THE BLACK ROT DISEASE OF GRAPES

Transcription

1 BULLETIN 21)3 THE BLACK ROT DISEASE OF GRAPES Iho DONALD REDDICK IARI ITHACA, N. Y. PUBPSHED BY TIlE UNIVERSITY

2 ORGANIZATION OF THE CORNELL UNIVERSI'l'Y AGRlCULTURAl, EXPERIMENT STATION. BOAHD OF CONT lwl THE TRUSTEES OF THE UNIVERSITY EXN.JRIlIfEN'l' rn( 1 S'l'.LU!'l!' T.rTIERTY H. BAII,EY, nirl'dol'. AI,BF1Wl' n. MANN, SPcl't'tllry. JOHN HI']NRY COMSTOCK, l~lltolllology. lienhy II. WIN(;, AniuUl! HUHhuuclry.,JOlIN CHAIG, HOl'ticulturp. '1'. LY'l',],I,B'l'ON LYON, l:loll 're('llllology. HEIWgR'1',r. 'YEBllER, PJanf nre, dillg. BEN.TA!'tlIN 1II. DU(i(J.\It. I'lnnt l'llyslulogy. JOlIN L. S'l'ONE, Farlll Pructice. J... NES E. ItlCF:, Poultry Husbundry. GEOIWFJ W. (~AYANAnGn, Cll'!lllj~tl Y. EL1\UCn O. I,'IPI'IN, Soil 'l', ch!li,lol!'y. WII.I,I.\1f A. S'rOCKING,,Tt., Du!ry InllnRtl')'. In;mBl~n'1' H. WIIE'l'ZEL, Plant J'nihology, G. F. WAIIIlEN, L'al'In J\lUllllgNJWut uwl FurlU Crops, CIcU,ur,ES S. WILSON. I'OlllOlogy. GLI~NN W. In~URICK, Elltolllolngr. [,OWEr,f, 11. JUDSON, IIol'tlculturv. 110WAH D W. RILI~Y, 1~n1'1l1 l\lpchllnics. liii~itlu'l"i' W. HARPER, Anllual IhlMmudl'Y.,T.U,mS A. BIZZELL, Soil 'l'l'chnology. CYRUS n. CHOSBY, Entomology. I'L.\REN"I\1 A. HOllEnl:l, Ponltl',\' Un,l.lHndry. P.\ til,t. WIn'I'1!J, PII\'!lI Crops. DONAI,D ngnihc'k, I'lant Pathology. II.AROI,D E. ROSS, Dult y Indllst1'3r U.UtRy n, LOyg, l'l!mt,brl..,dlllg. Awtnult w. nir,nmr'l" 1'lllnt Bl PC'ljlng. l~lmer S. SA-YAm;;,.\.nimal liuslwndry., E. S. GlJ'l'IUtU::, Butt"' lnllldng., BDWArtD n. MINNS, Farm Practice. l'aui, 'YORK, rrnrticllltul'll. LE'VIS I{NtltH:lON, Plaut Physiology. l{. C. I,IVEllMORJ.l" L'Ul'lll MtlnaglUllent. I,:j'=E B. COO!;;:, DIlJI'Y InduRiry. G. WAL'j$a TAlLEY, Jr., Anlmul Ilusllnmll'Y. HAaVEY L. AynES. Dnlry InduHtl'y. CLARA NIXO~. l'ou!iry TIusbUlldl'Y.' l\{or'l'mn P. B.mnus. l'lnnt i'utholo!,'y. 1,0[5 W. WINn, llulry Industry, EMMONS W. T,ELANn, Soli T('clulIllogy. CHA.ULFlI'! T. OHF1GOU.Y, :Plant Pathology. WALTElR W. FISK, Dairy Industi'Y. " ')!he regular bulletins of the Station aro sent freo of charge to persfilns residing fu :Ne~ York Sta.te wbo request tbem.

