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(716) 2aS-5M9 -fox DEPARTMENT OP AGRICULTURE CENTRAL EXPERIMENTAL FARM OTTAWA - • CANADA DIVISION OF BOTANY SMUT DTSEi^SES OP CULTIVATED PLA^TTS Their Causd and Control BT H. T. OUSSOW, Dominion £otani«t. Bulletin No. 73 P„blUh«J by diroctlon .f Hon. MARTI N^URRELL. Mlni.t.r of Aarloulturo. OtUw.. Ont. 630. J^ MARCH. iei3 C212 —1 Exp. Farms Service Bui. ■•,*■ ■ s. . .t'-,^ - .":£*«< ^ ,/> DEPARTMKNT OP AORf TRE CENTRAL EXPERIMENTAL FARM OTTAWA • CANADA DIVISION OF BOTANY SMUT DISEASES or OULTTVATKD P L A T^ T S Theii' Cause and Control H. T. O U S S O W, Dominion Uotanitt, Bulletin No. 73 Publith«d by direction mf Hon. ¥ARTIN BURRELL, Miniiter of Agrioulturo, Ottawa, Ont 3»47»— 1 MA.RCIX. 1U13 Th« RoBouraMa The Minister of AirHoviIturt, Ottawa. Sir,— 1 hare the honour to »ubmit for your approval Bulletin No. 73 of the Experimcnwl Farm Senea. on Smut Diseasea of Cultivated Plants, their Cauae and Contiol, prcparp.! by the Dominion Botanist. Mr. fl. T. Giissow. This publication deals with the identiHcation, treatment for prevention and, in some measure, for eradication, of smut diseases of our common crop*. These diseases *ork annually immense injury to Canadian agriculture, hence any reliable informa- tion on this subject that can be put into the hands of the farmer should bo of great value to the country as well as to the individual. The extenl of the injury wrought •he farirer by these various smuts can be grasped only after one has observed their cflecto in particular insUnces and then paused to calculat'^ the sum total of the loaaes. To such as have had opportunities of observing the losses caused by these fungi in both lesscied yit'ds and lowered grades of grain the estimate of tlS.OOO.COO loss to the Canadian farmer, per onnum. will not seem in th" least exaggerated. In my opinion, this bulletin should be very widely distributed throughout Canada but, of course, more " — ticularly in the prairie provinces. I have the honour to be, sir. Your obedient servant, Ottawa. March 25. 1913. J. H. ORISDALE. Direetor, Dominion Experimental Farmt. 30479—2 SMUT DISEASKS OF CULl'IVATED PLANTS. THKIR CAUSE AND CONTROL. BT II. T. Gl'HMow, Dominib,. HotitnUt, I. OEHXBAI REMABXS. 8mui DUfOtf* not ronfintd to eultivatftl plant*.— Ihc wi-Uknown eon»i)iouou diiicaiM ?ommonly (lou:ents, etc., in use may be rapidly sterilized by means of an ordinary knapsack spra.vir tilled with the formalin solution mentioned liefore. The whole pro- cedure would not require more than one-half hour after a little experience, and would eiist only a slight amount. The farirers -should insist on seeing this treatment carried out, and tli" thresher should be provided with a card setting forth that this treatment was carried out Keforc leaving the farm, whieh card should be signcnl by the farni'T and be demanded l)y the next farmer on the list, when the machine arrives on his preiui-ii-;. Farmers by exercising such care would greatly aid in the reduction of smut dis(>ascs through- out important grain-growing areas. The vitality of the smut spores. — (a) Natuml: The spores of certain smut ower of infection for a considerable period, when eventually such manure is spread on land 39170—3 The natural contamination of manure with smut «.pores should be carefully guarded against, hence it will be iirportnnt to know whether the life of the smut spores ii destroyed by the juices of the stomach or whether smut spores should be still con- sidered active afrents in disseminating the smut diseases when, contained in the manure of animals, they eventually reach the soil. Naturally, the most important smut fungi concerned in these investigations are those causing seedling infection, at for instance, stinking smut of wheat. Partly for this reason and partly because these spores may be obtained in sufficiently large quantiti<»i to render feeding experiments of vnliie, the spores of this fungus are generally used for the purpose. The most recent experiments on that point may be summarized as follows: 'The passage through the bodies of animals of all kinds, of stinking smut spores, resulted in destroying the germination of the great majority. Only those passing through pigs retain their germination to a greater degree.' Hence it will bo seen that there still exists enough danger from the spreading of these diseases by spores ingested by animals and contained in their manure. It tmut-spore-infeeted food injurious to the health of animalsf — There have been discussions from time to time in the agricultural press with reference to the probable injuries to live stock fed on smutted grain or food. Important text-books even now point out the danger of such practice. It is said that smutted grain, both seeds and straw and whether dry or green, is injurious. Disturbances of the digestive organs, loss of flesh, flow of saliva, paralysis of the hindquarters and the muscles of the mouth and throat, and in some cases death, are the symptoms not infrequently lecorded. The results obtained, however, from careful inquiry and experiments do not con- firm this serious nrrnignment, and we are led to believe that, as is often the case in such investigations, the conclusion is one of conjecture. Quite r-jccntly this important question has again received careful attention at the Agricultural Experiment Station, Rostock, Germany. The conclusi(.ri=5 of these experiments are briefly summarized here: — ' Notwithstanding the claim that material containing smut spores [notably stink- ing smut of wheat] fed to animals has resulted in causing injuries to their health, not one single instance could be discovered showing that any indispositi'^n of animals eoiild be attributed with absolute certainty to smut-spore-contnniinnted food. On the contrary, scientific experiments with animals under constant observation, to which larg? qmuititii-s of pure smut spores were given, have shown that the claims as to the injurious nature of smut spores have been exaggerated.' The animals subjected to experiment were pigs, cows, horses, sheep, rahbits, chickens niid pigeons. Although large qiiantities of smut spores were fed to the animals — often for several weeks — the observers are not able to express an absolutely definite opinion. It must be realized that animals show frequently, during feeding experiments of any kind, certain indispositions, which may or may not be a result of the diet. The same was observed in this series of experiments and led the author to conclude:— ' It appears to us advisable not to recommend the feeding of smut-spore-eon- taminated food, as it cannot be declared h.armlcss under all circumstanees. Prcsuant animals, and those naturally subject to slight intestinal troubles should receive no such food. In the opinion of other writers, smut spores contain a poisonous substance which directly acts upon the gravid uterus, hence care is necessary. The difficulty of ascertaining the true cause of indisposition of the animals experimented upon still leaves this important question undecided.' Dr. McAlpine, the Australian Government Plant Pathologist, states ' that it is interesting to note that the well-known boils of corn probably contain the same alka- loid as the ergot and the fluid extract is used in a similar manner.' The peculiar action of ergot on the grarid uterus is, of course, well established, as is the truly poisonous charncfer of this fungus body when given to animals in food. It may bo interesting to cite that we recently examined similar smut boiU on Chinese water rice (Zitania latifolia), due to the smut fungus Vsliiaoo rscai ita V. Henn., but which, we are assured, form an important article of food in ( hinn. As regards oat smut, in Bulletin 7 of the Government of the Northwt-st Ten; tories, p. C. tho following opinion is jrivcn : ' Wh"n abiindnnt in a (-ron «hicli i-. cut for green feid, oa'. smut may cause irritation and congestion. A number of fntulitiis amongst cattlo in nortluTii Alborta have been attributed to this. In Montana, a lot of cows were fed on smutty hay, ami within twelve hours after the tirst feed, otio-half of them died with symptoms of gastritis and cerebral excitement. No more of the h'v was fed, and no more deaths resulted. A post-mortem examination •sbowcd t'l stomach much distended.' We find these opinions more or less unanimous on the point that fnoil coiitnin inated with smut is at any rate unwholesome, and, although the matter is not defii itely cleared up. we advise farmers not to rim any risk of losing animals by givii,- them food of a so decidedly suspicious nature. Reproduction of smut diseases and infection of the host plant.- -Wn have alrea I.v discussed the production of the smut spores and their means of disjiorsal. Tb.> tiim of the dispersal of smut spores involves the question of the reprodiictioii as well ii- that of the mode of infection of plants. When the seed of a nlaiit has ripeiied, in annual plants, the life of this plant terminates with the fulfilment of its purpose, vi;' . that of reproduction. The continuance of this species of plant rests tlwn with tb'' seed. Likewise, when the smut spores have ripened, the life of the fnnsris has com.- to n termination, and reproduction depends upon the spore reaeliinir evi'iitii;.!ly n-r environment favourable for its development into a new generation. The new genera tion of the smut fungus will appear to us in the form of th-? well-known smut diM'as( s After being produced, the spores of some smut fungi require to reach the soil in order to propagate their kind. This purpose is aecomplished in stinkinp snint o!' wheal. .dviT^d smut of barley, naked and loose smut of oats and others, by ndherint' to tl •■ outside of the grains, and thus being sown when the grain is sown. Wlu-i finally thi- srioro has rea<^lied the soil, germination takes place and tlie spore iirodiices ;i stout, short piece of mycelium from which secondary or even tertiary spores may develoji. whieli by means of infection threads attack the youm; f in sei>cllini: wliieli I :w srowr' meanwhile. This mode of infection is known as .=cedlin, infection. Some higlier plants, besides producing seeds, reproduce themselves also by niean- of perennial 'roots' (Perennial Pow Thistle, etc.). This method is known as vegeta tive reproduction. In .son-.e smut fungi there exists a similar mode of perpetuation, although the spore itself still plays the important role. In the so-eaIle>I loose smut^ of wheat and barley, the spores are ripe at th> time of flowering of the barley or wheat, and the spores shaken loose by the wind fall upon the female organ of the (lowering grain, where they germinate— in a manner similar to that of the pollen grain wli-^n fertilizing the ovule— push their way into the ovary of the flower and -emaln dormant in the form of delicate mycelial portions without preventing the formation of a irrain, which, though containing the g?rm of disease, is apparently quite normal. Plants crown from such seed will eventually show the loose smut disease. This mole of infection is termed flower infection. A third method of infection occurs in Indian corn. Here the spores when ripe may immediately produce new infections. While in those kinds producing seedling and flower infection a period of rest is necessary, the com smut may spread in the field to a considerable extent the same season. Infection of the corn plant may take place at any time and at any young and tender portion of the whole plant. The importance of the knowledge of the various modes of infection is api^irent. when dealing with the control of the various smut diseases. In one instarnc tli" 39479— 3 J 10 bpores must be prevented from reaching the soil, in the other, the germ williiii llie grain muat be prevented from doing the damage, and, in com tmut, control dependi upon the extermination of the source of infection by another method. Smut diteasei influenced by certain conditions. — ^During the experiments carried out at the Central Experimental Farm, certain peculiar observations were made indi- cating that the development of smut diseases is dependent upon conditions of various nature. It has