This study is carried out to efficient usage of available nutrients to emerge good quality fodders with minimum disturbance of weed population with different mixtures of organic manures. Hybrid Napier (CO3) is a high yielding perennial fodder grass, commonly cultivated in Sri Lanka as a popular fodder grass. This grass was propagated through cuttings at spacing of 60 x 60cm with the treatment of four kind of organic combinations (poultry manure, cattle manure and goat manure: 3:5:2, 2:2:1, 5:3:2 and 3:1:1) and a free of any organic supply (control). Proper management practices such as irrigation was practiced according to the recommended amount and interval. Number of weeds were counted and categorized into grass weeds and broad leaves weeds weekly wise after planting the cuttings. The results revealed that the weeds population show significant differences (p > 0.05) with the different combinations of organic fertilizer applications. Broad leave weeds showed dominant establishment than grass weeds and they were greater competitor for fodder to achieve the sufficient nutrients of the soil. Though, they performed best in the combinations of 3:5:2, 2:2:1 and 3:1:1. However, optimum weed population with best performance of CO3 were maintained in the combination of 5:3:2. Therefore, perfect organic fertilizer combination may be helpful to make the field to achieve highest quantity of yield with optimum level of weed population and to acquire good quality forage. This study may support to convert the farm as cost effective and high income generating agribusiness.

Keywords : Napier hybrid, grass weeds, broad leave weeds, population of weeds, combinations of organic amendments.