Wart disease of the potato

Material Information

Wart disease of the potato a dangerous European disease liable to be introduced into the United States
Series Title:
U.S. Department of Agriculture, Bureau of Plant Industry. Circular ;
Orton, W. A ( William Allen ), 1877-1930
Field, Ethel C
United States -- Bureau of Plant Industry
Place of Publication:
Washington, D.C.
U.S. G.P.O.
Publication Date:
Physical Description:
11 p., 2 leaves of plates : ; 24 cm.


Subjects / Keywords:
Potato wart ( lcsh )
Potatoes -- Diseases and pests -- United States ( lcsh )
bibliography ( marcgt )
federal government publication ( marcgt )
non-fiction ( marcgt )


Includes bibliographical references (p. 9-11).
General Note:
Cover title.
Statement of Responsibility:
by W.A. Orton and Ethel C. Field.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
This item is a work of the U.S. federal government and not subject to copyright pursuant to 17 U.S.C. §105.
Resource Identifier:
029630069 ( ALEPH )
48812932 ( OCLC )

Full Text

Itiued March 7, 111o.

RI I\ A U 11' PLANT INDI HTRY-- circularr No. ,'.
B. T. GALLOWAY, Chief w>f Bireua





W A. OR1()N,P.\TI[,I.(>(,I-T,
IN \ .,T I I.ATI" NS.

"fill So



,('lf qf Si t ir o V, lY T. GAI,I.OWAY.
A.,,islldt <'lirf(f Rn r(aitm G. HAROLD PO WELL.
K'litor, J. E. ROCKWELL.
I'lilf Clerk, JAIES E. JONES.
[Cir. 52]


11 II 'i,->:




A hew disease <(f the poItat{o which Ias b.een exct -itin aharil' il Il'u ticOpe
is likely to 1we inilrod ed{ into this ao y :it allY timie. Tlthis circulal:
iS issu d to call the attention of Amliltlricaitl 'lr}owerl's ;a11(d importers of
potaton s to this, d1ti_'er and to I1ge- their cooperation inl aln il'irt to
prevent it fro in securing a t f{}ootholdh here. It is imilporhant tlht1 any
IA-e dli.;dco(vered be pmtly reported andll : 1 posi. 1,.i1' lle aii.s taken to
prevent its occurienIce.


The disease, which habee knol)wn :as "- wart-y disease." "" black
scab," -.canker," and caulillotwer.." is oe which attacks the. tIiber
prinlcipally v, and iconsequen tly is not otsierve1Id initil IiarvestiII timie.
In a bhad attack of the disease bi. dark, wdartv e'axc'rescences,. sometimes
as lIarge as the tuber itself. appear On its sidesl O.r eds. "The grow th
consists here ()f a lmass (of 'oral-like or moreIlOl'' or ( sabv exc'es-
c(Ice.s or il(hii -. similarityht ill appearance 0 tlhle r el-known )w cwo
iroot gall Of at ppIls)'. The adh(erent earth ca ihi eas4il wa;shi'ed Ot'
when thle character of the ,rowtl becomes more apparent. It is n{ot
spotingy and not detachalhe from the tuilber. It is of a somilewhat lighter
colors at the hase aInd dotted withi minute liirusty v-rPown spots o ver the
surface. ` Ill al advanced -.., the tulber, are wholly coxv-
eredl by this .i, thi, liavii,._ lost ever 1v resemibilanel to potatoe's. 'l' iev
are lumIp oI f ii i,.nl- ar foutli, nei'ver splhie.riea l oica m iuloti._. huit sil ply
i t mas of r.i_,_''.'I' and -.' ,1 excrescences -. A still mowirle
advanced stage Occurs wthtin thit tilligs hias utilizedt exe'rv partiche (f
food storedd in thl' tubi'r and liat reduced it to a hro'wi sh-bllhlack soft
1mass givin,'_. oil a veryl unplelasant putrefactive Tdhir. i'hi is the Itost
,d.i, st.,_.''' Of tlihe disease. andi tlhe tuber, which have reached it
(cal not be Iharvested whole. They break il pieces, and thil thle brown-
ish, pulpy im;"-. .rn-i-tiii_ almost entirely of sporess of the il'r_-ii',
Itir, :,2j


