SB | | BULLETIN No, 24, 7 hey H ©? : U. S. DEPARTMENT OF AGRICULTURE. DIVISION OF BOTANY DHE S GERMINATION OF SEEDS AS AFFECTED BY CERTAIN CHEMICAL FERTI “nw puns wo & — pase ep a~ Op He or + PELE ie fe g b WASHINGTON: GOVERNMENT PRINTING - OFFICH I IBRARY OF Cc Lae hE I Qoo. UNITED STATES OF # . BULLETIN No. 24. Poe Oe PARTMENT OF AGRICULTURE. ‘ DIVISION OF BOTANY. GO) es a> GERMINATION OF SEEDS AS AFFECTED BY CERTAIN CHEMICAL FERTILIZERS. BY | GILBERT H? HICKS. VY RNUFA TURES SVG IN SSS WASHINGTON: GOVERNMENT PRINTING OFFICE. 1goo, Ty 2, LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, DIVISION OF BOTANY, Washington, D. C., January 25, 1900. Sir: I have the honor to submit herewith, for publication as Bulletin No. 24, of this Division, a manuscript entitled “The Germination of Seeds as Affected by Certain Chemical Fertilizers,” by the late Gilbert H. Hicks, Assistant Botanist. Mr. Hicks left with the manuscript, which fortunately had been completed at the time of his death, a note acknowledging his indebtedness to Mr. John C. Dabney, formerly an assistant in the Division of Botany, for valuable help in conducting the experiments. Dr. H. W. Wiley, Chief Chemist of the Department, has courteously read the manuscript and suggested certain amendments which have been incorporated in the text. In the rapid extension of the use of chemical fertilizers in recent years, our knowledge of the precise physiological effects of this kind of fertilizers on different plants has not kept pace with the investiga- tion of their purely chemical relationship with the crops and soils on which they are used. The application of chemical fertilizers frequently takes place at the same or nearly the same time as the sowing of seed, and while experience has often shown the partial loss of a crop, appar- ently from some injurious influence of the fertilizer on the seeds, little definite practical knowledge has thus far resulted from these occasional accidents. The general conclusion that a commercial fertilizer, unless known to be of a noninjurious kind, should not be brought into direct contact with germinating seeds should be made the basis of estabiished practice. Respectfully, FREDERICK V. COVILLE, Botanist. Hon. JAMES WILSON, Secretary of Agriculture. D, ot D. pone HINOCICUTOM << 56S SSeS Sees» See ey a ee JEUEST OLY CHE DNHEN AIOE) 8 ee ee WOM Gh Mio XPORUMON US: ecmers- ces so oS ee = Rae co weenlnn sles cewt ewes ccc eeecces TMDLS) Syraltedan Ni AMERY Se ee See 2 ee nla SavyoneCrimMs On), CLOVEL SOCO << sac, sec cs coc cbs. cc wicca tccccsaciecss cence WonCGlimsvOns]—- 5 t~ ccc e ct lan cee eee a eee es ee 52 ge ot ILLUSTRATIONS. PLATE 1.—Fig. 1, Wheat experiment with potash. Right, check; left, potash sown in the rows. Fig. 2, Wheat experiment with phos- phoric acid. Right, sown in the rows; left, mixed with GHESOll as 58 222 oo a Bose Se SS oslo see een eee II.—Fig. 1, Wheat experiment with lime. Right, sown in the rows; left, mixed with the soil. Fig. 2, Wheat experiment with mixed fertilizers. Right, sown in the rows; left, mixed with thesoil) -2252- . 22 see see ee ee soomee Page. 11 THE (ERMIN ATION OF SEEDS AS AFFECTED BY CERTAIN CHEMICAL FERTILIZERS, INTRODUCTION. A large number of germination experiments have been made to ascer- tain the effect of different chemicals upon the sprouting of seeds. In earlier times the object of these experiments was principally to dis- ’ cover, if possible, some chemical to assist in the germination of old, weak, or naturally slow-germinating seeds. More recently such inves- tigations have been conducted mainly in connection with the use of fungicides and insecticides, to learn in what strengths chemicals might be applied to seeds without seriously injuring their vitality. Asa rule it has been found that the germination of seeds soaked in solutions of bases or salts is retarded or even entirely prevented unless these are extremely dilute, the injury being proportionate to the concentration of the chemical employed. In some instances it has been claimed that certain chemical solutions quicken the germinating power of seeds, and occasionally these claims have been quite startling. But interesting and important as have been the experiments in which chemicals were applied to seeds which were afterwards placed in a germinator