Most injurious in the United States from New England westward to Minnesota. Habitat: Fields, roadsides, and waste places.
If it were put to a vote, perhaps most farmers would name Quack-grass as the most obnoxious of its tribe; yet it makes good hay and two crops a year of it, is sweet pasture grazing which cattle eat greedily, and its matted "couch" of interlacing rootstocks make it an unsurpassed soil-binder in steep gullies or on road embankments where the ground must be guarded against "washouts." But it is its very tenacity of life that makes it such a pest when it gets into cultivated ground. If it could be kept in its place, or were not so hard to kill when it gets out of bounds, it would be a welcome friend.
The mischievous part of the plant is its jointed, branching, underground stem, or root-stock, which is capable of budding a new plant at every joint and taking such entire possession of the soil that other plants growing with it are so crowded and starved as to yield very poor crops or none at all. The same joints from which the buds shoot above ground also send down clusters of fine, fibrous roots which absorb most of the plant-food and moisture. Culms one to three feet tall, with flat, ashy green leaves, smooth beneath but rough above, three inches to a foot long and about a third of an" inch wide; sheaths smooth, shorter than the internodes. Fruiting spike erect, three to eight inches long, with spikelets sessile and alternately placed in each notch of the rachis with the broad side turned toward it; each contains three to seven seeds, which are about as long as a grain of wheat but not nearly so plump. Indeed the whole spike looks somewhat like a slender head of wheat, and the grass is a near relative of that noble grain. The glumes of some seeds have a short awn, or beard, and others have none; they do not shell readily, and often the entire spikelet breaks from the stalk. Too often the seed is an impurity of wheat, rye, barley, clover, and other grasses, particularly brome-grass and timothy. Also the plant is often infected with the fungous disease known as "stem rust" of wheat. (Fig. 31.)
FiG. 31. -Quack-grass (Agropyron repens). X 1/5.
There is no easy way to subdue Quack-grass; but it can be done, and in a single season, without loss of the use of the ground. It must be remembered that the storehouse of the plant is its creeping rootstock, the material for the growth of which comes from the food assimilated by the green leaves, therefore no green leaves must be allowed to develop. Professor Beal, the noted botanist of the Michigan Experiment Station, outlines the following plan, based on long practical use: "If convenient, pasture closely for a whole growing season, which prevents the production of new, thrifty rootstocks, then, if the sod be well turned under deep, rolled and harrowed, much of the grass will be killed at once. Ordinarily I plow late in the fall or very early in the spring, rain or shine, wet or dry, or even in June, and cultivate with a shovel-toothed cultivator every three days till the middle of June or later, if starting the work later. Rarely, if the weather be wet and hot, cultivate every two and a half days. Keep all green leaves from showing themselves. Do not delay to see green leaves. A harrow that does not cut off the stems below the surface of the ground is not efficient." A late crop of corn can be grown on this land and the last spears of the grass killed in its cultivation.
When the grass takes possession of cultivated ground its root-stocks are usually much deeper in the soil than in pastures and meadows. An early fall plowing, with the furrow turned just deep enough to cut the matted rootstocks free from the subsoil (usually about six inches), followed by toothed harrowing to work the soil free from the rootstocks so that they may be raked into piles to be dried and burned or thoroughly rotted in a compost heap, is another good way to fight Quack-grass. Two bouts of such fall plowing and harrowing, raking, and burning, the second a little deeper and crosswise of the first, with early and careful cultivation in the spring, followed by a hoed crop thoroughly tilled until midsummer, will clean out the weed; and the enlarged yield of the crop due to the needful extra cultivation will recompense the increase of care and labor.
Small areas of the pest may be smothered to death by being covered with boards, or spreading thick with manure or straw (not less than a foot deep and well packed down so as to exclude air), or with tarred paper pegged down so that the wind cannot stir it. Two or three months of such exclusion from air and sunlight will leave the rootstocks withered and dead.
Quack-grass rootstocks (not the rootlets) are much used in the drug trade. At present this country imports from Europe about a quarter-million pounds of it annually, at a cost of three to seven cents a pound. Since no country grows more Quack-grass than the United States, it would seem needless to go abroad for it. To prepare the plant for market, the smooth, pale yellow rootstocks should be gathered in the spring, carefully washed, and all the fine rootlets and buds removed from the joints, after which the rootstocks may be cut into short pieces on a feed cutter and thoroughly dried.