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Lea exemplaires originaux dont la couverture en papier est imprimie sont film«s en commencant par la premier plat et en terminant soit par la darniire page qui comporte une empreinte d'Impression ou dlilustration, soit par ie second plat, salon Ie caa. Toua lea autras exemplairee orlglneux sont filmte en commencant par la premiere page qui comporte une empreinte d'Impression ou d'illustratlon et en terminant par la darnlAre page qui comporte une telle empreinte. Un dee aymbolaa suhrants apparaftra sur la dernlAre image de cheque microfiche, selon Ie cas: la symbolo — ^ signifia "A SUIVRE", la aymbola Y signlfle "FIN". Les cartes, planches, tableaux, etc., peuvent ttro fllmte i dea taux da reduction diffirants. Lorsqua la document est trop grand pour ttra reproduit en un seul cllch«, II est film« A psrtir de I'angia sup4rieur gauche, de gauche k droite. et de haut m baa, en prenant la nombre d'Images n- DEPABTMBNT OF AOWCULTURB CEJSTTRAL EXPERIMENTAL FARM OTTAWA. CANADA DTVISION OF BOTANY A SERIOUS POTATO DISEASE OCCURRING IN NEWFOUNDLAND H. T. GtJsSOW BetimUi to fh* Dommion Bxperintittal Farmt, Ottawa, Ont. BULLETIN N"o. 68 POTOBKB, leOO 630.4 C212 Exp. Farms Service Bui. f dirMtion «f th« Hon. SYDNEY A. RSHER. Minittw of Agricuituro, Ottaw., Ont. ** J -'.V DEPARTMENT OP AGRirTTLTURE CENTRAL EXPERIMEiNTAL FARM OTTAWA. CANADA DIVISION OF BOTANY A SERIOUS POTATO DISEASE OCCURRING IN NEWFOUNDUND BT H. T. OOSSOW Botanhl to the Dominion Experimental Farmt, Ottawa, Ont. BULLETIN No. 63 OCTOBB3R, lOO© Publi.h.d by direction of the Hon. SYDNEY A. FI&HER. Mini.fr of Aoricultur*, OtUw^ Ont To the noTionrab1« The MinUtar of Ajrrfrnltnre. 8m,— I ber to lubmit for your approv*! Bulletin No. 63. entitled : ' A Rerioui PoUte DiMue occurring in Newfoundland' which hu been prepared by Mr. H. T. OUsaow, Boteniit to the Dominion Experimental Farm*. la thia buUetin reference i« made to the exiitenco and progn-ea of the diaeaie referred to, ia Great Britain and in Europe for aome years pMt. where it ii known aa the PoUto Canker. From ll.o facta brought together in thia Bulletin, reUting to the life history of this disease in Europe, and iu discoTcry by Mr. Oiiaaow in poutoee sent from Newfoundland, it is evident that ita occurrence in America ia a Tery aerioua matter and every effort poaaiblo should be made to limit the spread of thia diseaa«>. and to destroy ihc diseased tubers whenever they are found. All the illustrations used in this Bulletin are original and have been prepared by Mr. Gttssow, who has studied this disease in Europe, and hence haa been nblo to give full details of its life history. This deaoriptive matter with the illustration* wiU, it is hoped, enable any one to recognize Potato Canker wherever it may occur. I have the honour to be. Your obedient servant. Ottawa, October 87, 1909. Wm. SAI'NDERS. Director of Experimental Forme. OUTBREAK OF A SERIOUS POTATO DISEASE IN NEWFOUNDLAND POTATO CANKER (Chryaophlyctis endobiotica, SchUb.) BT ir. T. GU8.SOW, P.R.M.8. JlotaHUl to tht Dominion XxpninutUal furma, Oltaum nrntoDuonoir. During the past 13 year* a teriout potato iiinlady hai been rapidly upreadlng in European countriea. The di*mM. which naa been kno«-n in England since 1901, haa received in that country the foUowing namea: Black Scab, Warty Disease, Cauliflower Dueaae of PoUtoee. but it ia more properly designated aa PoUto Cnnk-r. It has hitherto been unknown on the continent of America, but haa n-iw made iU appearance oi thia aid* of the AUantic. having been recognized by the BoUnist of the Experimeuti. I InnlT*' '••••"^ tpecimtna of potatoea forwarded from a locality in Newfound- While it ia not very likely that potatoea will be imported to any extent from New- foundland into Canada, yet the extraordinary virulence of the diseaae in Great Britain, and the remarkable rapidity with which it haa spread over practically the whole of Europe, maka it neccaaary to iaaue a warning to all growers of potatoea to be diligently on the lookout for thia aerioua malady. There ia hope that the diaeaae may yet be nrreated before ap-Mding to other localitiea, if Umely notice be given to the potato growers of the Dominion. The investigation which haa been personally conducted into the natuiw of the diaeaae^ by the writei in Great BriUin, provea that it ia one of the most serious maladiea known. Where allowed to establish itself, it renders the culti- vation of pot?