AGRICULTURE CANADA CODE 86/02/21 NO LIBRARY/BIBLIOTHEQ OC5 WEEDS AND WEED SEEDS ILLUSTRATED AJSD DESCRIBED DOMINION OF CANADA DEPARTMENT OF AGRICULTURE BULLETIN NO. 4— NEW SERIES REPRINT OF BULLETIN NO. S-8 PUBLISHED BY DIRECTION OF THE HON. W. R. MOTHERWELL, MINISTER OF AGRICULTURE, OTTAWA, 1922. OTTAWA P. A, ACLAND PRINTER TO THE KING'S MOST EXCELLENT MAJESTY 1922 THE SEED BRANCH Commissioner Chief Analyst - - - Chief, Seed Division - Acting Chief, Feed Division Chief, Markets and Fertilizer Division Geo. H. Clark. A. Eastham. C. Sweet. Geo. H. Clark. G. S. Pearl. WEEDS AND WEED SEEDS Illustrated and Described The greatest difficulty in the way of producing a more abundant supply of clean clover and grass seed, as well as seed grain, is the prevalence of weeds. In order to produce high class clean seed, farmers must be constantly on the alert to keep the weeds on their farms in check and prevent the introduction and spread of new varieties. In various ways weeds lower the yield, depreciate the quality and value of crops, and add to the cost of production. They rob the soil of plant food and of moisture, thus increasing the effects of drought by taking up water from the soil and wasting it by evaporation; they crowd out more useful plants, being hardier, and, as a rule, more prolific; they increase the cost of every farm operation and cause depreciation in the market value of crops because of the presence of weeds in hay or of weed seeds in grain; the eradi- cation of the worst weeds is costly in labour, time and machinery, and fre- quently prevents a farmer from following the best crop rotation or from growing the most advantageous crops; many weeds are conspicuous and all are unsightly on farms, and thus depreciate the value of land; some weeds are harmful to stock, while others are injurious to their products; weeds attract injurious insects and harbour fungus diseases. New weeds are introduced on farms with grass, clover or other commercial seeds, and commercial feeding stuffs, which often contain vital weed seeds. They are spread from district to district through various transportation facili- ties, such as railways, and become disseminated within a locality in stable manure from towns and cities, and through threshing machines and farm implements. The wind carries some weed seeds long distances, not only in summer but with drifting soil and over the surface of the snow in winter. Streams distribute them along their courses. They are also distributed by herbivrous animals, through the stomachs of which the seeds pass undigested; or they attach themselves by special contrivances, such as hooked and barbed hairs, spines, gummy excre- tions, etc., to passing animals. Classification and Eradication Weeds are classified according to the length of time they live, as annuals or one-year plants; biennials, or two-year plants; and perennials, or many- year plants. In eradicating weeds it is of the greatest importance to ascertain under which of these heads they come. Annuals Annuals complete their growth in a year. As a rule, they have small fibrous roots and produce a large quantity of seed. Some weeds, called winter annuals, are true annuals when the seeds germinate in the spring, but they are also biennial in habit; that is, their seeds ripen in the summer, fall to the ground, germinate and produce a certain growth before winter sets in, and then complete their development next spring. Annuals may be eradicated from land, however badly infested it may be, through any method by which germination is hastened and the young plants destroyed before they produce seed. 36446—1 1 2 weeds and weed seeds Biennials Biennials require two seasons to complete their growth, the first being spent in collecting and storing up a supply of nourishment which is used the second season in producing flowers and seeds. Biennials must be either ploughed or cut down before they flower. Mowing at short intervals in the second year, so as to prevent the development of new seeds, will clear the land of this class of plants; but a single mowing will only induce them to send out later branches, which, if riot cut, will mature many seeds. Where ploughing is impracticable, such plants should be cut off below the crown of the root. Perennials Perennials are those plants which continue to grow for many years. They are propagated in several ways, but all produce seeds. Perennials have two distinct modes of growth; some root deeply, while with others the root system is near the surface. The most troublesome are those which extend long under- ground stems or rootstocks beneath the surface of the ground, as Canada thistle, perennial or field sow thistle, field bindweed and bladder campion. Representa- tives of the second class or shallow-rooted perennials are pasture sage, yarrow and couch grass. Some perennials extend but slowly from the root by short stems or offsets, but produce a large quantity of seed. Of these, ox-eye daisy, dandelion, goldenrod and yarrow are examples. Perennials are by far the most troublesome of all weeds and require thorough treatment, and in some instances the cultivation of special crops, to insure their eradication. Imperfect treatment, such as a single ploughing, often does more harm than good, by breaking up the rootstocks and stimulating growth. For shallow-rooted perennials, infested land should be ploughed so lightly that the roots are exposed to the sun to dry up. For deep-rooted perennials, on the other hand, ploughing should be as deep as conveniently possible. The nature of the land must determine the depth of ploughing. In light or gravelly soils shallow ploughing may be preferable as deep ploughing might interfere with the mechanical texture of the soil, which is so important in the storing of moisture. The rootstocks of some perennial weeds are very persistent. Some sections or cuttings from them will quickly take root when they are distributed by ploughing or cultivation. Where such persistent perennials have become well established, it is usually advisable to adopt the most convenient method of cultivation that will bring the rootstocks to the surface. They should then be gathered and burnt or otherwise destroyed. Most perennial weeds will, however, succumb to continued thorough cultivation that will prevent the growth of leaves. Plants take in most of their food through their leaves. Perennial plants, which live for many years, have special reservoirs where some of this food, after elaboration, is stored in such receptacles as bulbs, tubers and fleshy rootstocks. The first growth in spring, particularly flowering stems, is produced mainly by drawing on their special store of nourishment. Plants are therefore in their weakest condition when they have largely exhausted their reserve supply of food and have not had time to replenish it. The stage of growth, then, when ploughing will be most effective is when their flowering stems have made full growth but before the seeds, which would be a source of danger, have had time to mature. Summer Fallowing The practice of summer-fallowing land, whatever may be said against it, affords the best opportunity to suppress noxious weeds. For lands foul with persistent growing perennials, a thorough summer-fallow will usually be the most effective, and, in the end the least expensive method of bringing the weeds under control. "WEEDS AND WEED SEEDS 3 The amount and nature of the cultivation of a summer-fallow will depend on the habits of the weeds, the kind of soil, and the climatic conditions. In some extreme cases of perennial weeds, it may be advisable to allow the plants to exhaust their reserve vigor by growth until the flowers are formed, then cut and remove the surface growth, plough to the depth of four or five inches, and bring the rootstocks to the surface before they have had time to renew growth. After cutting and removing the surface growth, cultivators may, after several applications, be forced to the bottom of the furrow, thus unearthing the net- work of rootstocks. Perennial weeds having deep rootstocks may require a second and deep ploughing before all the underground vegetation can be unearthed. If perennials alone are to be dealt with, they may be treated as above directly after an early hay crop. When the destruction of annual weeds is the chief purpose of cultivation, deep ploughing two or three times during the summer, with surface cultivation each week during June and July, and less frequently later in the season, should secure the germination and destruction of the maximum number of seeds. On account of the soil and climate, one ploughing of summer-fallow is favoured in the Prairie Provinces. Short Rotation of Crops