and remains of the cell walls of the potato, is broken up, the spores
are liberated in millions, and the land is badly infected for year,,."
(Giissow, 191!:.) (See Pis. I and II.)
In a mild attack the eyes first appear grayish, then turn brown, andI
finally black, while in a healthy tuber these are whitish or purplish in
color. The tuber is only slightly disfigured and its keeping qualities
do not seem to be impaired.
While the tuber is the part of the plant chiefly affected, infection
may take place in all the young tissues of the plant, the roots, -tolon.,
stemus, and even the leaves.
All reports indicate that the p-tato wart is one of the most serious,
of all known diseases of the potato. It converts the tuber into :ian
ugly, irregular, and utterly unsalable growth. When established in
a field it may affect the entire crop, and the land remains so infected
that potatoes can not be successfully grown for six or more years.
We quote from writers abroad the following:
J. W. Eastham (Yearbook, College of Agriculture and florticulturle,
Holmes Chapel, 1904): "When once established in the land it is u-e-
less to grow potatoes again until the pest has been starved out or
otherwise destroyed; but so far as is known no other crops are liable
to )be attacked. Quite the worst case seen in Cheshire occurred oil
land that had not borne potatoes for six years; 'seed' from the same
source as that employed on this land yielded satisfactory results ele-
where, indicating that spores were not introduced )by the seed, whilst
the manure employed started no infection elsewhere. This indicates
prolonged vitality on the part of the fuu..-, which would render
star% in.' out a very tedious process."
E. S. Salmon (Gardeners' Chronicle, 1907): "*It is quite clear.
however, that the 'black scab' disease threatens to inflict such serious
injury on the potato crop as to warrant the Board of Agriculture
aklhilng official action. Tihe disease is viewed with alarm bv
both tlie scientific and the practical man, and yet no steps are bling
taken to deal with this pest which, if it is allowed to spread thlr mugh
the country and to reach Ireland, will cause losses of hundreds of
thousands of pounds."
Borthwick (1907), referring to an outbreak in Scotland, says: "The
whole crop was d:,jii:i_,,ed to the extent that they could not be used.
They were quite useless, the early varieties being, if anything, worse
than the late, especially thle early kidneys. The disease was first
noticed when the new potatoes began to form. It first appeared on
the stems as a greenish-looking canker, which attacked the tubers as
they grew and soon made them a mass of corruption."
ICir. 52'J

P x.. TAT F P. AM A

:,) i ,W' ; v 0 V. A- T n G .