been our experience when sowing wheat infected with the spores of stink- ing smut, that our check plots remained free from smutty heads just as the plots did which were treated. Such difficulty was never experienced with oat smuts. The opinions of otlicr investigators were obtained on this strange point, with the result that'our ohsorviitions woro confirmed in a large measure. Dr. C. E. Saunders, the Dominion Cerealist, who can speak with authority and from close experience of Ottawa conditions, expresses himself that although he does not make it u iis^iia! practice to treat tlie wheat for liis experimental plots for stink- ing smut, this smut may be considered of rare occurrence on the Ottawa farm. It is also the general belief that, as far as eastern localities are concerned, stin'diiR smut is of little economic importance. In th'i West, the conditions are very different. Dr. Eihv. C. .Tolinson, of the office of ^rain investiRations, United States I'epart- nient of Agriciiltnre, was also communicated with, and expressed his experience in a letter to nio as follows : — 'Your inability to produce stinking smut in Ottawa has been duplicated in mv own experience many times. In order to test tho various methods of trcitnionf, 1 have inoculated ?eed heavily with viable smut spores and then have planted it, treat ing some and u^ing some for coutrol. Th" resulting plants have been all clean, even in the control which should have been smutted. Undoubtedly there are many pointu in the physiology of this smut tv'iich are not yet understood, particularly with rcsar-l to the conditions influencing infection phenomena.' As is correctly suggested by the investisator, there remain a number of unex- plained features concerned in the successful infection of wheat by stinldnsi smut. Different dates of sowing apparently influencing attacks of smut fungi. — The points raised in the former par:i:;raph have also onijaired the attention ol' Kurop"an workers. Some of tl.ese furnish experimental evidence indicating that it is not a peculiar resistant e of the plant itself that i« to be considered as concerned in these surprising escapes tmrn inl'ection, but rather that a successful infection of plants is dependent upon one or a number of outside factors, favourable or the reverse, to the development of the smut fungus. We will refer here to some striking examples in this respect. A large field of winter wheat which had been sown about the end of October was much attacked by stinking smut (about 60 per cent), while the adjacent fields belonging to the same farmer, under the same variety of wheat and treated in a similar manner, but sown early in October, showed no sign of infection. Another farmer had sown spring wheat (without i»revious treatment for smut) in one field at the beginning of February, and in another in the middle of March. At harvest time 30 per cent of the first sown and less than 5 per e^nt of the latter sowing were infected with smut. In order to investigate this relation of the date of sowing, experiments were undertaken by Dr. Munerati (Jour. d'Agri., part 76, Vol. II, Paris, 1912) which uave results of considerable significance, which are quoted in the following table: — Infected whe^t. Date of sowiug. Treated. Untreated. October 11 0% 1% October 21 0% 3% November 10 1% 10% November 22 4% 90% February 10 2% 30% March 10 0% 6% 11 The results obtained indicate that the very tlifferent climatic conditions no doubt prevailing ul tlio liiii" of ihi^ various sowings liuve intlvicin'cd thi; nitu of infection. Wo hare mado similar observations concerning the Tirulonco of attack depending upon the different date of sowing of turnips in the case of the well-known club root disease. Dr. Muncrati in explanation of tlic ubove table states: 'A grain which is covor autumn and the earlier in the Kpriiip wheat is sown, the tntirc neccsiarj* it is to tr-at the urain with fungicides.' Canadian conditions may be vastly diflcient, but tliat such escapes fron: infection in the cn?e of wheat are known liere i- beyond any doubt. What, now. tiro the effect-i r.f such evidently climatic conditions on the decrease or increase of smut respectively? Tln' inihienec of temperature on the germination of wheat and of smut spores is well known. The lower the temperature, the slower is tlie germination of wheat. Wheat sown in experimental pot.s kept at so low a temperature as '.'j[--W I'., in., a few dciirees above frte/ing point, began to germinate, but its progress was very slow When kept at 77° F. the germination took place after some I'O hours, and the period from germination to the production of the first leaf which pushes through the prnf-e- tive sheatti was considerably .shortened by the higher temperature. Smut spores (Tilhlki) do not start into active life at all before 41° F. is reached, while their geTn-.in.''.tion maximum is about 77° F. Tiearina: these facts in mind, it is er.sily understood that wheat beginnini." t'^ Bcrminatc at a lower temperature than the smut spores, may be just in the incist susceptible stage when the latter begin their activity. On the other hand, when con- sidering that, under normal circumstances, the young wheat is only for sotnr eight to ten days in a fit condition for the fungus' attack, the plant may have out^'rown this stage before the fungus succeeded in effecting an attack. Thus it may be realized what an important role ihe temperatures prevailing at the time of germination really iday. Infe:t;on of the wheat plant takes place only during the normally short peri(Kl from the b"ginning of the germination to the point when the first green leaf is ready to push through the colourless sheath in which it is enclosed (.see tig. a-e">. That th.' rate of development may be greater in some varieties of wheat than in others is indl eated by the fact that Early Ohio wheat has shown itself in Germany to be very immune from stinking smut. This variety gorminates far more fjuickly than any other. However, even this wheat may be subject to a considerable amount of smut, depending upon the different dates of sowing, anything from to 62 per cent of smut showing. Vanetal susceptihUiiy of wheat towards stinking smut. — From these obseivations wo may conclude that the different rates of infection of different varieties of wheat are not due to any special degree of immunity or susceptibility, but rather to outside conditions of which temperature seems to be the most important. But the observa- tions of the different rates of infection have been taken into account by plant brecdi-rs who saw in them characters worthy of propagation for the purpose of breeding resistant varieties. We firmly believe that the underlying scientific principles con- cerning the fungus itself and its attack of the host plant are worthy to be taken into consideration wherever work is carried on along the lines of disease resistance. It has been shown that the fact that a variety may escaije infection is not a proof or even an indication of its being particularly disease resistant. Smut spores hihemating in the soil. — The question whether smut spores lying ia the soil over winter play a part in carrying over smut disease from year to year i» also of importance. To begin with, as far as th':; true loose smuts of wheat and barle,v IS ^'^^^^^l^^,^. Text fimire 1. F\i». 1--4 i>howing various atages of germination of wheat diirinc which infection by stinking "niut s|>i)re« noiy take place : (a) primary njotlet, (b) atem, (c) secimdary rootlets, (d) protective ulieaths, (e) iKiint wheru fir»t Kre>-n leaf pushes thruiigli the sheutli, after whicli stage no infection iKcnrs. (Drawings copied from let of diagrauiK '" The life of the wheat plant" i'suud by the Koyal Agricultural Society ot Kngland, pre|)arealls of 8tinio us to afford the spores time for germination before the frosty weather set- in. Grain smtif catiKcs great loaxes lo the grower and to the country. — It is not a difficult matter to realize that a large amount of damage must be done by smut funpi throiiffhout a great country like Canada. The collection of reliable data for all Canada of the damage due to smut in any one year would no doubt show a very large sum of money lost to the country — and which might be saved if every grain grower would co-operate in an effort to cut off all means of dissemination of these parasitic fungi. Many investigators have tried to estimate the damage caused by smut in other countries, and their estimates are most significant. Oat smut, it has been estimated, causes a loss of $18,000,000 per annum in the United States. This estimate is based on an average loss of 8 per cent of the total oat crop during the years from 1890-1893. The State of Wisconsin estimates its loss due to oat smut at 17 per cent of the total harvest, or five million dollars for the year 1902. Later figui^s (1907) show a loss of the wheat harvest estimated at 7 per cent or two and one-half million dollars. The official reports for the State of Wash- M iiiijcton eitiniated the lose in wheat for the year lOOS at two and one-half million ilollars. We hnvo frnm time to time examined gruiu ficldi all over the Dominion aud have fM'oaiiionall.v wi'ii tirl 1» of considerable iizc badly infected by nmut. fl'Mierally speak- ini;. the farmer who has but a few acres under grain leems to exorcise far less cnr» than ono who has several hundreds of acres. In some Indian reserves (trnin i» rniscd. but this is Renerally badly sniiitted, indicating that no treatment of any kind is tii^vu to the trrnin before sowinn. The more opportunities of this kind arc afforded to smut fiintji to Krow as they like, the longer time it will reit,n(M) per annum. Tlie following table will show the various yields of grain, their estimated value and losses: — Kind of fttdo. Year. 1910 IHU 11)10 1911 WIO 1911 TcituI Imrveau Biixh. 14!>,!)8!),(ioO ^1&,8.M,IIOO 323,4V.I,IM,(I 348,1K7,0IJU Valu*of cro|M. Ob««rvfd per- 01 nta((e dei- troytid by gmut AveraKB percentogx of ■mut. Average loaiws WIm' t . 1 112,973,000 138,S«7,000 p.C. 6-7 5 6 6 C,778,aMU ti,t)2(*,:«'io 114,365,000 126,812,0110 21,41 )l>,.1llll 23,004,OOU 6- 9 6- U 6-7 4-7 7 7J ^,i"'f',5-''0 BiiiU V 11 .•jKI.IIOO 5u,147,t>00 40,(Ml,0't« 6 5i 1,284,1118 1,260,220 Total lomi fur two y« Aver»iJB total logs f •am i33.7: 2,418 6,20!) iT one year 16,88 The total area under grain for the year 1911 was 20,998,230 acres; considering that the loss due to smut for that year amounted to $17,704,470, to ■ loss per individual acre would amount to $0.84 in the averag '. The cost of treating grain with formalin by the sprinkling method would be about 1 cent per bushel and, including labour, not more than 4 cents per acre, which would save the farmer 80 cents per acre under grain. Nevertheless, the grain-growing farmer is liable to lose this amount every year uulesa the treatment of grain to prevent smut is more generally practised. n. SPECIAL PAST. DESCRIPTION OF VARIOUS SMUT DISEASES, THEIR LIFE niSTORT AND TREATMENT. 