To keep farms free from weeds, few methods give such good results as a systematic short rotation of crops, with regular seeding down to grass or clover at short intervals. Weeds are most in evidence in districts where the production of cereal grains predominates and where the systematic alternation of crops is not generally practised. Thorough cultivation with a systematic rotation of crops, combined with the maintenance of as many sheep as can be kept to advantage, is a certain and profitable means of keeping weeds under control. Seeding to Grass Lands foul with some kinds of weeds, particularly annuals, may advan- tageously be seeded to grass for hay or pasture. The cultivation of hoed crops becomes too expensive for labour when the soil is polluted with weed seeds. Grain crops may also be unprofitable because of weeds, and they afford an opportunity for the weeds to increase. Seeding to grass and cutting the hay crops early will prevent most kinds of weeds from ripening more than a relatively small number of seeds, and the number of vital weed seeds in the sub-surface soil will rapidly decrease from year to year. If perennial weeds are also prevalent, it would be well to pasture with sheep and mow the roughage closely each year, before the spring growth has formed seeds. Farm Implements to Destroy Weeds The best time to destroy weeds is within two or three days after the first pair of leaves has formed on the seedling plant. In friable soils the "weeder" is a useful implement for that purpose. The "tilting" harrow is also satisfactory for comparatively loose soils and is preferred as a weed destroyer on firm or clayey land. Weeds are irregular in time of germination; consequently it is necessary to apply the weeder or harrow frequently throughout the growing season. Potatoes, or field of corn and cereal grains when sown with a drill, may advantageously be treated with such weed destroyers once or twice before the crop distinctly shows above the ground, and again, with corn and ordinary grain crops, when the plants are three to six inches high. Even relatively heavy harrows ordinarily in use will do little damage to the potatoes, corn or grain plants if the land is not wet, and the loosening of the surface soil benefits the crop in addition to the destruction of the weeds. 36446— 1 J 4 WEEDS AND WEED SEEDS For perennial weeds or seedlings that have become well rooted, a cultivator having diamond shaped or other relatively broad shares is needed for hoed crops. The disc is a favoured implement for destroying weeds in a summer-fallow or in preparing a seed bed. When, however, it is desired to unearth and remove the rootstocks of perennial weeds such as couch grass, a narrow-toothed cultiva- tor, that will loosen the soil and bring the underground vegetation to the surface, is preferred to an implement that will cut the rootstocks, the small cuttings of which may be excedingly persistent in growth. Weed Seeds in Seed Grain One of the principal reasons why weeds are not brought under better control on farm lands is because such large numbers of their seeds are put into the soil through lack of care in ordinary farm operations. The use of seed grain that has not been well cleaned is responsible for the introduction of many new weeds and the increase of those already in the land. In the spring of 1913 an inquiry was conducted by the Seed Branch to ascertain the sources of supply and the quality of the flax and grain used for seed. Samples representing, as accurately as possible, the average seed being used in the districts visited were taken from over 2,000 farmers throughout Canada and forwarded to the Ottawa seed laboratory where they were tested. According to this inquiry, about 75 per cent of Canadian farmers grow their own seed grain. Most of the grain and flax purchased for seed is secured from neighbouring farmers, but considerable quantities are obtained from grain dealers and seed merchants. The proportion of farmers who do not grow their own seed is largest in the newer parts of the Prairie Provinces and in Quebec, New Bruns- wick and Nova Scotia. Analysis of the samples collected shows that most of the grain and flax sold for seed contains large numbers of different kinds of weed seeds, and great care should be exercised in selecting and cleaning to prevent the introduction of new weeds. Weed seeds are also prevalent in homegrown seed. Oats: The extent to which weeds are sown with seed grain is shown by a summary of the tests of the samples collected. Of the 978 samples of oats analyzed, 547, or 56 per cent, contained seeds of weeds classed as noxious under the Seed Control Act, the highest number being 4,838 per pound and the average 76. Weed seeds other than those classed as noxious were found in 860 or 88 per cent of the samples, the largest number being 6,954 per pound and the average 239. With this weed seed content and the rate of seeding reported, weed seeds would be placed on the land sown with oats at an average rate of 44 noxious and 138 other sorts per square rod. Barley: Of the 408 samples of barley tested, 234, or 57 per cent contained noxious weed seeds, the highest number being 2,539 per pound and the average 53. Other weed seeds were found in 352, or 86 per cent, of the samples, the highest number being 9,968 per pound and the average 445. With this weed seed content and the rate of seeding reported, weed seeds would be placed on the land at an average rate of over 32 noxious and 270 other sorts per square rod. Spring Wheat: Of the 506 samples of spring wheat tested, 271, or nearly 54 per cent, contained noxious weed seeds, the highest number being 11,528 per pound and the average 79. Other weed seeds were found in 454, or nearly 90 per cent of the samples, the largest number being 17,415 per pound and the average 343 per pound. With this weed seed content and the rate of seeding reported, the weed seeds placed on the land would average about 50 noxious and 220 other sorts per square rod. Fall Wheat: With fall wheat the impurities were not nearly so high. Only 29 samples were collected, all from Ontario and mostly from the eastern part of the province. Thirty-seven per cent of these contained noxious weed seeds, the highest number being 176 per pound and the average nine; 76 per cent contained other weed seeds, the largest number being 187 and the average 68 per pound. WEEDS AND WEED SEEDS 5 Flax: Weed seeds were especially prevalent in the flax samples. Out of 144 tested, 127, or 88 per cent, contained noxious weed seeds, the largest number per pound being 15,424 and the average 662. Other weed seeds were present in all but seven samples, the highest number being 13,984 per pound and the average 4,087. With this weed seed content and the rate of seeding reported, the weeds placed on the land through sowing flax would average 136 noxious and 840 other sorts per square rod. Some of these weed seeds are difficult to separate, but most of them could be removed by a fanning-mill properly equipped and well operated. The lack of cleaning is indicated by the fact that nearly 11 per cent of the lots of wheat, oats, barley and flax were being sown direct from the thresher, with no cleaning whatever. Over 88 per cent were reported as having been cleaned with a fanning mill, but the samples showed that either the mills were not equipped with the proper sieves or else that they were not well operated. In a few cases samples were taken from lots that were to be cleaned before sowing, so that the figures given above are inaccurate to the extent to which weed seeds were removed from these lots by cleaning. However, comparison of these uncleaned samples with those which had been passed through a fanning mill indicates that little improvement would be effected. Weed Seeds in Grasses and Clover Except within limited areas, most farmers in Canada purchase grass and clover seeds. There is more danger of new weeds being introduced with these seeds than with seed grain, which is more generally home grown. In ordinary years Ontario produces all the alsike and red clover seed required for Canada and large quantities are exported, especially of the former. Timothy seed is grown to some extent in many parts of Canada but a large proportion is import- ed from the United States. Little alfalfa seed is grown in Canada. Most of our imported supply comes from the United States and Russian Turkestan. The following lists contain the names of the weed seeds most frequently present in alfalfa, clover and timothy. Alfalfa Seed. — Noxious. Ribgrass, ragweed, docks, chicory, wild mustard, dodder, wild carrot, campions, field bindweed. Others. Green foxtail, lamb's quarters, sweet clover, pale