Original source materials taken from USDA, Farmers’ Bulletin No. 1307, 1923 by L.W. Kephart, Associate Agronomist, Office of Forage Crops, Bureau of Plant Industry with judicious edits by SFJ. Please note that the base information herein reproduced was compiled a long time ago. Some of the conclusions herein drawn may legitimately be seen as contradictory; such is the case of many aspects of farming. It is up to the individual farmer to find applicable truth and balance. LRM
Quackgrass or witchgrass is a creeping perennial grass, related to common wheat, and one of the most widely distributed and destructive weeds in the North Temperate Zone. It is often confused with other grasses having similar names and habits, but can be distinguished by the seed heads, the leaves, and the long, running rootstocks.
Quackgrass can rarely be exterminated on large areas, but it can be brought under reasonable control. The best plan is to allow it to form a sod and then plow it in midsummer during dry hot weather. Attacking the weed in wet weather or in the spring when the rootstocks are growing vigorously is almost a waste of time. After plowing, the field should be harrowed frequently until winter and the following year planted with a cultivated crop. A smother crop may follow the cultivated crop. On small areas quackgrass can be eradicated by hand digging, smothering with tar paper, spraying with chemicals, or by other means.
Quackgrass makes good hay, pasturage, silage, and lawns and often can be utilized more economically than it can be destroyed.
Quackgrass, or witchgrass (also termed “couchgrass” and “wire-grass,” and having various other names), is a vigorous creeping perennial plant related to common wheat and widely distributed in cool, moist climates as a weed in cultivated ground. With the possible exception of the Canada thistle, quackgrass is the most notorious of all weeds and probably causes a greater monetary loss than any other single species of plant. Thousands of acres of the richest soils in the northern and eastern United States are so overrun with quackgrass as to be scarcely worth cultivating, while in several districts along the northern boundary entire farms have virtually been abandoned because the weed can not be controlled economically.
The weedy character of quackgrass is due to its remarkable system of creeping underground stems, or rootstocks, which spread through the soil in all directions, sprouting vigorously at the joints and resisting all but the most persistent efforts at extermination. Once well established in the field the weed is almost impossible to destroy, and it becomes more or less a permanent encumbrance on the land. Quackgrass is not entirely worthless, since it furnishes an acceptable quality of forage. The bad habits of the plant, however, outweigh its virtues.
DISTRIBUTION AND HISTORY
In America quackgrass occurs most abundantly in the region north of the Ohio and east of the Missouri River. (Fig. 1.)1 Within that area the weed is found in nearly every county, being in some localities the predominating plant. Quackgrass has been found by botanists in every State north of Florida and Arizona, but it rarely causes trouble as a weed south of the latitude of Washington and St. Louis. It occurs northward to the limits of cultivation, being common near Sitka, Alaska. During recent years quackgrass has been invading some of the valley lands and irrigated soils in the Pacific Northwest and in the region of San Francisco Bay, where it gives promise of being as troublesome as in the East. Quackgrass seldom thrives at altitudes greater than 2,000 feet, nor is it common in the semiarid regions of the Great Plains. In general, the distribution of quackgrass corresponds very closely to the regions where timothy and red clover are grown.
Quackgrass is probably a native of Europe, although its history in America is obscure. Some of the earliest explorers in New England reported the finding of fields of “wild wheat” on the shores of the St. Lawrence River and in the White Mountains. The grass which they observed, however, was probably sea lyme-grass. The first authentic record of quackgrass is that of the Rev. Jared Eliot, of Connecticut, a friend of Benjamin Franklin and one of the first reliable writers on American agriculture. Writing in 1751 he states that “Tillage will entirely destroy and extirpate all grasses and weeds; yea, even that stubborn grass called bluegrass (Dutch, wire, or couch grass) which is so hurtful to corn.” In 1813 the grass was definitely identified by the botanist Muhlenberg as occurring in New Jersey and New England.
Quackgrass first attracted serious attention about 1837, when it was noticed in gardens in the vicinity of Philadelphia. During the decade 1840-1850 the grass became generally distributed throughout the region east of the Allegheny Mountains, whence it was gradually carried westward by the emigrant settlers. By 1859 the weed had reached Kent County, Michigan, and it was just entering Iowa and Wisconsin in 1875. Minnesota was reached about 1890, but the spread of the grass through the Dakotas and other Western States is of comparatively recent date. At the present time the scene of the most active spread of quackgrass is in the prairie Provinces of western Canada.
In the Old World quackgrass has been a notorious pest as far back as there is definite record. In Lyte’s translation of Dodoens, written in 1578, there is found the quaint but significant passage that “Couche grass is a naughty and hurtful weed to corne” (grain). Subsequently, nearly every writer on European agriculture has paid his respects to couch-grass in no uncertain terms, and it remains today one of the two or three most troublesome weeds in Europe.
Quackgrass occurs in all the countries of western Europe, and in Russia south to the Caspian Sea. In Siberia a river and a town are said to have been named for the grass, although the plant is not known to be common in other parts of Asia. A form of quackgrass occurs in Algeria and Tunis, but not elsewhere in Africa. In the Southern Hemisphere quackgrass is found occasionally in Argentina, and it is a weed of some importance in parts of Australia.
HOW TO RECOGNIZE QUACKGRASS
One of the principal reasons for the wide distribution of quackgrass is the fact that it does not look like a weed. There are no bright, showy flowers, coarse, ugly leaves, or other features by which weeds are usually distinguished. To the casual observer the plant is simply a grass, and thus it works its way into the fields, becoming thoroughly established before it is recognized. It is more important, therefore, that the farmer should be able to identify quackgrass on sight.
In general appearance quackgrass resembles a thin-headed variety of wheat. The plant is, in fact, closely related to wheat, and as there are not many wild grasses which resemble that cereal, the occurrence of a wheatlike grass in the field should be regarded with suspicion. The grasses which might be confused most commonly with quackgrass on this account are western wheat-grass,2 slender wheat-grass,3 and wild rye4 in the Prairie and Rocky Mountain States and Italian rye-grass5 and perennial rye-grass6 in the Eastern States. None of these grasses is hard to destroy.
Positive identification of quackgrass can be secured by examining the seed heads, the leaves, and the rootstocks.
