Performance evaluation of intermediate maturing maize hybrid variety under different nitrogen levels and plant population density in West Shewa and East Wellega zone of Oromia region, Ethiopia

The experiment was conducted from 2019 to 2021 year to identify an optimum plant population and rate of N on BH546 maize hybrid variety at Bako National Maize Research Center study site and Ilu Gelan District. The experiment has two factors: three N rate (134, 180 and 226 kg ha-1) and four plant population density (62,500, 71428, 83,333 and 100,000 plants ha 1). Totally 12 treatments were accommodated in the experiment. ANOVA indicated that at Bako and Ilu Gelan, plant and ear height were significantly (p<0.05) influenced by plant population density. While at Bako, plant and ear height were influenced by main factor of N rates. Grain yield was significantly influenced by the main factor of N rates at both Ilu Gelan and Bako. At Ilu Gelan, it was also significantly affected by the main effect of plant population and the interaction effect of N rates and plant population. At Ilu gelan, 100,000 plant ha 1 delayed days to 50% male flowering. At this plant population, the maximum lodging percentage was recorded. The maximum grain yield (6437 at Ilu Gelan) and (7926 at Bako kg ha 1) was observed at N rate of 226 kg ha_1 followed by grain yield recoded at N of 180 kg ha-1 at both location. The maximum grain yield 6671 kg ha 1 was observed at N rate of 226 kg ha 1 with 83,333 plant ha 1. Application of N at the rate of 226 kg ha-1 with combination of 83,333 plants ha 1 was the most profitable of all the treatments, followed by plant population of 71,428 plants ha 1 with 134 kg of N rate ha 1 and 62,500 plants ha 1 with 226 kg ha 1 N rate. Thus, BH546 at plant population of 71,428 plants ha 1 with 134 kg of N rate ha 1 was suggested for producers around study areas and other areas having similar agro ecologies as it is economically feasible and easily accessible than the rest all treatments. Further investigation on time of N application supported by tissue analysis is mandatory.