Effect of Water Source and Weeding on: (A) Growth and nodulation of three Alfalfa (Medicago sativa L.) Cultivars

A field experiment was carried out during 2005/06 and 2006/07 seasons at the Demonstration Farm of the Faculty of Agriculture, University of Khartoum, to study the effect of water source and weeding treatments on growth and nodulation of three alfalfa (Medicago sativa L.) cultivars. The treatments in this study consisted of three alfalfa cultivars: A local cultivar, Hegazi and two exotic cultivars, Cuf101 and Siriver. The water treatments were: Bore hole water, river water with screen mesh at the entrance of plots and river water without screen mesh. Three treatments of weeding were applied: Monthly weeding, every two months and every three months. The treatments were assigned to a split-split plot design with waters as the main plots, weeding as the sub-plots and cultivars as the sub-subplots. The treatments were replicated four times. The parameters studied were: Nodulation (nodule number, weight and effectiveness) and growth attributes (plant density, shoot/ root ratio, leaf area index and leaf to stem ratio). The two introduced cultivars were significantly better than the local one in nodule fresh and dry weights, number of effective nodules, plant density, shoot/root ratio, leaf area index and leaf to stem ratio. The river screened water treatment was significantly superior in plant density, shoot/ root ratio, leaf area index and leaf to stem ratio. In all these parameters, the river water without screen treatment recorded the lowest estimates. Monthly weeding treatment showed a significant increase in shoot/ root ratio and leaf area index compared to the other weeding treatments.