The seed head of quackgrass is a long, slender spike, about as long and half as wide as a head of wheat and with the seeds arranged flatwise to the stem rather than edgewise, as they are in the rye-grasses. (Fig. 2.) The heads may or may not bear short beards, and these, if present, break off at maturity. The seeds shatter easily when ripe, but usually remain enclosed in the hull, like small grains of oats.
The young leaf blade of quackgrass is likely to bear at the base, at the point where it joins the stem, a pair of small yellow claws, or horns, which project from the opposite edges of the leaf blade and nearly encircle the stem. (Fig. 3.) These claws are very characteristic of quackgrass and are not prominent in any other common grasses except barley, wheat, and a few of the rye-grasses. A ragged membranous fringe, called the ligule, connects the claws at their bases. In many grasses the ligule is smooth or is replaced by hairs. The leaf blade itself is about the size and shape of a leaf blade of timothy, but is somewhat rougher on the edges and upper side and is more ascending, so that a patch of quackgrass has a distinctly bristly appearance. As in the case of rye, the quackgrass leaf often bears a curious slight constriction near the tip, as if the cord had been tied around the leaf and sharply pulled. (Fig. 4.) The portion of the leaf which encloses the stem has a tendency to be hairy when young and may be either split lengthwise or formed in a solid tube. The leaf blade is rolled, not folded, in the bud.
The color of quackgrass leaves varies. In the Western and Southern States the plants are often covered with a whitish bloom, which gives the leaves a bluish aspect. In the Eastern States the leaves are usually a rich dark green, readily distinguishable from the paler greens of timothy and wheat.
By far the most important characteristic of quackgrass is the elaborate system of creeping underground stems or rootstocks, commonly miscalled “roots.” (Fig. 5.) Very few grasses common in the Northern States are equipped with such extensive underground organs, and the finding of them beneath a stand of grass constitutes an almost positive clue to the nature of the species. In the Eastern and Central States the only other important rootstock grasses are the Kentucky and Canada bluegrasses,7 redtop,8 and nimble Will.9 In the West and Northwest brome-grass,10 bluejoint,11 and western wheat-grass and in the South Johnson grass12 and Bermuda grass13 possess rootstocks. In none of these except western wheat-grass does the seed head at all resemble that of quackgrass.
The quackgrass rootstocks are long, slender, cordlike, yellowish white structures, about one-eighth of an inch in diameter, smooth, bare, and hollow except at the joints, where they are solid and closely covered with scaly rudimentary leaves. Branches are produced freely by the rootstocks, one at nearly every joint, and they in turn may become branched or push to the surface to form leafy shoots. If the rootstocks are broken, branches may arise from any joint along their length. Ordinarily, most of the branches form near the tips. When a rootstock strikes an obstruction it often breaks up into a snarl of twisted branches. If not obstructed it may grow straight through the soil for a foot or more without branching. A collection of rootstocks usually is tough, tangled mass of stems very difficult to separate. When fresh, the root-stocks are firm, juicy, and tough, except at the joints, where they break with a clean fracture. As they dry, the rootstocks become brittle and are easily broken. The tip of each rootstock is armed with a sharp, hard point, which can penetrate the hardest soil or even a piece of soft wood or a potato.
The rootstocks have little to do with the absorption of food material and moisture from the soil, but serve as a means of spreading and as storehouses of food material. The true roots of quackgrass are mere fibers arising from the joints at the bases of the stems and on the rootstocks.
COMMON NAMES OF QUACKGRASS
The spread of quackgrass has been greatly aided by the lack of any single commonly accepted name and by the fact that the names that have been applied have also been used indiscriminately for almost any troublesome grass with running roots. The confusion of names has made it difficult to focus attention on the plant and has hindered concerted efforts to focus attention on the plant and has hindered concerted efforts at eradication. More than a hundred different names are known to have been in more or less general use, most of them variations of an old Anglo-Saxon word “cwice” or “quis,” meaning lively or vivacious. Typical derivations of this word appear in the common forms quitch, witch, quick, queck, quack, crack, crouch, couch, scutch, and Scotch. In addition, such names as dog, drag, Durfee’s, Chandler’s and English have had a local vogue.
At present quackgrass or some closely similar word is supplanting other terms in English and German speaking countries, although witchgrass is still popular in New England and couch-grass in some of the British possessions.
HOW QUACKGRASS IS INJURIOUS
DAMAGE TO CROPS
Quackgrass is an injurious weed only in plowed ground. In grasslands or roadsides and in waste places it is harmless except as a source of infestation and may even be beneficial for the herbage which it adds to meadows and pastures.
The chief sufferers from quackgrass are the small-grain crops, potatoes, beans, and farm gardens. Spring grain is more likely to be injured than winter grain, partly because it starts growth at the same time as quackgrass, and partly because it is often planted hurriedly in the spring on poorly prepared ground. The yield of spring oats and spring wheat is often reduced 40 to 50 percent by quackgrass; barley suffers somewhat less, while rye and winter wheat are injured only occasionally. Fields of potatoes and beans are often veritable meadows of quackgrass in the fall, because the spreading habit of these crops makes it hard to keep the grass out of the rows late in the season. Quackgrass which grows up in cornfields late in the summer does not appear to reduce the yield materially either of grain or stover.
Quackgrass is often troublesome in orchards and vineyards; however, it does not seem to injure the trees and vines more than any other grass. Strawberry patches and asparagus beds are almost totally destroyed if quackgrass gets into them, as there is no way of killing the grass without killing the crop. Home gardens are among the worst sufferers from quackgrass. Large market gardens are not bothered excessively, owing to the more frequent and careful cultivations which they receive. Crops like buckwheat, hemp, millet, sweet clover, fodder, corn, sorghum, vetch, and rape, which make a quick and heavy growth, are often not injured by quackgrass and may even be of service in eradicating the weed.
Besides reducing the yields of crops, quackgrass injures their quality. In some sections potatoes and other root crops are so frequently malformed by the sharp-pointed quackgrass rootstocks as to lower their grade on the market. Most of the larger field seeds, such as the grains and the larger grass seeds, are made almost unsalable if they contain quackgrass seeds in quantity. Notable examples of this are brome-grass and the wheatgrasses, the culture of which in the Western States has been seriously curtailed through fear of introducing quackgrass.