to sprout, conclusions drawn from the results of such experi- ments are not to be relied upon as applied to seeds planted in soils to which fertilizers have previously been applied. . Here the problems involved are much more complex. In the former case the seed is in contact for a short time only with a chemical solu- tion and one whose nature is known, and rarely indeed is this solution present after the radicle has appeared through the seed coat. Here the chemicals remain in the soil in more or less direct contact with the seed from first to last. Moreover, the chemical processes continually taking place in the soil have themselves a marked effect upon germina- tion. Add to this the hidden changes which the fertilizer constituents are constantly undergoing in contact with the humic acid, carbon diox- ide, and various salts in the soil, and we find that a study of the rela- tion of fertilizers to germination involves one in problems of a very difficult and yet withal of an exceedingly interesting and important character. 6 Comparatively little research has been made in this field. The pres- ent paper is intended to be merely suggestive, and is preliminary to more extended research in the same line which the writer hopes to undertake. HISTORY OF PREVIOUS WORK. One of the earliest important contributions to this subject was made by Tautphceus in 1876. In his experiments such salts were employed as are found to a greater or less extent in commercial fertilizers. They were applied to the seeds in solutions of various strength from 0.5 to 5 per cent, and the seeds were then placed in a germinating apparatus. Wheat, rye, rape, maize, beans, and pease were tested in this way, a check test being conducted with distilled water. The checks always germinated best, although rape seed showed scarcely any injury from the use of chemicals, even in solutions concentrated to a strength as great as 2 per cent. In the other seeds the vitality was seriously injured whenever the salt content of the solution was greater than 0.5 per cent. The chemicals employed by Tautphceus were potassium chloride, sodium chloride, calcium nitrate, sodium nitrate, potassium sulphate, and hydrie di-potassie phosphate. The plumule and radicle in all the experiments showed a normal development. The seedlings, however, were more vigorous in the checks, except in the case of sodium chloride, where a 5 per cent solution gave stronger plantlets than where dis- tilled water was used. He concludes that fertilizers which contain plant food in an easily soluble form should not be used in large amounts, at least immediately before the seeds are planted, lest their concentra- tion in the soil become so great as, on the one hand, to destroy the vitality of the seed, or, on the other, to injure the development of the seedlings. About the same time (1876) Henri Vilmorin published a short article in which he states that when the upper stratum of the soil contains a large proportion of mineral fertilizers, e. g., Chili saltpeter (sodium nitrate), beet seed germinates very slowly or not at all. Vilmorin’s experiments were conducted in pots containing earth, to which, after weighing, different fertilizers had been applied in amounts varying from 0.5 to 5 per cent. The germination of wheat and beet seeds sown in these pots was retarded to a marked degree when potassium nitrate, zaleium phosphate, and especially sodium nitrate were used in amounts equaling 5 per cent of the weight of theearth. With 10 per cent sodium nitrate the wheat and nine-tenths of the beet seed failed to germinate. It should be stated here that never in actual practice would the propor- tion of fertilizer to soil amount to anything like 5 per cent. Sodium nitrate is usually employed in quantities ranging from 150 to 300 pounds per acre. The soil on one acre to the depth of 8 in. weighs approxi- mately 2,000,000 pounds.' If, however, the fertilizers were drilled in ‘See Wiley’s Principles and Practice of Agricultural Analysis, vol. 1, p. 102. ft with the seeds, the percentage of saltpeter in the soil coming into immediate contact with the seeds, might readily reach the danger point. Hindorf claims that magnesium chloride and calcium chloride used in proper amounts exercise a favorable effect upon the germination and growth of