Quackgrass is a perennial, reproducing by seed and underground rootstocks. Rootstocks are pale yellow or straw colored, cord-like about 1/8 inch in diameter and vary from 2 to 18 inches in depth, depending on soil type and treatment. Roots arise only at the nodes. Stems grow up to 3 feet tall with 3 to 6 joints. Leaves are wide, shiny, and dark green in color. The lower dry sheaths, leaves, and stems are distinctly hairy. Upper sheaths glabrous or nearly so. Terminal spikes are 2 to 4 inches long and have 3 to 7 short-awned florets in a spikelet. The seed, with investing glumes, is elongated toward the slender, short-awned tip, broadest below the middle and tapered to the blunt base.
Prevention of Spread of Quackgrass
The occurrence of new infestations of quackgrass can be reduced by planting weed free seed, using livestock feed materials free of quackgrass seed and cleaning equipment before leaving infested fields. Particular attention should be given to grass seed or grass seed mixtures imported from the northern states.
Quackgrass Control Practices
Control of quackgrass shall mean preventing production of viable seed and destroying the plant's ability to reproduce by vegetative means.
Cultural Control Practices
Cultivation - Roots and rhizomes are killed by drying on the soil surface. Tillage with a heavy duty spring-tooth cultivator should be at a depth of 3 to 4 inches. The shovels of such an implement should be operated at a slightly lower depth for each successive cultivation. The first operation should be when growth starts in April. Succeeding cultivations should be made at intervals of about 1 week even though no growth of quackgrass is apparent.
Shallow cultivation or plowing in the late fall will expose rhizomes to freezing and drying during winter and reduces the stand and rapidity of spring growth. Intensive grazing before cultural operations are started is beneficial.
Competitive Crops - to be most effective, should be planted only after the quackgrass has been partially weakened by tillage. Closely drilled stands of sudan-grass or forage sorghum may be used. In gardens, a relatively close spacing of squash or pumpkins is effective.
Herbicides Approved for Controlling Quackgrass
The following herbicide may be used for cost-share with landowners. Other products labeled and registered for use on this noxious weed in Kansas may be used in accordance with the label directions but are not available for cost-share. Be sure to follow all label directions and precautions. For additional information consult the current KSU publication of AChemical Weed Control for Field Crops, Pastures, Rangeland, and Noncropland@.
- Glyphosate (Roundup). Application shall be made in the spring and fall when the plants are at least 8 inches in height. Follow label direction and precautions.
- Fluazifop-P-butyl (Fusilade). Follow label directions and precautions. ]
- Glyphosate + Diquat (QuikPro). Follow label directions and precautions.
- Nicosulfuron (Accent). Follow label directions and precautions.
- Nicosulfuron + Rimsulfuron (Steadfast). Follow label directions and precautions.
- Primisulfuron (Beacon). Apply when plants are between 4 and 8 inches tall. Follow label directons and precautions.
Biological Control Practices
There are no biological controls approved for use on quackgrass at this time.