A field experiment was conducted at the National Maize Research Program  (NMRP) Farm, Rampur, Chitwan during winter season, 2008/09 to study the effects of three  plant densities (55,555, 66,666 and 83,333 plants/ha) and three nitrogen levels (120, 160  and 200 kg/ha) on yield and yield attribute of hybrid maize (Zea mays L.) varieties Gaurav,  (a Nepali hybrid) and Rajkumar (an Indian hybrid).  The results showed that plant height  increases with increasing plant density and nitrogen level. Similarly, phenology was not  influenced by the densities whereas variety and nitrogen levels had a significant effect on  tasseling, silking and physiological maturity. Plant density of 66,666 plants/ha produced the  higher grain yield (11.19 t/ha) compared to that of 55,555 plants/ha (9.52 t/ha). However,  grain yield at 66,666 plants/ha did not show a significant difference with that of 83,333  plants/ha (10.54 t/ha). Increasing plant density from 55,555  plants/ha to 83,333 plants/ha had increased the stover yield, whereas, the Harvest Index (HI) and grain stover ratio were  not significantly influenced by plant densities. Similarly, 200 kg/ha N application produced a  higher grain yield (10.9 t/ha) than 120 kg/ha N application (9.76 t/ha), but was in par with  160 kg/ha N application (10.59 t/ha). The yield of the two hybrid maize varieties had no  significant difference. Plant density with 66,666 plants/ha and 160 kg/ha N application was  the most appropriate for inner terai environments of Nepal during winter season.

Tropical Agricultural Research Vol. 23 (3): 218-227 (2012)