) h, U S. DEPARTMEN I ( >F AGRICULTURE, I'.l REAU OF PLANT [ND1 STRY Circular No. •-'. i l.i IW \\ Chic of !*';•■ AN IMPROVED METHOD OF SEPARATING BUCKHORN FROM RED CLOVER AND ALFALFA SEEDS. HARRY 1'.. SHAW, Scibntifk Assistant, Sugar-Beet Investigations. . :■>;-, i in-,, j— os WASHINGTON : GOVERNMENT PRINTING OFFICE : 1908. BUREAU OF PLANT INDUSTRY. Pathologist and Physiologist, and Chief of Bureau, Beverly T. Galloway. Pathologist and Physiologist, ami Assistant chief of Bureau, Albert F. Woods. Laboratory of Plant Pathology, Erwin F. Smith, Pathologist in Charge. Investigations of Diseases of Fruits, Merton B. Waite, Pathologist in Charge. Laboratory of Forest Pathology, Haven Metcalf, Pathologist in Charge. Truck Crop Diseases and Plant Diseast Survey, William A. Orton, Pathologist in Charge. Plant Life History Investigations, Walter T. Swingle, Physiologist in Charge. Cotton Breeding Investigations, Archibald D. Shamel and Daniel N. Shoemaker, Physiolo- gists in Charge. Tobacco Investigations, Archibald D. Shamel, Wightman W. Garner, and Ernest H. Mathewson, in Charge. Corn Investigations, Charles P. Hartley, Physiologist in Charge. Alkali and Drought Resistant Plant Breeding Investigations, Thomas II. Kearney, Physi- ologist in Charge. Soil Bacteriology ami Water Purification Investigations, Karl F. Kellerman, Physiologist in Charge. Bionomic Investigations of Tropical and Subtropical Plants, Orator F. Cook, Bionomist in Charge. Drug and Poisonous Plant Investigations and Tea Culture Investigations, Rodney H. True, Physiologist in Charge. Physical Laboratory, Lyman J. Briggs, Thysicist in Charge. Crop Technology ami Filar Plant Investigations, Nathan A. Cobb, Crop Technologist in Charge. Taxonomic and Range Investigations, Frederick V. Coville, Botanist in Charge. Farm Management Investigations, William J. Spillman, Agriculturist in Charge. Groin Investigations, Mark Alfred Carleton, Cerealist in Charge. Arlington Experimental Farm, Lee C. Corbett, Horticulturist in Charge. Vegetable 'listing Gardens, William W. Tracy, si-., Superintendent. Sugar-Beet Investigations, Charles O. Townsend, Pathologist in Charge. Western Agricultural Extension Investigations, Carl S. Scofleld, Agriculturist in Charge. Dry-Land Agriculture Investigations, E. Channing Chilcott, Agriculturist in Charge. Pomological Collections, Gustavus B. Brackett, Pomologist in Charge. Field Investigations m Pomology, William A. Taylor and G. Harold Powell, Pomologists in Charge. Experimental Gardens and Grounds, Edward M. Byrnes, Superintendent. Fon kiu Seed ami Plant Introduction, David Fairchild, Agricultural Explorer in Charge. Forage Crop Investigations, Charles V. Piper. Agrostologist in Charge. Seed Laboratory, Edgar Brown, Botanist in Charge. Grain Standardization, John D. Shanahan, Crop Technologist in Charge. Subtropical Laboratory and Garden, Miami, Fla., Ernst A. Bessey, Pathologist in Charge. Plant Introduction Garden, Chico, Cal., August Mayer. Expert in Charge. South Texas Garden, Brownsville, Tex., Edward C. Green, Pomologist in Charge. Cotton Culturt farms and Fannies' < imperative Demonstration ~\York, Seaman A. Knapp, Special Agent in Charge. Seed Distribution (Directed by Chief of Bureau), Lisle Morrison, Assistant in General Charge. Editor, J. E. Rockwell. Chief clerk, James E. Jones. |Circ. 2] 2 CONTENTS. Introduction 5 The mucilaginous property ol buckhorn seeds 6 Coating buckhorn seeds after moistening them t> The dry sawdust method oi separation 7 Sieves or screens 8 Alfalfa or red clover seeds in two grades 9 The kind of Bawdusl to use 10 Drj sand or road-dust method 10 Wet sawdust method 11 An alternative method ind method Agglutinative method Method of separation uol injurious to clover and alfalfa seeds 12 [CiTi LLUSTRATIONS. Page. Fig. 1 . Typical plant of buckhorn ( Plantago lanceolata L. ) 5 2. Seeds of alfalfa (a); seeds of buckhorn (b) 6 3. Alfalfa seeds (a); normal buckhorn seeds (b); immature or abnormal buckhorn seeds (c) 7 4. Buckhorn seeds coated with a grade of sawdust too coarse to pass through a No. 22 mesh (a) ; similar seeds coated with sawdust passed through a No. 22 mesh and from which very fine particles have been screened out (6); similar seeds coated with very fine sawdust (c); similar seeds coated with white sand (d) 8 5. Perforated sheet zinc for sieve to separate average grade of red clover and alfalfa seeds. Holes one-fifteenth inch 8 6. Box screen designed by the writer, with interchangeable sliding frames for various sizes of mesh. Suggested for the use of the farmer who may raise but a few acres of clover or alfalfa 9 7. The same screen shown in figure 6 with