5Dennis Tonks,Jeffery L S, Webb B L. Response of seed ling alfalfa (Medicago sativa) to four postemergence herbicides[J]. Weed Technology, 1991,5: 736 -738.
6Fischer,Dawson J H,Appleby A P. Interference of annual weeds in seedling alfalfa (Medicago sativa ) [J]. Weed Science, 1988,36:583-588.
7Harvey R G. Bentazon for annual weed control in newly seeded alfalfa (Medicago sativa L. )[J]. Weed Technolo gy, 1991, (5) : 154- 158.
8Chester L,Foy,Witt H L. Annual grass control in alfalfa (Medicago sativa) with postemergence graminicides[J]]. Weed Technology, 1992, (6): 938-948.
9Cosgrove, Barrett M. Effect of weed control in establis hed alfalfa (Medicago sativa) on forage yield and quality[J]. Weed Science, 1987,35: 564-567.