1. ' Stixkino ' OB ' Bunt ' Smut or Wheat. (Plate 2, Tig. b, c.) Tho term ' stinking ' »n-.ut, tlioiijrh of n »omcwhat itriking character, is neverthe- less correctly applied to this form of sm\it. The expericneed farmer will readily discover its presence in 8?ed wheat, even to a limited extent, by the peculiar, decidedly implcnsnnt odour. This odour is due to n volatile alkaloid technically known as Trimethylamine, which reminds one of the pungent odour of herring brine, from which indeed it may be ch-^micnlly obtained. The odour persists for a considerable time and affords an excellent clue to the buyer of seed wheat which may be contam- inated by the spores of this smut. Stinking smut, like all the smut disenses, is due to a microscopio fungus, or rather, two distinct fungi, one a smooth-spored variety far less frequent in Canada (Tilletia foetcns (B. & C.) Trel.), and the other far more common variety with reticu- lated or net-like markings on the surface of the spores (Tilletia Tritici (Mjcrk ) Winter) (plate S, fig. 1). Many smutted ears of wheat have been examined in this laboratory but none contained tho characteristic, smooth spores of the first variety. For the purpose of this bulletin, it matters little whether stinking smut has been duo to the one or the other species of fungus, for they both respond to the preventive treat, ment in a n-.anner equally satisfactory. Appearance in the field. — Where no precaution has been taken and siu'itty grain has been used for seed, the disease will not become noticeable until the ears uuvq reached a certain stage of maturity, when those containing the germ of disease will appear darker green — bluish almost— and reirain so nnich longer than the normal, uninfected eare. The affected ears will stand invariably more erect, while those con- taining the ripening grain— steailily inireasiiig iti weiglit— will slightly bend down. On pulling one if the suspicious-looking ears and examining it more closely, we find that instead of normal grains, the ear will contain bodies somewhat larger in size and decidedly plumper and shorter (plate 1, fiif. c. f). This enlargement of the grain is tho reason for the loos?, open appearance of the ear, which will become more promi- nent as the ear matures, until finally the grain-like bodies are readily visible from the outside. On ren.oving a kernel from an infested wheat ear, there will be found another external difTerence from the normal wheat graia in the form of a short spur at the apex of the grain (plate 1, fig. e). Upon squeezing one of these bodies between finger and thumb, the skin will burst open and a dark-coloured smeary or dusty substance, according to the stage of ripeness, will exude (plate 1, fig. f) which strongly smalls of herring brine. This substance is entirely composed of the fungus spores. Under ordinary circumstances these grains, or, correctly speaking, 'smut balls,' do not burst open while in the field, and the infected ears are harvested with the sound ones. The fungut spores. — ^When such wheat is subsequently threshed, a large number of tho smut balls are broken, and the now free spores will infest the sound wheat grains. When badly-infectend tbe liie of the iporc* and enubin on* to nalice the estrotnc >lanfar of lound g in b««omin( infoctad, a photoffraph hat baas taken of tmut iporei among vhich a boman hair hai bean placed for compariaoB. Thia photograph ihowa the iporea, aa well as the hair, much enlarged, but both to tb« aaroe extent, and we can nuw meaaura for ounelrea that eight iniut tpore* may ba placed lide by tide in order to ttretch acroaa a hair (plate 1, fig' a). Onco thia minutenets of the aingle ipore ii comprehended, it will not be difficult to realica tha extreme caution iieceaaary to pierent them from flying about and ■ettling upon all aorti of farm machinery, implamenta, tools, manure heaps, etc., from which they will be ultimately conveyed to tbe soil, in addition to the danger of direct infc<'tion of tha soil which may tal(e place under the conditions already discussed in the introductory chapters. Each individual spore is eapa' i spreading the diseas->. We have already compared tha fungus spore to the ' seed ' of plants. Juh as tha seed or kernel of wheat ia tha agant ttiwoducing tha wheat plant, so is the fungna spure the ' seed ' of the smut disease. The spores of the stinking smut fungus are minute, round, brownish bodies with a reticulated surface — that ia with fine net -like markings. Longevity of ipore*. — The longerity of the stinking smut spores has be«n repeat- edly investigated. The loose spores may retain their life for at least three years, but in the case of the unbroken smut balls, the spores within are known to have germinated soma seven to eight years after production. Wheat that haa been kept for eight yaara under suitable conditiona of storage, and which at first germinated 09 per cent, showed only a r nnination of aome 47 per oe-t. This makn it practically useless to store infected wheat in the hope of securing freedom from smut. The longevity of stink- ing smut sporea is of importaaoa to the fnogua itaelf aa it is a natural adapution to the conditiona unuer which the fungus plant haa to lire. Should the spore retain ita life for a short time only— as is the caae with the true looaa smuts— then the possibility of reproduction would be rery limited and that is contrary to nature. The purpoae of the seed or the spore is to rq>roduoe its kind, hence planta depending entirely upon thia mode of reproduction hare generally long-liTed aeeda. Thv germination of the spore.— When wheat is sown which is infected with amat spores, either naturally or owing to lack of care, the sporee pass through varioua stages of development before the wheat plant becomea infected. At first, the smut spore bursts open at any point, and a abort, stout germinal tube is pushed out (plate 8, fig. B, ' 1 '). This is known u the promycelium. The next stage is the production of a series of sickle-shaped pairs of secondary conidia arranged in a circle around the apex of the short tube (plate 8, fig. B, ' 3 ')• Each member of this ' wreath ' of spores may produce another stouter, but shorter spore (plate 8, fig. B, 8), or directly, a fine hair-like tube, or the new spores may produce such tubes. These hair-like tubes of mycelium are the infection tubes. When these tubes are formed, during the period of tbe germination of the wheat, from the moment of the production of th'j first root- let up to the time the first leaf ia ready to push through its protective sheath, an infection is almost sure to follow. The infection tube pierces the young and tender tissues of the wheat seedling, and when successful in reaching the growing point, it continues to grow as the wheat grows, unnoticeable externally, until spore production, which takes place in the wheat ear. It has been previously stated that the conditions of temperature prevailing at the time of the germination of wheat and spore may determine whether an attack will result or not. In this connection it. may be mentioned that occasionally there may be found only one or more ears attacked by the fungus, while others of the same plant may be quite aound. This fact may be explained as follows : — Each ear of wheat is produced in a separate shoot with a definite and individual growing point. Generally speaking, the fungus attacks the various growing points at an early age, but when, for some reason other, the first eara have 39479— ti IS ••Mpcd infaetion. a Meoad growth which maj naaU may not havo lueeaatlad in ■Mkiag ita aacapa. and. tho rrawin* pointa balng invadad by tha funfua. will carry tha infaetion until uUimataly produrinv infaetad aara. Baaidaa. in the daralopmanl of plant ditaaaaa, to mueh dapanda upon tha aran balanca of eondltioni or ' eonatitu- tioo ' of tho hoat plant itaalf and tha vigour of tha fungua. Tha atronger will anrpaaa tha weakar alam«nt In thia way it would be raaionabla to expect occailonally that one plant may pioduoe aound and untound eart. nr sound, partly, and wholly diaaaaad grains in tha aama ear. which aa wa ha /a obaerred doM occur (plate 8, flg. c). Notwithstanding tha itatcment that the imut fungua. while growing within the plant cells, produces no risible ill-effects until the ear appears, yet the fungui may be feebly present in the cells, and in some instances not succeed in reaching the ear. whan that ear will eacapa infection but will show .- poorer quality. Whoro it ii daaired to produce a good strain of wheat, it would be unwise to start with seed grain known to reault from aa infected crop, however successful the treatment for smut nay be, for an impe- 'actly-dereloped grain possesses a reduced energy of germina- tion, and we know that rigour cf germination and the strength of the young plant nre important factors in aifacting an eacapa from infection. It is generally accepted thnt plump, well-daralopad grain produces the best planta, and grain of low rital energy yialda leaa well, beaidea being liable to infection to a much higher degree. Btinkin ' imut eonfintd to wAaat.— Microscopically and biologically, stinking smut of wheat ia quite different from other grain smuu. Each kind of grair has iu particular parasites which cannot aifeot any other plant. When smut aporea of wheat •re aown with oata or barley, or vtc« vena, these plants will not become infected. If thia were the case, their treatment or control would be uniform throughout, but we hare already explained tho different methods of infection that exist in rarioua amut forma and which require different modes of treatment. THE CONTtOL Of RTIXKINO BliUT. /• «( advitahle to trtat M wheat before lowing f — As it is decidedly doubtful if there ia any wheat sold in this countiy originally free from infection, or. if origin- ally free, kept in ouch condition, it appears advisable to make smut treatment just as much a part of one's routine as preparing the land for sowing. Though there cnnnot be any doubt that some wheat is more affected than others even when only a limited infectior. exists, it is very desirable to prevent its increase by treating it. Besides, there is much danger from the neglect of treatment owing to the fact that there are a number of fungi producing a more or less serious discolouration of the grain. W' have recently devoted considerable attention to the cause of the various discoloura- tions often found on wheat grains, and particularly abundant after wet seasons or on wheat from low-lying ground. There are fungi like Fuearium and Septoria which may cv^e destruction of the plant, or at any rate affect the yield and quality of grain, and other more superficial fungi like Cladoeporium, Heierosporium, Epicoeeum, Hormodendron, etc.. which cause spotting of the surface of the grain. The nature of these fungi is as yet little understood, but they are, no doubt, often reaponsible for tho decay of the grain wher- sown. It is reasonable to believe that seed treatment as recommended for smut would al'^o prevent any injury from fungi of thia nature, hence we strongly recommond that wiicat and other grain be always treated before sowing, For experimental purposes one may select small samples of wheat which nre reason- ably clean, but this is not yet possible under general conc^Uio^' of farming. The treatment for the prevention of smut, diseases, propagated by the spores of ▼arioua fungi adhering to the seetl. is directed ag»in«t the destnietion of these. There are two main methoda of treatment generally practised, each of which has peculiar advantagea and disadvantagea over the other, but, nowadays, where scarcity of farm labour ia an important consideration, that which requires the leas work ia to be pre- ferred. The two methods referred to are known as 'steeping or pickling' and ' aprinkling ' the grain with certain solutions. 