the frame withdrawn to show construction 9 8. Mixed sawdust passed through a No. 22 mesh (a); sawdust of same grade as a but with fine particles (c) sifted out through a No. 36 mesh (b) (the grade which should be used); fine sawdust sifted from b; too fine sawdust (c) 10 9. Fescue chaff (a); buckhorn seeds coated with chaff (b) 11 10. Small seed balls, each being a buckhorn seed to which alfalfa seeds cling 12 [Circ. 2] 4 B !' I AN IMPROVED & BUCKHORN AND A ETHOD OF SEPARATING FROM RED CLOVER PALFA SEEDS. INTRODUCTION. Many varieties of weeds are more or less commonly found in clover and alfalfa. Among these none is more common or more pernicious than li ii c k h o r n I Plantago la n ■ lata I., i . T li i s weed, \\ hich is also known as English plantain, rib-grass, and ribwort, is a perennial plant i fig. 1 I naturalized in this country from Europe. It fruits freely and can not be eradi- cated by mow ing because the lea \ es form a rosette close to the ground. T he seeds of buckhorn < fig. 2, b) are of the same general size, shape, weight, and color as those of red clover and alia I la (fig. •_>. a), and vary to ahoiii the same i s tent in these char acteristics. For this reason it has hitherto been found impracticable to separate the seeds of buckhorn from those of red clover and alfalfa Fig. 1. -Typical plant of buckhorn (Plantago lanceolata I. I. From "Farm Weeds in Canada," issued hy the Departmenl of Agriculture of the Dominion of Canada. i nder Instructions from Mr. Woods, Assistant Chief of Bureau, Mr. Shaw undertook to work out a satisfactory method of separating buckhorn seeds from [Clrc. 2] 5 6 SEPARATING BUCKHORN FROM CLOVER AND ALFALFA SEEDS. ■»« 1 / -' * # •••»* % '% * t * % « £ -% ~ *•«* % * / % # • ' ' \ Fro. 2. — Seeds of alfalfa (a) ; seeds of buckhorn (6). (Natural size. \ by means of any of the methods or machines in use. Most other weed seeds may be cleaned out without much trouble, owing to differences between them and clover seeds in one or more particulars. Many trials were made in the Bureau of Plant Industry with the best known types of cleaning machines, but the y failed to ef- fect a satis- factory sep- aration of bue kh orn seeds. Ex- peri m e n t s were then undertaken to work out an efficacious method that should be inexpensive and available alike to the farmer and to the seedsman. THE MUCILAGINOUS PROPERTY OF BUCKHORN SEEDS. The only point of sufficiently marked difference between buckhorn and clover seeds seemed to be the well-known mucilaginous character of the former. This mucilaginous character is possessed also by the seeds of peppergrass (Lepidium virginicum L.) and false flax (Camt - Una sativa Crantz). The mucilage forms a comparatively thick. glossy, transparent, external coating on the normal healthy buckhorn seed and is very absorbent of water. When moistened the seed becomes much swollen and very adhesive. A very small percentage of buckhorn seeds is found to be nonmucilaginous ; these are immature or abnormal seeds and possess low vitality. COATING BUCKHORN SEEDS AFTER MOISTENING THEM. The idea suggested itself that after moistening the seeds and thus developing the adhesiveness of the buckhorn seeds, an insoluble sub- stance in a fine state of division might be mixed with them, and that a portion of this substance would adhere to the buckhorn seeds. The latter would thus be increased in bulk, surface friction, etc., and might then be separated from the clover or alfalfa seeds by means clover. The results have been so satisfactory thai it is deemed wise to present them briefly for the information of fanners and seedsmen. An application for a patenl on the processes described to permit their general and unrestricted use by the public has been filed. — B. T. Galloway, Chief of Bureau, [Circ. 2] SEPARATING BUCKHORN FROM CLOVEB \M> \ll\U\ SEEDS. 7 of one of the common types of seed separators, or even by hand sieves. This proved to be the case with the exception of a very small per centage "f nonmucilaginous bnckhorn seeds (fig. 3, • I. / * r ' a *~ I % \ few G Fig. .';. — Alfalfa seeds (a) ; normal buckhorn s.nis 1 1, i : Immature or abnormal buckhorn eeds (c). i Enlarged three diameters, i The methods worked oul on this principle arc inexpensive, expe- ditious, and may be carried nut with the machines already in common use, or even with hand sieves, ami the materials needed arc likely to be accessible t<> every farmer ami seedsman. THE DRY SAWDUST METHOD OF SEPARATION. The alfalfa or red clover seeds infested with buckhorn are covered with water of about room temperature ami well stirred in order to uei all the seeds thoroughly. The seeds