Digitized by the Internet Archive
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1,. C. Potter (Gard. ,i, 19.',): -" Front ;ll accounts tile disease i's
'pr,'edim- rapidly in the infested :re1as Mid the amnllnt of .,." is
yearly illr,.i'ii.. X ++ In certain a:llotm tt, it has
leen fi'nii'l impossible to vrow potatoes."
John Peri (!): ivl Potato wart lias, alr read v become a teriols-t
trouble ill Inilay districts in this- country, and it is likely to develop
into the worst pest with which thie grower will have to deal uless
\ iori,- nmeasures are adopted to staillp it out."
T'. Jolnson (i[''.i: "It needs onl v a ve ry casual actquaintance witli
the faetsof the case in the British Isles from t lie liile of the discoferv
tif the trouble bY Potter inll 1-o'2 to tihe present lillie to warnl one ol
the necessity of t:lii,_' all possible steps to staluip out a dlisease which
may become as serious ais ordinary leaf-blight and less amienable to
treatment. It is now found in many districts in F.I_'landl,
Wal:'-. and Scotland. It is often so prionounlcei d as to destroy t*ie
w hole crop, and it is not confined to garden plots. Wartv\ t uiler-s are
naturally poorer in food matter than healthy ,li ,v and when not
destroyed in thIe held do not keep well in store. They \ u'ht to Ibe
dest-royed as soon as found, and on lio account saved for seed."
The Gardeners ( Chrollicle. li)s: "'This disease is excit-
i,_." some alarmi in (eri'lanyv. where it is said to be -t|r,:i]lii_''. It
appears to have beenn 1',,.-,iI/',d as of local occurrenlcel for sole time
inll thle n.i,,i1,orli iid of Dfisseldorf, Klberfeld. ,: Dill i 'll, tthis
season it has proved so injurious as to have entirely v destroyed thIe crop
in Iianv gardens where potatoes have been raised year rbY year."
6Dr. (). A1 ,pI, (1 is), oni the other i and. says: Ae.ornliii to rel)orts
of Spie, k'ririniL. Schneider, and J6stinig, who have observed it, this
year inll (TermllanllY, tlie disease is nlot of ecollnoilic importance."
The British Board of Agriculture and IFisheries mnade it a notifiable
disease in 1!'(7 under tlie I)estruetive Insects and Pests Acts, Is77-
1'.'",. ThIe follow ii- report ((Gardeners' Chroniceh, 1909) was made:
"'l'. board of iriniltture and fisheries desire to notify that i44
caes of wart disease or black seal) in this year's potato crop had been
reported to them lip to )October 3. lThese cases have occurred in tile
fill,,iwi g counties: Shropshire, ;.: Staiffordshire, 57; Lancashire, .50;
Chehire, :''; Warwickshire, 27,; W\orcestershire and Leicestershire, 4
eatl i: Derby'shire, 3; Merioneth, 2; and 1 each illn IPerthshire, Stirling-
shire, Dm1nfrie-shire, (Cumbnerland, N.'tiii:,,, llBerkshire, lF intshi re,
Brecanshire, and ;\ilni ,I: ni. A few cases ItI, 1r-r field crops ha\ve beenll
foruinli in the counties in which the disease is most common, but in tile
i.',.:t majority of cases the disease Ihas occurred on allotments or in
Lr:irdens int which potatoes are constantly rown i X. The dis,-
ease lias been known i inll certain districts for ten to fifteen years, and
as l-'r iwei- have taken no steps to check its progress, it is now canu-in,.
Kilr. 521


serious loss *. All cases of wart disease must be notified to
the secretary, board of agriculture and fisheries * *. In the
case of farmers who sell 'seed' potatoes, notification of the disease
is of especial importance, and failure to notify must be regarded as a
serious offense *. Persons co.iii'lirig wart disease are liable
to prosecution and a penalty of 10."

The disease has been reported from Eiigl:iid (see p. 5), from Scot-
land in Perth, Sterling, and (Clackmannan t(miintie,: from Ireland in
Down County; from Wales; from Germany in Westphalia and the
Rhine provinces; and from upper Hungary. It has not yet been
brought to the United States so far as known, but has already crossed
the Atlantic and become prevalent in Newfoundland, where it was
lately discovered by I)r. H. T. Gufssow, I)ominion botanist, who pre-
sented a very iiitr',-tiLg paper on the subject in December, l.',..
before the American Phyt,>i:th ii i'gial Society. Knowing the serious
character of the new pest from personal observation of the losses
caused in England, he promptly issued a warninig bulletin. The
Canadian government proposes taking active measures to prevent the
further introduction of the disease. Doctor Giussow stated that there
have been recent importations of seed potatoes from Newfoundland
into the United States.

The (or :iisin causing" the disease is a fungus discovered in l.s9,;
in potatoes from upper Ihiing;,ry by Schilbersky, who named it
(% ,//,,/y '1 ,, .'f ,,wdoh1Vo1ca and placed it in the lowest group of the
Chytridiacea;, Olpidiacea,. By others the fungus has been supposed
to be 0. 1.,'.. A /(<)roa.p6 x. VWe quote from the excellent description
of Prof. T. Johnson, as follows: '"The vegetative form consists of a
naked mass of protoplasm which may be distinguished in the host
cells (just below the epidermis) by being denser, lwinogllgeit'tu-, and
finely granular. It may *be seen abulLttig on the host protoplasm,
and dlil)ptii._. with it, as it devours it, occupation of the ,nlhrging
cell cavity. The l)rotoplasm follows and then the cell wall. This,
though 1-ri- i%. does not, like the protoplasm and nucleus, disappear.
The starch grains are the last attacked and remain white and unin-
jured for some time in an invaded cell. The parasitic pla-.iiiodiuin
passes from cell to cell by boring its lpaugeo thriigh the host cell
wall It is in this stage that it stimulates to active cell
division the surrounding host cells and produces the gall or wart."
[Cir. 521


S' II.