plantain, Russian knapweed, yellow foxtail, rocket, barnyard grass, black medick, Russian thistle, maple-leaved goosefoot, smart- weed, lady's thumb. Red Clover Seed. — Noxious. Ribgrass, docks, ragweed, campions, Canada thistle, stickseed, wild carrot, wild mustard, false flax. Others. Green foxtail, lamb's quarters, pale plantain, black medick, lady's thumb, sheep sorrel, yellow foxtail, sweet clover, plantain, mayweed, barnyard grass, knotweed, crabgrass, witchgrass, catnip, cut-leaved geranium. Russian thistle, heal-all, bedstraw, black bindweed, pigweed, blue vervain, smartweed, field peppergrass. Alsike. — Noxious. Campions, docks, ribgrass, false flax, Canada thistle* ox-eye daisy, stinkweed, wild mustard. Others, Black medick, sheep sorreL lamb's quarters, chickweed, plantain, green foxtail, mayweed, worm-seed mus- tard, pale plantain, cinquefoil, heal-all, shepherd's purse, catnip, old witch grass, common peppergrass. Timothy Seed. — Noxious. Canada thistle, campions, ox-eye daisy, rib- grass, docks, false flax, chicory, sow thistle, wild mustard. Others. Cinque- foil, sheep sorrel, plantain, lamb's quarters, chickweed, worm-seed mustard, pale plantain, peppergrass, green foxtail, mayweed, heal-all, witchgrass, evening primrose, shepherd's purse, yarrow. In buying grass and clover seed, it is well to remember that Extra No. 1, which contains no noxious weed seeds and not more than 30 other sorts per ounce, when sown at the rate of 12 pounds per acre will place about 36 weed D WEEDS AND WEED SEEDS seeds on every square rod sown, whereas No. 3 seed, containing the maximum number of weed seeds (80 noxious and a total of 400 per ounce), sown at the same rate, will place about 480 weed seeds, nearly 100 of which may be noxious, on every square rod. Samples of timothy and clover seed containing more than 10,000 weed seeds per ounce are sometimes received at the seed laboratory. In many cases proper sieves will remove most of the weed seeds and so prevent their return to the land at the rate of several thousand to every square rod. Weed Seeds in Commercial Grain Ordinary commercial grades of grain that have passed through terminal elevators contain large numbers and many kinds of weed seeds. This is due to the fact that in handling grain at terminal elevators, cars containing many noxious and other weed seeds are mixed with clean grain of the same grade, thus contaminating the whole bin or bulk lot. On account of this, such grain coming out of the terminal elevators is unfit for seeding; most of it is so foul with weed seeds as to constitute a dangerous source of noxious weeds unless carefully handled. Analysis of five samples of No. 2 Canada Western oats, taken from shipments from five terminal elevators at Fort William, showed the oats to average 313 noxious weed seeds per pound, including nine species, and a much larger variety and number of other weed seeds. In transportation many seeds are scattered along the right of way of the railroad and thus introduce weeds into new localities. The danger of spreading weeds through feeding dirty grain to horses and other stock is not sufficiently realized. A farmer who feeds his horses oats containing wild oats and mustards will later find these plants growing in patches all over his field, wherever the horses' droppings have fallen. Large numbers of weed seeds are put on the land with manure. Many seeds pass uninjured through the digestive tract of farm animals, while others become mixed with the manure and offal from the stables through handling grain and other feeds. When manure is piled and allowed to "heat," the vitality of most of the weeds is destroyed; but when drawn to the field from the stable, or not left long enough in the pile to become well rotted, manure is one of the most important means of weed dispersal. It is especially dangerous when secured from town or city stable, where dirty grain or hay is fed. Grain con- taminated with weed seeds should not be brought on a farm even for feed until it has been crushed or ground so as to destroy the vitality of the weed seeds. Weed Seeds in Screenings Most of the western wheat and flax and some of the oats and barley entering the terminal elevators at Fort William and Port Arthur passes through the cleaners before it is re-shipped eastward by lake or rail. The screenings thus obtained approximate 100,000 tons annually. This material is made up of broken and shrunken kernels of wheat, oats, barley and flax as well as varying proportions of a large number of weed seeds. Elevator screenings vary widely in composition, depending on the kind of grain cleaned, place of growth and season or climatic conditions. A sample which is believed to have been quite representative of the material screened from the 1913 crop was made up as follows: Broken and shrunken wheat, oats, barley and flax, 40-7 per cent; wild oats, 2-8 per cent; wild buckwheat, 11-7 per cent; lamb's quarter's 20-2 per cent; cruciferous seeds including wild mustard, hare's ear mustard, tumbling mustard, ball mustard, stinkweed, common peppergrass, false flax and wall- flower, 4-3 per cent; other seeds, 2-2 per cent and chaff, 18*1 per cent. Besides those mentioned above the seeds occasionally found in elevator screenings which are classed as "other seeds" in an analysis like the above include: Panicum WEEDS AND WEED SEEDS / capillar e, Setaria viridis, Phleum pratense,Lolium temulentum, Agropyron tenerum, Hordeum jubatumf Rumex sp, Axyris amarantoides, Amaranthus retroflexus, Amaranthus graecizans, AgrostemmaGithago, Silene noctiflora, Saponaria Vaccaria, Cleome serrulata, Rosa pratincola, Trifolium hybridum, Astragalus caryocarpus, Hedysarum boreale, Oenothera, biennis, Gaura coccinea, Gilia linearis, Lappula echinata, Agastache Foeniculum, Dracocephalum parviflorum, Stachys palustris, Plantago major, Plantago Rugelii, Symphoricarpos occidentalis, Grindelia squar- rosa, Iva axillaris, Iva xanthifolia, Ambrosia trifida, Rudbeckia laciniata, Helian- thus scaberrimus, Helianthus Maximiliani, Coreopsis tinctoria, Achillea Mille- folium Artemisia biennis, Cirsium undulatum, Cirsium arvense, Sonchus arvensis, Lactuca pulchella. Weed Seeds in Feed Made from Screenings About 60 per cent of the material composing elevator screenings has been shown to be excellent feed. The remaining 40 per cent made up of small seeds such as lamb's quarters and various mustards often render feed in which they occur disagreeable in taste and sometimes injurious to the health of stock. Recleaned Screenings with Inspection Certificate is sold by elevator companies and has given satisfaction as feed when the cleaning has been thor- oughly done so as to remove all of the small seeds including the various mustards. The composition of these recleaned screenings varies with the season and the thoroughness of the recleanings but the average sample contains approximately the following: cracked and thin wheat, 35 to 50 per cent; wild buckwheat, 25 to 50 per cent, oats and barley, 1 to 5 per cent; flax, 1 to 5 per cent; wild oats, 2\ to 10 per cent; mustards, \ to 4 per cent; other seeds, 2 per cent; chaff, 2 to 20 per cent. The percentage of mustards, other seeds and chaff should be kept as small as possible. When grain or screenings is not properly recleaned before it is ground to make feed, the vitality of many of the small weed seeds is not destroyed. The impossibility of pulverizing all of the seeds when the entire screenings are ground up together by an ordinary chopper is well illus- trated by the analysis of a sample that had been ground with the idea of putting it on the market as a feed. One-eighth ounce contained, lamb's quarters, 260; tumbling mustard, 215; false flax, 8; cinquefoil, 7; green foxtail, 6; wild mustard, 2; hare's-ear mustard, 2; stinkweed, 2; other sorts, 15. This is equivalent to more than 90,000 weed seeds per pound. Weed Seeds in Mill Feeds The screenings which are separated from wheat in the large flour mills are usually ground or pulverized by special machinery and mixed with bran and shorts. Many of the mills do the grinding so carefully that their bran and shorts contain few, if any, vital weed seeds. But many weed seeds are to be found in the by-product feeds from some mills. In the spring of 1913 the seed laboratory examined 396 samples of bran, shorts and chopped feed which had been collected thoughout Canada by the inspectors of the Department of Inland Revenue. Analysis showed that 140 of these samples contained noxious weed seeds, the average number being 57 per pound. Twenty-four of the samples contained more than 100 noxious weed seeds per pound, and one sample of chopped feed held 1,104 seeds of wild oats, stickseed, catchfly and stinkweed per pound. Only 144 samples were free from vital weed seeds of any kind. The following seeds were most common: Noxious. — Wild oats in 74 samples; wild mustard, 30; hare's-ear mustard, 27; false flax, 25; stinkweed, 24; ball mustard, 23; catchfly, 21; docks; 8; ragweed, 6; Canada thistle. 