wheat, rye, barley, oats, peas, red clover, and rape, and that they never cause injury unless used in greater amounts than would occur in agricultural practice. The injury which then results he attributes to chlorine. Nessler (in 1877) stated that he had noticed that hemp seed sown in fields fertilized with ordinary cooking salt at the rate of 250 kilos per hectare germinated unevenly and made a poorer development than in other fields. Experiments led him to conclude: (1) A 0.5 per cent solution of cooking salt is injurious to the germi- nation of rape, clover, and hemp. Wheat withstands this solution, but is injured by a 1 per cent solution, and hemp by a quarter of 1 per cent. (2) A 1 per cent solution of ammonium sulphate had no appreciable effect upon wheat grains, but the plants were injured somewhat by a 0.75 per cent solution. W. Jarius (in 1885) studied the effect on germination of various salts used in commercial fertilizers, and concluded that in general (with some notable exceptions) solutions of these salts in strengths of 0.2 and 0.4 per cent favorably affected germination; also that no ill effects can possibly result from the use of fertilizers, since their solution in the soil can never exceed 0.4 per cent. In his paper the conclusions of Tautphoeus and Nessler are criticised. Jarius’s experiments were conducted in pots of pure sand previously moistened for twenty-four hours with the solution. The seeds were planted so that one-half of each, including the micropyle, projected above the surface, “in order,” as the author says, “that observation might be facilitated and an unimpeded access of air be secured.” This impractical method of making the tests largely or quite invalidates the conclusions drawn by the experimenter, at least from a practical stand point. A more important study of this subject, because conducted under conditions nearer to those of the field, was published in 1896 by Claudel and Crochetelle.! In order to make use of an inert substance which would play the mechanical role of the soil without giving any chemical reaction in contact with the dissolved salts, they employed chemically pure (as nearly as obtainable) sterilized sand. Four hundred grams of this sand were placed in a porcelain saucer and the seeds laid equidistantly upon the surface; another layer of 400 grams of sand was placed on top of them, the seeds of all the species being planted at a uniform depth of 8 to 10 millimeters. In order to maintain as nearly as possible the same degree of moisture in all the saucers, the amount ' Annales Agronomique, 1896, pp. 151 to 142. 8 of liquid supplied was based upon the amount of sand (800 grams) rather than upon the strength of the solution. After ascertaining the amount of liquid (200 cubic centimeters) necessary to moisten 800 grams of sand, each of the lots after planting received this amount of dis- tilled water, together with a solution of the chemical more or less dilute, according to necessity. Readily soluble materials were used, as potassium sulphate, ammonium sulphate, sodium nitrate, and potas- sium chloride. Slag and superphosphates were mixed with the super- ficial layer of the sand, direct contact with the seeds, however, being avoided. The results of these experiments are worth a somewhat extended mention. Potash fertilizers under the form of sulphate or chloride of potassium in general retarded germination, this retardation being greater for the chloride than for the sulphate; the difference was especially noticeable for the Leguminosae and flax. Ammonium sulphate had a disastrous effect upon the sprouting, though in unequal degrees, colza, flax, wheat, and mustard being very sensitive to its influence, while sainfoin and wheat were less so than any other seeds. To make sure that this injury was not due to too large an amount of the fertilizer, the experiment was repeated with wheat, oats, barley, colza, clover, and beans in solutions of 0.5, 1.2, and 5 parts per 1,000 of the sulphate of ammonia. The results showed that wheat, barley, and oats are practically insensible to this salt in solu- tions up to a strength of 2 parts per 1,000, but a 0.5 part per 1,000 affected colza slightly and clover to a marked degree. With 5 parts per 1,000 of the salt, all germination was arrested. Sodium nitrate acted in