EFFECT OF APPLICATION TIMING NITROGEN LEVELS AND SEEDING RATES ON CHARACTERS QUALITY OF BREAD WHEAT

Abstract

A Held trial was conducted at the Experimental Farm, College of Agriculture, Abu Ghraib, Baghdad, Iraq in two winter seasons (2000-2001 and 2001-2002). The objectives were to investigate the effect of application timing of nitrogen levels and seeding rates on some quality characters of bread wheat, cultivar (Abu-Ghraib-3), and to identify the most critical stage of growth after planting (according to Zadoks etal. scale (1974)) for application timing of nitrogen.The experiment was applied in a split-split plot arrangement with RCBD design with three replications. Seeding rates 80,120 and 160 Kg/ha were assigned in the main plots, nitrogen levels 200,300 and 400 kg/ha in sub plots and application timing of nitrogen in sub-sub plots, nitrogen timing where: include five combination of growth stages (ZGs21, ZGs32 and ZGs49), the results showed that : Significant reduction in protein and Ash percentage in grain and protein and glutine wet percentage in flour when seed rate was increase from 80 to 120 and 160 kg/ha , in both seasons .Nitrogen levels of (300 and 400) gave significant increase in all studies characters in both seasons. All of application timing* that include the stage after tillering ' was significantly effect in protein percent. In grain and floyr and in Glutine precent. Of flour in both seasons. A significant interaction between seeding rates and nitrogen levels , between seeding rates and application timing and between nitrogen levels and application timing. The intraction among three factors gave significant effects in all characters in both seasons . A significant positive correlation was found among all of characters in both seasons.