Nitrogen timing on weed density and diversity in finger millet production in Lake Kyoga basin in Uganda

Finger millet (Eleusine coracana L.) is the second most important of the millets after pearl millet and a major food crop grown in the semi-arid an arid regions of the world. It is a staple food for the resource poor people in East Africa. Regardless of the increasing area under finger millet production for the last 10 years in Uganda, the yield has stagnated between 1.39-1.6mt/ha. This low yield in finger millet has been attributed to low soil fertility and infestation by weeds. A screen house experiment was conducted in Makerere University Agricultural Research Institute Kabanyolo (MUARIK) to determine the optimum timing for application of the second split dose to maximize nitrogen use efficiency, reduction in weed density and diversity with 2 nitrogen application rates (0, 40 kg Nha-1) at tillering and flowering. The SEREMI 2 finger millet variety was used as a test crop. A blanket application of phosphorus (20 kg P ha-1) as TSP (46 % P2O5) and half dose of nitrogen (40 kg N ha-1) as Urea (46%N) were applied at planting in all plots. The second dose of nitrogen was applied at initial stages of flowering in some plots and in other plots, the nitrogen dose was split 25% applied at tillering while another 25% applied at 50% flowering. Results show that nitrogen application at early stages of growth with the second dose split twice (25% at tillering and another 25% at 50% flowering) increased the weed density and diversity as compared to when another split applied at 50% flowering. However, nitrogen applied at flowering had a substantial increase on grain yield with the highest being 1003.7 kg/ha compared to 870.37kg/ha recorded from nitrogen application at tillering.