental field of the Raban Al-Safiya Company, south of Baghdad. This study aims to know the effect of plant densities and Earthing up on the percentage of lodging and their effect on the growth traits, of the 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. The results showed that the plants density 100000 plant ha-1 gave the highest plant height (286.310 cm), number of leaves (18.200 leaf plant-1), leaf area (7243 cm2 plant-1), leaf area index (7.180) , While the plant grown at low density (53333 plant ha-1) gave lowest days to 50% flowering (62.67 days) , highest stem diameter (2.041 cm) , lowest percentage of plant lodging (14.1%). The stage of four week after emergence Earthing up  gave the lowest number of days to 50% flowering (64.43) days and gave the highest plant height (281.320 cm), stem diameter (1.975 cm) , number of leaves per plant (18.125) leaf area (7122 cm2 plant -1), leaf area index (5.425). We conclude from this study that performing the Earthing up for sorghum crop four weeks after emergence resulted in a reduction in the number of days to reach 50% flowering and a decrease percentage of plant lodging and thus led to an increase in the yield per plant. Also, increasing plant density led to increased competition between plants for growth factors, especially light, which led to an increase in some vegetative growth traits, resulting in an increase in grain yield per Keywords: Plant density, Sorghum, Growth traits, Earthing upunit area.