In common with many other grasses quackgrass is an active agent in spreading the red rust of wheat. It is also a frequent carrier of the poisonous fungus known as ergot and acts as a harbor during winter for the Hessian fly and other injurious insects.
Although the damage to crops is the most obvious injury caused by quackgrass, by far the most serious charge against the weed is the labor cost of keeping it under control. There is no way of estimating the amount of money spent each year in combating quackgrass, but the total without question is huge. Carefully kept accounts indicate that the cost of growing potatoes and beans is increased 15 to 40 percent if quackgrass is present in the field. Similar figures probably apply to other cultivated crops. Although the labor factor is commonly overlooked, in reality it is the most convincing argument against allowing quackgrass to remain on a farm.
HABITS OF QUACK GRASS
LENGTH OF LIFE
Quackgrass usually can not be made to disappear merely by leaving it alone. Although the individual rootstocks rarely live more than 15 months the formation of new rootstocks is such a continuous process that the plant can live indefinitely, even though no seeds are formed. Instances are not rare in which old grasslands that had not produced quackgrass seeds in more than 20 years gave rise to vigorous patches of the weed when the sod was plowed and the rootstocks broken up.
CLIMATE AND SOIL PREFERENCES
Quackgrass makes its most luxurious growth in cool, moist climates and in rich soils. It grows but weakly in regions of long, hot summers, although it is able to withstand short periods of very dry weather better than most grasses. It thrives as far north as the limits of cultivation and practically never winterkills. Quackgrass is one of the first plants to start growth in the spring and one of the last to stay green in the fall. In the latitude of the Corn Belt it is earlier than any other grass except rye-grass and orchard-grass, often having shoots 2 inches long before winter wheat resumes growth.
Quackgrass grows equally well in sandy, clayey, or gravelly soils, the extent of growth depending entirely upon the supply of water and plant food. It never occurs in swampy places or on muck soils or peat, and, conversely, seldom is troublesome on dry hillsides or other poor, hard soils devoid of organic matter. That the plant can withstand the presence of fairly large quantities of salt in the soil is shown by its occurrence on irrigated alkali ground in the West and its presence on the New England seacoast, where it grows right down to the water’s edge. Experiments with chemical weed killers have shown that quackgrass survives an application of 20 tons or more of dry salt to the acre.
Compared with other weeds quackgrass is a poor seeder. An average head contains about 25 viable seeds, and as a rule the seed heads are not so numerous as those in a good stand of wheat. In a test at Lansing, Michigan, in 1916, the yield of quackgrass seed was found to be at the rate of about 18 bushels per acre. As the unhulled seeds are about the size of small oats this can not be considered a heavy production.
The production of seed depends somewhat upon the ease with which the plant spreads underground. When the rootstocks are free to develop rapidly, as in loose cultivated soil, the plant produces but little seed. When the rootstocks are closely crowded, as in grasslands, the seed heads are abundant. Similarly, more seed is produced on poor soil than on good soil, and more in dry seasons than in seasons of plentiful rainfall.
Like those of many other grasses the seeds of quackgrass are short lived and do not germinate well. When kept in open containers, such as grain bins, or sacks, most of the seeds lose their power to germinate in about four years. An occasional seed, however, retains its vitality for a much longer period. Hence, hay, grain, or other materials which are known to contain quackgrass seeds should be used with caution. When buried in the soil all quackgrass seeds within the upper 3 inches either germinate or die within two years. Those buried at a greater depth may persist for five years or more and grow when brought to the surface. Seeds which find their way into the silo usually have lost their power to germinate by the time the silage is removed. In manure the seeds retain their vitality for one to six months, depending upon the degree of heat and moisture in the pile. Very dry trashy manure which has not heated is dangerous to spread upon the land until it is more than a year old. In wet, heavy manure the seeds usually decompose in from six to eight weeks. The decay of the seeds can be hastened by turning the pile inside out about once a month, as the seeds in the center decay more rapidly than those on the outside.
Fresh seeds of quackgrass seldom show a germination of more than 50 percent. Germination increases slightly with age and may reach 70 percent by the time the seeds are 6 months old. One cause of the low germination is the presence on the seeds of a species of rust, which frequently attacks the plant very abundantly in the fall. Quack grass is often so badly rusted, especially in the Northern Central States that only four or five viable seeds are to be found in each head.
In common with many weed seeds the seeds of quackgrass have the very dangerous characteristic of being able to germinate before they are fully ripe. Experiments conducted at the Minnesota Agricultural Experiment Station have shown that some of the quackgrass seeds are able to grow before the plant is fairly out of blossom. Germination of over 30 percent was obtained from seeds gathered in the hard-dough stage, which occurs about two weeks before the seeds usually are considered ripe. Any crop that is harvested after July 1 in the southern part of the quackgrass region or after July 15 in the northern part, therefore, is likely to carry viable seeds of the weed.
While quackgrass seeds germinate most abundantly in early spring and in early fall, they may germinate at any time during the growing season, provided there is sufficient moisture in the soil. Plants which grow from seed in the fall usually produce seed the next year, but spring seedlings seldom bear seeds until the second summer.
The first rootstocks do not appear on the quackgrass seedlings until the second or third month, or when the leaves are about 6 inches long. (Fig. 6.) Until that time quackgrass seedlings are hardly distinguishable from other grass seedlings and are easily destroyed by cultivation. When the rootstocks begin to form, however, they multiply rapidly and send up leafy shoots in profusion. A single quackgrass seedling in the course of a season gives rise to a patch of grass a foot or more in diameter. If not destroyed, such a patch widens in all directions at the rate of a foot or more a year. Most of the rootstocks are crowded in the upper 8 or 10 inches of the soil, and very few are found lower than a foot below the surface. The extent of the rootstock system of a single plant often exceeds the combined lengths of the above-ground stems. Individual plants which had been carefully dug up contained nearly 50 feet of “root” system, having 40 or more seed-bearing stems and over 200 leaves. Not infrequently an entire patch of quackgrass measuring several feet in diameter iS connected by the same set of rootstocks and is a single plant.