1* Before dealing with nut treaticent, it may be mentioned . .at waabinff gnin tliorouffhiy in running wi wr, in order to get rid of the amut aporaa, it praeti*<>d with •atitfactonr retult*. provi< ng it ii done properly and that there ii a irood water aupply availal>l«. The irr«in may be plared in barreli for thla purpoae and the water allowed to flow in from below ; it will aoon rite to the top and orerflow. By viforoua afita* tion of thn itruin with a itick, the tmut ballt will rise to the top and the iporea will be carried away. Heed grain of apecial value may be treated quite aatitfactorlly in thit mann?r. For aomo year* chpn.iral aolutiona have been uioaute the time required it left. Heforr treating any wheat, it should be rpmembpred that, oceaaionally, unbroken aniut bnlU may be contained in the grain: theee will eventually break, often at the hnmt ilcoiraWe moment, i.e., after treatment, and of course re-infect the graia with •tiiiit siwrci. No solution has been found to |>enetrate the unbroken smut balk in the rhort time during which they are subjected to treatment, hence the aporea inside nro not kille<]. The fanning niHI will remove smut halli very completely from the wheat, tad owing to the danger pointed out, any wi.eat containing smut balls should be sent to the u.'U bi'fore trcatinff— if none is available at the farm. Should, however, any smut balls appear on the surface of the solution when grain is being treated, it is necessary to remnvo them quickly. The smut balls are much lighter than tlu> grain, and will risa to the surface when the latter is vigorously and repeatedly stirrc«»iin use only wooden pails, barrels or tanks. Note particularly that grain treated with blucstone is highly poisonous to live stock; it shou". only be used for Beed purposes, and any that may be left over should be de«!ply b'.i sd. Formalin is a solution of formaldehyde gas in wuter, and whf>n buying it, it should be of not less than 40 per cent strength. This is the usual strength. The stock solution should always be kept in a well-stoppered bo:.le. Formalin is nowa- days preferred, partly because of the greater facility in preparing the proper solution, and partly because grain, treated with formalin, when once thorougEly dry, is not injurious to live stock. Form»lo mere coincidence, it is the most important factor in the whole life history of the funfe-i producing loose smut in wheat and barley- After many years of research on this problcn;, the repeated failure of all investi- gators to reproduce loose smut in wheat by spore infection of the young wheat plant, which so readily takes place in stinking smut, seemed to indicate that the solution of this question would lie in a different direction. Naturally, it was at first expected that the spores of loose smut would adhere to the wheat grain and germinate as the seed grew, or that the spores no doubt present in large numbers in the soil would retain their germination over winter until the new wheat was sown. The life history of the stinking smut, the spores of whinh grow so readily in artificial cultures even years after harvest, of course influenced the opinions advanced. But the spores of the loose smut fungus persistently refused to germinate, and, indeed, as was shown later on, they retained their vitality for a few months only. Flower infection taket place.— It was then that the independent researches of Brefeld and Hecke as late as 1903-1904 conclusively proved that the perpetuation of the loose smut diseases took place through flower infection and not in any other way, confirming in this manner the results of the earlier experiments carried on by Frank Maddox in Tasmania in 1895 and later, viz., 'that putting smut germs on the ovary about the time the pollen is ripe will always reproduce the disease the following year.' Thus the mysterious connection existing botween the production of ripe smut spores just at the time of the production of the flower in wheat was explained. The flower of the wheat plant.— To thoroughly comprehend the following chapters in the life history of this smut, let us briefly study the flower of the wheat (see Plate 3, figs. 1-5). Towards the end of June, or in July in many parts of Canada, the young ear of the wheat will show a large number of fine, yellowish appendages pro- truding from the upper part of the scales which later on enclose the mature grain (plate 3, fig. 1). These are the stamens of the wheat-flower with their large anther cells containing the pollen or male reproductive bodies (plate 3, figs. 5, c, d). On removing dexterously the outer glume and the pale, wo discover the remainliif parts of the flower, consisting of two thin, fringed scales, and the pistil with two feathery styles (plate 8, fig. 3; b, e, f). When the pollen in the anthers is ripe, tlic-c burst and the pollen grains (plate 3, fig. 5) are discharged and caught by the feathery styles where they are held fast (plate 3, fig. 4). Here they soon begin to germinate and push through the style into the interior the pollen tubes which ultimately reach the ovary, when fertilization of the ovule is effected. Germination of smut spores. — During this period the production and dispersal of the ripe smut spores take place. The spore of the loose smut of wheat is considerably smaller than that of the stinking smut (plate 1, fig. b). On germinating in suit- able media we find that its development differs greatly from that of other smut spores with the exception of loose smut of barley. We find no secondary spores but simply germ tubes, however far the artificial culture may be carried (plate 8, fig. c; 1-:J). Ibis mode of germination is in acconlr.nce with its mode of reproduction. In cultures the life of the loose smut spore ol wjieat soon fxhuusts itself, while the stinking smut may be carried on indefinitely. This observation confirms the statement regarding the brief life of the spore, which indeed is similar to the 'fe of the pollen grain. PlatH 3. Fiijs. 1 .. till- flower of wheat; figB. B-9 flower infection a- d puition of the(f<-rm of anii.t in tluirraiii ,.j'5 J ■" '■■''' "^ "'T^i '" *"*«••: (») »nthers (natural Hiz«). 2). Sinsfl.- spikel c t of wheat . ar: (a) antbem ':.'",','*' •"'•?^"'' "' nowi"-. (b) the featb jry b;.* , , ovary ; (f) ovule. (4). Pait of »tvle (b) covered with iK.Ilen grams (c) .i Pollen grains (c) BhowinK germination tube (d). 8. a.-etirm „i wheat grain shoauig tile youiJK i.laiil (h). 7. Tli= young plant removejii from tlie wheat gram, mii.h enlarged, (g) the Kcutelluiii or disk through which the young plant aSnorbs itti fiwd from the Ixjdy of the grain, (h) t.»- growmg point, (i) the primary root, (j) ita eheath, (k) secondary root, (I) black lines showing position se snut fungua as found in the grain. 8. Part of the style (b) showing a liKwe smut of mycelimri s|"ire (n| r" wlial tube (o) into the tissues. S M.orfiscopical preiwratioii" showing myeelial ma* the ti.,8ues of the ir- i,u (m). (Figs. 1—6 from " The life of the wheat plant." Fig. >>f fuiig afti r Hecki .8, y after rji..g.) 39479—51 Analogy of vmut $pore» and pollen grnint, — Pollen strains which do not reach the ■tyle but fall to the earth or elsewhere soon succumb, because their only function it the fertilization of the orule. The smut spore likewise succumbs very quickly if it does not reach the style of the wheat flower. Having been successful in reaching that spot necessary for its perpetuation, it germinates in a manner similar to but not necessarily identical with, that of a pollen grain, pushing its germinal tube first through the fine hairs of the feathery style (plate 3, fig. 8), then through the style itself, and finally, into the ovule, where its progress is arrested for the time being. Its germination is only by means of the germ tubes which it sends into the forming seed, causing a direct infection of the young grain. Thers is no need for secondary spores, nor any necessity for a prolonged life in the spore stage, inasmuch as the fungus lies well protected within the grain. To perpetuate its kind, the spore must reach the flower of the wheat. If the period of flowering is over the smut spore must die. Stnul fungus Uvea in the ffrain.— During the development of the grain the smut fungus now within it makes but little growth, but remains alive, though quite dor- mant like the seed itself. The filaments or mycelium of the fungus were first success- fully demonstrated by Ilecke in the tissues of the young plant. Later in 1910 Wilhelm Lang provided convincing evidence of the presence of the germ within the grain (plate 3, fig. 9). Every infected grain will give rise to an infected wheat plant, the ears of which will contain a new crop of spores, and thus a new life cycle will begin. Loose smut cannot he controlled by formalin or hluestone.—From the above des- cription of the life history, it will be readily understood that this smut cannot be controlled in the manner prescribed for stinking smut. Though there may be hundreds of thousands of spores present on the surface of the wheat grains or in the soil, we know that they are dead, or at any rate need not be taken into consideration •s carriers of infection. We also know that the germ of the disease lurks within the embryo of the grain, without revealing its presence by any external symptom. Even the recognition of the germ within the ambryo is a matter of difficult technique. But all the same the disease is present and will appear, with hardly any exception, in the plant growing from such seed. Remove whole plant if affected. — However often a farmer may pull out diseased ears as they appear, every new shoot will produce new smutted heads, hence the whole plant should be destroyed immediately the disease becomes noticeable. It will also be realized that the prevention of this kind of smut must be, if at all possible, along very different lines from that of stinking smut. Successful treatment regarded with doubt.— The opinion cxpr-ssed by Brefeld that, owing to the presence of the smut fungus in the grain, it would not be possible to kill the smut fungus without destroying the germination of the wh?nt itself, was shared by a large number of other investigators. Discovery of hot water treatment. — However, when the question regarding the control of smut diseases had received the attention of a large number of investigators, who, at that early date, were still in the dark about the life history of the loose smuts, one of them, Mr. J. L. Jensen, of Denmark, discovered in 1887 that hot water of certain temperatures would destrov the life of smut spores, especially of those diseases propagated by spores adhering to the surface of grain, without injuring to any marked extent the germination of the grain itself. At first, the method was employed simply against stinking smut of wheat, oat smut, and others of the same kind. But the method was ultimately improved, when it was found that by carefully treating grain which contained the loose smut germ within its tissues, control of the disease was obtained, and, at the present stage of our knowledge, it would seem the only one •ificient in checking the recurrence of loose smuts. 27 Preliminary remarki on hot water treatment. — The hot water treatment consiata aimply in the immersion of the infected seed grain for about ten minutes in water kept during this time at a constant temperature not below 122' F. and not aboTe 126» F. TV«7Z cause lost of germination. — It is also claimed and proved by experience that from C-10 per cent of good sound grain will be injured in the treatment, while seed with n low rower of germination at the beginning will lose far more of its germinat- ing power. Eren though considering an average loss of 8 per cent from hot water treatinent as unavoidable, this could easily be made up by an increase of 8 per cent in the rate of sowing. In one bushel and o half — the usual rate of sowing per acre — a little over 7 pounds would have to be added, which would mean the very slight increase in cost of 7-8 cents, whereas a loss of 5 per cent from smut in the field would really amount to a loss of $1.25 per acre or so. Co-operative work in hot water treatment. — In Denmark smut-treating planta have been installed during the past ten years to a considerable extent in the creamery and brewing pstablishments, where the grain of the farmers in the locality is sub- jected to the liot watqr treatment at a small cost, and in which plants there may be treated in ten liours as much as 260 bushels (certainly sufficient for farms of con- siderable si'.e). Notwithstnnding such co-operative arrangements, which would make hot water treatmont, especially of large quantities of wheat, more feasible, we cannot conceive of its being made the general practice in Canada, especially in the West, where the problem of manual labour and even the water problem itself will offer roost serious objections, at any rate for some years to come. But we strongly urge the farmers not to be negligent on this account, but follow strictly the suggestions made along the following lines, by which it is hoped that the problem of loose smut of wheat may be eventually solved. Begin slowly and persist in your efforts, and loose smut will cause very little damage. Dr. C. E. Saunders, in conversation on the subject, stated that some years ago loose smut was a factor of considerable moment in his Ottawa experimental plots, but at the present time it only occurred in a negligible percentage, and he hoped that it would disappear entirely. This result is largely due to the untiring efforts of Dr. Saunders to control this smut by every possible precaution. Raising of one's own seed supply from pure seed.