a manner similar to ammonium sulphate, but less enegetically. The 1 part per 1,000 solution had no appreciable effect upon wheat, barley, sugar beet, colza, and beans, but seriously injured buckwheat and to a considerable extent clover. The 2 part per 1,000 solution had but little effect upon wheat, barley, and colza, but entirely prevented germination in buckwheat and beans, while sugar beet dropped off considerably and clover was badly injured; all the seeds germinated more slowly in this solution than in those of less strength. In the 5 part per 1,000 solution no seeds sprouted except barley, which germinated 100 per cent. Phosphoric acid was used in the form of slag and superphosphate, the former being alkaline and the latter acid. In very feeble amounts, 2 parts per 1,000 and less, the addition of superphosphate slightly hastened germination; with 4 parts per 1,000, on the contrary, a con- siderably less number of seeds sprouted. The authors conclude that in acid soil the use of superphosphate does not retard germination, if the free acid is quickly combined with the bases of the soil. The slag favored germination in all cases, especially in those of the Leguminosae. Anattempt was made to ascertain whether this advan- tage was due to the phosphoric acid or to the lime, and it was found 9 that the basic phosphate of lime acted favorably upon the germination of vetches, while the acid phosphates were injurious. I*ree lime gave better results than the carbonate, but was inferior to the slag. Summing up, the authors conclude: (1) In the amounts employed, and leaving the seeds constantly in contact with the material used, sulphate of ammonia, sulphate of soda, chloride of potassium, sulphate of potassium, and the superphosphates, exercised an injurious action upon the germination of seeds in general. (2) Not all the species sown were influenced to the same extent; for example, the wheat resisted the best among the species tested, whereas lentils, lucerne, and flax were very sensitive to the action of the fertili- zers used. (3) Alkaline substances with a basis of lime or of potash favored in a marked degree the germination of certain seeds, notably those of the Leguminosae. The slag used produced better effects than the lime alone. In the same paper the authors give the results of experiments con- ducted to obtain information concerning the acids set free or originat- ing during the germination of seeds, which showed that the amounts of acids thus formed are sometimes very great; hence it is concluded that lime, slag, and liquid manure act by saturating these acids in pro- portion to the amounts formed. Aso, that the loss of phosphoric acid, which is excreted in considerable amount in the germination of wheat, for instance, is hindered by these alkaline substances, and thus con- served for the use of the young plant. These conclusions, in the opinion of Claudel and Crochetelle, explain to a certain extent the beneficial ettect of lime, slag, and ashes upon acid soils. Seeds of clover were found to produce more acid for a given weight than any other seeds studied, thus explaining the fact that clover does not appear in acid soils prior to the addition of lime, ashes, or slag. Professor Buffuin, of the Wyoming State Experiment Station, made quite an extensive study of the effect of alkali soils upon germination, and found that even small per cents of alkali in the soil retard germi- nation, although as a rule about as high a per cent of seeds germinated in a soil containing 1 per cent of alkali as in alkali-free soil, provided the seeds were left long enough. DEPARTMENT EXPERIMENTS. In any study of the effect of fertilizers upon the germination of seeds planted in the ground the following possibilities should be kept in :nind: fertilizers may influence— (1) The swelling stage. (2) The nature-and availability of the reserve materials. (3) The awakening and growth of the embryo. (4) The young sprout before it reaches the surface of the soil. We expect to show in this paper that the principal effect is upon the 10 sprout after it has broken through the seed coat. It has already been established by Deherain and other investigators that plants in the seedling stage absorb a proportionally greater amount of mineral mat- ter than in more advanced periods