5; stickseed, 5; western false flax, 5; tumbling mustard, 3. Other Weed Seeds.— Lamb's quarters, 180; wild buckwheat, 94; green foxtail, 11; lady's thumb, 9; chess, 9; American dragonhead, 7; worm-seed mustard, 7. 8 WEEDS AND WEED SEEDS Danger of Spreading Weeds through Seeds in Feeds The presence of vital seeds in feeding stuffs is objectionable because many- weed seeds retain their vitality after they have passed through the digestive tract of domestic animals. In an experiment at the Maryland Experiment Station* twenty-two kinds of seeds were fed to animals and the manure spread over sterile soil. It was found that only one kind of seed, Spanish needles (Bidens bipinnata) failed to germinate. Docks, ragweed, purple cockle, tumbling mustard and pepper- grass, were all capable of germination. In another experiment f a cow and horse were each fed two pounds of the unground grain screenings with middlings, bran and wheat straw, each morning and night for seven days. On the evening of the seventh day the animals were bedded with sawdust and the dung of one night collected. The sawdust and dung were thoroughly mixed and put in boxes and set on a bench in the greenhouse. The dung was collected on May 24. On June 21, the following weeds had grown: Cow Dung — Horse Dung — 149 Lamb's quarters. 1,213 Lamb's quarters. 12 Pigweed. 28 Foxtail. 14 Bindweed. 11 Pigweed. 4 Foxtail. 12 Bindweed. 2 Timothy. 6 Timothy. 3 Clover. 2 Morning glory. 5 Mustard. Poisonous or Deleterious Effects of Certain Weed Seeds Investigation has shown that many of the complaints made by live-stock men in regard to the injury to the health of animals caused by certain feeding stuffs is due to the presence of poisonous or otherwise injurious weed seeds included in the feed. Sometimes animals refuse to eat feeds and the trouble is often traceable to the presence of seeds which are bitter or otherwise disagree- able in taste. Comparatively little work has been done in this connection but the following seeds are authoritatively stated to be poisonous : Brassica arvensis, Brassica nigra, Erysimum cheiranthoides, Thlaspi arvense, Sisymbrium altissimum, and Camelina sativa. The following are also objectionable in feed on account of injurious properties or disagreeable taste: Agrostemma Githago, Lolium ternu* lentum, Saponaria Vaccaria, Lappula echinata, and ergotized grains. Weed Seeds in Farm Lands It is important to consider not only the large number of weed seeds sown with improperly cleaned grain but also those already in farm soils. Some of our worst weeds are so prolific in the production of seeds that relatively clean fields may be badly contaminated in two or three years if these weeds are allowed to go to seed. For instance, a single plant of wild mustard, stinkweed, foxtail, pigweed or campion produces from 10,000 to 20,000 seeds, worm-seed mustard about 25,000, shepherd's purse about 50,000 and tumbling mustard about 1,500,000. With such productiveness, soils become quickly infested with weed seeds, although on account of their inconspicuousness the presence of the seeds is not fully realized. Only a careful examination will reveal their kinds and numbers. • Bull. 128, Maryland Agri. Exp. Station "The Effect of Animal Digestion and Fermentation on the Vitality of Seeds.' 1908. t Boll. 168, Maryland Agri. Exp. Station "By-Product Feeds." 1912. WEEDS AND WEED SEEDS 9 In the spring of 1914 the Seed Branch gathered some data on the prevalence of weed seeds in farm lands. Fields were selected in Alberta, Saskatchewan, Ontario and Quebec, records of their culture and cropping were obtained, and samples of soil at different depths and in different parts of each field were taken and examined at the Ottawa seed laboratory. In the four provinces 74 fields were selected from which 573 samples were taken, 191 from the surface, 191 from a depth of 2-3 inches and 191 at from 5-7 inches. From a definite weight of the air dried soil of each sample, the weed seeds were separated out, identified and counted. To convey some idea of the prevalence of weed seeds in these samples, four typical fields under different conditions have been chosen and the seeds found in them are tabulated below. At Lacombe, Alta., a field was examined which had grown oats and barley regularly without summer fallow from 1904 to 1912. It was nearly always fall ploughed but was harrowed before ploughing to sprout the weed seeds. In 1913 it was seeded to timothy and alsike. The following is a list of the numbers and kinds of weed seeds found in samples from this field. Seeds found of surface in 6 oz. soil Seeds found in 6 oz. of soil taken 2 to 3 inches deep Seeds found in 6oz. of soil taken 5 to 7 inches deep. Ball mustard .. 51 .. 78 .. 4 Ball mustard Lamb's quarters Black bindweed .. 59 . . 70 .. 2 .. 1 .. 1 Ball mustard . 39 Lamb's quarters. . . Black bindweed . . . Lamb's quarters Black bindweed . 69 2 Grass .. 1 Sedge Other sorts Other sorts 2 Total ..134 Total ..133 Total . 112 It is noticeable that the prevalence of weed seeds is nearly the same at all three depths. Six ounces of air-dried soil has an approximate volume of 8-58 cubic inches, and from the above figures it may be calculated that a square yard of the surface inch of this field contains about 20,240 weed seeds. Near Brantford, Ont., samples were taken from a field which had been in sod for six years, having either grown a crop of hay or been pastured each year during that time. The following weed seeds were found in these samples. Seeds in 6 oz. of surface soil Seeds in 6 oz. of soil 2 to 3 inches deep Seeds in 6 oz. of soil 5 to 7 inches deep Ragweed ... 9 ...67 ...20 ...14 ...11 ... 2 Black bindweed Green foxtail .. 17 .. 1 .. 8 .. 22 .. 9 .. 1 .. 1 Black bindweed . 11 Black bindweed Lady's thumb Crabgrass 5 Green foxtail Lady's thumb Crabgrass Lamb's quarters Sleepy catchfly Knotweed 4 Lady's thumb Crabgrass Lamb's quarters Old witch grass 7 1 Sheep sorrel Yellow foxtail 3 Lamb's quarters ... 1 Total 127 Total . . 59 Total . 28 In this field the number of weed seeds in the surface inch greatly exceeds the number at either of the two lower depths. A square yard of the surface inch of this field contains about 19,183 weed seeds. 36446— 2 10 WEEDS AND WEED SEEDS Samples were taken from a field near Guelph, Ont., which for the last ten years has raised the following crops: 1905, meadow; 1906, corn (field was fall ploughed in 1905) ; 1907, oats; 1908, bare fallow; 1909, winter wheat seeded with timothy and clover; 1910, pasture; 1911, ploughed in early summer, seeded with millet and thoroughly cultivated after millet was removed (this treatment was owing to the prevalence of white cockle); 1912, barley seeded with alfalfa; 1913 and 1914, alfalfa. The following weed seeds were found in samples from this field. Weed seeds in 6 oz. of surface soil Weed seeds in 6 oz. of soil 2 to 3 inches deep Weed seeds in 6 oz. of soil at 5 to 7 inches deep White cockle .. 9 . . 10 .. 7 .. 4 .. 2 .. 1 White cockle . 6 . 8 . 5 . 1 White cockle 6 Black medick Black medick Black medick. . . fi Lamb's quarters Black bindweed Lamb's quarters Black bindweed Lamb's quarters 8 Dandelion Canada thistle Total . . 33 Total .. 20 Total 20 The prevalence of weed seeds at the three depths in this field is practically constant, while a square yard of the surface inch contains about 4,984 weed seeds. It is significant that this field, which has been under a good system of cultiva- tion, contains only about a quarter as many weed seeds as either of the two other fields mentioned. Examination of samples taken from a spot along a road fence at Rouleau* Sask., shows how seeds may be spread by the wind. Weeds had been blown across a prairie field and lodged against the fence. The following seeds were found in the samples taken. Weed seeds in 6 oz. of surface soil Weed seeds in 6 oz. of soil 2 to 3 inches deep Weed seeds in 6 oz. of soil 5 to 7 inches deep Stickseed Wild mustard Hare's-ear mustard Stinkweed Black bindweed 330 267 99 3 159 15 12 9 9 3 Stickseed Black bindweed Chickweed . 3 . 6 . 3 Lamb's quarters 6 Lamb's quarters Rye grass Pigweed Milk spurge Wall-flower Total 906 Total . 