It is commonly believed that quackgrass has been widely distributed by means of dried pieces of rootstock carried in hay, straw, packing material, the roots of nursery material, in shipments of potatoes, and in similar ways. The danger from this type of infestation appears to depend somewhat on the rapidity with which the rootstocks are dried. The tops of some quackgrass kept in the greenhouse for four months without water died and the soil became very dry. When the soil was watered at the end of four months the grass began to grow as vigorously as ever. On the other hand, some bare fresh rootstocks which were exposed to the direct rays of the July sun for eight hours ceased to grow, even when artificially forced. It should be remembered, however, that in the field the rootstocks seldom become thoroughly dry, because of the rootlets and particles of soil which adhere to them.
By far the most important habit of quackgrass is its tendency to become root-bound when allowed to grow without molestation. In an old pasture or meadow the rootstocks usually are massed in a thin layer just beneath the surface, while in a cultivated field they are scattered through the soil to a depth of 8 or 10 inches. This fact is of the utmost importance in attempting to control this weed and is the weakest known point in the life history of the plant.
There is no quick and easy method of controlling quackgrass, nor is there any one system that is satisfactory under all circumstances. Weather conditions, the kinds of crops grown, the supply of labor, and many other factors influence the choice of method, and these conditions vary widely in different localities and even on the same farm in different years.
Experience has shown, however, that certain phases of quackgrass control are quite constant and dependable, and these may be accepted as principles upon which the practice of control should be based.
Quackgrass control depends more than anything else upon the character of the season. Fair weather is absolutely essential. Unless the season is reasonably dry and warm little headway can be made. Indeed, cultivation in wet weather is decidedly worse than useless and should be avoided under all circumstances, as the weed not only is not harmed but is actually encouraged to spread. Wet weather, of course, can not be foretold, and it often happens that rainy weather sets in after a campaign of eradication is well under way. Under such circumstances the only thing to do is to accept the situation philosophically, abandon the work temporarily, and await a more favorable season.
Excessively dry weather is sometimes as bad as wet weather. During long rainless periods the rootstocks dry out slowly and become dormant. The leaves cease to grow, and in that condition the plants are not injured by harrowing or cultivating.
In general, the ideal weather for killing quackgrass is hot days and cool nights with just enough moisture in the soil to keep the grass growing.
TIME OF YEAR
The best time to attack quackgrass is in midsummer, just as the plants are forming seeds. Not only is there greater likelihood of favorable weather at that time, but the rootstocks are then at their point of lowest vitality. In the spring and fall the plants make heavy vegetative growth and store large quantities of reserve food material in the rootstocks. In midsummer vegetative growth is less active and the plants make a supreme effort to produce seed, the formation of new rootstocks practically ceasing and the old ones being drawn upon heavily for their reserve food material. In this weakened condition the rootstocks are less able to withstand attack and are much more easily killed than at other times of the year. In experiments at the Arlington Experiment Farm, near Washington, D.C., the weight of the rootstocks beneath an average stand of quackgrass was found to be at the rate of about 5,500 pounds per acre in April, 3,500 pounds in August, and 5,300 pounds in November, with a corresponding decrease in the content of starchy food material in midsummer. Other experiments showed that four cultivations begun in July were as effective in destroying quackgrass as six to eight cultivations begun in April. A further advantage of beginning in July is that the work is more likely to be done carefully in midsummer because other farm work is less pressing.
SIZE OF AREA
On large tracts of land that are thoroughly infested quackgrass can rarely be completely exterminated. Even with the most careful culture a few rootstocks are certain to persist and these are enough to re-infest the area. The best that can ordinarily be expected is to bring the weed under reasonable control and by the use of a proper system keep it within such bounds that cultivated crops can be grown for four or five years at a time without undue interference. If one will reconcile himself to this fact and be content to control the weed rather than to eradicate it the problem will seem much less irksome.
On small areas quackgrass can and should be absolutely destroyed. Success on small areas depends entirely on the amount of time and effort one is willing to spend on the work.
PLOWED AND UNPLOWED LAND
The tendency of quackgrass to become root-bound has already been noted. Because of this tendency quackgrass is far easier to control in grassland than in land that has been in cultivated crops.
The difference between plowed and unplowed land and the effect of different methods of plowing on quackgrass are illustrated in the accompanying diagrams.
Figure 7 represents the cross section of a field that has been plowed and cultivated in the ordinary manner. In this field the quackgrass rootstocks are scattered through the soil to the depth of the furrow slice. When such a field is plowed, as at the right of the diagram, the rootstocks are simply mixed more thoroughly into the soil and the field is in no better condition than before.
Figure 8 represents a similar field that has been left in grass for a year or so. Here the rootstocks have become massed in a shallow layer just beneath the surface. The field, however, was plowed at the regular depth, thereby redistributing the rootstocks through the soil and putting the weed back in its original conditions.
In Figure 9 is illustrated a system of controlling quackgrass that is effective and was formerly quite popular. In this system the field is in grass and two plows are used. The first plow goes only 4 inches deep and throws the mass of rootstocks into the bottom of a deep furrow alongside. The second plow follows immediately behind the first in the same furrow, plowing an additional 8 inches and throwing the soil on top of the rootstocks just turned. In this way the rootstocks are buried under 8 to 12 inches of soil and are nearly all killed at one operation. When this type of plowing is carefully followed the results are very satisfactory. The work requires skillful plowmen and special types of plows, however, and the soil must be deep and easily turned. Only rarely is it worth the extra trouble.
The best method of plowing quackgrass land is that shown in Figure 10. Here the field has been in grass, but instead of plowing deep the sod has been turned very shallow and the rootstocks left in a compact mass near the surface, where they can be readily stirred by the harrow and dried.
Cultivation of a crop like corn or potatoes, in the manner in which that operation is usually performed, is almost entirely worthless as a means of destroying quackgrass. On the contrary, it is one of the most effective means of spreading the weed over a farm. Instead of harming the grass the teeth of the implement tear out the rootstocks, break them in pieces, and drag them down the row, setting up a new area of infestation wherever a piece is dropped. The cultivator and the harrow are among the most efficient distributors of quackgrass on the farm, and if carelessly handled may do more harm in a single hour than can be overcome in several years.
