Title: Influence of varying nitrogen levels on growth, yield and nitrogen use efficiency of hybrid maize (Zea mays)
Abstract: Present investigation was carried out at Natore Sugar Mills area, Natore, Bangladesh during 2014-15 to evaluate the growth and yield responses of hybrid maize varieties under different levels of nitrogen fertilization.Two hybrid maize varieties viz.BARI hybrid maize-7 and BARI hybrid maize-9 were tested under four nitrogen levels (N0= without external nitrogen supply, N1= 115 kg N ha -1 , N2= 230 kg N ha -1 , and N3= 345 kg N ha -1 ).All recommendations agronomic practices were used for both the variety.Yield and yield traits (plant height, plant girth, total leaves plant -1 , effective leaves plant -1 , noneffective leaves plant -1 , total root plant -1 ,straw weight plant -1 ,cob length, grain free cob, cob girth, grain line cob -1 , total grain cob -1 , grain number line -1 ,1000-grains weight, grain weight cob -1 ,grain yield, straw yield and biological yield) were measured during and on the completion of the study.BARI hybrid maize-9 achieved maximum yield (10.99 t ha -1 ) and it was followed by the BARI hybrid maize-7 (10.37 t ha -1 ).Results of study revealed that yield traits and final yield significantly increased with increasing nitrogen fertilizer from 0 to 345 kg ha -1 .Among various tested N-fertilizer doses, highest grain yield was obtained from the plot treated with N3 treatment (345 kg ha -1 ) but it was not statistically differing from the N2 treatment (230 kg ha -1 ).Therefore, N2 treatment (230 kg ha -1 ) could be recommended for variety BARI hybrid maize-9 as the best economical nitrogen level for maximum economical yield of maize.