This publication describes Quackgrass characteristics and identification information. Control methods such as intensive cultivation, special cropping, and chemical application recommendations are also included

Derscheid, Lyle A.

Wallace, Keith E.

Wallace, Wilford H.

English

Public Research Access Institutional Repository and Information Exchange

South Dakota State University Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange SDSU Extension Fact Sheets SDSU Extension 1961 Control and Elimination of Quackgrass Lyle A. Derscheid Keith E. Wallace Wilford H. Wallace Follow this and additional works at: https://openprairie.sdstate.edu/extension_fact Recommended Citation Derscheid, Lyle A.; Wallace, Keith E.; and Wallace, Wilford H., "Control and Elimination of Quackgrass" (1961). SDSU Extension Fact Sheets. 1428. https://openprairie.sdstate.edu/extension_fact/1428 This Fact Sheet is brought to you for free and open access by the SDSU Extension at Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. It has been accepted for inclusion in SDSU Extension Fact Sheets by an authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For more information, please contact michael.biondo@sdstate.edu. Historic, archived doculllent Do not assume content reflects current scientific knowledge, policies, or practices. SDSU ® Extension For current policies and practices, contact SDSU Extension Website: extension.sdstate.edu Phone: Email: 605-688-4 792 sdsu.extension@sdstate.edu SDSU Extension is an equal opportunity provider and employer in accordance with the nondiscrimination policies of South Dakota State University, the South Dakota Board of Regents and the United States Department of Agriculture. Quackgrass Quackgrass 1 is one of the most widely spread of the eight noxious weeds in South Dakota. It is particular-ly wide spread in northern counties, but is found in all parts of the state. It has been reported on over 150,000 acres of over 11,000 farms in South Dakota and the reports do not include some rangeland infestations. Quackgrass is a perennial grass that spreads by seeds and underground stems (rhizomes). It produces a great quantity of viable seed, which may retain its ability to germinate for at least 4 years in storage or in the soil. Quackgrass seeds cannot be removed from seed of many of our common grasses,especially brome-grass or wheatgrasses. If at all possible, sow only certi-fied grass seed. Seeds of other crops must be cleaned with extreme care. Screenings or forage infested with quackgrass seed often serve to spread the seed to new areas. Manure or mud on implement wheels or on the feet-of ... animals, and improper! y cleaned seeding or threshing equip-ment can also spread quackgrass seeds to a new loca-tion. The rhizomes spread laterally in the upper 3 to 6 inches of soil. They are capable of producing new plants at each node (joint) and may grow through the soil for considerable distances, producing new shoots at frequent intervals, eventually forming a dense sod. Pieces of rhizomes may be carried on the plow or other tillage implements such as the field cultivator, or in mud on implement wheels, and thus spread the weed to uninfested areas. Quackgrass is frequently confused with other grasses. Some ways of distinguishing it from several other grasses are summarized in table 1 and illustrated in figure 1. 1 Agropyron repens L. By Lyle A. Derscheid, Professor of Agronomy, Keith E .Wallace, Ex-tension Weed Specialist and Wilford H. Wallace, Instructor in Agronomy 1 r:, f C n l-0 m ::, -... 2-n 0 ::, f - ~ a. ~ a· •❖ s· a -s· . ::, 0 -INTENSIVE CULTIVATION Cultivation is used primarily for starving other weeds. However, for quackgrass, it may be used for starving the plant by reducing root reserves, drying the rhizomes and top growth so that they die, and oc-casionally, exposing rhizomes to freezing. Root reserves can be reduced throughout the grow-ing season, but dry weather (summer) is necessary for drying the rhizomes and cold weather (fall) is need-ed for freezing. Root reserves are depleted more rapid-ly if the weed is growing on fertile soil or has received an application of nitrogen. Likewise, heavy grazing for a year prior to cultivation will aid in eliminating the weed. Spring. Cultivation is aimed at reducing the root reserves. Cultivate it whenever leaves become 2-3 inches long ( about every 3 weeks). A sharp one-way disk operated at a depth of 2 or 3 inches is the preferred implement, On unplowed sod use it once lengthwise and once crosswise for the first operation. If a one-way is not available, plow shallowly and disk to cut up the sod. Use a disk harrow for later operations. A duckfoot field cultivator is a satisfactory implement when trash does not prevent its use, but it may carry rhizomes from one area to another. Summer. Every 3 weeks with a one-way disk or duckfoot cultivator to reduce root reserves has been quite successful. In dry seasons, a heavy duty spring-toothed field cultivator may be used to aid in reducing root reserves and to lift rhizomes to the surface of the soil where they will dry in 4 or 5 days of dry weather. Weekly cultivations with a spring-toothed harrow are needed to bring to the surface