12 Total 6 These results indicate that a large number of weed seeds of many kinds bad been carried to this spot and show that the wind is an important factor in spread- ing weeds, especially on the prairie. Germination of Weed Seeds The seeds of most annual weeds, when embedded in the soil, retain their vitality for several years. The seeds of the Mustard family and others, when ploughed down soon after ripening, seldom germinate the following year or until they are brought by further cultivation near the surface. Light surface culti- vation during the early autumn usually serves to stimulate germination in freshly ripened weed seeds and a considerable proportion of them may thus be destroyed, whereas by deep ploughing the difficulty is simply deferred to suc- ceeding years. WEEDS AND WEED SEEDS 11 The germination of weed as well as other seeds is affected by heat. Many kinds of weed seeds, such as some of the grasses and mustards, will germinate in the late autumn or early spring when the soil is quite cold. Others, such as wild buckwheat and lamb's quarters, require a warmer soil, and the seeds of foxtail and purslane continue dormant until stimulated by the heat of summer. Late autumn or early spring cultivation is not effective in destroying the seeds of weeds that will not germinate unless the soil is quite warm. Distribution from Weed Patches Patches of perennial weeds, such as field sow thistle, field bindweed, Canada thistle and couch grass, should receive prompt attention. The roots are com- monly distributed by farm implements used for cultivating and new patches are established from broken roots that have been dragged along by the plough or other implement. Any method of cultivation that may be effectively em- ployed to unearth and destroy the underground stems and fleshy roots of per- ennials should be used when patches of them are first observed. Patches of field bindweed and sow thistles may be smothered by covering them for a year with straw or farmyard manure. Hand Weeding Seed Crops Even with the greatest care and the best cultivation some weeds are almost sure to appear in clover and grain intended for seed and the only practical means of handling them successfully is hand pulling or spudding. With clover seed crops especially it is essential that the fields be carefully gone over and the weeds removed or destroyed before they go to seed. Failure to do this often results in the production of clover seed that is badly contaminated with weed seeds and its market value is thereby greatly reduced or entirely destroyed. Making Weed Seed Collections in Schools No subject in agriculture is better adapted for presentation to school children than the study of seeds. The collection, identification and study of seeds give scope for the training of a wide range of faculties and the intrinsic value of the information so derived is of real value to any one engaged in crop pro- duction. It is, therefore, advisable that those responsible for directing children in collecting and studying seeds should understand the seeds it is most import- ant to know, and their relationship to the different branches of crop production. Unfortunately, it is not difficult to make a fairly large and representative collection of weed seeds in almost any district in Canada. There are a number of weeds which occur practically everywhere. On the other hand, a great many are associated with certain crops, or with certain types of soil, or are limited to particular sections of the country. The weed seeds which may be found in almost any district include lamb's quarters (Chenop odium album L.), wild buckwheat (Polygonum Convolvulus L.), wild oats (Avena fatua L.), and wild mustard (Brassica arvensis (L) Ktze). 36446—21 12 WEEDS AND WEED SEEDS Impurities of Grain The following list includes the most characteristic impurities of grain grown in different parts of the country. It should be possible to secure all of the seeds here listed in any school section in the province or district indicated. It will be noticed that most of these weeds are annuals: — *Wild buckwheat. "Lamb's quarters. *Wild mustard. Wild oats— very common except in Prince Edward Island. fBall mustard (Neslia paniculata.(L.) Desv.) fStickseed (Lappula echinata Gilibert) . tWestern false flax (Camelina sativa (L.) Crantz). t/Hare's-ear mustard (Conringia orientalis (L.) Dumort). tStinkweed (Thalspi arvense L.) tCow cockle (Saponaria Vaccaria L.) •(Tumbling mustard (Sisymbrium altissium L.) Purple cockle (Agrostemma Githago L.) — Very common expecially in wheat. Perennial sow thistle (Sonchus arvensis L.) — One of the worst weeds. Its seeds are found to some extent in grain from Eastern Canada and Southern Manitoba. Lady's thumb (Polygonum Persicaria L.) — One of the commonest impurities of grain except on the prairies. Spurrey (Spergula arvensis L.)— Characteristic of grain from the Maritime Provinces, Quebec, and British Columbia. Hemp nettle (Gaieopsis Tetrahit L.)— Especially common in Prince Edward Island, Nova Scotia and Quebec. Wild vetch (Vicia angustifolia (L.) Reichard)— A very common impurity of grain in Ontario and Quebec. Chess (Bromus secalinus L.) — Very common in Ontario fall wheat. Darnel (Lolium temulentum L.) — Occurs com- monly in Red River Valley and occasionally throughout the Prairie Provinces. Great Ragweed (Ambrosia trifida L.) — Wheat from some districts of the West often contains considerable quantities of these seeds. Chicory (Cichorium Intybus L.) — Frequently found in Quebec seed. Worm-seed mustard (Erysimum cheiranthoides L.) — A very bitter seed that renders chopped feed made from grain containing it very unpal- atable to some kinds of stock, especially hogs. Often found in grain and sometimes in timothy seed. Impurities of Grass and Clover Seeds Ribgrass or Buckhorn (Plantago lanceolata L.), one of the most frequent and injurious impurities of Canadian-grown grass and clover seed; espec- ially common in red clover; difficult to remove by ordinary cleaning machinery. Green foxtail (Setaria virdis (L.) Beauv), very common in red clover seed and difficult to remove. Night-flowering catchfly (Silene noctiflora L.), the commonest impurity of alsike, found also in timothy and red clover. | Docks (Rumex species). JCanada thistle (Cirsium arvense (L.) Scop. JSheep sorrel (Rumex Acetosella L.) JBlack medick (Medicago lupulina L.) JPale plantain (Plantago Rugelii Dene.) ICommon plantain (Plantago major L.) JLamb's quarters. Cinquefoil ( (Potentilla monspeliensis L.), the commonest impurity of timothy seed. Chickweed (Stellaria media (L.) Cyrill), stitchwort (Stellaria graminea L.) and mouse-ear chickweed (Cerastium vulgatum L.) occur commonly in timothy and less frequently in alsike. Peppergrass (Lepidium apetalum Willd) common in timothy. Ox-eye daisy (Chrysanthemum Leucanthemum L.), frequently found in Quebec timothy, and not uncommon in Ontario and Prince Edward Island timothy. *Common impurities of grain everywhere. fPrevalent on the prairies, and not infrequently found in other parts, especially where low-grade Western grain has been used as seed or fed without being first cleaned and ground. {Very frequently found in red clover, alsike and timothy seed, especially in the east. WEEDS AND WEED SEEDS 13 THE NOXIOUS WEEDS The Seed Control Act, 1911, empowers the Governor in Council to specify the weeds that are to be classed "noxious" within the meaning of the Act. This makes it possible to include any new .weeds that may be introduced and become dangerous without amending the Act. The following are the weeds classed noxious under the 1919 Order in Council. The arrangement is according to botanical order. Wild Oats (Avena fatua L.) Introduced from Europe. Annual, 2 to 6 feet high. Plants closely resemble cultivated oats. Head spreading, usually nodding; seed-bearing stems very slender, bend- ing with the weight of the seeds, giving the head a drooping ap- pearance. The seeds vary somewhat in size and greatly in colour, from almost black to brown, gray and white. All forms are similar in shape to cultivated oats, but are slim- mer and at once distinguished by the stiff twisted awn, the hairs which are particularly prominent at the base, the slanting horseshoe-shaped scar, and the minute stalk (rachilla) supporting the second or "bo- som" grain. In Wild Oats this is stout, becoming wider and terminating at the top in a slanting surface, while in cultivated oats it is thread- like throughout its entire length. In threshed grain many of these distinguishing marks may be broken off but usually some remain. False Wild Oats, often confused with the above, are a form of cultivated oats. The plants appear to be identical with those of the cultivated variety in which they occur but the seeds resemble those of Wild Oats in having both the long stiff awn and horseshoe-shaped base. They are, however, generally less hairy and stouter and do not differ in