Evaluation of Napier Grass (Pennisetum purpureum (L.) Schumach) Accessions for Agronomic Traits Under Different Environmental Conditions of Ethiopia.

Ten Napier grass accessions were evaluated for their agronomic traits under diverse environmental conditions of Ethiopia. The study was conducted in randomized complete block design with three replications. Data on plant height and dry matter yield were analyzed using the general linear model procedures of SAS and least significance difference was used for mean comparisons. The combined analysis of variance indicated that the main effect differences among genotypes, environments and the interaction effects vary significantly for measured agronomic traits. The combined analysis for plant height differed significantly (P<0.05), which ranged from 103.80 to 132.03 cm with a mean of 114.93 cm. The local accession gave the highest mean plant height followed by accession 16819 and 15743 while accession 16792 gave the lowest over locations. Of the total variance of dry matter yield, environment main effect accounted for 40.6%, whereas genotype and genotype by environment interaction effects accounted for 14.8% and 38.8% respectively. The highest mean dry matter yield was recorded at Adamitulu (13.06 t/ha) followed by Areka (12.80 t/ha), Hawassa (11.80 t/ha), Debre zeit (10.50 t/ha) and Holetta (7.05 t/ha). The combined analysis indicated that dry matter yield varied significantly (P<0.05) among the tested accessions and the yield ranged from 7.97 to 12.57 t/ha with a mean of 11.04 t/ha. Accession 16819 and 16792 gave the highest and lowest dry matter yield respectively. Generally, Napier grass accessions respond differently across the testing environments due to differential responses of the genotypes to various edaphic, climatic and biotic factors.