— The solution of this problem lies in the practice of growing one's own seed grain, starting with clean seed grain or such as has been treated with hot water. The difficulty of the hot water treatment will be largely avoided and success in prevention of loose smut proportionally increased if the farmer will start rightly. Method for securing smut-free seed grain.— The first year he may begin by secur- ing, say, three-quarters of a bushel of the very best wheat of that variety which haa given the greatest satisfaction in his neighbourhood. This small quantity is easily subjected to hot water treatment in the way to be described presently, and it will suffice to sow one-halt' acre. It is important that this half-acre plot should be far enough rpmoved from any other wheat field to prevent smut spores from being blown over from an infected field. From the observations recorded in a former chapter, it would seem that 500 yards away from other wheat would prove a safe location for the ' seed grain ' plot. It may be difficult or impossible in some typical wheat-growing centres to remove the seed plot thus far from other growing wheat. We would recommend as an alternative to surround this plot with a shelter belt of trees or shrubs. In the West, the Siberian pea tree would provide a very suitable shelter. These belts will very effectively eliminate the danger from outside infection. If the treatment has been successful, and that will depend upon the amount of care with which it haa been practised, the smut should be entirely absent from thia m«.lulf acra plot. It would b« adyitable, howerar. to earafully axarn' .-, the plot btfon flowerinff time and nmora at one* erary plant, roota and all, oi T.neat that •howa a •uipicion of amut Thia remoTal of affaeted planta may wfely Jt carried on btfon the iporea are npe, and thU ia the moat correct time to nrnoy,- il.em. ela- the reiy act of gathering eara with ripe tporea will acatter them wholeaale, and the walk- ia« through the plot with a handful of gathered amutty heada will be the wor»t BMthod of infecting the flowering grain, which would otherwiae have remained f from amut. Thia should bo weU borne in mind. Aa aoon ai the spores are ripe ii toon haa taken place to a large extent, and remoTing the plants carelessly will make It wora^ It M adyisable to proyide paper baga and carofuUy draw the heads of an affected plant together. in»ert the baga over them, and then cut off the whole number of heada. The plant should then alao be pulled up. The yield of this seed plot should be quite free from smut. Un.ier ordinary con- ditions It would yield 1(V-16 bushels of grain or sufficient to sow 6 to 10 aCrea in tlie next year, the yield of which would provide seed grain for a considerable area. It ia just aa easy to treat fire bushels of wheat aa three-quarters of a bushel and. where the experimental treatment haa proved aucceaaful. the farmer might well start with fire bushels of treated wheat The seed plot should be maintained each year; by paying additional attention to the quality of the atrain in selecting one's wheat for the ' first seed plot ' the benefit from the trouble— if the care exerciaed haa any right to thia name— would be largely mereased. Grain luhjeeted to hot %eater treatment it free from all kindt of tmut.—Jt may be pointed out here that any kind of grain treated with hot water requires no separate treatment for other kinds of smut, as the hot water will destroy the spores of all amut diaeases. We do not consider it neceaaaiy to treat with hot water seed grain obtained from the seed plot or even that produced under field conditions under the circumstances described, unless, of course, loose smut has become re-established, when the hot water treatment should be resorted to again. We do recommend, however, to treat the wheat with bluestone or formalin for the other kinds of smut, if it has not been subjected to the hot water treatment. Stinking smut, it should be home in mind, may be introduced by a threshinK machine which has been previously employed in threshing wheat infected by this kiud of smut. The hoi water treatment for loose smut.— We have already referred to the great power of resistance to frost possessed by stinking smut spores; it is an established fact that resting or inactive organs or parts of planU like seeds, tubers, fungus spores, etc., are much less susceptible to external influencea than the growing plant, hence' the death of germinating spores on exposure to frost. Reasons for the success of hot water treatment— Dr. Appel, of the Imperial Biological Institute for Forestry and Agriculture, Berlin, Germany, who has largely contributed to our knowledge of the control of loose smut, points out that the spores of loose smut will germinate in artificial media after only four hours, when kept at a temperature of 77° F. He concluded that the mycelium resting in the wheat germ might be stimulated into activity in the same brief period of time by immersing the infected grains in water of this temperature. That is to say. the resting fungus may be awakened from its condition of rest before the wheat grain itself would be influ- enced in a like manner (i.e.. start to germinate), which may be considered out of the question within four hours. Hence it was reasonable to believe that the action of water of a higher temperature would destroy the germ of disease, now in a more vulnerable state, without exerting too injurious an influence upon the life of the grain. We have already pointed out that injury is actually caused to a more or less large, but nevertheless negligible, extent, but we have also shown that loose smut is very satisfactorily controlled by these means, and that it is at present the onlv method known. ^ 89 JeoMii'i oriirinal hot water method has been coniiderably modified owing to th« advanced reaearehoa. particularly of Appel, who demonitrated that aoakinf the irrain preTioiia to the real hot water application ia of decided adTantage. We have explained the acicntiflc principle* of wich treatment, and will quote tome interesting flguret given by Dr. Appcl* which ahow the reatiltt very convincingly. It waa flrat neccatary to demonstrate whether previona aoeking followed by the main treatment would reduce the amut disenio and what temperature would be the moat advantageoua. Wheat waa aoaked for four houra, or the time which it took the aporea to germinate at 77' F. Varioua temperatures were uaed; the wheat wai then treated with hot water in the usual way, with the following roault :— Temperature of wafer of prcliminnry soaking. . 34°?. 48"F. fI4°F. SB'F. Perrentflge of smut in field plot noted 4fl% 31% Mrj, o«>j, The percentage of smut in an untreatod check plot waa 4-9%. Tn addition. Dr. Appel investigntod the question of the length of time neces.sary or most advantageous for the preliminary treatment. Some of the aame wheat aerved the purpose as used in the first experiment. Length of preliminary treatment 2 hours. 4 houra. 6 hours. Percentage of tmut in field plot notwl 2-7% 1.1% 0% In this experiment the temperature of the water was 64' F. The conclusion drawn from the above experiments, of which a considerable number were performed, is as follows : — ' It is thus shown that a reliable method for the control of looae smut of wheat (and barley) has been discovered, viz., soaking the grain for a period of from 4 to 6 hours in water of a temperature from 68° F. to 86° F., followed by a treatment with liot water at a temperature not below 122° F. and not above 129° F.' The next point to consider is the length of time required for the ' main ' treat- ment, i.e., the exposure to the hot water. This will depend to some extent upon the facilities for mcintaining the correct temperatures, but the general rule ia 10 minutes at an even temperature of 124°-125° F. We have endeavoured to explain in the foregoing lines the reason for the various manipulations, believing that the successful control of any enemy of plant life depends largely upon a thorough acquaintance with its nature or life history. The farmer will immediately realize tliat there are some serious objections from the practical point of view to this treatment, but then it must not be forgotten that at the present time this method is the only one known to control loose smut. After all, the apparent difficulties may be larjiely overcome by systematic work, and. by the exercise of care, this trcatu-.cnt will give highly satisfactory results. We will now carefully describe tlie carrying out of this treatment. SIMPLE METHOD FOR HOT WATER TREATMENT. (O) PBGLIMIN'ARY TREATME.\T (SOAKINO). Apparatus required.— 1. One reliable thermometer; the ordiuary bath-tub or room thermometer is very undesirable for this purpose, but a good dairy thermometer will serve the purpose well. 2. One large wooden barrel or any kind of metal tank or large vat. 3. A number of good strong grain bags which will allow the water to pass through rapidly. 4. Some kind of stove, boiler or fireplace to heat the water. 1909. • Otto Appel, Theorie & Praxis der Bek&m pf nng, Ac, Bar. D. Bot. Qea.. Vol. «7. Heft 19. so Proerdun.—i. Heat water iu the boiler to almost boiling. Pour into large barrel or tank (b^ore proceeding further refill the boiler with water) and add tlowly. with Tigoroua ttirring, cold water untU the temperature ia exactly 8«* F. ITnlcaa the water ia well atirred the correct temperature cannot be taken. Read the temperature without reraoTing the thermometer from the water. The mercury bulb ihouUl alwayi lemain aubmerged when taking the reading. 8. FiU grain baga three-quarter* full with the grain to bo treated and tie them up looa-ly Immcrie into barrel with water at 86' F.. move bag tereral timea up and down, which will force out the air quickly. Take care the wotor covert the grain at leaat aereral inchei. Allow the grain to remain in this water four hourt. J NoTE.-The temperature of the wat»r will become lower when the grain ia intro- duced. Should it cool down too quickly, i.e., tink below 68"" F.. allow Ave hourt for toaking. Treat the grain, if poaiible. in a heated room to prevent the rapid tinking of the temperature. By placing the barrel or tank in a largo wooden box, tightly packed with wood thavingt. hay or ttrnw all around, and covering it with a lid. the tempera- ture remaint fairly conttant for four hours, once the grain has aittimcd the tempera- ture of the water. One ordinary barrel will treat about one buthel of grain or a little more. Uae two or three barrel* or one of larger tize if more grain it to be treated. The larger the barrel and the greater the volume of wutcr, the more easily will the temperature be kept conttant. (6) MAIN TREATUENT WITH WATEn. Addilioma requirements.-T^o large bnrrelt or vats, each capable of holding from two to throe bagt of gram. A water can with a tprinklcr attached. Procerfttre.