size from those of the cultivated variety in which they originate. False Wild Oats germinate readily the fall they ripen while the germination of true Wild Oats is deferred. Eradication. — It is impossible to clean land of Wild Oats in one or even two seasons,, but the following measures will greatly reduce their numbers and if persisted in will clean the land: Fall or spring discing followed by (a) shallow ploughing in early June with deeper ploughing in late July, or (b) ordinary ploughing in June sown to green feed. There is reason to believe that Wild Oats will not retain their vitality in the soil for more than five years. Seeding to grass and leaving in seed for this period should therefore prove effective in destroying them. 14 WEEDS AND WEED SEEDS Couch or Quack Grass (Agropyron repens (L.) Beauv.) is widely distrib- uted throughout Canada and a most injurious weed in all kinds of soil. It is perennial by wide-spreading but shallow fleshy % rootstocks, forming large matted beds. Flow- ering stems rather freely produced, smooth above, downy below. Flowers in 3 to 7-flowered spikelets, forming a narrow spike with the spike- lets lying flat against the stalk. Leaves dark green, rather distinctly rib- bed, and more or less hairy be- low. The seeds are seldom found in cereals, timothy or clover seed but occasionally in the coarser grasses, and in litter from hay or straw con- taining mature Couch Grass. Eradication. — To destroy this persistent weed let it exhaust its substance in the production of a hay crop, which should be cut and removed as soon as the head is formed and before it is in blossom. Plough shallow and cultivate until the rootstocks have been brought to the surface when they should be gathered and removed or burned. This may be followed by a cleaning crop of rape, buckwheat or millet and a hoed crop the next spring. In the Prairie Provinces shallow ploughing late in June when land is dry followed by back-setting as soon as possible in the fall and a thorough cultiva- tion the following spring, has given good results. Plough shallow after hay crop and unearth rootstocks with successive cultivation before growth is renewed. Docks (Rumex species). — The most common member of this group is Curled Dock (Rumex crispus L.) shown in the illustration. It is a perennial with a deep tap-root. Stem 2 to 3 feet, smooth, erect, terminating in wandlike racemes. Root- leaves, oblong-lance-shaped in outline with much crested or waved margins, 6 to 12 inches long, on long stalks; stem-leaves on short stalks and much smaller or absent towards the top of the stems. Curled Dock is a common weed in meadows, pastures and waste places through- out Canada, being very abundant in southern and western Ontario. The seeds of the Docks ** are commonly found in clover AvW seed. They are very similar in <^.\%\ appearance, but have the fol- i B^ft lowing points of differentiation: IH W Curled Dock seeds, illustrated, ^HV * ^ of an inch long, shaped ^ir V like a miniature beech-nut, nearly symmetrical, both ends pointed, widest near the centre, the edges very slightly margined, reddish brown and highly shiny; Clustered Dock (Rumex conglomeratus Murr.), apex of the seed pointed, base rounded, smaller, plumper, dark reddish brown; Bitter Dock (Rumex obtusifolius L.), seed unsymmetrical, widest below the centre, edges unmargined, the base with a rough scar, brownish yellow, dull. Eradication. — Short rotation of crops. Hand pulling. WEEDS AND WEED SEEDS 15 Russian^ Thistle (Salsola Kali L., var. tenuifolia G.F.W. Mey.) is an annual introduced from Asia. It is abundant in several localities in the dryer parts of Alberta and Saskatchewan, chiefly along roadsides, fire-guards and in neglected fields and is frequently found, though not seriously troublesome,, in the eastern provinces. Russian Thistle is a large succulent weed and thrives where the land is too dry for other plants. It is bushy, of a prickly appearance, due to the thin, thread-like, prickle-tipped leaves which characterize the young plant, and the short, triple, spiny ^ k ^ bracts on the flowering branches of the older plants. It varies in appearance at different stages of growth. The young plant is dark green, the slender leaves, about two inches long, drop off soon after the seed is formed. The some- what spherical branched top of the mature plant, when broken away from the root, is blown about by the wind and scatters its seeds widely. It is not a thistle and could be more appropriately called a tumble weed. Flowers solitary, borne in the axils of the leaves. The seed is about T*g- of an inch in diameter, cone- shaped, the large- end concave with a well marked protuberance in the centre of the cavity. The coat is thin and transparent, showing the grayish-brown, coiled germ. The seeds are generally enclosed in a papery envelope, the divisions of -which are winglike. They occur quite frequently in imported alfalfa seed. Eradication. — Badly infested fields should be seeded to grass. Avoid spring cereal crops. Purple Cockle (Agrostemma Githago L.) — Introduced from Europe. An- nual and winter annual. Erect, 1 to 3 feet high; branches few; whole plant covered with soft, silky hairs; not viscous. Leaves 2 to 5 inches long, narrow and pointed. Flowers purple, borne at the tips of the stems and branches, If inches across. Fruit capsule ovoid, with 5 teeth at the apex. It occurs in grain fields throughout Canada. The seed is pitchy black, from ^ to J of an inch in diam- eter, somewhat flattened, rounded triangu- lar; the thin edge notched by the scar of attachment; rough, covered with rows of short teeth. It is difficult to separate the seeds from wheat without a heavy loss of grain. When ground with wheat, the seeds give the flour a dark colour and a bad flavour. They are a ^W^ f| very common impurity in seed wheat and are found less frequently in seed oats. Eradication. — Summer fallow. Hand pulling. 16 WEEDS AND WEED SEEDS Night-Flowering Catchfly {Silene noctifiora L.). The name of this plant is quite apt. The stems are covered with a sticky substance, by which small insects are often entangled on the stems and leaves. Its few, large, creamy white flowers open at night or during a cloudy day and close when the sun shines. The stem is from one to three feet tall, rather stout, branching. Catchfly is a very common weed in meadow and grain fields and in hoed crops. It is a rank grower and heavy seeder and is particularly trouble- some in clover fields. Its seeds are impossible of separation from alsike except by the use of special machinery, and consequently seed harvested from fields containing much catchfly, must be sold at a very low price. From timothy and red clover its seeds are separated with only a little less difficulty than in the case of alsike. On account of the plant's pungent flavour and woody texture it is objectionable to live stock, whether in pasture or cured fodder, and when at all prevalent in hay a considerable waste results. The seed is about ■£$ of an inch in diameter, very slightly flattened, dull grayish-brown, with 8 to 10 curved rows of tubercles on each side. Eradication. — As the plant is propagated entirely by seeds its suppression is accomplished by preventing it from seeding and by inducing the seeds already in the soil to germinate and then killing the seedlings. Catchfly will not long give trouble on land worked under a short rotation of crops. Its appearance in alsike fields is largely due to its being sown with the clover seeds. Bladder Campion {Silene latifolia, (Mill) Britten and Rendle) and White Cockle {Lychnis alba, Mill) are near relatives of catchfly. The seeds of these two plants are not nearly so common in clover and timothy seed, but the plants are much more diffi- cult to eradicate from fields in which they become established. Bladder campion is perennial, with deep-running root stocks and is the most dangerous weed of this group. It has become widely dis- tributed in the eastern provinces during recent years, and has proven to be very difficult to sup- press. The whole plant is pale green and in the common form perfectly smooth; stems one foot to eighteen inches high, forming large tufts; leaves in pairs, meeting round the stems; flowers white, nearly an inch across, drooping; calyx much in- flated, pale green, veined with bright purple, toothed at the contracted apex. White cockle is a biennial or short-lived perennial, sparingly distributed in Ontario as yet. The rootstocks are thick, sending up a few short barren shoots and long branching flowering stems, 1 to 2J feet high. The whole plant is viscous hairy, but not so much so as catchfly. It is wider branching, has many stems, the leaves are