3 THE BLACK ROT DISEASE OF GRAPES.* HOST PLANTS Consideration of the origin. evolntion, distrihution, and methods of care and cultivation of the plants affected by a specific disease is often of assistance in reaching condusiolls as to the o.rigin and history of the disease as well as its pos!>illle distribution and economic importance. In few cases is the information on this phase of the subject in such accessible forl11 as in the case of the crop affected by the mack Rot. So far as kno\vn, the Dlack Rot is confinell to members of the family Vitaceae and becomes of economic importance only on cultivated varieties of the genus Fitis. For New York, and, in fact, for American couditions generally, except the South and extreme VI/est, we are C011- cerned with the development only of those species of the grape indigenous to North America. A most satisfartory account of the evolution of our commercial varieties of grapes is found in Dailey's " The Evolution of Our Native Fntits" ('98), in which 126 pages are devoted to "the rise of the American grape." This author states (I. c.. II7) " that 1ll) less than a hundred hooks have been published in this counti y on the grape," This does not include a monograph by Hedrick ('08). in \vhieh is an excellent historical account of the American grape and the grape industry,, From these sources, we learn that after repeated attempts it was found, relatively early in the history of American viticulture, that the EuroI)ean grape (Vilis villifcra) could not be grown successfully in. ou!' northern latitudes since the vine was 110t harely nor vigorous enough to withstand our cold winters no!' the attacks of insect pests and fungous diseases. Attention was then turned to American species as,n source of stock, al1cl at the present time our. four 1110St important commercial varieties are derivatives of our native wild species. These varieties are Concord, Niagara, Catawba and Delaware. The latter is thought to be part 'vinifcra, as might be inferred from the fact that it is more subj ect to l\fi1dew and Phylloxera than the others. * Also presented before the Faculty of Cornell University May 28, as a major thesis in partial fttlglment of the requirements for the degree of Doctor of Philosoph;:.. ('98) Batley, L. H, Sketch of the Evolution of our Native Fruits. The MaclIlillan Companv. tondon, I 89S, :xiii and (08) Bednck. U. P. The Grapes of New York. Rept. N. Y. (Geneva) Agr. Exp. Sta. 1907, Part II: 1-:;64. 19o5. Published by the State of New York as' Ann, Rept. pept. Agr. IS: Vol. 3. Part II. [289]

4 :2(_)O BULLETIN :293 From the above :facts we would be led ill expect in our American vines a more resistant and hardier stock, ::;ince they are remuved (Jllly a shurt distance from ancestors that haw gruwll ttp with and are able to with stalld. to a certain extent at least. the invasiuns an(l depredation,; of native!>l'st:-i and lungous (\isurders. Howcver, untler culti vatioll anll artificial propagation, and especially because o[ the aggl"l~gati()n of a large l1umhcl' of vines in a vineyard, many more opportunities are o/i'ered for the illcrcil"cd prupagatiull anti wider dissemination of insects and fungotls enemies. l':c()nii.:lllc ITl11'IJRT,\,,]CE Of TIlE GRAPE. INDUSTRY Notwithstanding the relatively restriclell localities in which grapes can he grown in the State of New 'York, the indu"tl'y i;; of considerable ('C C li1lijortancc. L'igurcs are of interest in this connection. In the census report for 1900, we fmel that New York ranks second only to Cali~ farnia in the total value of the grape null. The Ca1;10rni<1. cumlitions are such that it is plj:i:->illk to gww the yiniferotls varieties there, CllllscqtWnt1v tile prndllctioll of wille and raisins is very large. in addition to the larg:e number of grapes grown 01' eating IlU t of hand. InN cw Y urk, til(! total value 01 the grape C1"OP in [~)OO, inclulling the then relatively small amonnt of jt1icc prol1t1l"cd, was $2,7(> Th(~ following tallle. taken fro111 the same S01HCl" shows the relative value of the grape and oth'~r crop,,: Hay [lnd forage Cl"OpS, Corn, Potatoes,.oats, Wheat, All orchard pl'oc1th:ts. indth1ing apples. apricots, cherries. pt~adles, All forest,. Grape, Tohacco, pears, plums and prunes, $ , ,850 r 5,0I1), ,()29,o ,597 IQ,542,272 7,621,108 2,763,71r I,172,236 Unfortunately, statistics regarding the value of 1.he VarlO1.l!'. orchard products arc not made separately, but it is eddent that grape raising is one of the important fwit indt1stries of the St ate. The Cllantauqua grape belt alone in W05t('1'11 N ew York is estimated to cover acres at the present time. ~nd according to Prof. Hedrick (1. c. 78), the present acreage of the State is not less than 50,000 acres.

