Influence of Plant Populations and N Fertilizer Rates on Growth, Development and Yield of Late Maturing Maize Parental Line (142-1-e) at Eastern Wellega Zone, Oromia Region, Ethiopia

Abstract

The experiment was conducted on 142-1-e maize unfixed parental line at Bako National Maize Research Center study site for the last three years (2019-2021). The objective of the study was to identify an optimum plant population density and N rate on 142-1-e maize parental line which gave the highest seed producibility and maximum net benefit. The experiment consisted of two factors: four level
of N (111, 157, 203 and 249 kg ha-1) and five level of plant population densities (44,444, 53,333, 66,666, 88,888 and 133,333 plants ha-1). Totally, the experiment had twenty treatments (4*5) laid out in RCBD design in factorial arrangement each treatment was replicated three times. Different growth, phonological and yield characters of 142-1-e maize parental line were collected. Plant population
densities significantly (p<0.05) affect plant, ear height, girth and barren plant percentage, number of kernels ear-1, thousand seed weight and seed yield of 142-1-e maize parental line. Days to 50% female flowering of 142-1-e maize parental line was highly significantly (p<0.01) affected by both the main effect of N rates and plant population density. The tallest plant (253.1 cm) and ear height (158.3 cm) were observed at 133,333 plants ha-1, followed by the plant and ear height recorded at plant population of 88,888 plants ha-1. The thickest girth (21.72 mm) was recorded at the plant population densities of 44,444 plants ha-1. The maximum barren plant percentage (24.6%) was recorded at plant population of 133,333 plants ha-1. The highest seed yield (4123 kg ha-1) was recoded at 88,888 plant population ha-1 followed by grain yield recorded at 133,333 and 66,666 plants ha-1. Application of N at the rate of 157
kg ha-1 with of 133,333 plants ha-1 was the most profitable than all the other treatments, followed by net benefit obtained at plant population density of 88,888 plants ha-1. However, 157 kg ha-1 of N with 133,333 plants ha-1 reduced the seed size extremely. Due to this, 88,888 plant population ha-1 with N rate of 203 kg ha-1 is recommended for 142-1-e maize parental line at Bako and Other areas with similar agro-ecologies.