are allowed to stand in the water for five minutes it' the latter i- 65 \\ or over and for eight minutes it' below thai temperature. The water i- then drained oil thoroughly. This may he done with any common -trainer or sieve of about 22 meshes to the inch. The moisl seeds are then scattered into dry sawdust and thoroughly mixed until tin' seeds fall apart freely and no -mall seed masses remain. This mixing may he done with the hand-, with a rake on the barn floor, or with any suitable apparatus. It may he accomplished in two or three minute-, when it will lie found that the sawdust ha- absorbed the free surface moisture from the alfalfa seeds, ami that all the mucilaginous buck- horn seeds have become coated with the sawdust t fig. t). The proportion of dry seeds to sawdust should be as follows: Seed-. one part : sawdust, four or five parts, preferably five parts if resinous -aw dust 1"' used. [Clrc. 2] SEPARATING BUCKHORX FROM CLOVER AND ALFALFA SEEDS. SIEVES OK SCREENS. Two screens are required to effect the separation of buckhorn seeds and sawdust from alfalfa seeds: an upper one of sheet zinc perfo- Fig. 4. — Buckhorn seeds coated with a grade of sawdust too coarse to pass through a Xo. 22 mesh (a) : similar seeds coated with sawdust passed through a Xo. 22 mesh and from which very fine particles have been screened out (6) ; similar seeds coated with very fine sawdust (c) : similar seeds coated with white sand (d). (Natural size.) rated with round holes of one-fifteenth-inch diameter (fig. 5), and a lower one of No. 22 mesh wire cloth. The mixture of seeds and saw- dust is fed continuously upon the upper screen. The sawdust and free seeds pass through to the lower screen, and the coated buckhorn seeds are retained. The sawdust alone will pass through the lower screen, leaving the clean al- falfa seeds to lie discharged by thai screen into any suit- able receptacle. Care should be taken that too great a quan- tity of the mixture is not fed upon the upper screen at once. in which case some of the less heavily coated buckhorn seeds may be thrust through, or the sawdust may be rubbed off and the buckhorn seeds allowed to escape. The separation may be undertaken as soon as a thorough mixture of the seeds and sawdust has been effected. The two screens may be used together in a light frame such as may be constructed by any carpenter or by the farmer himself. They may be used in a seed [fire. 2] Fig. 5. — Perforated sheet zinc for sieve to separate average grade of red clover and alfalfa seeds. Holes one-fifteenth inch. x.'ii ural size I SEPARATING BUCKHORN FROM CLOVER AND ALFALFA S] 9 separator, or in some such box as thai shown in figures 6 and 7 it' only a small quantity of seeds is to be treated. On the other hand. the seedsman may blow "lit the saw- dust with a fan and separal e the buckhorn w i t h a screen. The most common t \ pe of seed cleaner is a combination id' fan and -ir\ es, the \\ hole separat ion hid ng effected i n One Operation. ].-,, ; . r, \-... designed by the writer, with Interchange- Should the t \ i )i ■ ill' :l1 '''' sliding frames for various sizes of mesh. Suggested for the use of the farmer who mav raise l>ut ;i few acres. machi in 1 be em- , iV ,t or alfalfa. ployed that oper- ates by means of inclined piano, rebounding angles, and an oscil lating motion, the sawdusl should first be fanned or sifted out : then such a machine will effect a very complete separation of the buckhorn seeds. ALFALFA OE RED CLOVER SEEDS IN TWO GRADES. Should the first-mentioned type of machine or should hand sieves be employed for this work, it is advised that the clover or alfalfa seeds be first separated into two grades those pa - - i ng t h fou gh a round hole of one-fif- teenth inch and those too large to pass through such a hole. The latter grade will be found t o eon tain coin pa ra tivel y few buckhorn seeds and will represenl but a small proport ion of the total seeds. The buckhorn should be se pa ra t ed from the smaller grade by the sheet zinc sieve already mentioned, and from the larger grade through a similar sieve having holes one-thirteenth [CIrc. I'] Flo. 7. — 1 ii shown in figure 6 with Hi frame withdrawn to show construction 10 SEPARATING BUCKHOBN FROM CLOVER AND ALFALFA SEEDS. of an inch in diameter. If the seeds are thus divided into two grades very few clover or alfalfa seeds will he carried over with the 1 nick- horn seeds. The old methods cause a good deal of waste in this respect. THE KIND OF SAWDUST TO USE. Sawdust from any kind of wood may he used. Some of that used by the writer was mixed sawdust from a carpenter shop and some was from a planing mill. All