* -a extremely difficult. It ia not desired to unnecessarily alarm the growen of r », but it muat be borne in mind, that if thia disease ia through in- difference or . ^.igence aUowed to eatabliah itself in Canada, there is no hope of being able to aave a crop that is once attacked; moreover, the ground on which a diaeaae^ crop may have been raiaed, will be unfit for the cultivation of thia important crop again for a period of six yeara. In thia oonnection practice and acience must, aa alwa-^ go hand in hand, and if our object inkeepbg the diseaae out of the Dominion, be atttiined everybody who thus renders assistance, will deserve credit fo.- aaving the potato growera of Canada from disastrous losses. Hiitory of the Diieaae. The first existing record of the disease is attributed to Prof. Schilberszky. who dis- covered the disease in Hungary, in 1896. («) In December, 1902. the Journal of the English Board of Af culture published an account of this disease by Prof. M. C. Potter who referred its cause to the same fungus as that described by Sohilberazky, viz. Chry»opVyetit endohiotiea . Curiously enough, in the same number thia identical XIV, 1896, p. 36. (cit. Soraoer. HanUbuch der Pflanzenkruikheiten, 1MB. Vol. 2, p. 116.) 3 diiMM WM flMcribnl bjr Mr. UeoriD Ma«aM of K«w, who, how«T«r, tpfrrxttl it to ih* fMiua Otdumytu (ip. Itproidi; Trabul), • dliMM which wai rtmtnkil w nopurrinC on bM>t-root in Alfcria, but which aoconliiiir ti) information rtveired by the writer from Prof. Tnbut, it duo to a Inlalty diffirrnt oriraniam than that on the potato, Th* Icalict of tha Bo«rd of Affriciiltura ami FiiheriM No, lOS, publi*h'd aubaMiuantly, rvprati the prrar in identifteation of the diieaaa at one that i» caused bjr (Eiompett Uftroid—, trMtlnr It aa ■ynnnymou* with CkrfopMgrtit mdohinlim. Although the i«riou«neM of tha diica*'' waa raooipiitad, no ■]rit<*niati« atapa were taken to top it from iprradinc, until it wa« aehoduled an a notifiable diaeaae by the ' Daatructlve Inaect and Pceta Onler o{ IBM' (iMiicd under the Peslnirtiv» Inaaot and Peata Acta, 1877 to 1007) which renden penmna conccalinir thi* diw>nM< liable to proM*cution and a heavy p^alty. During tlie yeare that hare elapMo poaaible to recognize the diaeaae in nil ita atogea it ii tit HJrablu to deacribe carefully ita AppearaiiM in the Field. The diaeaae ia unfurtunati'ly nut noticeable, until the potato crop it being har- vested, thiia the diaeaae i« lialiie to contaminate the ground, without being obaerved, an ia not the cnie with ditcaaca affecting plnntn ut>ove ground, auch aa ' Late blight,' I'lillfoiilithorii infenlani, (Mont.) de llary. Where the diicaae ia prevalent, practically no hcoltli.v tubcra will de\'clr>p. The tul'cra when lifted, thow aigni of vnriouK degrret of injhry. Some appear on caaual cxamin ititm to be aound. fiut the ' eyca ' of the tubera xhould be carefull.v pxaniinod, tlioup arc till' places where the diseiiKo ix first noticeable. The eyes of BiT"ctcd tiibcra sliow an abnormal development of the dormant shoot. A careful untrained obacrver can eaaily recognize the presence of the e in this stage. At the same time it is in this condition tlint the disease is most liltely to escape detection and to be spread by menns of infected tubers used for teed. In the earlier stages of tlio di«cas<\ the eyes will be f nind to be slightly protrudinjr in tlie form of u siiiple or comjHiund group of amnll nodules vorying from the sire of a pin't hend to that of a pea. Figure 1 ' A ' show* n section through a tuber slightly affecteil. the nodules being plainly visilde nt four points where in healthy tubers eyes would Imve l)een situated. V Hf^ I'iU. I.- IVlTtNBI SHOWINS DuUM Of ri iiifpcted potato it washed in water, thii tmall i odule is enxily <)!«• tinguishablu from a sound eye by its colour. Tbo colour of a souml eye may Ik> wliiti', rose or purplish, while the diseased nodule is ot' a ruHty lirown colour showing ito resemblance tu an eye of the potato, with which every grower ii« doubtless funiiliur. There can be no doubt that Ihc iliscasc was introducinl into Ncwfoundliuiii t>y means of disoase lond \ .n be infected, tho diseasi! will have Rained n foothold and the future ' 'iltivntiv u of potatoes thro\iKli<>iit the country moy be wriously influenced. Great care siiii.ld be taken, when pliiiiting potatoes, especiflUy when imported from vr\ lart of Ei. v- to ascertain whether the seed t\ibers tome frtp.ed, there may be but slifrlit dnnger of importing seed tul)ers from JJew..^ .i.dland, yet, thiit the disease may be in- troduced in this way, is not impossible, especiolly as the extent of the distribution of tho disease cannot be accurately ascertained at the time of writing. Further (stuges of the disease are as follows: Some tuln-rs will be found, when the crop is harvested, with more or less than one-half of them covereean. when du(f ; showini? in the centre a partially Hound tul*r«,vere