T,;. *I M W -f T Y Exc( '(:' i -,

WA!RT' DI -I. \ -1. ()F TIlE I ()TAT'O.

During the summer the pllasmodiimI rounds up), f6 ,1i ,i,,,," I smooth, yel-
lowish wall about itself. Later the contents of these zoospii~tn,/ia
break up into nuimerouls zoospores, which escape throuw.1il a hole in
the wall and attack healthy polV j)ato tissue.
"As the tuiber ripens the parasite replaces( tie sulilner spoi':ii
by i. v ii iL ones, which carry thlie disease tIhrI iu the winter and serve
to Iopa'_"'alt+ it in the spii'. The restinll In _'i:i,
:;o-70 pi in diameter, iare very irmnerous in diseased tubers and are
easily lI,.ul.l/ ible Witli a I)ocket lens. 'rider tie microscope the
wall is seen to be not -smooth, but rid-_-,, d or aniuhtlar. 'lie'lse brown
lid,_,'' or bands form part of a kind of epispmore which arises is tlhe
-lio:i-ii'iiuil ripens, and seems- to e formed fromi thlie residual con-
teints of thle host cell when niot also from its cell wall as well .
The cl)ispore is tihusi deposited from wvitliouit as a third laver on tIe
thick,,iiil.- wall of the sporanlilllu. If this more or less artificial
epispore is ignored, then one may speak of tire spore wall a,
smooth As a ru'tile tliere is oily oe resting spor:i_'lliill il
a host cell; occasionally there re ie two." It is exceeding-ly diffiult to
!', 1111iiil!ie these restiil,. spores artificially. lro'lessor Jolnson suc-
ceeded in ),li ,_ i1,, about ;. 1 i inatioi by pl1.,i \ \- thlem in potato juice.
lie writes: "At last the potato juice, exe. i-ii,_' pos-iyiblY a clieio-
tactic iinf iuce, ,ave success; and sporlli'aonia with split walls and
escaping xzoosl)oreI's were found. 'hese slioXed tihe iiIn -lii" i li
riiov'ilients observed il tlie sporn/l-i:i of certain other Chytridians
distuirled during their i,.liug" period. Eacli spor'anhimni contains
liundreds of mor'e or less pear-shape'd iuniciliate zoospores. The zoo-
spores ineasure from 1.5 to 2.4 p ill di:anieter. The body is actively
aiuieboid(, while thle ciliilii is co(ilmaratively passive."' (T. jolilnson,
I ii'. ,)
Infection takes place usually at tlie 'eye.s" of Ithe tuicr tilhroui-hi tlhe
zoospores of either the sillier or i-t ii,-" -l,,in :ir,'_ia whicli are found
illf.-tiin' thle sil i'lri h,,inL'" soil. It is also believed by Jolhiisoii anid
others that infection nial. take place thrlrOIllI-h the internal pa.-..', of
plasmiodia from diseased -seed passing thi oi,_,li the tolonis :li i-lin'. tlhere-
fi uill, and so into thlie inewlyv-foriled tubers.


.\it the present timnle tlie l'niited States hias no .,_ i-I lion that will
pl'e'ent thlie inmportlation of such a trouble. No (n1nuranittine is liuain-
tained :i,,'ai,-i plant diseases, nor is the Secretiarv of A2-ii ii llure
authorized to inspect or reject infected potltoes, -,'',l ,, or rnur'sel'y
stock of anyy description.
't1ir 521j


The most effective protection against the importation of potatoes is
the tariff of 25 cents a bushel. Yet in spite of this the following
quantities have come to our markets from abroad:a

Year ended June 30-

(Country from whliii imported. 1906. 1907. 1908.

Quantity. Value. (Quantity. Value. Quantity. Value.

