The experiment was conducted in Horo district of Western Ethiopia. Five -by-two factorial experiment arranged in a randomized complete block design was the method used. The purpose of the experiment was to compare the varietal differences and to evaluate the effects of flower bud removal on tuber yield and quality in Irish potato varieties. Pruning treatments viz. normal growings were applied to five potato cultivars, Guduru, Horro, Beletech, Menagsha, and Jalene. Randomized complete block design arranged in factorial with three replications employed. The results of analysis of variance revealed a significant differences between varieties. Effects of flower bud also showed significant variations except the number of tubers per hill. Interaction between cultivars and treatments showed significant differences for some quality characters. Variety Beletech interacting with bud removal records the highest (18.13%) and (1.51) in dry matter content and specific gravity, respectively. In contrast, Guduru and Jalane interaction with bud removal record (13.5%) and (1.05) in dry matter and specific gravity, respectively. Removal of flower buds decreased total leaf area, plant height, and increased tuber yield by 23.5%, and average tuber mass by 21.5% compared to the unpruned. The result clearly indicated that removal of buds of the upper two younger leaves improved the tuber yield and quality of potatoes. Most of the characters showed positive correlation to each other unless for total marketable tubers per hill and total un-marketable tubers per hill, average individual tuber weight per hill and total unmarketable tuber number per hill, and average individual tuber weight per hill and total tuber number per hill. This indicates that as the number of tubers per hill increases, the total assimilated storage per tuber decreases. The result is of paramount importance to increase the productivity of potatoes in the study area.

Keywords: Flower bud, marketable yield, bud removal, tuber