sawdust too coarse to pa<> through a Xo. 22 mesh should he discarded, a- well as that fine enough to pass through a Xo. 36 mesh (fig. 8). Fig. 8. — Mixed sawdust passed through a No. 22 mesh (a) ; sawdust of same grade as a but with fine particles (c) sifted out through a No. :\C> mesh (6) (the grade which should be used) ; fine sawdust sifted from h ; too fine sawdust (c). (Natural size i Mr. C. V. Piper, of the Bureau of Plant Industry, suggested the use of the chaff of various grasses, such as fescue and redtop. as being exceedingly light, absorbent, and of the proper size. Thi- was tried and found exceedingly successful. Whenever available it may be used in preference to sawdust (fig. 9). The chaff should be used in exactly the same manner and proportion as the sawdust. DRY SAND OR ROAD-DUST METHOD. This method is not considered quite as good as the preceding. Road dust and sand are not nearly as absorbent as the materials just discussed; consequently, a larger proportion of them must be used. say. about one part of seeds to eight of sand or dust. Furthermore, being so much heavier than sawdust or chaff these materials entail more labor. However, the same method is applicable to them. All sand or dust too coarse to pass through a Xo. 36 mesh should be dis- carded, as well as that which is so fine as to pass through a No. 50 mesh (see i\ VLFALFA - 11 WET SAWDUST METHOD. Use four parts of sawdust prepared as described, two parts of seeds, and one part of water, all l>y measure. Sprinkle the sawdust with water, stirring or mixing meanwhile until the sawdust i- uniformly moistened. An ordinary watering pol may be used for this purpose. Mis in the seeds thoroughly. Compress the moist mass with the BHR * * : ^SJEUSmbb2E9B? ^ - 4 # ** * * 4 • ^. '/It V * - Fig 9 Fescue chaff {a) ; buckhorn seed coated with chaff (6). (Natural si hands or a shovel and let it stand for aboul fifteen minutes so that the buckhorn seeds may have time to thoroughly absorb moisture and become adhesive. Then break up the mass and spread out before a fan, in a current of air, or in a seed drier until quite dry. When dry. separate l>y any of the methods above described. AN ALTERNATIVE METHOD. Sawdust, eight parts; seeds, four parts; water, three parts. Mix the dry seeds and dry sawdust together; then sprinkle the water in and mix thoroughly, a- in the process just described. Separate as before. WET SAND METHOD. Proceed exactly as with the wet sawdusl methods, using the same proportions, but with perhaps rather less water. AGGLUTINATIVE METHOD. Moisten the seeds as in the wet sawdust method; drain them thor- oughly; place them in a pervious vessel of any kind. In these ex periments a piece of perforated sheet zinc was converted into a cj lin- [Circ. 2] m £ % A *J 8w. 4* * 4* T Fig. 10. — Small seed balls, each being a buckhorn seed to 1 which alfalfa seeds cling. i Natural size, i 12 SEPARATING BUCKHORN FROM CLOVER AND ALFALFA SEEDS. drical vessel. Pack the seeds into such a vessel or into shallow trays having wire-cloth bottoms of No. 20 mesh, or finer. Set these recep tacles before a fan, in a current of warm air, in the open air and sunshine, or in a seed drier until the alfalfa seeds fall apart freely When moderately dry. screen them through sieves as mentioned in describing the dry sawdust method. If the seeds are made too dry the clover will be too easily detached from the buckhorn. The alfalfa seeds will pass through the sieves, but the buckhorn seeds will be found to have collected about themselves a small number of alfalfa seeds, thus forming small seed balls (fig. 10), and these seed balls will not pa — through the sieve. The loss of good seeds by this method obviously will depend on the num- ber of buckhorn seeds pres- ent, but the good seeds thus thrown out may be saved afterwards by one of the other methods if desired. This method is the simplest and, aside from the percentage of alfalfa seeds clinging to the buckhorn seeds, the cheapest to operate. Ordinarily this loss will be from ."i to 10 per cent. METHOD OF SEPARATION NOT INJURIOUS TO CLOVER AND ALFALFA SEEDS. In order to be able to assure the readers of this paper that the red clover and alfalfa seeds cleaned by these method- are not injured, germination tests were made with both treated and untreated seed-. No difference in the average germinability could be discovered. Since the operations subsequent to the application of the sawdust, chaff, etc.. are identical with ordinary seed-cleaning processes, other impurities will he eliminated at the same time. Approved : James Wilson. Secretary * >- i- to ^' to ^j | (£ — lil > 7 SSS^ST- D ==^ _ 1 o