A Review of Non-Chemical Management of CouchGrass (Elymus repens)

Couch grass (Elymus repens) is a morphologically diverse, rhizomatous, perennial grass thatis a problematic weed in a wide range of crops. It is generally controlled by glyphosate or intensivetillage in the intercrop period, or selective herbicides in non-susceptible crops. The aim of this reviewis to determine the ecacy of non-chemical strategies for E. repens control. The review shows thatindirect control measures like crop choice, subsidiary crops, and fertilizer regimes influence E. repensabundance, but usually cannot control E. repens. Defoliation (e.g., mowing) can control E. repensgrowth, but ecacy varies between clones, seasons, and defoliation frequencies. Tillage in theintercrop period is still the main direct non-chemical control method for E. repens and its ecacy canbe increased, and negative side-eects minimized by an appropriate tillage strategy. Some new tillageimplements are on the market (Kvik-up type machines) or under development (root/rhizome cutters).Alternative methods that can kill E. repens rhizomes (e.g., steaming, soil solarization, biofumigation,hot water, flooding) often have high costs or time requirements. More studies on the eect of croppingsystem approaches on E. repens and other perennial weeds are needed