User:Birhanu29

=Summary=

The study was conducted in Adet Agricultural Research Centrer (AARC) and Bure disrtict with the objectives of assessment of bread wheat production, marketing systems and selection of N-efficient bread wheat varieties. A survey was used to collect data on bread wheat production & marketing systems. Ten bread wheat varieties with two N levels were evaluated under rain fed conditions using a randomized complete block design with three replications over two locations. Analysis of variance revealed a significant difference (p<0.01) among treatments for grain yield, agronomic parameters, quality and Nitrogen use efficiency traits. Estimates of phenotypic and genotypic coefficient of variation at Adet indicated variability for number of tillers per plant (19.9, 11.5) and septoria (30.7, 24.5), respectively. The highest phenotypic and genotypic coefficient of variation was scored for septoria (84.4, 47.1), grain yield (30.8, 14.4), total grain nitrogen (55.9, 39.5), total straw nitrogen (38.7, 22.4) and number of tillers per plant (37.2, 18.1) at Bure. Estimation of phenotypic correlation coefficient among traits at Adet indicated that there was significant correlation between thousand seed weight (r=0.33) and grain yield. Spike length was negatively correlated with grain yield(r=-0.13). Plant height exhibited a positive significant association with thousand seed weight (r=0.40) and biomass yield (r=0.34). Nitrogen use efficiency for yield (r=0.92) had positive and high correlation with nitrogen uptake efficiency. At Bure, plant height (r=0.18) and number of spikelets per spike (r=0.26) showed significant positive correlation with grain yield. Thousand seed weight showed significant negative correlation with grain protein content (r=-0.51) and gluten (r=-0.47). Grain yield (r=0.43) and biomass yield (r=0.42) showed significant positive correlation with hectoliter weight. Nitrogen uptake efficiency (r=0.9), nitrogen utilization efficiency (r=0.5), grain yield (r=0.8) and biomass yield (r=0.6) showed highly significant positive correlation with nitrogen use efficiency for yield. At Adet, Katar (6.9 t/ha), Senkegna (6.8 t/ha), Bobicho (6.7 t/ha), and Gassay (6.5 t/ha) at higher N levels, and Kubsa (6.4 t/ha) at both N levels were top ranking varieties in grain yield. The highest grain protein was scored by Millennium (14.4 %), and Densa (14.1 %) at higher N levels. Katar (14.17) and Digalu had scored the highest nitrogen utilization efficiency. At Bure, Kubsa (4.67 t/ha) at recommended N level, Paven76 (4.52 t/ha), Bobicho (4.24 t/ha) at higher N level and Kubsa (4.22 t/ha) at recommended N level were the top ranking varieties in grain yield. Kubsa (12.63 %) at both N level and Katar (12.9 %) scored the lowest grain protein content. Kubsa (37.25) and Katar (36.99) at recommended N level and Gassay (36.86) at both N levels had scored highest in nitrogen utilization efficiency.