I ishel.. TDolla rs. Bnshcls. Dollars. BIsuhelt. Dollars.
Austria- hungary .................. 34,909 17,146 741 331 1,723 746
Belgium ..........................! 37,275 1 14,422 75 84 6,889 3,650
Bermuda ........................... 68,964 95,205 87,048 135,569 | 80,711 109,561
Canada ............................ 421,106; 126,798 11,393 5,970 177,102 80,006
Germany................ ...........: j i .,2 69,761 39,419 19, 984 62,059 38,368
Netherlands ....................... ., 1,. 5,379 5,704 2,184 38,892 18,169
Spain ............... ...... .... ; 1,774 1,558 7,730 7,408 II 'it. 11,596
United K Lh,.1.'. ................. 1,192,074 504,377 5,673 3,706 ', .'.;' 1,321
Other countries...................... 30,419 1S, 417 19,134 17,399 23,061 19,615
Total......................... 1,948,160 853,063 176,917 192,635 403,952 283,032

The principal ports of entry of potatoes in 1 is were as follows:
Aroostook, M1-., 67,71;1; bushels; Ban',or, Me., 56,312 bushels; Boston
and Charlestown, ;,-., 34,901 bushels; New York, 202,069 bushels;
Passamaquoddy, 'Me., 3,2.'-,; bushels; Porto Rico. 19,"., bushels; Key
West, Fla., 2,643 bushels; Arizona, 8,243 bushels; (Champlain, N. Y.,
l,.,-H' bushels; other ports, 8,057 bushels. Total, 4;,.'-' bushels.b
Since the interest and ko\\vIdge,; of the public must be our main
dependence in pl ,iiting the establishment of the potato wart in
America, it is urged that all importers, dealers, and consumers of
foreign potatoes watch for the disease and promptly report to the
Department of Agriculture at Washington any cases discovered.
All infected potatoes should be boiled or burned. No part of any
lot cnhtaiingi diseased potatoes should be used for seed purposes.
If the disease is found on growing potatoes, heroic measures should
be taken to eradicate the trouble by buringm the entire lot and planting
no more potatoes on that field for six or seven years.
There should be some modification of our laws so as to enable the
Secretary of Agriculture to deal promptly with special ,dang'ers of this
sort arising from the importation of infected plants.

Bulletin 76(, Bureau of .iii-li-, U.S. Dept. of Agriculture, )p. 54.
b Inforiuation furnished by Bureau of Statistics, U. S. Dept. of Agriculture.
I 'ir. 52J


1896. Scll ii .u-:K Ein tnecr Shorfparasit dler Kart,felknollhn. Berichlite dler
)citselihen l Botanichen( i ,. 1 I- H i.ii'i, vol. 1t, 1'" ;;(8 .
I 't912 (Anon.) Some potato diseases. The Journal (Of t(he Boardl of \igriculture,
vol. 9, 1902 -;, p. 307.
1lh2 '\ (ifI'HERs, \ diseasess of trs amind plants. I I- ,loiirnal of the R'oyal]
\_III, ,I tlii.l Society of l'tigland. vol. 63, 1902', p. 2sS.
19112 P'orrnl:, M. C. A new potato dlisease (<'hl'/ophjlp' .,,1,totioo). TheI
Jouiirnal of thIe loarnl of \ ii i ,lli r. vol. I9, 1902 -,, p. '20.
1903. (Ano in. A now Iotato ilisease. Tlt \griuiiltriial ( ziI/Itte, ol. 5)7, 19 o:, p. 2t.
I'.II (Anon. i The warty lis'ease of potatoes. Tii ( arildemirs' Chlironicl, vol. .1;,
1903;, p. ;2H.
I')',. CAlui'TIn.uRs. I'otato canker in Lan.iashlire. Tih ,liornal of the ioNyal
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Royal Ilorticuiltural Society, vol. 27, 1903, p. si5.
lI'' ii. o. .i Warty potato diisease. The (iardener-' (Chronicle, vol. :33, 'i.;
p. 1,.
I' I. MA(l)oi,(;aLLi, R. S.TEWA a \'I. fungns disease of Ilttatoes. Trallsactiols,
Ilighilanl anil Agricultutral Societv of Scotland, ser. 5, vol. 15, 190:, 1). 312.
1904. (Anon.) la iilaique noire des pomnmcs ie tirre. Bulletin Mhnsuiel di I'Oili) .
de T. -ii-iinitii,]l A;i. ,.1, -, vol. 3 190)4 no. S, Ip. 924.
I',114. (Anon.) B/lack scahb (<'W omy/'<'. lt'oiiil. Tra .). Que(,nsland \-t i, ,l iii.,l
Journal, vol. 15 (1904), no. 2, pp. ,:'.-i ,7.
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l'Ii4 (Anion.) Black scab of potatoes. Tlie Agricultural (Gazette, vol. 59, 1]'i1,
p). 36S.
1l,11 (AInon.I Black scab of |potatoes (O, douiit,., 1, Ir,,i; Tra:l.-Cl rii, lqplil/Hi.s
,iflob/,",to', Slihilb. ). I.eatlet no. 10.5, ioard ,f AVriiiillt rc adii isheries,
London, April, 1904.
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I lorticultliral Society, vol. "-"., 1',l Ip. 118,9.
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;19. 10-1, p1). 257.
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Agricultural Society of Fl'i-. ii, ., vol. (6(, 1', p, 1(;7.
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190I 5, I ), p. 4(i.
19'l."1. (GROVE, W. B. Wartydisease(of potatoes. The ( harners' Chronicle, vol..;-e,
).'i p...U".
ICir. 521 9