To be effective against quackgrass, cultivation and harrowing must be thorough, frequent, and persistent. Half-way cultivation is worse than none. The weed thrives on an occasional stirring, and if it is to be destroyed must be cultivated so often that it does not have a chance to become rooted. There is scarcely a better way to make two blades of grass grow in place of one than to cultivate a patch of quackgrass at long intervals.
A USEFUL ROTATION
Based on the general principles already mentioned, the following system of cropping is suggested as a means of holding quackgrass in check on large areas. Such a system can seldom be followed exactly, but on most farms it can be modified to meet local conditions and will serve as a basis on which to work:
- Seed the land to grass, pasturing closely or cutting for hay.
- As soon as the grass is sod-bound, plow shallow in July immediately after haying.
- Harrow until frost as often as new leaves appear.
- In the spring plant a cultivated crop.
- The following year, if the grass is still abundant, sow a thick smother crop.
SEEDING TO GRASS
The object of seeding to grass is to obtain a tight, thin sod with the rootstocks matted near the surface. If possible, the field should be used for pasture, as this makes the most compact sod. In heavy clay soil that is closely pastured, the grass will become densely sodded within a year or 18 months. In sandy soils from two to four years are required. Hayfields require about a year longer than pasture fields to become well root-bound. For grazing purposes horses and sheep are better than cattle, as they bite more closely and trample the ground more. When the infested land is being used for a garden, the garden often can be located elsewhere for a time and the space used for a poultry yard or converted into a temporary lawn.
When the rootstocks have been brought near the surface, plow in midsummer at the time when the quackgrass normally would be in full bloom. This occurs in most parts of the northern United States between June 20 and July 10, although blossoming may be delayed if the season is dry. Plowing should be only as deep as is necessary to get under the lowest live rootstocks. In an old pasture 3 inches is sufficient; in a meadow from 3 to 6 inches. In cultivated land it sometimes is unnecessary to plow to a depth of more than 4 inches, as the old rootstocks at the lowest depths are often so exhausted that they are not dangerous. Turn the furrow flat and cover all the leaves completely, being particularly careful to plow out the back furrows.
Plowing to a depth of only 3 or 4 inches with the ordinary stubble plow found on most farms is somewhat difficult, although it can be done with a steady team. When large areas are to be plowed it usually pays to obtain a special sod plow designed to turn a thin flat furrow. The so-called prairie breaker (Fig. 11) is excellent for this purpose, although somewhat heavier than necessary. A type of plow known by some manufacturers as the Scotch bottom or clipper bottom also does good work and can be used for general plowing as well. Some so-called Scotch bottom plows, however, are especially designed to turn the furrows on edge, which, if course, is not the result desired in this case. If the sod is hard and tough a rolling colter, a fin colter, or the new combined colter and jointer helps to cut the rootstocks. When plowing a meadow which for any reason has not been mowed it will be necessary to attach a light chain or a No. 9 wire from the clevis to the handle near the end of the moldboard in order to turn the tops under the shallow furrow.
After plowing let the field alone for a week or 10 days or until the grass has begun to send up new leaves. This helps to exhaust the rootstocks. When the new leaves have reached a length of about an inch harrow the field crosswise with a spring-tooth harrow, to tear the chunks of rootstocks apart and to shake off the soil. Repeat this operation as often as the quackgrass leaves become an inch long. In seasons of normal rainfall four or five harrowings before frost will be enough, although the number may run as high as eight or ten if the rowing conditions are especially favorable.
The best all-round harrow for subduing quackgrass is the spring-tooth type, although there are a number of special quackgrass harrows that do excellent work. The disk harrow, either plain or cutaway, is a good tool, provided the work is well done. The disks cut the rootstocks into small pieces, however, instead of dragging them out as does the spring-tooth harrow, and these small pieces are likely to take root again if the field is not harrowed frequently. The spike-tooth harrow and the duck-foot types are useful in soils that are not loose or stony.
Always choose a hot, dry day on which to harrow and try to stir and turn the rootstocks to aid in drying them. Often the dry rootstocks can be raked into piles with the harrow or a hayrake, after which they should be carted away and burned.
In the fall, if the rootstocks are not well loosened from the ground, plowing should be repeated. Allow the field to remain rough over winter, to expose the rootstocks to the frost. If there is danger of soil washing, sow a bushel of rye to the acre as a cover crop.
In the spring, as soon as the weather permits, loosen the rootstocks from the soil with the harrow. Do not plow unless the ground is very hard or the grass firmly rooted. Lack of plowing will not injure most crops. Plant a cultivated crop that is easily kept clean, corn in checkrows usually being the most convenient. Sugar beets are also excellent, as they require close cultivation and can be kept clean in the rows. In some sections soy beans in rows for seed have proved very satisfactory. Potatoes, tomatoes, cannery peas, and bushy types of field beans are to be avoided, as it is practically impossible to keep the weed out of the rows of these crops during the latter part of the season. Tobacco is unsatisfactory, because it is too easily injured.
Of the many types the disk cultivator is one of the best for subduing quackgrass. If the ground is not stony the disks cut the grass off cleanly, do not clog, and are easily handled. The disks must be kept sharp, which is sometimes difficult in sandy soil. In gravelly and stony soils there is nothing better than the ordinary five-shovel or six-shovel corn cultivator, although the spike-tooth or harrow-tooth cultivator, where it can be used, tears out more of the grass. Cultivators of the scraping or knifeblade type, as well as duck-foot implements, are excellent when sharp but are quickly dulled, in which condition they tend to jump and slide over the weed and to push it ahead instead of cutting it.
A smother crop is any crop that makes a heavy, dense growth and kills the weeds by crowding and shading. In very rich soils the smother crop can sometimes be used in place of the cultivated crop the first year after the ground is plowed. Ordinarily, however, the smother crop must follow the cultivated crop, as otherwise it can not be depended upon to make a sufficiently heavy growth to kill quackgrass. Its purpose is to clean up the stray plants that escape the cultivator. Since a smother crop must make a dense growth to be of any service, it usually pays to fertilize this crop heavily with manure or commercial fertilizer.