of development. Indeed, in the case of the bean, soda is taken up in the early life history of the plant, whereas none whatever is used when the plant is fully developed. In experiments conducted by us in one of the greenhouses of the U.S. Department of Agriculture the following kinds of seed were used: Jones’s Winter Fife wheat, Curled Simpson lettuce, French Breakfast radish, and crimson clover. Previous tests had shown that all of the varieties were of strong vitality. Common potting soil, sifted and clean, was thoroughly mixed and placed in greenhouse “flats.” At the beginning of the experiment each flat was given enough water to suffice while the experiment was in progress, and all were treated alike throughout the test except in the matter of fertilizers. A check flat containing soil only was provided for each kind of seed. The fertilizers used were the following: Nitrate of soda, muriate of potash, bone black made soluble by treatment with sulphuric acid, and lime made from powdered oyster shells. In addition to these, there was employed a mixed or “ balanced” fertilizer consisting of bone black (treated as above), 600 parts (by weight); muriate of potash, 100 parts, and nitrate of soda, 200 parts. This fertilizer contained approximately the following proportions of plant food: Nitrogen, 23.7 per cent; phos- phorice acid, 54.7 per cent; potash, 21.5 per cent. It is to be noted that all of these fertilizers are readily soluble in cold water. The seeds in each test were plump and sound and approximately of the same size. The varieties were all planted at the same depth in four rows, each containing an equal number. In no case was the soil firmed after planting. Fifty eubic centimeters of fertilizer were added to the soil in the following manner: In one flat of each experiment 12.5 cubic cen- timeters was equally distributed in each row, the seeds sown upon the fertilizer, and a covering of soil added. In another flat the top inch of soil was carefully removed and 50 cubic centimeters of the fertilizer thoroughly mixed with this soil, which was then replaced and the seeds planted therein. A third flat contained soil only, as above stated. The weight of 50 cubic centimeters of each fertilizer was as follows: Bone black, 43.5 grams; muriate of potash, 43.0 grams; nitrate of soda, 57.5 grams; lime, 31.0 grams; mixed fertilizer, 35.5. The fertilizers were used in the following strengths by weight: Bone black, 1.52 per cent; muriate of potash, 1.31 per cent; nitrate of soda, 1.75 per cent; lime, 0.94 per cent; mixed fertilizer, 1.08 per cent. While these pro- portions are greater than would obtain in ordinary practice, it is believed that they were not too large to give reliable results. . }t tet Bul. No. 24, Div. of Botany, Dept. of Agr. PLate |. Fic. 1.-WHEAT EXPERIMENT WITH POTASH. RIGHT, CHECK; LEFT, POTASH SOWN IN THE ROWS. Fig. 2.—WHEAT EXPERIMENT WITH PHOSPHORIC ACID. RIGHT, SOWN IN THE ROWS; LEFT, MIXED WITH THE SOIL. Bul. No. 24, Div. of Botany, Dept. of Agr. ; PLaTE Il. FIG. 1.-WHEAT EXPERIMENT WITH LIME. RIGHT, SOWN IN THE ROWS; LEFT, MIXED WITH THE SOIL. Fic. 2.-WHEAT EXPERIMENT WITH MIXED FERTILIZERS. RIGHT, SOWN IN THE ROWS; LEFT, MIXED WITH THE SOIL. 11 TRIALS WITH WHEAT. ‘4 ° in the experiments with wheat four rows of 50 seeds each were used in each test (Pls. [, II). In the following table, which summarizes the ; results, the percentages given are the average of the four rows: Effect of chemical fertilizers on the germination of Jones’s Winter Fife wheat. Time re- | Average quired for | 4 verace per | height of Fertilizer. How fertilizer was applied. | germina. | “Verage per | sprouts | tion of first cent sprouted. | Qnim.) on | sprouts. | fifth day. rs x , ins In 5 - 10 | ¢ Days: days. | days. Sn [SOW IIT NONCONS = terete «cts cele ccc sco mcacs We iee ta sna as 00 ODI Wisden tan seme Potash (KCl) -.---- NivinacedayiGleS0le eee once toes sce | RP ae Dees 00 11 ae) |e Phosphoric acid |{Sown in the rows ..-...-..--..--------- | 3.0 S150) esod0 16.6 (bone black). (Mixed WILUHES OF lee sors Sactoas Stoo sa nace 2.5 87.0! 89.0 46.2 Se ONO erieccritiv coll cs-2s eee seee|stoseeeczese| 00 | 00 [2200200022 Sown i » rows 2.5] 8 3.5 31.5 Lime (oystershells) \Sriredwith soll -22.lssc| 2B) 85 | 90.8 8? : ee jSown in therows......--.