1906. (Anon.) 1,h., k seal of potatoes in North Wales. The Joarnal of the Board
of Agriculture, vol. 13, 1906-7, p. 441.
1907. (Anon.) Warning. The Journal of the Board of Agriculture, vol. 15, 1907-8,
p. 119.
1907. (Anon.) Warning to potato growers. The Agricultural Gazette, vol. 65,
lKp, p. 279.
l',o7. BoRTrJWWK. Warty disease of potatoes. Notes from the Royal Botanic Gar-
den. Edinburgh, no. 18, August, 1907, pp. 115-119.
1907. DEAN, A. Black scale) in potatoes. The Gardeners' Chronicle, vol. 42, 1907,
p. 417.
1"7. I-IEIunm, E. Der Kartoffelkrebs in England. (Centralblatt ffir Bakteriologie,
Parasitenkunde,und Infektionskrankheiten, vol.24, 2d1 part, 1907, pp. 208-213.
I'In. SALMON, E. S. "Black scab" or "warty diseasee"' of potatoes (I'i,,,,.-
t., 1. endobiotica Schilb.). Thle Gardeners' ( lir.,ii l., vol. 42, 1907, p.
.;! .-:.

1907. SALMON, kI. S. Black scab or "warty disease" of potatoes. (Chryo-
phJlyctis, elobiotic( Schilb.). Bulletin of the County Councils of Kent and
Surrey, 1907."
1908. (Anon.) Black scab) in potatoes. Journal, Departm ent of Agriculture and
Technical Instruction for Ireland, vol. S, no. 3, April, I',', pp. 441-443.
I',i'. (Anon.) Wart disease (black scab) of potatoes. The Journal of Ilorticul-
ture and lliiomie Farmer, vol. 57, .;1 ser., 1')', p. 4",7.
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Agriculture, vol. 15, 1908-9, p. 671.
1908. (Anon.) Potato scab and legislation. The Gardeners' (Chronicle, vol. 43,
] 1, p. 2 :,.
1908. (Anon.) Some potato diseases. The Gardeners' ('Iiii.- l- vol. 44, 1908, p.
1908. (Anon.) \'arty disease in potatoes. The Gardeners' ( ii,',il,., vol. 44,
1',i-, p. 266.
1908. (Anon.) Black scab of potatoes. The (Gardeners' Chronicle, vol. 44, 1908,
p. 449.
1908. (Anon.) Varieties of seal) in potatoes. Ti,, Journal of the Board of A.-rir.ul-
ture, vol. 15, 1908-9, p). 749.
1908. (Anon.) Black scab in potatoes. I e iil.i No. 91, D)epartment of Agriculture
and Technical Instruction for Ireland, 1908."
14'1i1 APPEL., 0. Der Kartoffelkrebs. Illustrierte Landwirthschaflliche Zeitung,
vol. 28, 1908, p. 832.
1908. JonNsON. Potato black scab. Nature, 1908, p. 67.
1908. ,IJOSTING. ID)er Kartoffelkrebs. D)cutschc Landwirtscliaftliche l'resse, vol. 35,
1908, p. ;' -
1908. POTTER, M. (C. Note on the warty disease and corky .sea) of the potato. The
Journal of the New Castle Farmers' Club, July, 1908."
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