Interactive Effects of Location and N- Fertilizer Rates on Grain Quality Traits of Bread Wheat Varieties at Arsi Zone, South-Eastern Ethiopia

Nowadays it is not only the amount of yield that is important, but also the quality of the grain produced, because the quality of the grain determines the direction of use. In view of this, the current work was conducted in 2017/2018 cropping season with factorial combinations of two bread wheat varieties (Lemu and Wane), five N-rates (0, 46, 92,138 and 184 kg N ha<sup>-1</sup>) and two different locations (Lemu-Bilbilo and Tiyo). The experiment was laid down using a RCBD with three replications. The results explained that, with the exception of 1000 grain weight (TGW) and hectoliter weight (HLW), the remaining parameters included in this study are significantly influenced by the interactions of location x N-rate x variety, while the two-way interactions of location x variety and N-rate x variety were affected all studied parameters except HLW which didn’t affected by the interaction effects of location x variety. The maximum grain yield (7721 and 7481 kg ha<sup>-1</sup>) was achieved from Wane and Lemu at Lemu-Bilbilo and Tiyo at N-rates of 184 and 92 kg ha<sup>-1</sup>, respectively. The peak value of gluten index (GI) (87.9 and 87.4%) was determined in Wane and Lemu varieties, respectively, in unfertilized plot and at N rate of 138 kg ha<sup>-1</sup>, sequentially and at par with 138 and 184 kg ha<sup>-1</sup> for wane and at par with N rate of 46 kg ha<sup>-1</sup> plus with unfertilized plot for Lemu variety in Lemu-Bilbilo. The value of GI recorded at unfertilized plots and N-rate of 46 kg ha<sup>-1</sup> was significantly at par for Lemu variety, while for wane significantly the same as the GI obtained at N-rate of 46 and 92 kg ha<sup>-1</sup> at Tiyo. The effects of N rates at Lemu-Bilbilo was significantly on the same level, but the peak value of wet gluten (55.1%) and dry gluten (20.7%) were gained at 184 kg N ha<sup>-1</sup> in Tiyo and significantly the level of 46, 92 & 138 kg N ha<sup>-1</sup> for dry gluten and 138 kg N ha<sup>-1</sup> for wet gluten. In Lemu-Bilbilo the HLW was increased with an increased N-rate, while in Tiyo it had increased to 92 kg N ha<sup>-1</sup>. Based on parameters examined, the N rates of 92 and 138 kg ha<sup>-1</sup> for both varieties at the Tiyo and Lemu-Bilbilo study sites were therefore economically justifiable.