----. aeieers =e | 5.5 0) 9.0 00.0 ; Mixed ...---.-+---- Wise divi Ghai SOil 222 << 2s ac etesls seme | BB 46,0 80, 0 15.4 : (HINDU < Sac cab eo goss Oe CBU OOOO OSE GOD CONDE nen Ae ae erate aan 2,5 89.5 90.5 54.0 : : Analyzing these results we notice, first, that the potash and nitrogen ; - - fertilizers prevented germination entirely. Second, that in every case at the end of four days the germination was greater when the fertilizers were mixed with the soil than when they were sown in the rows and the seeds placed in direct contact, although the difference in the case of lime was very slight. Third, that germination was retarded when the fertilizers were in direct contact with the seeds, except in the lime experiment. Fourth, that on the fifth day the germination of the wheat sown in soils mixed with the phosphorie acid and lime fertilizers was only slightly less than that of the checks, and that it had nearly or quite P| caught up with the checks on the tenth day. Fifth, that lime in the rows gave a slightly greater percentage of : germination than the check on the tenth day. The increase, however, is not large enough to warrant the conclusion that lime is really beneficial to germination. That it is, on the contrary, to a certain extent detrimental if used in amounts equaling 0.94 per cent may be inferred from the fact that the average length of the sprouts was con- siderably less on the fifth day, even when the lime was mixed with the soil, and much less when sown in the row. The experiment teaches that care should be exercised in applying muriate of potash and sodium nitrate to soils in which wheat is to be sown, as an excess of these salts will seriously injure and may prevent germination. Also, that a combination of sulphate of lime with acid phosphate and a little free sulphuric acid is not likely to injure the germination of wheat, even when used in some excess. 12 The serious damage caused by the mixed fertilizer was undoubtedly due to the potash and nitrogen which it contained. After the completion of the ten days’ experiment the unsprouted grains of wheat were taken from the nitrogen and potash flats and tested between damp blotters in the laboratory, with the following results : Laboratory test of residual wheat. Per cent Fertilizer. How fertilizer was applied. germi- nated. ; (i: Mean SHOT OWS os erecinta cor ace a tates lee slo ate eysic ict c Sivas Srere ra ae ee ee nee eee 50 Potash......---.-- \| Mixed with soil........... 70 oa a AREA Gog Devers we), (2: eet Sian yh edn ee eR RE Be re aE at oe Ei 49 Nitrogen ...-.-..- We Boasts loti sto! bee she ae 3 5 ie ee 8 2 ee See eh ang Sapo aceunt 84 Many of the seeds were found to be decayed when taken from the flats. TRIALS WITH LETTUCE SEED. Lettuce seed, if kept thoroughly wet for the first forty-eight hours of a germination test, sprouts very freely, even as high as 98 or 100 per cent by the third or fourth day. In these experiments this excess- ive moisture was not maintained, hence the low germination of the check. The seed was planted in the afternoon of May 19. Four hun- dred seeds were used in each test. Effect of chemical fertilizers on the germination of Curled Simpson lettuce seed. il ) : { , 1 Per cent germinated | germinated Fertilizer. How fertilizer was applied. First sprouts. : on the on the fourth day. | twelfth day. Poth (Hee Gnti dbl (ease eo seers aeoscenScesuel Geaadondae sacsas No sprouts.) Nosprouts. fix? Nemes IAMiixedswith ‘solo 4..< 25. coca ee sae [ese eeeeeeeeee No sprouts. | No sprouts. awe ae fiplu, the TOWwss- 2-252 -2ccee eects see May °6,p.m..) No sprouts. 2.5 Phosphoric acid - -) Mixed with! soile2-220 2 otmecc seers May 21,p.m .. 2,5 45. 25 rage (\ Cin the mowss-ce see esuash toads aeaene te eee eee sae No sprouts., Nosprouts. Nitrogen = ----2~-: Ul Misced “with«soil’ 2.6 22222022 eietacle see eee No sprouts.) Nosprouts. TRme {\ploctheirOws-eo ees se eo eee May 23, a.m .. 0.75 | 36 a eh a ie Mixed swith is0il.2_f22cc5a- cece coe as) a yeoenoeeees 4.0 39. 75 sane ens oe Se NL GO-TO W Simca cmaice sos sores oc el ieee oe ee No sprouts.) Nosprouts. Mixed fertilizer -- Mixed: with S01)... <.jece scene ese ce] - eee eee rnene No sprouts.| No sprouts. Olid es Saat eo aoeeer b Sseesee Aen cs cGinmacon 2 eee ieeece May 21,2.m .. 