-Into the first barrel pour a quantity of nearly boiling water and add cold water tlowly until the temperature it accurately 112" F. (Fill up the boiler immediately, aa more water will be requirwl in a abort while). Then take out the gram from the soaking' barrel and place in thit one. Move teveral times up and down and allow to remain for 16 to 20 minutet. Meanwhile prepare the other barrel: pour in hot water as near boiling as postible. add cold water -Jowly, with stirring, until the temperature is exactly 129" F Then take the bags out of the second barrel (the one with the water at 112° F ) and nlace m the barrel with wuter at 120» F. This will cause th« temperature to sink to some extent; should it sink, below 122» F. fill the sprinkling can with hot water and sprinkle into the barrel, but under no circumstanaces upon the grain or the bags containing it. When, however, the baiw are well covered with water, at least four or five inches, the hot water may be saf. ' added. To mix it with the whole contents lift the bags up and down, or move them around the barrel. The prain must remain for exactly ten minutes m this last barrel, during which time the water should be mnintamed evenly at a temperature from 124''-127'' F. It should nevor sink below 122° F nor be hotter than 129° F. The former will be ineffectual in kllung the smuZ the latter will cause unnecessary damage to the grain. (c) DRVIXO TIIK TRKATKl) CHAI.V. Of all the difficulties of this hot water treatment, the complaints about the trouble in drying the grain after treatment exceed all others. When taking the bags out allow them to drain thoroughly. On sunny days the grain may be spread out in a thin layer in the open air, when shovelling or moving it with a wooden rake will render it sufficiently dry for sowing in a few hours. It is necessary t emphasize the caution that should be taken as regards the reinfection of treated grain, which subject has been fully dealt with under the chapter on stinking smut Whenlhe temperature is below freezing, or on dull or rainy days, the grain should be spread out in a thin layer on the clean, dry floor of the barn. It is most important to keep n on nhovellinir the irrain over to ollow of nir b-inir mixed with it. when it will dry far mow quiekly. Hc«idM. irrain which it left lyinu untouched ii liable to becom* mou dy. and this will deatroy ita ircrniinntion. At timca. eapecially on dull daya, it ii atlvwaWc to chill the irriin by plncinu the bncrt for ■ minute or two in cold wafr. movinir the ban aeroral tlmea up and down before apreading it out for dryinr Thia ha» been found of advantnjrp. wpecinlly when barley {« heinir treot»d. In rare eaaea, grain haa bejrin to aprout while aprea.l out for dryinir. Thia "auaea no harm what- ercr. providii.R tl,o trrain i:, town before it ia abaoliitely dry. In the laboratory wa have found *hat irrain that Saa aproutcd .ind i,i nllowcj to irct fairly dry will reriva completely when sown without much delay and (rrow iuit as well aa untrentod a-sed. rURTIICR RCMAIKH. Daniih co-opentive method for hoi water treatment.— In Denmark, where the hot water treatment ia probably mont widely practi«etl. nrruniremcnta have been made with brewenea and creamcriea in which iteam and a permanent water lupply arc avniloble. The farmers briiiff their prruiii to auch centres and havu it trcateigne ) K.t • . tl nr.*^ Srr"'- " *"■ •* '""";! "'" """" ■« "^ »'•"" -'tain*! t. ntr. :■ I " '' i""^"" °'' •""''* P"««"« Ther.. i. „„ ro-omblaimo of thi« tne irliimM, hut rather the whole flowering portion leemi im :!v~J, .por;?of",.'l"rj" •"'!* '*r"V'"'-Ai in the ca«e of .tinkin., .mut of wh.^u. tho «.Tfnino« H'o-Ie of Bernnnat.on of .t.nk.ng an.! i,«,se .nu.t .pore, of wheat. In the former (TilUtia) we ob.erTed the 'wreath- of .eeon.lnry pair, of coni.lia. in the lutter there occurred no eon.d,« but infection t..bo. were formal. I„ the covered .nn.t of barley we It observe another n.o.le of gern;ination. The .pore, are .lightly l.rgor than tho J of loo.e .mut of wheat, perfectly .moot h and olive-brown. On being Tla'^i" „ .Trlen .olution. they germ.nate freely, pro.lueing a .l.ort. .tout germinal tube divided by .epta mto four cell.. At the.e .epta are produ.e.l or .cgn.ente.! a numUTr of ie.ondary con.d.a which multi,.ly. even if detaeh-nl. .iuularly to the mode of growth of brewer, yea. Such cultures ,nny be kept alive for a con.iderablo thne durln. which the con.dia increa.e in lurge nun,b,.r., hut. on becoming oxWcdth! .econd«r.y .per.-,, will produ.- the info.tion thread. l,y n.ean. of which the t'nl^! enter, the iving plant tis.ue. When sown wUa the -.aWey. the ..leveling covert r.:i^s.i:;g7nSior'' '-'- '- '- "'°- '"^' "- -^'^^-^^^^^^^^z^ Trealminl.-¥orum\m troatmout aj recor.iraended for stinking ,mut is of the greatest value for the form of smut 1 1 ^^B vM V 1 F"^^ \ vnil E r a. ^K ^ f Plate r>. The Htiiuts of OaU. (a) Covered Hinut of oats; n.-te the iiinn* natural ap|K'ar- ance of the t«r at* compared with (b) Hhowing the naked snint of uatt<. 86 8. fis. 2), are exceeding^^ igL and arf ea^i rbl„l''"'K'T ^he spores (plate caught by the loose, open glumes of th/JTnw?,- * ? "^"J" ^'"'" ^''^y '^i" t*" fast and become en ra^llb^^irL the ' J.m ' ^^ T ^J""*', '" ''•''•'^ '^'^ "« ''^^ in size. The amount of woSnTod.^!! A a^^ *''*' u""''' " *'"' >"«" '""^ases of oats. When bad"y affecteT the oatfiefd w^l' "'^" '^' '"'Vl •"'^*'''" "^ « ^^^ to the presence of so manyhekd, of smut ^lrTr"-\r'^ ^"^'' '"''°"' "^'"^ harvested will be badly inLtS whh sm. i J^rl '^"•" ^''^ ""'^' *'"' ^"'^ ^•''"l' » threshing machine as oneTf thTmosr mnnr f'/? T ""Z """* ''^ ""-y '««".urus exisi ot their kocpine diate destruction^Vtwf/rorririn ZLTrJ-f Zf^t^ ''' '^- the hTSeliSre Zz^i^: ^^^ztz^oZ V' r-^r '>^ ^'^^ - "- this chemical becomes nece«sarwWh wfll p!,1 ^ "•"*' "' " '°"^«' ''*'«°" "^ formalin possesses a sufficS penetraT vl IT ^""^V'"^"^ *» the ^rain. whereas this smut very satisfactorily The samltreamr/ '*' «PP»«tion has controlled stinking smut in wheat treatment is recommended as described for 6. Covered Smut in Oats. (Plate 5, Fig. a.) ough^k^^it'Tt'tfoC^M^^^^^^ f """' '^T'"^' -^^-•-''-A thor- adoption of correct method^ treatmenT FromV; f1 '"''"' ^^'^"f '^ ^°' *^« only necessary to recognize the varTousdrfferpntTi*'%^'™"'\ "^ ^^^w. it is methods of treatment, ie it is mrin.nT!*"^- °- '"'"* ''^'"^ '^''"^ ^iff^ent loose smut and covered smut of barW T^ . t distinguish, for instance, between bluestone in the trealnTof loose sLt whit w ""' T"^* '" "^'"^ ^"^''l'" - by these means at all. ' "^ "^^ "°^ ''°°'" <=«"»°t bs controlled r/ie «ll " (c) Female infloregcenoe or" cob "destroyedby smut l"' ^ large smut bo,I on the n« ' Jiro attacked, considerable malformations take place. More or leas large, round swell- ings may bo produced in these localities, vaiyinp from the size of a pea to that of a walnut. Those swellings are bladder-like to the touch, and sooner or later will be like pockets containing the spore powder; still later, this mass bursts the covering mem- brane and the spores are visible from the outside. The corn smut spore (plate 8. fig. 6).— The com smut spore is about twice the size of the loose smut spore of wheat or barley, with a fine, prickly surface, and often showing granulated contents. Its life history is similar to that of the covered smut fungi, inasmuch as it produces secondary conidia on germination, but it is very distinct from any of the other fungi described here, differing largely from them in tlio mode of infecting now plants. New mode of infcction.-V^c know that besides flower infection which takes place m the true loose smuts of wheat and barley, there is the 'seedling' infection in the ease of the naked smut of oats and the covered smut of oats and barley. Although the progress of the smut in com is so readily traceable, investigators have been greatly puzzled at finding that the spores produced no direct infection of th° seedlinir or the young plant Spores thickly sown with the com seeds hardly ever produced that infection of the young plant which took place so readily in the cas» of the covered smut spores sown with oats or barley, or even in the case of stinking smut above rovnd ''"' °" discovered that infection took place almost exclusively Brefeld-s discoveries very important—The careful and exhaustive researches of Urefeld again threw more light upon the subject. To this successful investigator the farmers in every country owe a great debt of gratitude; his painstaking researches and the discoveries he made, particularly in connection with the biologv of smut fungi, which of course resulted in the adoption of the cf/ective methods for control now in practice all over the world, have saved many countries untold losses. Brefeld's n:ethods of germinating and carrying on cultures of microscopic fungi have never in our opinion been 8un>a88ed. He succeeded in germinating the com smut spores in nutritive solutions. Brefeld's investigations into the biology of this fungus have been successfully repeated m our experiments. Germination of corn smut spores (plate 8. fig. E; l-4).-0n germinating the com smut spore produces a short, stout promycelium divided into four sections, at the top and at each section of which there are produced a number of slender secondary oonidia, a manner of germination which recalls that of the covered smut spores The spores eventually become detached. The promycelium itself may separate and' form more or less large clusters of yeast-like spores which multiply profusely Their development m artificial cultures is so rapid and rigorous that soon spore-bearing branches are forced out into the air. where they will branch and produc» spores in long chains (plate 8. fig E; 4). These spores are considerably smaller than those produced withm the artificial medium. Spores do not cause direct infection— csrial conidia neces«ary.-Infection experi- ments in which the ordinary black spores were used, proved generally a failure, but if the spores were contained in a nutiient solution they began germinating rapidly; the 40 conidia produced fornsed, in a short time, a greyish film on the surf aee of the medium, and air conidia were produced subsequently. As soon as that was the case and the conidia were transferred by means of an atomizer (or throat sprayer) to the growing plant, an infection took place within some twelve days, provided the plant was young and tender; in which condition it is far more susceptible thnn, when growinj? ol>l >r. the vulnerable spots become few and far between until the plant becomes altogether resistant when fully grown. From these observations, we may conclude that the erial conidia are primarily responsible for the infection of the com plant. Weatlier affects smut.— Infection of the corn plant is aided by the condition of the weather. When the weather is very dry, corn smut is very rarely visible, but some ten days after a rainfall the first smut boils will appear. The moisture is not only necessary to start smut spores lying in the ground into active life, but also causes a rapid growth of the corn, especially after a long period of drouth, which results in the production of many tender spots at which an infection may take place. Lessons from the life history. -The observations on the life history of corn smut teach several important lessons. It is shown that the infection takes place at almost any time on any part of the growing plant throughout the whole season. For this reaaon it is most important to remove the first signs of a forming smut boil, prefer- ably before the spores are formed. Remove affected plants or portions.— Vfhen removing plants which show the black spore powder, they should not be carried about the field, but the infected parts should be collected in paper bags and destroyed by fire. Danger of throwing smut infected plants on manure pile.— It is hardly probable that a farmer will carelessly throw infected portions on the manure pile. This would be equivalent to introducing the spores into nutrient media, as done in our laboratory cultures. The moisture of the manure heap is one of the most favourable conditions for the development of the spores, where the secondary spores will go on growing throughout the year, even through the winter, the spontaneous heat of the manure heap preventing freezing. Such manure, when spread on the ground, especially in spring, will cause corn, planted thereon, to become badly infested. This is another point not to be forgotten in preventing com smut. Rotation of crops important— Rotation of crops is another important factor in the prevention of com smut. Spores resulting from an infected crop may lie in the soil over winter, germinate early in spring and spread the infection to the new crop sliould com be again planted the second year. Select seed corn from sound plants.— Care should also be taken to select the seed com from a field which is free from corn smut. While no direct seedling infection takes place, tne spores adhering to the corn may reach the surface of the ground where they will germinate and produce air conidia, which as we know are necessary to commence or spread an attack. Seed treatment unsuccessful— Seed treatment for corn smut is not generally recommended, as the smut spreads mainly above ground. Brefeld has shown, how- ever, that in experimental cases infection may take place below ground. Of 500 artificially infected seedlings, 20 succumbed owing to the development of a more or loss large smut boil just above the crown of the root. In some such cases, the upper- m-st series of adventitious roots also became involved. 