International Journal of Manures and Fertilizers

International Journal of Manures and Fertilizers Vol. 4 (2), pp. 592-599 February, 2016. © International Scholars Journals

Full Length Research Paper

Determinant of optimum plant density, nitrogen and phosphorus fertilization for different wheat genotypes

D. D. Majaivana1*, L. I Magwende1 and Haile F. Olonga2

1Tigray Agricultural Research Institute (TARI), Alamata Agricultural Research Center, P. O. Box, 056, Alamata, Ethiopia.

2Ethiopian Agricultural Research Institute (EIAR), Kulmussa Agricultural Research Center, Assela, Ethiopia.

*Corresponding author. E-mail:

Accepted 02 April 2015


Optimum seeding rate and nitrogen (N) and phosphorus (P) fertilization are the most important production factors for higher grain yield. Indiscriminate use of seeding rates and N and P fertilization does not only increase production costs but usually decrease wheat grain yield. Study on the interaction effect of planting density and N and P-fertilizer levels on bread wheat varieties was conducted in 2014 cropping season on vertisols of Ofla and Emba-Alaje districts of southern Tigray, Ethiopia with the objective of determining the optimum plant density and optimum N and P fertilization for different Wheat genotypes. The experiment contained split-split plot design on which three recently released bread Wheat varieties (Mekelle 3, Mekelle 4 and Danda’a) were assigned as a main plot, Four level of N/P205 combination (46/46, 92/69, 115/92 and 138/115 kg N/P205 ha-1) arranged in a sub plot and four levels of planting density (150, 300, 400 and 500 plant/m2) assigned as sub-sub plot factor and replicated three times. The analysis of variance indicate that variety, fertilizer, planting density, variety x fertilizer, variety x planting density, fertilizer x planting density, and variety x fertilizer x planting density interaction, have significant (P<0.05) effect on grain yield of bread Wheat varieties. Nitrogen and phosphorus fertilizers and variety showed significance (P<0.05) effect on biomass yield, seeds per spike, effective tiller number and plant height. Grain yield, plant height, effective tiller number/m2 and biomass yield of bread wheat variety increase linearly with planting density and N/P205 fertilizer rate. More grain (6.93 and 5.21 t/ha) for Emba-Alaje and Ofla, respectively was recorded from the interaction effects of 138/115 kg of N/P205 ha-1 with 300 plant/m2 planting density for variety Mekelle-3. However, 115/92 kg of N/P205 ha-1 with planting density of 500 plants/m2 reached higher economical return (MRR=3166.12).

Key words: Variety, planting density, economic analysis, fertilizer.