Response of maize (Zea mays L.) to nitrogen and planting density in Jabitahinan district, Western Amhara region

The optimum nitrogen (N) level and planting density (PD) have not been studied for the newly introduced BH-QPM-545 maize variety in the Jabitahinan district agroecology. To determine the optimum N level and PD, field experiments were conducted in the 2014 and 2015 rainy seasons. A factorial arrangement of three N levels (120, 240 and 360 kg ha(-1)) and four PD (53,333, 61,538, 83,333 and 90,900 plants ha(-1) with a corresponding plant spacing of 75 x 25, 60 x 25, 60 x 20 and 55 x 20 cm, respectively) were compared using randomized complete block design with three replications. Analysis of variance (ANOVA) was computed using SAS (version 9.0). The ANOVA showed that plant height, cob number per plant, and cob length were significantly affected by the main effects of N and PD (P < 0.05). But thousand-grains weight was significantly affected by the main effect of planting density only (P < 0.05). All maize yield contributing traits were not significantly affected by the interaction effects of N and PD (P > 0.05). However, Stover and grain yields were significantly influenced by the main effects of N, PD, and their interaction (P < 0.05). Cob length, cob number per plant, stover, and grain yields were increased with increasing N level from 120 to 360 kg ha(-1). Besides, cob length, cob number per plant, and thousand-grains weight were decreased with increasing PD from 53,333 to 90,900 plants ha(-1). However, stover and grain yields were significantly increased with increasing PD from 53,333 to 90,900 plants ha(-1). The highest grain yield was recorded from the combination of the highest N level (360 kg ha(-1)) and the highest PD (90,900 plants ha(-1)). But economical grain yield was recorded under the application of 240 kg ha(-1) N and 90,900 plants ha(-1) although further research using different environments are needed.