5 THE DL~\CK H.OT [JV'E.\SE UI' Cn.\pI>s NEW YURK STATE l;[c\l'e rmgiunfi Since frequent reference will be made to the various grape districts (If ]\ t'w York, it may l1(,l be out uf l,\ace at this puint tu define these regiobs a liltle 1110re defi.nitely. 1\ descriptioll of til(; four (listricts of the ~tate is given by 1 kdrick. together with a history of the rise of thc i!ltlu=.try ill each section. Dorsey ('ut)) h<ls put this data in more acl'cssible form. In poillt of time. the H ulison Ri\'(~r ndlcy regirm i" the oluest. The production of the C011<:o1'(1 in this locality ol!t:itrip~ that of any other nricty, while t11<.; Dl lawarc stanlls seco11l1. Yet thi:; region is oftvll rderrell to as the Delaware regiob. It is practically conlined to the four counties of [.T[,ter, Columbia. Urange, anrl Uutchess. The sccond regilll1. knmvn a~ the C'cntral L:ake region. is 110t so deti. nitely loeaterj. It indtliks areas honkring 011 Keuka, Canandaigua, Seneca, and Cayuga lakes, and is located in the fonowing' counties: CJntario, Yates. Schuyler, Stcuh(,!1, and Seneca. Catawhas Hnd Delawares are grown extensively in the section and grape-growers often rder to it as the Keuka Lake or Catawba region. The Chautauqua belt is tlje most distinct of any of the grape regions. The Concord is the prt.'do1l1illatil1g and almost exc1l1sive va r: iety. :\s this Yariel)' was not introtiuccll into Chautal1qua county until I RS6, the remarkable de\'e10pl11cnt of the rcginn is worthy of note. The belt llow extends the whole length ()f that county anrl a part. of Erie county, and extends hack fro111 the lake. front for a distance of three til live mile~. The most recent belt is the Niagara. I t lies a[ung the N jagal'a river and the shore nf L"kl." Ontario. The following counties arc included: Niagara, Orleans, ]'donroc, and \Vayne. THE DISEASE HISTORY Thi~ disease has l)ccn known in America for many yeal'~ as the " Black Rot." This name was given to distingllish it from the gray or h1'own rot caused by til(' 111ilde\\'~, etc. When the disc[l!'lc was introduced into France, the English name was carried over, anr1 from th,ere it has spread into (ier1l1[lny, Italy, Asia Minor, and elrewhere. Locally, and owing to mistaken identity, it is s01l1etilljes referred to as Dird's Eye alld as Apple Rot, thus being confused with Anthracnose. (,Of)) Dorsev, M. J. The Gml'e Distri('.ts nf New Y (Irk and TallIe of Variettes. N. Y. (Geneva)" Agr. Exp. Sta. Bul. 315:

6 D"lJLLETlN 2~}3 On the occasion of 11i5 visit to the Dufour vineyards near Lexington, Ky., while on his second visit to America, Francois Andre l'vii::haux writes in his travels (1805):.. But his (Dufour's) success is not equal to his attention - the fruit always rots before it arrives at maturity. \Vhen I saw them, the bunches were few and stnnted, the grapes small, and everything appeared as though the vintage of the year r802 would not be more abundant th:1.11 those of the preceding years." From the descriptions of various of the pioneers ill the American grape industry, there ~eell1s tn lje 110 rlol1ht that the foliage and part of the fruit was often destroyed by the Downy Mildew (Pla.smopam vitir:ola), and also that many of the dusters had a different kind of disease which We arc ahle to recognize from descriptions as the Black Rot. Such (liseases were unknown to the Old \Vorld vine-growing districts, and there seems to be no question that both the Mildew and Black Rot are indigeno1ts to America. The native \'ines have for ages been attacked by these diseases. so that by a selective process only the most resistant remain. The le'is resistant viniferous varieties never having experienced such ahacks were not ahle to withstanrl the 1\,filc1.ew, Black Eot, and Phylloxera, and consequently succumbed. That this iii the case is attested also by the wide-spread ravages of these fungous pests on their introduction into Europe. TI1t1s, the (~ady American attempts itl viticulture with the Europeari ville were failures, and it was only when the ameliorated.-\merical1 vines were med that the grape industry in this country was placed on a finn basis. The diss~mination of the disease to the various new vineyards of the country was a very easy l1latter, for these early vineyarc1ists were anxious to obtain the very best varieties, and they not only went to the wilds the111~ selves to look fqr desirable kinds, but also a~ked puhlicly that persons send them cuttings.. Longworth marie sllch a request in the columns of : the Cincinnati Gazette in 1848 or 1849, according to Bailey (1. c. 67),. Dufour, as early as 1804, an(1 Longworth, about 1848, encountered losses which were so serious as to make the business unprofitable and their vineyards were abandoned, and this too without their knowing what the real trouble was. Longworth and his followers were using extensively the new American vine, Catawba, hut even this varietv under vineyard conditions was unable to withstand completely the attacks of fungi and insects.... With the rise of the grape industry ahotlt St. Louis, the Black Rot... also became prevalent there, and in 1860 to 1804 was epidemic. (l80s) MiI;:haux, F, A. Travels in America, Second Jot.u,'ney. London l 1805~

