Effect of Plant Spacing and Harvesting Age on Plant Morphological, Dry Matter Yield and Chemical composition of Guinea (Panicum Maximum) Grass intercropped with Silver Leaf Desmodium (Desmodium uncinatum) at Koga Irrigation, Amhara Region, Ethiopia 2 1 Mihret Anteneh 1 and Fentahun Meheret Agricultural Office, of North Achefer District 2 Bahir Dar Universities, Colleges of Agriculture and Environmental Sciences, P.O.Box: 5501, Bahir Dar, Ethiopia The experiment was conducted at Koga irrigation site with the objectives of evaluating the effect of plant spacing and harvesting age on morphological parameters, dry matter yield, and chemical composition of guinea grass (Panicum maximum) and silver leaf Desmodium (Desmodium uncinatum) grown with the intercropping system. A randomized complete block design was using in factorial arrangement with two factors (plant spacing and harvesting age) and three replications each containing nine plots with a total of 27 plots. The harvesting ages( 60, 90 and 120 )days with a plant spacing of (20 , 30 and 40) cm. The sliver leaf Desmodium was seeded after two weeks of the grass planting well established. A total of ten plants from each plot were randomly selected to collect data for morphological parameters(PH,LL,NT,NL RL,NR LSR ). All data were analyzed following the procedure of SAS software packages (SAS, 2004).The result indicated that the interaction effect of plants pacing and harvesting age hadn't a significant effect on morphological parameters except for leaf stem ratio and number of leaf when guinea grass intercropped with silver leaf Desmodium, but each main effect had a significant level at (p<0.05). A total of 12.5ton/ha DMY and 86.33cm PH were obtained when guinea grass was intercropped with silver leaf desmodium at plant spacing of 20cm and 40cm at harvesting age of 120 days respectively. On the other hand, the highest DM (94.4), Ash (15.97), OM (85.98), ADF (46.15), and ADL(11.64) content of the mixed sample of guinea grass and silver leaf was recorded at the late (120 days) harvesting where as the highest CP(19.21) content was from the early (60 days) harvesting age. The results of the experiment indicated that intercropping system for morphological parameters of guinea grass and silver leaf desmodium except leaf to stem ratio was increased simultaneously with plant maturity and at wider plant spacing. Therefore among tested plant spacing, the wider (40cm) and intermediate (90 days)