all the rhizome frag-ments that have been buried. Quackgrass fragments enclosed in clods, partially covered with soil, or anchored to the soil are not likely to be dried enough to be killed. Late fall. Cultivation will aid in the freezing of rhi-zomes when temperatures are below 20 degrees F. In order to freeze them it is essential to expose as many rhizomes as possible. The last cultivation should be a deep cultivation or plowing and leave the surface rough. It will aid in preventing erosion and may result in additional kill by freezing. An entire season of cultivation is generally re-quired to eliminate quackgrass. However, early spring cultivation followed by a crosscultivated crop of corn reduces the stand and holds the weed in check. Allow the quackgrass to start its growth and plow deeply. The plant is buried deeply. Reappearance is delayed and root reserves reduced because it must produce a long shoot to reach the surface. Either cultivate deeply before planting the crop or plant immediately after plowing. After-small-grain-harvest cultivation during late summer and fall reduces quackgrass stands, especially during dry years and when freezing has been effective. SPECIAL CROPPING The three cropping systems presented here have practical use in areas unsuited to long periods of inten-sive cultivation. Plan One. During the first year plant small grain underseeded with sweet clover. Plow under for green manure the following year. Plow 5 inches deep and cultivate extensively until fall. The third year, plant a row crop and do a thorough job of cultivating. Pick up stray plants. Plan Two. Plant small grain and seed it to sweet clover. The next year cut the clover for hay. Plow 5 inches deep immediately after cutting the hay. Follow an extensive cultivation program until Sept. 10-20, when rye should be seeded at 2 bushels per acre. The third year combine the rye crop and plow to a depth of 5 inches immediately after harvest. Cultivate extensively until fall. Finally plant to a row crop the fourth year and do a good job of cultivating. Clean up stray plants. Plan Three. This method is especially effective when the spring of the first year is dry. Cultivate ex-tensively the first year from the time the quackgrass reaches a height of 2 inches until June 15 or July 1. Drill in German millet, proso millet, or buckwheat where it is adapted. Cut the German millet for hay, but harvest the proso millet or buckwheat for seed. 2 In wet years, the buckwheat is the best known sum-mer crop for quackgrass control. Resume original cropping system the second year. Pick up stray plants. CULTIVATION, CROPS, CHEMICALS The following chemicals, all recommended for eliminating quackgrass, are expensive and prevent the use of treated land for a season. As a consequence, it is seldom practical ro-rely on chemicals alone for control-ling large infestations. Dalapon* is sold as a powder to be dissolved in water and applied as spray. It is more effective when used in conjunction with tillage operations than when used alone. You cannot expect to kill more than 90 or 95'% of the: weeds. Dalapon is more readily absorbed by plant tops than by roots. Early spring application of dalapon when little or no leaf growth is present will control but not eliminate quackgrass. Apply 4 pounds acid equivalent (5½ lbs. of 85% sodium salt) per acre in 10 to 20 gallons of water. This treatment can be made during late April or early May. Plow after a good rain has leached the chemical into the soil. Potatoes or sugar beets can be planted soon after plowing. However, residual effect of the chemical in the soil may injure corn or peas planted less than 4 weeks after the date of spraying. Planting of corn should be delayed 5 weeks under dry condi-tions and planting of all beans ~hould always be delay-ed 5 weeks or longer. Late spring application of dalapon when 4 to 8 inches of leaf growth is present is effective for elimi-nating 90 to 95% of the weeds. Apply 6 pounds acid equivalent (8 lbs. of 85% sodium salt) per acre. Plow 7 to 10 days later. Use a cultivated crop, smother crop or clean tillage to secure higher percentage kill of the quackgrass. However, planting of a crop must be de-layed several weeks as the residual effect of the chem-ical affects crops the same as when applied during early spring. Fall applications of dalapon are also effective. Mow and remove the current year's growth. When re-growth is 4 to 8 inches tall, spray with 10 pounds acid equivalent (12½ pounds of 85% sodium salt) of dala-pon per acre. Spray before frost has injured leaf growth. Plow 7 to 10 days later. This system should kill 90 to 95% of the weeds. Crops sown the following year are not affected. A single application of dalapon at the rate of 10 pounds per acre in early spring gives seasonal control for areas that cannot be cultivated. Retreatment will be necessary to achieve elimination. Two applications of 5 pounds per acre applied 6 weeks apart is equally effective on quackgrass and less injurious to trees. This treatment can be used safely under fruit trees that are old enough to bear fruit. TCA * is more effective when applied to rhizomes during the fall of the year. It is sold as a powder or granules