Almost any crop that produces a rank growth can be used for smothering. Corn in thick rows for fodder is perhaps the most generally useful. It should be planted with a drill in rows 2 feet apart, using not less than 2 bushels of seed to the acre. If the corn makes a sufficient growth to smother the quackgrass it will not need cultivating after the first two weeks.
Buckwheat has quite a reputation as a destroyer of quackgrass. (Fig. 12.) The particular advantage of buckwheat is that it need not be planted until the end of June, thus allowing time for the cultivation of the ground during the spring. This fact is a disadvantage, however, if the cultivation is neglected. Buckwheat must be planted on well-prepared ground and should be seeded at the rate of at least 5 pecks to the acre.
Hemp is an excellent smother crop in regions suited to its growth. Under present conditions it is not a profitable crop unless there are local milling facilities for preparing the fiber. Still, for killing weeds on a small scale, it may be found more generally useful. According to the Wisconsin College of Agriculture, hemp is the best crop for smothering weeds in that State; yet soil infested with quackgrass must first be prepared properly in order to destroy the mat of weed roots and thus give the hemp a chance. A good method is to plow such soil in late summer or early fall, and work it thoroughly with a spring-tooth harrow until freezing weather. All loosened roots should be raked together and burned. If the land is not fertile, it should be given a heavy application of manure in the fall. Beginning in early spring, thorough working of the soil should be continued until the date of seeding the hemp. If the weeds are thoroughly subdued and kept under control until the hemp is planted, good results will be obtained; otherwise the weeds are likely to choke out the hemp.
Rape, especially the Dwarf Essex variety, is a good smother crop if planted in thick rows on rich soil. It has been especially recommended for controlling quackgrass in parts of Canada. As the crop is usually grown in this country, however, it does not make a growth heavy enough to have much effect on the weed.
Spring barley, following a season of clean cultivation, has been used with very good results in some of the Western States. Barley is more leafy than the other small grains and is well able to hold its own against quackgrass.
Peas or vetch with oats which have been used with success in the cool portions of the more northern States, especially in the Pacific Northwest, are useful only on rich soils well supplied with moisture.
Golden millet, also known as German millet, has long been known as a good smother crop, but this reputation is scarcely observed as far as quackgrass is concerned. It grows but little taller than quackgrass, and if the soil is sufficiently rich to make a large growth of millet the quackgrass is encouraged also.
Recently sunflowers have attracted attention as a smother crop for quackgrass and are reported to have been very satisfactory in northern Michigan and South Dakota. They must be planted thick and should be given a good application of fertilizer to start them rapidly.
In the region south of the latitude of Chicago, Red Amber sorghum is a good smother crop. It should be planted in 14-inch rows with a grain drill and allowed to mature for seed.
Sweet clover has sometimes been known to smother quackgrass and where it makes a rank growth may destroy the weed. The plants must be thick on the ground, however, and must attain a height of not less than 6 feet. Unless the soil is very rich the sweet clover and quackgrass are likely to grow excellently together, making a good forage combination, but not eradicating the weed pest.
MISCELLANEOUS METHODS OF CONTROL
Usually the most convenient way to destroy a small area of quackgrass is to dig it out by hand. The work must be done thoroughly, however, for any small piece of rootstock left in the soil may renew the weed. Simply cutting off the leaves of the grass and digging out as many of the rootstocks as can be reached conveniently with a hoe is not enough. The entire area must be carefully dug over to the depth of the lowest rootstock and each piece removed by hand or by sifting. A convenient way is to throw all the soil into a pile outside the area, throwing it back again as the rootstocks are removed. The treated area should extend at least a foot beyond the borders of the quackgrass in order to get all the rootstocks. The best season for digging is from June 15 to July 15.
SMOTHERING WITH TAR PAPER AND OTHER MATERIALS
A less laborious but slower method of destroying small patches is to cover them from May until September with tar paper, straw, manure, old tin roofing, boards, or any other material that will totally exclude the light. The tar paper should be of a heavy grade and laid so as to overlap about 3 inches, and the laps should be weighted with earth to make a tight joint and prevent the paper from blowing away. (Fig. 13.) Straw must be pulled 3 feet thick and manure at least 1 foot to keep the grass from growing through. All coverings should extend 2 feet or more beyond the limits of the patch.
CHEMICAL WEED KILLERS
The only way to destroy quackgrass with chemicals is to soak the ground with some powerful plant poison; hence the process is practicable only on a small scale. Likewise, there is no way to kill quackgrass with chemicals without killing all other vegetation. The method is chiefly useful for keeping the grass down around fences, foundation walls, yards, gutters, and other places where no vegetation is desired. Sometimes quackgrass can be prevented from spreading to un-infested areas by enclosing the patch with a narrow strip of ground soaked with a weed killer.
PASTURING WITH HOGS
As hogs are very fond of fresh quackgrass rootstocks, they are often turned into a field that is being plowed. It is possible to reduce quackgrass greatly with hogs by withholding other feed and giving the animals plenty of water and shade. The hogs can not be expected to gain while on quackgrass pasture, but this loss may be offset by the destruction of the weed. Hogs which are strong rooters, such as Tamworths, are best, and their noses, of course, should not be ringed. Six hogs will remove a large percentage of rootstocks from an acre in one month. Sheep will also pick up many quackgrass rootstocks.
PRECAUTIONS NECESSARY TO KEEP QUACKGRASS OFF THE FARM
Prevention is always better than cure. While it is not always possible to keep quackgrass from the farm there are certain precautions that should never be overlooked.
USE GOOD SEED
Quackgrass is most commonly brought on the farm in grass and grain seed. Oats, barley, brome-grass, and slender wheat-grass are the most usual carriers of the weed, although wheat and rye, if not well cleaned, may bring it. In wheat and rye the quackgrass seed is likely to be hulled, in which condition it closely resembles the rye. European brome-grass seed has been an especially prominent carrier of quackgrass seed in the Northwestern States. American-grown seed, however, is not always free from the weed. The smaller field seeds, such as timothy and the clovers, if properly cleaned, rarely contain quackgrass seed.