8. Bnooif CoBN Shut. t (Plate 7, Fig. a, 1.) Broom corn, the plant which yields the flexible long, upright ' seed heads ' used m the manufacture of brooms or whisks in common use on the continent of America, w as yet little raised in Canada. During the last 'wo years, experiments with broom com were carried on at the Central Experimental Farm and some of the branch i'"il™t« P ^"* ^^"' °^ *^^ experiment it was noticed that some varieties were fully 30 to 40 per cent smutted. Smut interferet with quality of ' hrush'-Whcre broom corn is Taise.1 for seed, tne smut of course seriously interferes with its production. For the purposes of broom-makmg ;ong, straight, thin 'brush' or seed heads are desired. The thick central axis which is sometimes producwl renders the brush of inferior quality. Broom corn smut will prevent the production of useful 'heads.' The long, slender stalk desired will be found to be replaced by a short and curved one, and the undesirable central axis will be prominently developed. Smutty heads are entirely useless for seed or manufacturing purposes. Seed production frustrated.— Out experience with broom corn smut prove.l the destructive nature of this disease which considerably interfered with the raising of usable brush. The smut which was noticed was confined to the ' seed heads ' or, to be more correct, to the reproductive parts of the flower, which normally would produce a seed. The production of seed was entirely frustrated, and the seed-bearing stalks forming the commercial product for the manufacture of brooms were twisted, short and stout. Appearance of disease.— The affected heads showed, in the place of seeds, large, protruding, brown bodies (plate 7, fig. a, 1). which on breaking open with the fingers. were found to contain a spore powder similar to stinking smut of wheat in appear- ance, but without the unpleasant odour. Smut of broom com a distinct f/enus.— Microscopical examination of the spore powder revealed numerous olive-brown, roundish spores with a perfectly smooth surface and somewhat granular contents (plate 8. fig. 6). Their size approx- imated that of the oat smut spores. This form of smut is technically known as bphacelotheca Sorghi (Link) Clinton, which is the third genus of smut fungi treated of m this bulletin. It differs from the first genus, Tilletia, principally in the mode of germination and in the size and shape of spores. From the second genus, Ustilago, It difiers mainly by producing its spores around a central axis or columella and with- in a definite, more persistent membrane, whereas in Ustilago the spores are either entirely free or covered with a very thin, perishable membrane. Oermination of spores.— On germination, the broom corn smut spore behaves similarly to the covered smut spore of barley or oats. It produces the short piece of septate promycehum with secondary lateral or terminal conidia with very plain indi- cations of attachment to the mycelium. In water, fusion of mycelial tubes occurs commonly. The secondary conidia multiply in a yeast-like manner in nutrient solu- tions. After exhausting the solution they produce delicate infection tubes. Seedling infection.— When spores are sown with broom corn seed, the young seedling is infected directly by the germ tubes issuing from the secondary spores. In this respect, the broom corn smut infection is identical with those caused by the covered smut fungi of barley, oats, or naked smut of oats. Control— We have found in our experiments that the formalin treatment, espe- cially the dipping method with removal of the floating smut balls, very satisfactorily controlled this disease. It reduced the high percentage of the year previous, to less than one per cent of the whole crop. I Plate:. ;aj Sinutof br.K.m<'.,rr, ; sm„t ImlU : (:.» n„n>,al pRrt» „f -ar cm lusi- a 8..und »r.in • (3) wiifKl p-am of broom corn , ; An ear of millet a(Tect.'- N»ked«mut»|x)re8ofo»U(renninatinif Ml ?Iri» 1. l'fo™ycelmm produces th n infec- ICr.?'^"":^,' <3>i''°.««»nd.ry .pore. P^dnK^nfec ionlSb^ ^"'r *^' "''""""» """'-^ "' s^onriary fcarlpta^, (2 production of serondary .i»res 3) i^mHif^ *'■ *?""'. """'•('oreBgemiinatinir. (i) idia from Mcondary conidia. ^ "^ ' ' ' •««Mary gpore. Kerminatmg, (4) prodSction of air cm- •. Smut iliwaiiHi are perpefittod primipally by iporet. The wind diiprning tht tporef, ipore* adhpring to the grain ituclf, or the living fungui within the grain, infected iniplrnicntt, grain bng«irc toiiip«Tatur« ■ink below rtH" F. allow five hoiirn for noBUing. Tri-ot prefprnW.v iti ii hriit<"l room to avoid tho inoonvpnirnt fall in tpriiiHTHtiiri' of th« wator (b) Final Irratm^nt. Hrind th- titiipcraturc of water in n ae^nd barrel up to lia* F. Uoinovu bair« witli Kruiti friin. tlif 'soak' iind triinufcr to the amoiid hnrrd. Kwi' inimerwHl for l:. to 20 iiuiiiitf:*. M,.;iii\vhil.' hiivo wiitiT in a third burn-l l>roimht up i» a tetnptTii- turo of 1'21>^ F. AftiT the 15 to '.'0 iiiiniit •■< in thi> »ix-oiid burrt-l traint'i-r tin- irr.iin quiclJy into the tliir.l barn-l. Ihn- the (train rtninins u fiirlhiT H> niiniiti-. I'ndor no firi'ini'.*t»nci'~ cxtrnd ibr tiin- utiitiil. or iihortrn if. Ncilbrr Iw rarrlr-" nor di«- rcKiirl accurarv .if li'Mi!)iratiiri'-i, or tin' tri'atinrnt will not !»• «ur(T««fiil. Sjionbl the t.nip<'ratiir in tlip tbir.l I ami "ilil; b.'biw U'l'' F. iift.T tbi' (iruin in put in. tuim' the ton piTJituri' by (•ari'liiliy nibliiiff bi't wulfr from a gprinklinif can. Nivcr pour hot ualcr ijirpi'lly on tiio ijruin. Tlic lariror the volumo of water, the ir.or- fa-y will it be found to uiainfuin thu fonipiratun-. After tli« 10 niinut»'a in tht> third barrel have fxpirecl. take out the (jruin, drnin and aprund out to dr>'. THKATMKNT KoR COBS SMUT. Seeil treatment of any kind U uaele-i^. • Watch for the first aymptoni^ of Porn smut, remove either the whole plant or eut out below place of infection with n sbarp knife. Destroy eolleet"il ninterii'l by fire. Do not permit the spore.'* to develop in the forming smut boil. The sooner this is destroyed, the more gucceasfully will further spreadinvr be prevented. Infested cornstalks should not be thrown on tin manure pile where the sjiorcs will remain netive even throup:h winter, and the manure wbttu apread on the laud will reproduce the disease 48 III. APPENDIX. DIRECTIONS FOR OBSERVING THE GER^nNATION OF SMUT SPORES IN ARTIFICIAL CULTURES. (a) COLLECTION OF THE MATERUL. . "^f 'Pom of some species of smut fungi are short-lived, while others may retain thnr Titality for a number of years, though naturally their energy of germinfltion, ns well as the percentage of germinating spores, gradually declines with the advance of age. Tlie spores of the true loose stnuts. as of wheat and barley, lose their power of Kcrmination aft«r a few montlis, and the failure to gern^inate any unknown species of smut aftor some montlis of storage, may be regnrded iti some instances as an indi- cation of fheir producing flower-infection. Where this is experienced, the ahsenc- of secoiidi.ry coni.iiu will provide further proof. Thd spores of these fiinKi should ho collect"d on a bright summer's day, when tliere is no ii-.oisture in the air or on tlie plants. The spore dust should he shaken into dry glass tubes and sealed with a well- fitting cork. As it sometimes happens that the spore supply spoils on subsequently l-ecoming wet. n niiini.er of very small tubes shoiil.] he separately fillnl. corUcd and kept in a stoppered glass jar for future use. This method will prevent tlie whole >'o:k from Iviiiir ypoiled. The stock spores should be ker.t. pref-rably, in a cool place. Tlic ■■■■'„ir mat. .rial of stinking smut of wheat and certain covered or naked smuts of the fr, Ills Ustilaijo keep their gormination for years, and. as long as the material IS collcted dry and preserved in this con.lition, failures to germinate the spor, s will rarely bo cxpcriencod. (6) PRKPARATION 07 NUTRIENT SOLUTIONS. Mos^ spores will commence germination in pure water, but in order to observe the production of secondary spores of Tilletia, for instance, water alon" will not suffice. This IS equally true of a number of other species of smut fungi. Practicallv every observer employs his own methods, whicli, dep ii linjr on the condition of the s; ores, are accordingly more or less successful. In preparing the material for the onginal drawings in this bulletin the author tried various methods, until he found that the simplest possible composition of the me cover- '^lass will be quite dry. Do not use artificial heat for drying. Lift up tlic watch- y:lass and drop three or four drops of pure alcohol on the culture and allow it to I'vaporate. This will fix the material firmly enough for our purposes to the surface of the cover-glass. Next take the cover-glass up with a pair of forceps and immerse right side up into Xylol, rock gently to and fro until all traces of vaseline have disap- peared. Remove and dry once more. The preparation is then mordanted for one minute. Tse four grammes tannic acid, which dissolve under gentle heat in 16c.c. distilled water; add lOe.e. of a cold saturated solution of sulphate of iron and 2 e.e. cold saturated solution of fuchsin in !>."> per cent alcohol. This solution should be prepared 24 hours before it is required, when its action will be more perfect. A singli' drop of this mixture is filtered on to the preparation, and it is allowed to act one minute. Pour off and rinse the cover-glass gently in distilled water to remove super- fluous mixture. Before quite dry, stain the preparation from 30 to 90 seconds, according to the desired depth, with a saturated solution of fuchsin in 95 per cent alcohol — one part in ten parts of distilled water. Again wash off the stain in distilled water until no more colour is removed, and dry in the air. When dry, mount in Canada balsam. If the culture has remained uncontaminated and the cover-glass was clean wh->n start- ins, the preparation will be found satisfactory and will keep indefinitely. Follow the game procedure with other stag?* of development of the spores under obaerration. I 50 DESCRIPTION OF SMUT FUNGI DEALT WITH IN THIS BULLETIN. •II ^''* ^°"°'^'"8f ^ey fo' identification of the smut fungi referred to in this bulletin will be found useful to the agricultural teacher and student. This review is adapted from Dr. George Perkin Clinton's ' UsUlaginalet/ North American Flora, Vol. 7. rart I. published by the New York Botanical Gardens, October 4, 1906, which we regard as the most up-to-date nomenclature on the subject. About 11 genera of the UstUagtnacea are known with some 120 species, while the TilUtiaceoB are represented by 8 genera including about 78 species. They occur on cultivated and wild grasses and a large number of other plants. Their importance diminishes with the economic value of the plants attacked. Family 1. USTILAOINACE^. Sori usually forming exposed dusty or agglutinated spore-masses. Germination by means of a septate promycelium, wliich gives rise to terminal and lateral sporidia (capable of yeast-like multiplication in nutrient solutions) or else to infection- tnrcads. Spores single. Spore masses (sori) dusty when mature. Without definite false membrane J. Ustilago. With false membrane of definite fungus cells. II. Sphacdotheca. I. Ustilago (Pers.) Roussel, Fl. Calvados ed. 2, 47, 1896. Sori on various parts of the hosts, at maturity forming dusty, usually dark- coloured, spore-masses; spores singl", produced irregularly in the fertil-^ mycelial threads which early entirely disappear through gelatinization ; small to medium in size; germination by means of a septate promycelium producing only infection- threads or with sporidia formed terminally and laterally near the septa : spo -idia in water usually germinating into infection-threads but in nutrient solutions multiply- ing indefinitely, yeast fashion. A. Spores reddish-, olive-, or black-brown. 