تأثير بعض مستويات السماد النتروجيني في نمو وحاصل ثلاثة أصناف من الذرة البيضاء

Abstract

A field experiment was conducted in two seasons (spring and autumn 2009) in silty loam soil, in Ramadi-city / Anbar-governorate, to investigate the effect of four levels of nitrogen fertilizer (0, 100, 200 and 300 KgN.ha-1) on growth properties, yield and nitrogen use efficiency, of three sorghum cultivars (Rabeh , Inkath and Kaffer). Factorial arrangement was used according to the randomized complete block design (R.C.B.D.) with three replications. The result showed the followings : 1. Inkath cultivar showed, the longest period from mid-bloom to maturity, highest grain yield (6.17, 6.47 T.ha-1) and grain protein yield (608.7, 637.2 Kg.ha-1) in spring and autumn respectively. Rabeh cultivar showed the highest nitrogen use efficiency for the dry matter (11.15, 28.39 Kg.KgN-1) in spring and autumn respectively. Kaffer cultivar recorded the shortest period from emergence to mid-bloom, it was superior in harvest index (44.78 , 39.28%) and grain protein percent (10.69, 10.62%) in spring and autumn respectively. 2. Nitrogen application had increased the most properties of growth and yield. The level of nitrogen fertilizer (300 KgN.ha-1) gave the highest total dry matter (15.82, 19.60T.ha-1); 200 KgN.ha-1 gave the highest grain yield (6.24, 6.57 T.ha-1) ; 100 KgN.ha-1 showed the highest nitrogen use efficiency for the total dry matter (11.86, 28.73 Kg.KgN-1) and nitrogen use efficiency for the grain (7.60, 7.84 Kg.KgN-1) in spring and autumn respectively. 3. There was a significant interaction between cultivars and levels of nitrogen fertilizer for all properties. Inkath cultivar produced the highest grain yield (6.83 T.ha-1) at 300 KgN.ha-1 in spring, and (6.91 T.ha-1) at 200 KgN.ha-1 in autumn , it showed the highest nitrogen use efficiency for the grain at 100 KgN.ha-1 (8.47, 8.40 Kg.KgN-1) in spring and autumn respectively.