Influence of Nitrogen Fertilizer Levels on Growth and Development of Bread Wheat (<i>Triticum aestivum L</i>.) Varieties at Kulumsa, South-Eastern Ethiopia

Abstract

In the Ethiopian highlands low soil fertility, notably nitrogen deficiency, is one of the main constraints limiting wheat production and productivity. For this purpose, an experiment on the effect of different nitrogen fertilizer levels on the growth and developments of bread wheat varieties was conducted at Kulumsa, south-eastern Ethiopia, during the 2017/18 cropping season. The experiment consisted of factorial combinations of two bread wheat varieties (Lemu and Wane) and five N rates (0, 46, 92, 138 and 184 kg N ha^-1) performed in a three replicate randomized complete block design. The result revealed that, the interaction effects of variety and N fertilizer rate showed less effect than their main effects and only days to grain filling period and the spike length were significantly influenced by the interaction effects of variety and the N rate. It was indicated that, the Wane variety was shorter days to heading, maturity and grain filling period than Lemu variety whereas Lemu was taller variety, more effective tillers, number of grains per spike and gave better aboveground biological yield than Wane variety at the study site. Conversely, significantly the longest days to heading and maturity were recorded at the highest N rate (184 kg ha^-1). The days to grain filling period was increased with rising N rate for both varieties. The peak spike length was recorded at N rate of 92 and 138 kg ha^-1 for Lemu and Wane varieties, respectively. The maximum aboveground biological yield recorded at the top N rate 184 kg ha^-1 and significantly at par with that of 92 and 138 Kg N ha^-1. Therefore, it was concluded that the response of growth and development of Lemu and wane varieties were different for N fertilizer rate.