7 TUE BLACK ROT DISEASE UF GRAPES 293 After morc than fifty years of grape culture we have the first scientific inquiry into the nature and cause of the rotting of the fruit. In September, 1861, Dr. Geo. Engelmann ('61) read a paper before the St. Louis Academy of Science, in which he clearly describes the two most serious grape diseases. These are easily recognized as Downy Mildew and Black Rot. The J ouma! of Proceedings reads as follows: "Dr. Engelmann exhibited specimens and numerous drawings of two species of fungi, which infest otlr vineyards to snch an extent as to materially dil11illi~h the crop and influence the cultttre o.f the grape, at least that. of the Catawba, ill. Ollr region." Dr. Engelmann's description is as follows;., The second kind of rot - the black rot - is brought on by a very different kind of fungus, which I believe to be undescribed by botanists. It evidently belongs near Ehrenberg's genus and ought to bear the name llmpelicida. It makes its appearance only on nearly full grown berries, exhibiting in the first stage a discolored spot 011 the side, but never at the base of the berry, about two lines in diameter, with a dark' spot in the centre. This spot soon becomes light brown and remains so, while the surrounding part of the herry gets darker and exhibits a rough 01' (under the magnifier) ptlstulolls surface; gradually, now, the berry shrivels l1p and turns black. The individual fungi are little spherical bodies," ctc. Fift.een years later, the same author ('76) read before the same s()~ dety a description of a leaf spot of grapes which we can easily recognize as the leaf st.age of the Illack Rot. This reads as follows: "I exhibit to you, todry, another grape fungus which is new to me, and seems to have been unknown to those grape growers with whom I have C011- versed. A yellowish-brown spot, a few lines in diameter, appears on the leaf, 011 the upper side of which, a good eye, or a glass, will discover a number of very minute black specks. These are little globules.13-. IS line in diameter, which have a little opening at the top from which they emit their microscopical spores by the thousand." Little note seems to have been taken of these two ptlblications by Engelmann t1ntil a relatively recent date. This doubtless was due to the fact that, scientifically, the Journal had a limited distribution and, practically, that the papers were not accompanied by any suggestions as to means of control. At any rate, it was 110t until the introduction of the Black Rot disease into the vine-growing regions of France that a serious and extended study was made of the cause of this disease with means of control. ('60 Engelmann, Geo. "Two species of fungi which infest our vineyards." Trans. St. Louis Acad. Sci., Jour. Proe. 2: ('76) Engelmann, Geo. Oak and Grape Fungi. 'Trans. St. Louis Acad. Sd.,, Jour. Proc. 3: ccxv-ccxvi. (1876)

