Response of white maize hybrids to various nitrogen fertilizer rates in Qalyubia, Egypt

Two field experiments were conducted during the two successive summer growing seasons of 2016 and 2017 to study the effect of three nitrogen fertilizer rates, on the growth traits, yield components, yield and some kernels chemical properties of three white single cross hybrids of maize. Almost traits of maize under study, were significantly increased by increasing nitrogen fertilizer rates in the both seasons, application of 150 kg N/fed significantly gave the maximum values of studied traits except, No. of days to 50 % tasseling and tasseling as well as No. of barren plants/fed which were significantly decreased with increasing nitrogen rates in the both seasons. White single cross (S.C.) hybrids of maize were significantly differed in all maize traits under study in the both seasons. S.C. 30K8 was significantly surpassed S.C. 7071 and S.C. 2031 in mean values of No. of plants carried two ears/fed, No. of ears/fed, No. of rows/ear, No. of kernels/row, No. of kernels/ear, grain yield/fed, grain yield/plant and harvest index as well as gave the lowest mean values of No. of barren plants/fed and the shortest period from planting to 50 % tasseling or silking in the both seasons. Moreover, S.C. 2031 surpassed the other two maize hybrids in mean values of leaf area/plant, ear weight, 100-kernel weight, ear yield/fed, biological yield/fed, kernels nitrogen content, kernels crude protein content, kernels nitrogen uptake/fed and protein yield/fed in the two seasons. Meanwhile, S.C. 7071 recorded the highest mean values of No. of green leaves/plant, plant height, ear height, shelling % and stover yield/fed in the two seasons. Planting S.C. 30K8 and fertilized by 150 kg N/fed recorded significantly the highest mean values of No. of plants carried two ears/fed, No. of ears/fed, No. of kernels/row, No. of kernels/ear, grain yield/fed, grain yield/plant and harvest index as well as gave the lowest mean values of No. of barren plants/fed during the both seasons. Meanwhile, growing maize hybrid of S.C. 2031 under the same nitrogen fertilizer rate surpassed the other treatments in mean values of leaf area/plant, ear weight, 100-kernel weight, ear yield/fed, biological yield/fed, kernels nitrogen uptake/fed and protein yield/fed during the two seasons. Whereas, the maximum mean values of plant height, ear height, shelling % and stover yield/fed in the two seasons were produced from maize hybrid of S.C. 7071 with the same rate of nitrogen fertilizer rate.