larger, the flowers more numerous and pure white. WEEDS AND WEED SEEDS 17 Eradication. — Prevent seed production. Seeding to clovers and grasses gives these plants an opportunity to establish themselves. If the infested ground is in meadow, it should be broken up and a rotation of crops adopted that will allow for deep and thorough cultivation eachfTspring before seeding and again as soon as the crop is removed, as could be given by sowing peas, vetches or other crops to be cut green for fodder, followed by a hoed crop, and the third year cereal grains. Occasional plants in new seeding can be destroyed by apply- ing a handful of salt to the root after cutting in hot; dry weather. • t. White Cockle. Catchfly. • Bladder Campion. c;S^ The seeds of the three plants are very similar in appearance. With catchfly the tubercles with which the surface of the seed is covered are not symmetrically arranged, while with bladder campion and white cockle they are in concentric rows. With white cockle the rows are slightly farther apart than with bladder campion. Cow Cockle (Saponaria Vaccaria L.) — Introduced from southern Europe, Annual. Stem simple, branching above or much branched from the base, 1 to 2J feet. The whole plant is smooth, succulent and of a gray- ish-green appearance, like the leaves of a cabbage. Leaves ovate-lance-shaped, clasping the stem. Flowers pale rose- pink, |-inch across, in loose corymb-like cymes. Calyx ovate, 5-ribbed and much inflated, winged and angled in fruit. The smooth roundish fruit capsules contain about 20 seeds each. A troublesome weed only in the Prairie Provinces. The seed is round, hard, dull black, about -^ inch in diameter, and is often confounded with the seeds of wild vetches. It can be distinguished from vetch seeds of a similar size by its minute- ly roughened surface, or by cutting it open after soaking, when the germ, which lies in a circle around the seed just be- neath the seed-coat, will be seen. It in no way resembles the inside of a vetch or pea, which when the seed-coat is re- V moved after soaking, can be easily sep- arated into similar halves. The seeds are a common impurity in commercial wheat and are almost as objectionable to the miller and baker as are those of Purple Cockle. Eradication. — Summer fallow. Hand pull to prevent seeding. 36446—3 18 WEEDS AND WEED SEEDS Stinkweed (Thlaspi arvense L.) Introduced from Europe. Annual and winter annual. Whole plant bright green and quite smooth. Root leaves borne on foot stalks; stem leaves clasping the stem with the arrow-shaped base. Flowers clear white, J of an inch across. Pods flat, J- inch across, pale green and winged, notched at the top. Just before the seeds ripen the pods turn a characteristic greenish-orange shade, easily noticed when this weed is growing among crops. Stinkweed is now found in every pro- vince in Canada, but nowhere is it such a terrible pest as in the Prairie Provinces where it was introduced with the first settlers. The seed is about ^ of an inch across, a little longer than broad, deep purplish-brown, un- symmetrically oval in outline, flattened, with rounded edges. The flattened surface has 5 or 6 loop-like lines, which start at the basal scar or notch and run concentrically around a central groove, are frequently found in western grain and grass seeds. i The seeds Eradication. — Summer fallow. Disc as soon as the grain crop is removed. Late fall and early spring cultivation. Harrow once or twice when grain is two or three inches high. Western False Flax (Camelina sativa (L.) Crantz). — Introduced from Europe. Annual and winter annual, 2 to 3 feet high, erect, slender, branching near the top. Root-leaves lance-shaped and narrowed into a foot stalk; upper leaves arrow-shaped, sharply pointed. The lower leaves and the lower part of the stem downy with star-shaped hairs. The upper part of the stem smooth and covered with a fine bloom. Flowers numerous, small, |-inch across, pale greenish-yellow. Pods f-inch long, balloon or pear-shaped, margined and tipped with a slender beak, on slender foot-stalks, curv- ing upward, each containing about 10 seeds. Seeds yellowish-brown, I about ^-inch long. The minia- ture root of the germ very promin- ent, lying along the seed. Seed- coat finely pitted. The seed is a very common impurity in flax, especi- ally from Western Canada. It also occurs in Ontario, particularly in fall wheat. False Flax. WEEDS AND WEED SEEDS 19 y"m. \ Flat- seeded False Flax (Camelina dentata Pers.) was introduced into Manitoba in 1906 with imported flax seed. The seeds vary much in shape and size, being generally larger than those of Western False Flax, irregularly oval or oblong in outline, thickly flattened and pale yellow in colour. The plant may be distinguished by its early leaves, which are broadly dentate. The seed is found chiefly in flax seed. Eradication. — False flax is propagated entirely by seeds. Prairie soils infested with the weed should receive a thorough discing or shallow ploughing in the spring before seeding. When a crop of winter wheat is infested, harrowing in the (j spring kills the young plants without injuring the wheat. Badly infested fields should receive a thorough summer-fallow, Flat-seeded with cultivation the previous fall. False Flax. Small -seeded False Flax (Camelina microcarpa Andrz) resembles # Western False Flax but is more slender and has smaller pods. The • seeds are only about -fa of an inch long, dark reddish-brown; scar of attachment a white point in a notch at the base of the seed. They often occur in large quantities in alsike and timothy seeds. * ♦ 9 Eradication. — This weed does not long give serious trouble where Small-seeded a short rotation of crops is practised and where thorough cultivation False Flax. and seeding to grasses is done with spring grains instead of fall wheat. The first crop of alsike in the fall wheat districts usually contains some false flax and should not be taken for seed unless the weeds are first hand- pulled and destroyed. Ball Mustard (Neslia paniculata (L.) Desv.). — Introduced from Europe into the West about the same time as Tumbling Mustard, Hare's-ear Mustard and Cow Cockle. A tall annual or winter an- nual. Stems erect, very slender; strong plants throwing out a few long branches. Whole plant yellowish-green and covered with small, appressed, star-shaped hairs. Lower leaves lance-shaped, narrowed at the base; stem leaves arrow-shaped, clasping the stem at the base, blunt-pointed. Flowers small, f of an inch across, orange-yellow. Ball Mustard is very prevalent in the Prairie Provinces. The seed is enclosed in small, round, one-seeded, shot-like pods, com- monly called "seed," which are borne on slender foot-stalks, about J-inch in diame- ter, roundish, green- ish-brown, roughly net- veined, somewhat like a small piece of dry earth. The contained seed is yellow, with the miniature root of the germ prominent. The whole pods are generally found in grain, as they do not open to discharge the seed. Eradication. — Similar to Stinkweed and False Flax. i 20 WEEDS AND WEED SEEDS Wild Radish (Raphanus Raphanistrum L.). — Introduced from Europe. Abundant in the Maritime Provinces. Annual and winter annual, 1 to 2 feet high, with a few long branches starting low down. The root is slender, not swollen as in the garden radish. The plant resembles Wild Mus- tard but the flowers are fewer and larger, notice- ably paler yellow and conspicuously veined. The constricted seed pods are the most distinctive characteristic; with these no mistake can be made in identifying the two plants. In Wild Radish the seed pods have no valves, but are composed of two joints, the lower one small, ^ of an inch, and seedless, which remains attached to the footstalk; the upper cy- lindrical, lj inches long, with several one-seeded cells form- ed by transverse partitions. This seed-bearing portion sep- arates from the first joint, leaving it attached to the footstalk; in threshing, it is often broken up into single- seeded sections. The seed itself varies much in size and shape, being about f of an inch long, oval, irregular, slightly flattened, reddish brown, the surface very finely netted. The seed pods are frequently found in grain, especially oats. Wild Radish is a coarse, vigorous weed, not less objectionable than Wild Mustard though less difficult to suppress. Grain crops polluted with it are troublesome to harvest as the bulky nature of the plants prevents the elevation of the grain in self-binders and greatly increases the amount of binder twine required. Eradication. — Summer fallow. Hoed crops with thorough cultivation. Rotation of crops. Wild Mustard (Brassica arvensis (L.) Ktze)., and other wild