8 [ri Augu!">t herries attacked by Dlack Rot werc sent to the :\atiunal School of ;\gricultun: at Montpdlier, France, by 1\1. Ricard, steward n f all e~(ate near the tuw11 oi Ganges. There, Professors Viala anri Ran.z recugnized the disease as ljlack H.ot. Immediate measttres \n.'n~ taken to exterminate the disease. In I 88tJ, there was very little mack 1{01 owing to the clry weather, uut the disease was found sparingly ill lither localities. Tn 18R7, rot was very serious in many new localities, :'0 it seell1~ quite likely that the Black Rut had been iii France to a limited extent fnr sc\'(;~ral years prior to 1885, the date of its discovery the're. It pl'nhahly gained an easy entrance into France on the American!'tock that was imported on which to graft European vines as a means of combatting the Phylloxera. The fir"l elaborate and well-illustrated account of the Black Rot disease was made by Pwfessnrs \ iala ami Ravaz ('86). In.T une, I887, Professor Viab was detailed hy the French government to visit America in the interest of French viticulture. A period of six months was gh'cn to the invc~tigation and in company with F. La1l1son Scribner, of the United States Department of Agriculture, all the large grapegrl)willg regions in the States were visited.,\s a result of this trip, a btilletin was published from the United States Department of Agrit'Ulture. hy these gentlemen ('88), ami the year foilowing 1here appeared tl volume [rom Professor Viala ('89) ot! tlw subj ect. Since that time thest;' two gentlemen, as well as mnny others, both in United States and Europc, have made freqllent contributions both to the nature of the parasite and to means of prevention or control. GEUGRAl'HICAL DISTRIllUTION It is a relatively easy matter to obtain inforl1lation on the spread ami present distribution of the Black Rot disease. This can be (lone quite accurately by making a bibliography of the literatnre relating to the di~l'ase. From examination of shch litcrattll'c one can see that after the introduction of the malady into France, it very rapidly spread to arljaccllt vine-growing regions, then to Germany, Italy, and Asia Minor. At the present time, practically no vine-growing section is entirely free fro111 the disease, with the One exception of California in. ('86_l Vial~; P.!'t Rava::, I.:., Mem~i.re ~l1r lille nouvelle pw)adic de In vig'nc,. Je Black J3.o t n Otltr1tllre nol~).. AI!ll, 1 Ecole Nat. Agr. Mo.ntpclhcr :I: I Also pul1hshed separatt'ly. Blblwthl'qlle citt Frog. Agr. et Vlt. 188ii: I-OZ. 4 Illates... CR8) Scrilmer, F. L., ano Viala, P., Black I~ot. U. S. Dept. Agl'., Bot. Div., Sec. Veg. Path. Bul. 7: 1-2(). IIlRR. t plate. ('89) ViaJa, P. Une MiRSioll Vitic:1le ell Amerique. Montl1ellier and Paris pages and 8 chromolithographs.

9 295 western Cnitcd States.!\IcAlpill(.: and l~uhinsull (\)8 (?») stale that i\lassce has rejlorted it fro.11 \'iduri:l in 18~13, but that they have nev!.:r found it. The datl: (Jf their publication is approximately 181)8, as can be gathered from Iitl::rature cited. Some * have predicted that California vines \vuuld eventually StlCl'U Il1U, but this i::; not at all certain since the weather conditions there are very difiercnt and are prnljaljly such a,; entirely tu prevent the perpetnatioll of the para~iie even if introduced. The writ<'r i:; inclined :::trollgl y to the lath: r view, since it does not ~cel11 pussible that with the importation of grape stock from the Ea~t there should not have been carrier! over an occa~ional source [)[ infection. ECONOM Ie I ~ll'or'l'ance All writers are agrccrl that mack Eot is the most seriolls fungous malady with which the vineprdj,t has tn contend. The Phylloxera ha~s been overcome to a great extent, while neither Downy nor Powdery l\iilclew are as clili1cult to conil'c']. l)ala on this point art! so evident and so general in Experiment Station literature that it will be sufficient to give emir a few gcneralities. It has heen recognized, generally, that Black H.ot varier with the seasoll, there being all abumlance of it in wet ~ea:ions and much less in dry ones. A1sn, that the rot is 1110re seriotls in the, warm and humid regions than it is in coul anrl tlric!' regiobs. Thus, in North Carolina the entire crop may he lost within a week ailer blossoming time, ""hile ill New York the greatest losses come when the Lcrry is one-half to twl) thirds grown. Seri1mer ('~o) bl'lievcll that ll1ack Rot.. did not attain the same vigor of dcvclop:l1ent in the northern grape-growing regions' that it did farther to the "ontll," Ilut even if that Le true, New York vineyardists all know that in ~OIllC years the conditions could not be worse farther south. IJeginuing in 1903 and continuing with illl:rcasing vigor up to 19D7, Black Rot oecame so destructive in 110th the Niagara and Central Lake regions that the entire crop ill many vineyards wus often lobi. In I<)06, in a large vineyard of 200 acres at Romulus, N. Y., not enuugh grapes were saved to pay for operating expenses, and this 111 spite of the *Scribner. F. Lamsun New Ohsl'J'ntil)!]S 011 the Fungus of Black Rot of Grapes. Proc. Soc.. Prom. i\gr. Sci. 9: 68-7:). rsaa. ('90) Scribner, F. Lamson. R~jJnrt 011 the Extent, Severity, ilnd Treatment (If Black Rot alld Brown l~ot in Northern Ohio in I8Rg. U. S. D. A., S('c. Veg. Path. Bul. II: 1. c::. 77. I~)O. '98 (?) McAlpine, D.,Ind Hobinson, G. H. )\dditions to the Fungi all the vine in Australia, Depi. Agr. Victoria. Bo pp. No date.

