摘要：cassava （Manihot esculenta Crantz） is a perennial woody shrub with an edible root, which grows in tropical and subtropical areas of the world. In Africa, cassava provides a basic daily source of dietary energy. It plays an important role in food security and incomes of many rural households in the southern Ethiopia. However, information available on production practices of cassava for the region is insufficient. Hence, field experiment was conducted at Awassa Agricultural Research Center for two successive cropping seasons from 2004 to 2006 to investigate the response of cassava to planting position and planting material. The treatments used were three planting positions （slant, vertical and horizontal） and five planting materials （main stem top part, main stem middle part, main stem bottom part, branch stake top part and branch stake bottom part） were combined in factorial arrangement and laid out in randomized complete block design with three replications. The result revealed that root yield was significantly （P 〈 0.05） affected by the interaction effects of the planting position and planting material. The highest yield （25.2 ton ha^-1） was obtained from the main stem top part planted in slant position whereas the least yield （6.5 ton ha^-1） was obtained from main stem bottom part planted in horizontal position. Based on the findings of this study, areas like Awassa with moderate rainfall slant and vertical planting of main stem top and middle parts could be used as planting material.

摘要：The research was conducted to study the effect of crude enzyme from cow rumen fluid on nutrient quality of cassava substrates through hydrolysis method. Completely randomized design （CRD） in this research consisted of 4 materials from cassava with its 11 combinations （the total was 15 treatments） with 3 replications. The fifteen treatments were tuber （T）, leaves （L）, peel （P）, onggok （O）, tuber ＋ leaves （TL）, peel ＋ tuber （PT）, tuber ＋ onggok （TO）, leaves ＋ peel （LP）, peel ＋ onggok （PO）, onggok ＋ leaves （OL）, leaves ＋ tuber ＋ peel （LTP）, leaves ＋ tuber ＋ onggok （LTO）, peel ＋ leaves ＋ onggok （PLO）, peel ＋ tuber ＋ onggok （PTO）, peel ＋ leaves ＋ tuber ＋ onggok （PLTO）. Rumen fluid was centrifuged at 10,000 rpm for 15 minutes in 4 ~C. Supernatant was reacted with ammonium sulphate （60%） and incubated in the freezer at 4 ~C for 24 hours. The ground cassava was added by rumen fluid crude enzyme at the dosage of 1% （b/v）. The cassava substrates were kept for 24 hours in room temperature. The addition of rumen fluid enzyme on cassava did not significantly affect dry matter losses （0.96%-2.08%）, but it significantly decreased crude fiber （8.61%-17.83%）. And On the other hand, it increased total sugar （15.19%-29.52%）. The conclusion of this research was that the addition of rumen fluid enzyme on cassava substrates was able to decrease crude fiber （17.83%） and the best total soluble sugar was in tuber （29.52%）, but for dry matter, it was similar to control in the range of 0.96%-2.08%.