to be dissolved in water and applied as a spray. It is absorbed by plant roots. It seldom kills more than 90-95% of the weeds. Plow shallowly to get a maximum number of rhizomes on the surface of the soil. Spray immediately with 20 pounds of TCA acid equivalent (25 pounds of 90% sodium salt) per acre. Residual effect may injure some crops seeded the next spring. Potatoes, flax, sugar beets, alfalfa, birdsfoot tre-foil, and oats are seldom injured; but corn, soybeans, and red dover may be severely injured. Barley and wheat are intermediate in sensitivity. On undisturbed sod use 100 pounds of TCA acid equivalent (125 pounds of 90% sodium salt) per acre ( ¾ lb. of sodium salt per square rod) during the late summer or early fall to get similar results. Atrazine and simazine* are formtJlated as wet-table powders to be applied as sprays or as granules to be applied dry. The granules have not been tested ex-tensively for use on quackgrass. Both chemicals are used in the same way. Apply 4 pounds of active ingredient (5 lbs. of 80% wettable powder) per acre during the fall. Plow the following spring and plant corn. Cultivate the corn if needed. Residual effect of simazine generally injures small grain seeded the year after corn, and atrazine frequently causes injury. Spring applications of either chemical are less satisfactory because they act too slow-ly. They do· not .kill the quackgrass until July whic-h is too late to help the corn crop. Little is known about the effectiveness of either chemical used in any other manner. However, ·it has been used at lower rates following treatment with amitrole. This system is discussed below. Amitrole* is a powder to be dissolved in water and applied as a spray. A mixture of amitrole and ammonium thiocyanate is a liquid sold under the trade name Amitrol-T. Both are effective for control -ling and eliminating quackgrass. They are handled much the same as dalapon, however, they seldom leave a residue in the soil that is injurious to a crop. •D alapon-2,2 dichl oropropi onic acid, TCA -trichl oroacetic acid; Atrazine--2-chl oro-4-eth ylamin o-6-isopropylamin o-s-triazine; Simazine-2- chloro-4,6-bis-(ethyl-amin o)- s-triazine ; Amitrole--3 -amin o-1,2,4 -triazole Summary of Vegetative Characters by Which Quackgrass Can Be Distingui.shed from Several Other Grasses Grass Growth Habit Quackgrass _________ sod-forming Bromegrass ___ _ sod-forming Western Wheatgrass _________________________  sod-forming Slender Wheatgrass ________ bunch-type Ryegrass __________ ____________ bunch-type •For location of these plant parts, see illustration. Leaf blade* flat, smooth hairy at base flat, smooth rolled, rigid, ro':_Igh upper surface; saw-toothed edges flat, smooth flat, smooth 3 Leaf sheath* hairy, split, over_lapping smooth, continuous smooth, split smooth, split smooth, split Rhizomes* Auricles* Ligule* white short, short clawlike tan generally large, none smooth tan long , minute, colored smooth none none minute, hairy none short very short, membranous Mature Quackgrass Quackgrass Brome grass I ~--I~;;?;:~ 3 --+...-~ 'f --o s Western Wheatgrass Slender Wheotgrass Perennial Ryegrass A mature quackgrass plant, with a young plant growing from the same rhizome. The detailed drawings of the young leaves of Quackgrass, Bromegrass, Western wheatgrass, Slender wheatgrass, and Perennial ryegrass show the difference in (1) base of the leaf blade, (2) ligule, (3) auricles, ( 4) leaf sheath, and (5) the cr.oss.+section of the leaf sheath. Apply amitrole at the rate of 4 pounds active ingredient (8 pounds of 50% material) per acre in 20 gallons of water dur-ing the spring when quack-grass is 4 to 8 inches tall. Plow 10 to 14 days later and plant a crop. Better control is obtained if the crop is seeded immedi-ately. A cultivated · crop, smother crop or clean tillage aids in eliminating the weed. "Amitrol-T" can be used in the same way at a rate of 2 pounds active ingredient (1 gallon) per acre. After quackgrass has been treated with amitrole and plowed, ah application of atra-zine or simazine kills annual weeds and weakened quack-grass sprouts. App 1 y 2½ pounds active ingredient (3¼ pounds 80% wettable powder) of either atrazine or simazine per acre when planting corn or immediate! y afterwards. Corn is the only crop that will not be damaged by these chemicals. COST OF CHEMICALS The cost of these chemicals varies somewhat from year to year. However, the approxi-mate cost of a pound of active ingredient is as follows : dala-pon-$1.60, TCA-55 cents, amitrole-$4.50, "Amitrole-T" -$5, simazine or atrazine sprays-$4, and simazine or atrazine granules-$4.45. Cost per acre will vary with the amount of chemical u s e d. Amount of chemical needed will depend on method used or time of application. ( Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the Cooperative Extension Service of the South Dakota ( State College of Agriculture and Mechanic Arts, Brookings, John T. Stone, Director, U.S. Department of Agriculture, cooperating. \ 5M-3-61-File: 15.122-8725 4 

Control and Elimination of Quackgrass

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Control and Elimination of Quackgrass

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