1. Spores perfectly smooth, small, 4-10^ in length. Sori in individual spikelcts. (a) Spores light»r-coloured on one aide. Sori 6-10 mm. in lengtl). Hosts: Avena; spore-mass brown-black 1. U. levis. Hosts : Hordeum : spore-mass purple-black . . 2. U. Hordei. (b) Spores uniformly coloured. Sori usually des- troying inner and basal parts of the ^P'l'e'et Z.N. Crameri. 2. Spores echinulate or verruculose (occasionally minutely or obscurely). (a) Spores, small 4-9;i in length. Sori in spikelets. rather completely des- troying them. Hosts: AverM oriiim Sorghi Link. Tilletwi Sorghi-vulgaris Tul. Uatilago Sorghi Pass. Usliliifjo Tulasnei Kiihn. Cintractia Sorghi-vulgaris Clinton. bodi^iir;^ in" t^ri:j; tinTThe^ler^o' '"™r, ^"^""-^ *° "-- forir.s. protected for ^o^e tim^ety ^"Xfsetem^Tanr uf u^S r" tr tL'^H^ brown cpore-mass becom ng scattered leavinir nalcpH tl,» Ai.t-. ,P*"'?, *"«. "'"e- tissue: sterile cells of membrane break^ up^om^thl't^nt^ZjlTy: t°^^^^^^ to s„b.pher,cal, chiefly 7-18^ in length; spores subspher caf to ,pheS smooT CO' .ts often granular, 5.5-8.6^ in diameter. "Pnerical, smooth. Grain smut of cultivated broom corn. Family 2. TILLETIACE2E. Sori either forming dusty erumpent spore-mosses or else permanently imbeddprf in the tissues. Germination by means of a short promycelium which ,,,LlT ■ rise to a terminal cluster of elongate sporidia that, with or wXut fti^ n^f'''' ^rodu^c. similar or dissimilar secondary sporidia or germinate dS/iri^L'ti^: Spores single, dusty at maturity T'll f Tillciia Tul. Ann. Sci. Nat. Ill, 7: 112. 1847. Sori in variou. parts of the hosts, usually in the ovaries, forming a dusty snorp- n:ass; spores single, usually formed singly in the ends of the mycelial threTdsthTt disappear mora or leas completely through gelatinization, "t m"dium to large lize; germination with or without fusing in pnirs, may, ir nutrient solutions, give rixe to • considerable mycelium bearing secondary air-sporidia. Spores smooth I. T. foetent. Spores rcticulat?, sori 5-8 mm. in length 2. T. Tritici. 1. TUletia foeteng (B. & C.) Trel. Par. Fungi Wise. 3S. (18»4.) =Ustilago foetena B. & C. TUletia Uevis Kiihn. Suri in ovaries, ovate or oblong, 5-8 mm. in length, more or less concealed by the glumes, all or only part ot the ovaries of a spike infected ; iporet light- to dark -brown, oblong to chiefly subspherical or spherical, occasionally somewhat angular, fu-tid especially when young, smooth, chiefly lG-i'2 n, the most elongate rarely 28 ^ in lengtli. Smooth spored stinking smut of cultivated wheat. 2. TUletia Tritici (Bjerk.) Wint. Rab. Krypt. Fl. 1: 110. (1881.) =Lycoperdon Tritici Bjerk. Urcdo Caries DC. Sori in ovaries, ovate to oblong, 5-8 mm. in length, more or less concealed by the glumes; sterile cells few, hyaline, subspherical, with medium thin wall, smaller than spores; spores chiefly subspherical or spherical, light- to dark-brown, with winged reticulations about 1 n high by 2-4 ^ wide, 16-22 fi in diameter. Bough spored stinking smut of cultivated wheat. EXPLANATION OF BOTANICAL TERMS. The use of botanical or scientifio terms has been excluded as completely at possible from the pages of this bulletin. In the resume of the genera anil spec- us, however, full use has been made of them. The student will meet the same terms in every text-book and should be familiar with them. The use of these terms insure* accuracy and saves time and space. The terms are arranged alphabetically and their n^eaning is briefly explained. The following abbreviations hiwo b'en olso employed: — ' H,' a letter of the Greek alphabet; used as a syii:bol in biolojfy, denoting the unit of length. It is also referred to iis 'micron' or iiiicTO-millimeter, and is equal to one-lOOOth of a millimeter or one-25000th of an inch, mm.= millinieter = OOJiOt in. dm.= decimeter = 10 centimeters or 3-937 in. Anfjular, angular shapes or indentations in fungus spores, the result of pressure. Anlliir, that portion of a stan-.en containing the pollen grains. Autnc'.avr, an apparatus used for sterilizing liquids or solids by superheated steam. Cenirii>ctal, growing towards the centre from without. Conidia, technical name for certain types of fungus spores. Columella, small, pillar-like body of sterile cells within the sporangium or sorus of fungi. Echiimlate, showing minute prickles. Ellipsoidal, oblong with uniformly rounded ends. Elongate, oval, elliptical, or still longer in proportion to breadth. Erumpent, bursting or pushing through the epidermis of the host plant from within. Fertiliiation, the act resulting in the production of a fruit or seed. Gelatinization, an expression describing the breaking down into a jelly-like mass of fungus hyphffi or membranes. Genus, genera, the name of a group of plants or animals the species belonging to which all bear the generic name as the first portion of their scientific name. Qlumes, chaff-like portions of the flowers in grasses and cereals, which serve to protect the flower. I S4 Tlott or hott plant, the t«nn uied in plant patholozy for any plant which entertuini or feeda a parasitic ortranism. Hyaline, colourlcaa like clear water. Inflore$e»nee, comprising the flower or arrfln^cment of flowcri, or a ahoot compriiing one or more flowers. Medium, media, in mycology or bacteriology the various aubstancea, liquid, gela- tinou-4, or solid, u«ed for the artificial cultivation of fungi or bacteria. Mordant, any substance preparing an object for the retention of colour. Objects difficult to stain, like flagella of bacteria, must be mordanted before they will take a stain. Mycelium, the vegetative portion of a fungus plant, composed of threads known indi- vidually as hypha;. 0>'ar!i, a receptacle containing tho ovules and from which the fruit is formed. Ovate, egg-shaped. Ovule, an immature seed. Pale, the inner part of the two bracts or scales which enclose the individual flowers in tho apikolct of grasses. Pistil, femalo organ of a flower composed of the ovary or seed-case, the stigma or etigmas for the reception of the pollen, and usually of a connecting portion, the style or styles. Promycelium, the more or less short, stout septate or unseptate mycelium produced on geruunation of the smut spores, either bearing secondary spores or producing germ tubes. Bachin, the axis of an inflorescence. BetictUation-i, marks or lines crossing like the meshes of a net: reticulated surface = surface with net-like thickeninfis. Septum, septa, the dividing line or lines found in fungus mycelium. Septate, fungus mycelium may be divided (septate) or without division (non-septate). Sorus, sori, somewhat incorrectly used in mycology to describe the erumpcnt or other kinds of spore-masses of fungi. Spherical, round, circle-shaped. Suhspherical, almost but not quite spherical. Spikelet, a cluster of one or more flowers enclosed by a common glume or pair of glumes. Bporidia. same as conidia or fungus spore; generally used for smoll or secondary spores. Stamen, the male part of the flower, composed of anther and filament (stalk). Stigma, the terminal portion of the pistil which receives the pollen grains during fertilization. Style, the elongated stalk-like portion of a pistiL Verriiculoae, covered with warts. IHDEZ. AppaiMlix " Barley, imnt diseases of (PI. 4) ^^ corered nmut of '~~ appearance in field '™ germination of spores of '!z tipore dispersal of «., treatment of i« loose smut of i. infection of flower in •'; life history ■'' relatrd to loose smut of wheat •" treatment of '• Bluestone treatment ^|! •zhaustion of solution used fm- ;" formula for 'sprinkling' -" " " ' steepinK ' '" iniury to srain after -', lime water foUowinir '- Broom corn smut (PI. 7a) ]] appearance in field ' j distinct lenus | J eermination of spores of *• seedlinz infection by jj seed production frustrated by *I spoilinir quality of brush jj treatment of *' Copper sulphate. See Bluestone. Corn smut (PI. 6) 'J aerial conidia of ^ Brefeld's researches on "J Kermination of snores of ^ importance of first .siuns of JO infection of nlaiits by 39 life history of nnd 'e-ssons from 40 manure pile carries spores of, over winter 40 not confined to flowerine parts 37 prevention of 40 rotation of crop 40 seed «elect ion 40 " treatment useless 40 smut boils 37 Covered smut of barley 33 " " oats 36 IDamase caused by smut diseases 13 Dates of sowiua aflectinsr severity 10 Dryintt (train after treatment 30 difficulties to overcome : ™ mixinR with road-or sawdust JJ sproutinc while " ' Explanation of botanical terms 53 Fannins mill, use of. important Flower infection. .S''< 1 arlcy nnd Wheat. ^^ of wheat Fodder infe'ted with smut, danicerous 8 Formalin. Fdi maldelivlo treat iiiert ^9 exhaustion of solutnn used for -" formula for ' sprinkhns " -" " ' hteeping -" injury to erain following Frost, action of. on restine smut spores II •■ " eerminatinn smut spores 13 " " treated grain while wet 21 60 Qi>rminatten of tmat fnnti in •rtlllcl»l enllnrM «• of «hMt iraia •• (iiaiii, trpstment of. for imat. 5m BlnMtona trpatnifDt i( formalin trpiifment •«. 1! hot water troatmrnt 2I, If Host olant action of amat funai on J flo»«r infection of • ff-edUnK iiif.ction of t lender partt of, infcetad t varioua methoda of infactioii of I Hot water treatment- description af 29 eflrctira for all kln^l* of amnt Z» inlnrr to Titalitr of Krain after 31 aixcial machinaa for (I Injurioaa action of treatment on grain— •Vee under hlueatone. formalin, hot water, froat. Introduction Part 1 ; Ker for identifrini imut fnnni SO Lcosp smi.t of barleT S3 " " or naked amnt of oats 94 " of wheat tt Machines for treating srain for amut 21 Millet smut (PI. 7b) 43 appearance in 6eld of 43 low TitalitT of bought seed 43 seedlinir infection by 43 spores and their Rarmination 43 treatment 43 Naked amnt of oats 34 Oats, amut diseases of (PI. 5) 34 covered smi.t of 33 appearance in field !!.!!!!! 3< spore dispersal at thresbius 37 treatment of 37 naked smut of ','.'.'.',', 34 appearance in field of .......'.'...'.'. 3| (termination of spores of '. 33 intensi'. t of infection by 3S «Dore dispersal !!!!!!! 36 treatment |_| 3g severe lossea due to !!!!!!!" 34 Keprcduction of amnt diseases y Seed treatment Reneral— of laree quantities. See various host plants. Seedling infection occurring in— broim corn covered smut barley .......!.!.!.!.!. oii ofits oi Iro^e smut of oats « iriliet ." .' ■.'.'.■ ~ stiiiking smut of wheat •.'...'..'.'.'.".'.".'.'.'.'.'.'.'..'.'.'.".'.''.■.■'.■.■ j» Kmit diseases — due to microscopic fungi . infliunced bv date of sowinar m weather '.'.'.'.'.\\'.\'.'.\'.\'. \j loses to aifrieulttire from J.1 Pit ronfimd to cultivatwl plants .'.'.,.. js ri?r of, 6 (PI. ») . vitalitr of. natnrRl ;"T'"i 7 aftfr iiaMing throoRh body of •nimBlt ' Rnli'tinna. chamioBl, for smut trtatmant— bluMtone {« formalin 12 no loaa of (tronfth ™ Special. Ptrt II " 5;>hace(othcca SoriM *' StiokioR Saint of wheat '* Sulphate of copper. See Blueatona. Biimmurr ■ 8ii>''eptibiIit.T of Tarietie* " Tbrerhiiig machine, cleaninx of from imiit iporM ^ imiHirtant agent for spreading »mut diwaaM » niUHa loetetu '*•*'"' Tritici '*•'' Treatment— .,,, mrtliud of. for large quantities of grain -" Sie under various host plaDt«. t'ttilofo Avenae 34, 51 Crameri <•'• 51 Bordei „, *J lerU '•*» " nurfn , 3' Tritici ':;•;' Zroc *2 Varietal susccptibilitf for amut " Weather, i'ailuence of on noTority of smut '••'<' Whaat, Buwer o{ J* gtrmiiiation of grain of 1- poUeii grains of • "is amut iiiscufcwi of (I'l. 1 & S) " loose smut of, appearance in field *; biological features of ~ bluestonc and formalin useless m j" co-operative work. Danish ^' flower infection in •? fungus living in grain « Eermination of spores of " ot water treatment -"• ^ life history of •••••.■• ."H life of spores of. brief • — • -Z loas of vitality of grain through treatment -^ raising of clean seeds supply -' removing affected plants -* ripening of spores of ; -- significance of spore ripening -J stinking smut of. appearance in held jJ bluestone treatment for '■> confined to wheat }jj formalin treatment for 'i garniiiiotion of spores uf ''_ longevity of sporeii of j ' spores of ,u treatment of • }2 washing in water to prevent '»