Effects of weed control methods on seed yield, seed protein and percentage of seed hardiness in annual medic (Medicago scutellata cv. Robinson)

Abstract

Annual medics alongwith high quality residues production are capable to produce high percentage of hardseeds which play a significant role in sustainability of Ley-farming system. To study the effect of two selective post-emergence grass herbicides on seed production and characteristics of annual medic during pasture stage, this experiment was conducted in 2009 growing season. The treatments were : control (without weed control), hand control of weeds, Nabu-S and Gallant herbicides. Results showed that application of Gallant herbicide caused over 85% damages to annual medic population in the pasture. The application of Nabu -S herbicide successfully controlled all the weeds. However, it caused a significant decrease in seed yield, seed protein, per cent of hardseedness as well as protein content in produced dry residues by annual medic. Weed control by hand significantly increased the quality and quantity of seed produced in annual medic pasture. Application of herbicides is not highly recommended as it imposes some deleterious effects on annual medic.