BE CAREFUL ABOUT HAY AND STRAW
Any hay or straw harvested after July 1 is likely to carry quackgrass seeds as well as pieces of the rootstocks picked up in raking. The rootstocks are not dangerous if thoroughly dried, but some at the bottom of the stack usually remain moist. Very frequently the appearance of quackgrass around an old straw pile is traceable to the thrashing machine, which brought in the weed seeds hidden in crevices under the shakers and in the tailings spout. Hay balers are also frequent offenders in this respect. Do not hesitate to clean these machines thoroughly with a broom before they are permitted to drive on the farm. Any local law on the subject should be enforced.
DO NOT SPREAD INFESTED MANURE ON GRASSLAND
Manure that is thought to contain quackgrass seeds should be piled until well rotted of spread on land that is to be cultivated within three weeks. The young seedlings do not develop rootstocks until they are 4 or 5 weeks old, and can be destroyed as easily as other seedlings before that time. Infested manure should never be used for top-dressing pastures or meadows, as there is no way to kill the young seedlings without destroying the pasture or meadow. Quackgrass seeds usually get into manure through the bedding, although they may come from the hay or grain fed to horses, as the seeds are not always killed by the process of digestion.
DESTROY THE FIRST SMALL PATCHES
When quackgrass first appears on a farm it should be totally exterminated regardless of trouble or expense. Cost is no consideration in destroying a small patch of the weed. The area should be marked with stakes and the weed destroyed utterly. Repeated digging and removal of the rootstocks is satisfactory, but covering the patches with tar paper is more certain. The particular method is of little consequence; the object is to kill the weed before it can gather headway.
WATCH THE HARROW AND CULTIVATOR
Careful cultivation is most important. If necessary to cultivate through a patch of quackgrass, lift the implement when crossing it, or at least clean the teeth thoroughly after passing. A few minutes spent at this point may mean the eventual saving of hours.
COLLECT AND BURN THE ROOTSTOCKS
When piles of rootstocks have been collected in the field by the harrow or cultivator, cart them to some out-of-the-way place and burn them. The temptation is to dump them in the road or along the streams or fence. From such places they are easily carried to adjoining land and may cause much ill feeling in the neighborhood.
DO NOT LET QUACKGRASS GO TO SEED
The wisdom of preventing quackgrass from going to seed by cutting it when in full bloom seems too obvious to need discussion. Unfortunately, the blooming period comes just when other farm work is very pressing and few farmers care to take the time to cut weeds. Because of the serious nature of quackgrass, it pays to cut it when necessary, even if other work must be neglected for a few hours. As quackgrass seeds can grow before they are fully ripe, the weed should be cut before the seeds are hard.
UTILIZATION OF QUACKGRASS
Although quackgrass is known chiefly for its bad habits as a weed it is by no means entirely worthless. When cut early it makes hay equal to timothy and is perhaps a better hot-weather pasture plant than any other crop except sweet clover. In several other ways quackgrass has been found useful, and its utilization should not be despised or neglected simply because the plant is a weed.
It is not necessary, of course, that quackgrass be planted purposely or that it be used in any way that could possibly cause harm. Several cases are known where the grass has been introduced into new territory as a promising forage crop, with results disastrous to the neighborhood. Planting quackgrass, for forage purposes at least, is entirely unnecessary, as there are always other plants that answer the purpose quite as well and are much less difficult to control. Similarly, the practice of selling quackgrass hay should be strongly condemned, as the hay is almost certain to contain viable seeds.
Where quackgrass already occurs in abundance, however, and there is little possibility of it injuring other persons, there is no reason why it should not be used; indeed, there are many times when it would be more profitable to utilize the plant than to try to keep it under control. Consequently, before undertaking an expensive program of eradication, weigh carefully the value of the cultivated crop that might be raised, the cost of raising it, and the value of the quackgrass hay and pasturage.
USE AS HAY
Most weedy grasses are tough, unpalatable, or otherwise undesirable for forage. Quackgrass possesses nearly all of the qualities desired in a hay plant, being palatable, nutritious, prolific, hardy, leafy, easily harvested, and adapted to wide variations of soil and climate. Were it not for the difficulty of controlling the grass in rotation areas, it might well have become one of the standard forage grasses of North America. (Fig. 14.)
In appearance and feeding value quackgrass hay closely resembles ordinary timothy hay. The stems of quack grass are somewhat stiffer and coarser than timothy, the color is paler, and the leaves are rougher, but the differences are not so pronounced that the two can be readily distinguished in a mixed lot. Cattle, horses, and sheep will eat a mixture of quackgrass and other grasses without showing any preference, but all animals will reject the grass if it is cut so late that the dried stems are hard and tough.
The chemical analyses of quackgrass as compared with that of the standard hay grasses are presented in Table 1.
Quackgrass should be harvested for hay not later than the early blossoming stage, ordinarily about 10 days before it is time to cut timothy. Early cutting eliminates the danger of harvesting viable quackgrass seeds and ergot. The yield of quackgrass hay from a new meadow is from 1 to 2 tons to the acre, approximately the same as that of an ordinary timothy meadow. In the region south of the Great Lakes a second or even a third cutting can be harvested during wet seasons.
Quackgrass meadows are unusually free from weeds, owing to the vigorous growth of the grass and to the fact that it is cut early, before weeds have a chance to go to seed. Such common meadow weeds as oxeye daisy, wild carrot, and fleabane are seldom associated with quackgrass.
One disadvantage of quackgrass from the standpoint of hay production is the fact that it becomes root-bound. As the plant becomes root-bound the yield falls off rapidly, usually decreasing from one-quarter to one-half the second year and almost disappearing by the third or fourth year. The meadow may be restored to maximum production, however, by stirring the sod vigorously in the spring by means of shallow plowing, thorough double disking, or harrowing with a spring-tooth harrow. The matted rootstocks are thus torn to pieces and stimulated to produce a vigorous growth of leaves, so that in a few weeks the grass is in as thrifty a condition as ever. When handled in this way a quackgrass meadow may be maintained almost indefinitely without the expense of the periodic reseeding necessary with other grasses. Like all grasses, quackgrass responds to the use of fertilizer, and often a yearly top-dressing of barnyard manure or a light application of sodium nitrate, sulphate of ammonia, or other nitrogenous material is profitable. On some soils it pays to use phosphate fertilizer.