40.5 | 73 Potash and nitrogen prevented germination entirely, as in the case of wheat; furthermore the mixed fertilizer had the same effect. Phos- phorie acid and lime greatly retarded germination, and even prevented it toa large extent. It is noticeable, however, that although the phos- phoric acid mixed with soil appeared to be slightly more favorable than lime under the same circumstances, yet the latter really affected germi- nation much less injuriously, as evidenced by the fact that when in direct contact with the seeds the phosphoric-acid fertilizer almost com- pletely prevented germination, giving only 2.5 per cent sprouts on the twelfth day, while 36 per cent sprouted in the lime test within that period. 13 At the close of the greenhouse experiment part of the sound lettuce seeds were removed for a test between damp blotters in the laboratory. The results are very interesting, since they indicate that the principal injury from the application of the fertilizers, especially when mixed with soil, accrued to the young sprouts after leaving the seeds and while yet beneath the soil, rather than to the seeds themselves. The labora- tory tests continued three and one-half days. One hundred seeds were used in each test. Laboratory test of residual lettuce seed. Wet eae opt e1s ae + | Per cent Fertilizer. How fertilizer was applied. | germinated. , (UIE KT Gam O WSs aise iaiae er earstarme cic clo hos aioustaie wre ao aiete sieicvereimere'« | 62 Potash ..-..--------------+- Millia cd witnails. s6ce.08 5 G0. > oocadcactoc cous cea. 2ncan | 93 i ee [@ENiet ROMO WW Ste ace tec ape ee a: Swtnsee ria ge atorsievnceleicie yses | 80 Phosphoric acid ..-..------- WiMxedewabh sOllecceiecsccccceccvescecccccersc-.cces--ce-) Nottestad. NGtrOS AVPLIE ONE TOW Secs ses- satan mater oe bee ee ee eee 36 nO Sees cn ae cn 2a: WED edawiGhySOllmencsicatccemasce nce cece ac dudes coc =o se 79 Time (MTN GIMOW Ses eccctc Sess car cpt ceceiet cece o-0eSecccecse| NOt tested: HANG) BSCR SPOOR Bis ae ie tats MeVOE eur EGU SOI li iaccrsnc ciscin aise = Sas cs.cie ats Sis oc-d arene ertaisles | Not tested. 3 haere RUNGE NE LO WAe ae oe Be eee aes = ace cieucameel st cecces Sue 90 Mixed fertilizer ...-...-..-. Wea xedswiruhhSOtlet 2c. oo kc cnt Sesceeiawesee ees cacueeccece 93 The sprouts were mostly normal and healthy in the potash and mixed fertilizer tests. Those derived from seeds which had been in direct contact with the nitrogen and phosphoric acid were somewhat sickly and weak. Unfortunately, the record is not entirely complete, since neither the seed tested in phosphoric acid in rows nor the limed seed was given a laboratory test; but the very high germination of the two mixed-fertilizer lots, neither of which had sprouted at all while in the soil, adds further evidence to the apparently established fact that the injurious effects of the fertilizers were principally wrought upon the hypogeous seedlings, and that owing to the protecting power of their teguments, perhaps to some extent also to the dormant condi- tion of the seed contents, the seeds themselves were not injured by the fertilizers employed. TRIALS WITH RADISH SEED. The soil experiment represented in the table below occupied ten days. Two hundred seeds were used in each trial. These were planted in the afternoon of May 21. Lffect of chemical fertilizers on French Breakfast radish seed. . Per cent | First sprouts er cent Fertilizer. How fertilizer was applied. appeared. of germi- | nation. ae = es : == ” Sa (eth etrows eecee ees ae has = oes chaz oe Sede ce se Re. pate } - IQS in eae easec es cae saoes Wee acim) ek cae ce j; No sprouts. ...| 1/5 ; ee (PICU EIU OW Sie eee cc cee tees 208 ees a ocie ch May 26, a.m . 19.0 Phosphoric acid .-..--....-.- Wits dnwithssoll.. css. 2 cic anise twee oe .---| May 24, a.m -. 95. 0 7 En @lnkthe molwWis estes cen Bcaecaas bees aon be May 25, p.m .. 2.0 Nitrogen -..-.-------.------- (Mixed with soil ...........: Ce ae oe oe ee ee May 26, a.m -. 6.5 . WETIAUH GIP OWS tents at et ese bcmelia: wedebesc.es May 24, a.m -- 37.5 Lime ...-.2.-.--2--+-+++--++- (Mixed WiAthrSOllem ens et eto te ees kc =| ences doy.224224: | 93.0 ye Eaten hee \fIn THSITO WS ye cies eats Bae ne May 25, a.m’ ..| 34,5 Mixed fertilizer -............ Mixed! withisoil 22, te. 06.-ke cto eo oe... May 24, p.m ..