Department of Plant, Soil and Microbial Sciences Weeds

Quackgrass (Elytrigia repens (L.) Nevski)

Life Cycle:

Perennial. Emerges in the spring, flowers in early summer, and sets seed in late summer. Plants remain green all year.

Emergence:

Seeds germinate well within 2-inches of the soil surface. Very few plants emerge from seeds at depths of 4-inches or greater. Rhizomes are capable of producing shoots from 6-inches below the surface, but are more likely to produce shoots when buried only 1- to 2-inches.

Reproduction:

Mode(s) of Reproduction: Reproduces by seed and the spread of rhizomes.

Dispersal Mechanisms: Local populations are established from the spread of rhizomes. Seeds will not germinate in areas of established quackgrass.

Longevity: Seed quickly looses all viability in 2 to 4 years.

Dormancy: Seed does not enter dormancy. Up to 90% of fresh seed will germinate when exposed to fluctuating temperatures. Viability declines rapidly after initial dispersal.

Competitiveness:

High levels of infestation can result in up to 85% yield loss in potato. Very high densities (893 shoots/yard2) have also been shown to reduce corn yields by 37%. 

Preferred Soil/Field Conditions:

Prefers areas of reduced tillage and fertile areas where tillage occurs.

Management:

Biological

Predation/grazing: Some work has been done with domesticated geese, which preferentially feed on quackgrass. Quackgrass is susceptible to pollen allelopathy from Timothy (Phleum pretense), which reduces seed production and over time can reduce local populations.

Decay: No information.

Mechanical

Tillage: Quackgrass is poorly controlled by mechanical means unless repeatedly cultivated or plowed each time it begins to re-grow. Often, fragmented rhizomes can worsen the infestation locally and can spread quackgrass to other fields with rhizomes stuck on equipment.

Rotary Hoeing: Not effective.

Flaming: No effective.

Cultural

Crop rotation: Highly competitive fall planted cover crops (e.g. hairy vetch) and spring planted cover crops that quickly accrue biomass (e.g. buckwheat) have been shown to drastically reduce quackgrass populations.

Planting date: Most likely will not affect quackgrass infestations.

Chemical

Application timing and effectiveness: Several herbicides are labeled for control of quackgrass. Herbicides that can be applied postemergence and that are systemic are the most effective. Please refer to E-434, "MSU Weed Control Guide for Field Crops," for herbicide recommendations.