Mixtures of quackgrass and other grasses are more common and more desirable than quackgrass alone. Although a sod grass, quackgrass often grows in irregular patches rather than in solid stands, and it is well to have other grasses to fill the bare spots in the field. Orchard grass is especially well-suited for mixing with quackgrass, as the two mature about the same time. Perennial rye-grass, tall meadow oat-grass, and meadow fescue also do well as companion crops. The plants most commonly associated with quackgrass are timothy, red clover, alsike clover, and redtop. Alfalfa and quackgrass made a very good mixed hay, although the quackgrass tends to run out the alfalfa in two or three years if the seed bed is not free from the grass at the time the alfalfa is planted.
One way of handling quackgrass land is to sow the field to sweet clover, which by its rank growth forces the quackgrass to grow taller, while the grass lightens the clover hay, making it more easily cured and adding somewhat to its palatability. To prepare for the sweet clover, the quackgrass is double disked early in the spring and seeded immediately with from 12 to 15 pounds an acre of hulled and scarified sweetclover seed. The seed is sown broadcast and covered by rolling rather than harrowing. One cutting of quackgrass and one of mixed grass and clover are obtained the first year, and two cuttings of mixed hay the second. The yield of each cutting averages about 2 tons an acre on good land, which is more than either crop would yield alone. Since sweet clover is a biennial plant, it fits in very well with the rejuvenation process required for quackgrass.
USE FOR PASTURAGE
Quackgrass is not as abundant in pastures as in meadows, owing to its tendency to become sod-bound and disappear, but where it occurs it is a good grazing grass. It starts growth earlier in the spring than bluegrass or redtop and continues to furnish green pasture until late in the fall. It withstands hot, dry weather as well as or better than bluegrass and makes more growth on sandy soils or soils poor in lime. A good sod of quackgrass bears close grazing by cattle, although sheep sometimes injure it by too close nibbling.
A quackgrass sod must be rejuvenated every two or three years. If other grasses predominate in the pasture, however, usually it is not advisable to disturb the sod simply for the sake of encouraging the quackgrass. As quackgrass when fully matured is not eaten by live stock, the area should be closely pastured or kept closely mowed to induce the development of new leaves.
A rather unusual form of pasturage is furnished by the rootstocks, which are sweet, succulent, nutritious, and relished by hogs and sheep. The animals may be turned on a newly plowed field to graze, or the rootstocks may be raked off and fed like hay. During the latter half of the season the rootstocks often contain more nutriment than the above-ground portions of the plant. In Europe the rootstocks are fed to animals rather than burned or thrown away. Some caution should be used in feeding them, as they have a diuretic effect and may be harmful if fed in excess.
USE AS SILAGE
Almost any combination of quackgrass and a leguminous forage crop can be used successfully as silage. Often a field of mammoth clover which has become infested with quackgrass can be saved by putting the crop into the silo when it is too old and hard to make good hay. The quality and keeping properties of pea waste from canneries, which is often ensiled, are improved by the presence of quackgrass. Quackgrass does not make good silage by itself unless cut while very green, since the mature crop is not sufficiently succulent. One advantage of ensiling quackgrass is that the seeds are killed in the process.
USE IN ROTATIONS
Because of the fact that quackgrass must be plowed occasionally to maintain the vigor of the sod, it can be worked in to good advantage with short rotations. One of the best of these is quackgrass and buckwheat. When the sod shows signs of deterioration, the field can be plowed shallow and harrowed once, soon after haying. Except in the extreme northern part of New England, buckwheat can then be planted in time to produce a profitable crop before frost. The buckwheat should not be planted thick enough to injure the grass by shading, 3 pecks of seed to the acre being sufficient. Some growers make a practice of seeding from 4 to 6 pounds of perennial rye-grass or tall meadow oat-grass with the buckwheat in order to insure a good meadow, the quackgrass, of course, taking care of itself.
Quackgrass is also grown in rotation with fodder corn, the sod being plowed shallow in the fall and left rough over winter, so that the grass will not smother the corn in the spring. Almost any crop that makes a quick, rank growth can be grown in rotation with quackgrass, provided it does not occupy the land for more than three or four months.
USE AS A SOIL BINDER
The tough interlacing rootstocks of quackgrass are very useful for holding the soil on railroad embankments, terraces, gullies, river banks, and hillsides that tend to wash. The plants are readily propagated either from seed or from cuttings of the rootstocks, the cuttings being preferred, because the young plants thus become firmly rooted more quickly. Either the seeds or rootstocks are best planted in early spring in shallow trenches dug about 1 foot apart across the face of the slope.
USE AS FOOD
Both the seeds and rootstocks of quackgrass have been used in times of emergency for food. The seeds yield a fair quality of flour, similar in appearance to rye flour. When gathered in the spring or fall the rootstocks can be ground into flour, which produces a rather heavy, light-colored bread. During the World War this material was used quite freely in southern Bavaria, where it was declared superior to most wheat substitutes. Neither the seed flour nor the rootstock flour is of the highest quality, and its preparation is somewhat laborious, but it is nutritious and not unpalatable.
Decoctions or teas made from the dried rootstocks are well known in central Europe, where they are thought to have a slight nutritive as well as medicinal value. A coffee substitute has also been prepared from the roasted rootstocks. Attempts to utilize the rootstocks in the production of commercial alcohols and sugars and as a substitute for barley in malting have not proved successful.
Note — The scientific name of quackgrass is Agropyron repens.
1 This map is based upon records in the Office of Forage-Crop Investigations, Bureau of Plant Industry, and sketch maps kindly furnished by officials of the following State agricultural experiment stations: Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Maryland, Virginia, West Virginia, Ohio, Kentucky, Indiana, Michigan, Wisconsin, Minnesota, North Dakota, Iowa, Missouri, Colorado, Wyoming, Idaho, California, Oregon, and Washington.
2 Agropyron smithii.
3 Agropyron tenerum.
4 Elymus spp.
5 Lolium multiflorum.
6 Lolium perenne.
7 Poa pratensis and P. compressa.
8 Agrostis palustris.
9 Muhlenbergia schreberi.
10 Bromus inermis.
11 Calamagrostis canadensis.
12 Andropogon halepensis.
13 Cynodon dactylon.