| 92.0 (CHIGES 2220 eB Saad aR GNG SSS GCE OB Eee Ea eee a er ee Seer me ae May 24,a.m .. 96:5 14 Here again it is seen that the potash and nitrogen fertilizers practi- cally prevented germination. The fact is striking, however, that, while the sprouting was seriously injured in all of the tests in which the seeds were sown directly upon the fertilizers, when the latter were mixed with the soil the germination of the radish seed was nearly as high as in the check test. An examination of the radish seeds remaining at the close of the soil experiments revealed the fact that many of them which had been in immediate contact with the potash and nitrogen were badly decayed, while those taken from the soil-mixed fertilizer lots were generally, to all appearance, quite sound. This I attribute mainly to the fact that in the case of wheat and lettuce “seed” we are really dealing with fruits, in which the proper seed is encased in external teguments, whereas the radish seed has only the true seed coats. Laboratory tests were made of radish seed taken trom the flats of the potash and nitrogen experiments, with the following results: Laboratory tests of residual radish seed. | Per cent Fertilizer. How fertilizer was apphed. | germi- nated. aye (Te ENS LOWS soe cece aie steioiolleinst eit eda dese e ieee eee eas 20 Potash. ...-.---------++---++- Mixed withisoilt 2202. h = 2 os \(in the TOWS: sss scecc sus ecieee e menreneoer IN O}SPLOWGS sere eeee mee gee aes Poe Ryo WMixed.s....:sccecanten conse see seee aren |e sdoearees Keahrerone , 3 (Tn the TOWS). <> .cn.2e= 505 oceceeee ereeeee ee eeeee OM aSa5s552 Baeso—ssce Phosphoric acid ..-..-.------ {Mixed Spa Sere e a.ccce es Cee ae OEE eee | May 28, a. m.. 31 Pre Mn the Towsts sc sos foo See ee eee eee Nosprouts Sey Bea e ans Nitrogen ..-..-.--------.+--. IMI x60' 322 2. ccac ce oz eae eee en ee | eee Chea aos Resor oon Tas fdinithe rows’ <.22 - 22 220. Soe seeseaee ee oee eee May 28, a. m.. 1 Sa ee Se VME sede ae7 Sonor sce oe ee eee eee May 23, a.m.. 38 a See Ta theerows) occ csc oe eee Ee Pee INOISPLOUtSHe<<| senescent Mixed fertilizer..-........... (Mixed Ee ne er ee ee Oe SAGE ot aDe Mayu a.m. ilo Gheck 255 222.5 tc poco dame lee ticise sis canter een eset e (ene ee eee eee eet May 23, a. m.. 31 Pi ess as) The injurious action of the fertilizers upon the crimson clover seed seems to have been much more marked than in the case of any other seed tested, but any definite conclusions are precluded by the extremely low germination of the check. This seed tested in the laboratory between moist blotters showed a vitality of 974 per cent. The seed, however, was 2 years old, as was the case with the wheat also, while the lettuce and radish seed are supposed to have been grown in 1897, As with wheat, lettuce, and radish (practically), the muriate of potash and sodium nitrate prevented germination. Lime, too, was almost prohibitive when sown in the rows, although it gave better results than any other fertilizer when mixed with soil. Liebenberg claims that the use of lime renders the reserve materials of the seed more available to the developing seedling and therefore helpful to germination. This is certainly not the case when an excessive amount is applied. CONCLUSIONS. Summing up the results obtained from these experiments, we may safely conclude: (1) That muriate of potash and sodium nitrate used as fertilizers in strengths of 1 per cent or more are very detrimental to the germina- tion of seeds, whether applied directly or mixed with the soil, (2) That fertilizers composed of phosphoric acid or lime are much less injurious to germination than sodium nitrate or muriate of potash, and if not used in excess may be harmless. (3) That commercial fertilizers should not be brought into direct contact with germinating seeds. (4) The effect of treating seeds with chemicals before planting is no index to the action of those chemicals when applied as manures to the soil. (5) That the chief injury to germination from chemical fertilizers is inflicted upon the young sprouts after they leave the seed coat and before they emerge from the soil, while the seeds themselves are injured only slightly or not at all. (6) It is highly improbable that potash, phosphorie acid, nitrogen, or lime used as fertilizers actually favor germination. O 2 as LIBRARY OF CONGRESS SL OO0ebs&o40as