Brassica species. — Wild Mustard is the commonest and one of the most injurious weeds belonging to the Mustard family. It is general throughout Canada in farm crops and waste places, being especially abundant along river valleys. It is an annual. Stems erect, branch- ing, 1 to 3 feet high, rough, with stiff, somewhat downward directed hairs. The purple at the junction of the branches with the stem is a striking characteristic. Flowers bright yellow, fragrant, f-inch across. Seed pods 1 to 2 inches long, knotty or slightly constricted between the seeds, ribbed and rising obliquely on short, thick footstalks, tipped with a long empty or one- seeded, two-edged beak, which breaks away whole from the ripe pod. Each pod contains about 15 to 17 seeds. When ripe the pods split and much of the seed is left on the land at harvest time; thus the plant rapidly increases on land devoted to cereal grains, particularly oats. The seeds vary somewhat in size, but are generally about -fa of an inch in dia- meter, quite round, dark brown or reddish black, almost smooth to the naked eye but slightly pitted under a glass and have a decidedly pungent taste. They are frequently found in great numbers in grain and occasionally they occur in small seeds. Among the other wild Brassicas, not so common, the seeds of which closely resemble those of Wild Mustard, are Indian Mustard (Brassica juncea (L) Cosson), Black Mustard (B. nigra (L.)Koch) and Bird Rape (B.campestrisL.). Eradication. — Similar to Stinkweed. Avoid cereal crops where practicable. WEEDS AND WEED SEEDS 21 Hare's-ear Mustard (Conringia orientalis (L.) Dumort). Introduced from Europe, probably with flax seed, about 1892. Annual and winter annual. Stems erect, with few branches, 1 to 4 feet high. Whole plant perfectly smooth, and, when young, covered with a fine bloom like that of cabbage. Leaves fleshy, without teeth, the root-leaves obovate, gradually narrowed to the base; those on the stiff stems, which become wire-like when ripe, oblong oval, shaped like a hare's or a rabbit's ear, clasping the stem by two rounded, ear-like lobes. Flowers creamy-white, J inch across. Pods square, 3 to 4 inches long. • Hare's-ear Mustard is quite gen- eral throughout the Prairie Prov- inces, especially in southern Al- berta, in grain fields, on stubble and by roadsides; spreading rapid- ly. The seed is dark-brown, 0 rounded oblong, pointed at the scar end, tV of an inch long, granular roughened; when soaked in water, covered with short, erect, white mucilaginous hairs. In shape it resembles the seed of common False Flax. The seeds are commonly found in western grain. Eradication. — Similar to Stinkweed. reduce this pest A few years in meadow will greatly Tumbling Mustard (Sisymbrium altissimum L). — Introduced into the Prairie Provinces from central and southern Europe about 1887. Annual and sometimes winter annual; 2 to 4 feet high, stem branching, the lower part and the root leaves downy and glandular, with a musky odour; upper part of the stem and the much divided leaves smooth. The young plants form a rosette of soft, pale green, downy leaves, shaped much like those of the dandelion. On the flowering plants the leaves change very much in shape from the root up, no two being alike. Flowers pale yellow, f inch in diameter. Seed pods 2 to 4 inches long, very slender and produced abun- dantly along the branches. Each pod contains about 120 seeds, and a single plant has borne as many as 1,500,000 seeds. When the seeds are ripe the whole head of the plant breaks off and is blown across the prairie, scattering the seeds far and wide. The seeds, as in many "tumbling weeds," are not easily shed from the tough pods; consequently a head of this weed may blow about the prairie for a whole winter, dropping a few seeds at intervals for many miles. It occurs in grain fields and along roadsides. The seed is small, -£% of an inch long, olive brown or greenish yellow, minutely roughened with mucilaginous glands, oblong, angular, cut off transversely at the scar end, sometimes almost square from compression in the pod, grooves conspicuously darkened. The miniature root of the germ is prom- inent and plainly visible through the thin skin. Eradication. — Similar to that given for other mustards. •J • ).) WEEDS AND WEED SEEDS Wild Carrot (Daucus Carota L). — Introduced from Europe and now spreading rapidly in the clover seed producing districts of Ontario. It is an objectionable weed along roadsides, waste places and old meadows and occasionally gives trouble in cultivated fields. Biennial, with a large succulent root. Stems, flowers and leaves as in cultivated carrot. The fruit when ripe separates into two seed-like halves, commonly called seeds, each having 5 inconspicuous ribs running lengthwise and 4 winged secondary ribs bearing a row of barbed prickles which are easily rubbed off. The true seed is inside the fruit. The seed in the fruit is becoming quite a common impurity in Canadian grown red clover seed, but is more frequently found in imported stock. It seldom occurs in alsike. Eradication. — Wild Carrot can best be kept in check in cultivated fields by a regular rotation of crops with thorough cultivation of hoed crops. Old meadows infested with it should be broken up and cultivated for a few years. Sheep will help to suppress it in pasture lands. Field Bindweed (Convolvulus arvensis L). — Introduced from Europe. Perennial, deep-rooting, with extensive, creeping, cord-like fleshy rootstocks; these throw up numerous slender branching and twining smooth stems, which form thick mats on the surface of the land and twist around any plants growing within reach, using them as sup- ports and choking them out. Leaves about 1 to 1\ inches long on slender stalks, ovate or heart- shaped, arrow-shaped at the base. Flower- stalks slender, about the same length as the leaves, provided with miniature leaves at some distance below the large, open, funnel-shaped pink flowers, which are over ^~^ an inch across. Fruit a round, _^^fck & mk cartilaginous, 2-celled capsule Jl H containing 3 to 4 seeds. The B B B B seed is rather large, £ of an H Bff ^H W *nck l°n&> dark brown, pear- ^r to^G^ shaped; one face convex, the ^ other bluntly angled with flat sides. Surface roughened with small tubercles; the basal scar is a roughly lined, reddish depression at the lower pointed end. Field Bindweed is exceed- ingly hard to eradicate because of the almost incredible persistence of the fleshy rootstocks. Although widespread throughout the Dominion and in restricted localities very troublesome, it is not yet a very common weed of Canada. The seeds are not often found in grain or clover seed. The plant propagates mostly by rootstocks and in many localities produces few seeds. Eradication. — Persistent cultivation to prevent leaves forming, small patches with straw or manure. Smother WEEDS AND WEED SEEDS 23 Clover Dodder (Cuscuta species). — Introduced from Europe. An annual parasite with slender yellowish and reddish stems, which twine about the host plant and become attached to the clover stems by suckers through which it obtains nourishment from the host. Flowers whitish or pinkish, in clusters along the thread-like, twining stems. There is prob- ably no weed legislated against so much as Dodder. It is a serious pest in southern Europe, parts of the United States, Chili, and other temperate to warm climates having long summer seasons without frost. During years of shortage in clover-seed crop of Canada it has frequently been introduced and widely distributed in imported seed; but its ravages have been noted on red clover in only a few instances, and those in southern Ontario and the Pacific coast in years Wk Jfi^ following an exceptionally late fall I I I B without frost until October. The seed ^Hr wm *s sma^> from ^ to -fa of an inch in $ jyr diameter, yellow or brown, irregularly spherical, and more or less angled on the inner scar-bearing side; the surface granular roughened. Alfalfa Dodder has given trouble in southwestern Ontario and in the Prairie Provinces,, where it is known to have continued in alfalfa for three years. Eradication. — Badly infested fields should be ploughed under before seed forms. Small patches may be cut out and destroyed. Blue Bur or Stickseed (Lappula echinata Gilibert). — Introduced from Europe. Annual and winter annual. Erect, branching, whole plant covered with short white hairs, which give it a grayish appearance. Leaves linear-oblong; root-leaves about 3 inches long, nar- rowed at base; stem-leaves stalkless. Flowers small, about J-inch across, pale blue, erect, in leaf}', more or less <(7\ffi* j fcifitS one-sided racemes, and with minute bracts. It occurs by > ¥