10 BULLETIN 293 fact that the o\vners sprayed until the middle of July and, as they oelieve, did thorough work. In 1907, there was very much less rot owing to the dry season. This was general in all grape-growing sections. In 1908, the only region which seems to have been seriously affeded was that of the Central Lakes, and even in this it was restricted to certain localities. In general the season was very ury, but in a few localities ahout the lakes there was an abundance of rain * anci losses in unsprayed vineyards were as high as seventy-five to eighty per cent. In fact, ill some vineyards there was so much rot that it diu. 110t prove profitable to glean out the good clusters. In spite of the fact that Black Rot has 110t been serious in most of the grape-growing sections of New York the past two years, the writer has never had difficulty in finding an occasional berry clestroyed by the Black Rot fungus, even in well-kept vineyards in the heart of the Chautaqua belt. This belt is decidedly the most free fro111 rot of any of the sections. These facts would seem to indicate that the rot may at any time become an important factor again, depending 011 the advent of a season favorable for its development. Epidemics or this disease affect economic con<.1itions only in the locality in which the grapes are growl1. Grapes are regarded more or less as a luxury and the lack of grapes does not have the same general effect as the lack of wheat Or of potatoes. SIGNS OR SYMPTOMS The general signs or symptoms of this disease have been described at. various 'times in the horticultural papers, but the first accurate, scientific description is that of Engelmann. The descriptions are sufuciently clear.as to leave no doubt concerning the identity of the disease. All green parts of the vine may be attacked, but the old parts never are. Julien ('97) states that in ;N'ivernais, France, only the fruit is attacked. Stevens and Hall ('09) also note the fact that the fruit of Scttppernong and,?ther rotundifolia varieties of southern United States is rarely attacked. On the leaves (Fig. 13I.) Some time in June or early in July, Black Rot appears 011 the leaves,in the forin of reddish brown, more or less drculal' spots. The first evidence Of the spot is the slight blanching of a single one of the smaller (*} See meteorological data on page 347. ('97) Julien, Ch. Sur Ie developpcment d 1 Black Rot de Ia Vigne dan& Ie. Niver~1a1s. But. Soc. Myc. France, IS: (09) S~evens. F. L.. and Hall, J. G. Notes on Plant Diseases OccurrIng in North Carohna. Ann. Rept. N. C. Agr. Exp. Sta. 21: l. c

11 297 areola of the leaf. Soon the blallching extends to adjacent areolae, and if an areola is entered it is usually entirely involved. The spread of the FIG. I31.-Black Rot lesions On leaf of Niagara grape.. lime 27, t!)os. (Natural size.). Photo Spot is concentric but not perfe~tly circular. The slnall veinlets,(orm the. margin of the spot so that the outline is finely crenulate. By the time: the spot is.. 3 to.4 mm. in diameter, it has a cincreous appearance:

12 At thi:; earlv "lagc the margin. while ~hari'ly defined, is not changed in l:olur. I :\: the time the spot is t 111m. in ciiameter, the margin appears as a hlack line. while the rel11ainlier ot lhe sput is grayish brown. A lil tje later Llw margin is a browni5h baml unci the brown gradually extel1rl~ imranl until thl: whole spot is CtJ\,';l'l~d. As S0011 as the browll IJanu atiaim somc width the IJ!:lddsh line 011 the margin is to be secn FIG. IS'3.-Black Rot lesiolls 011 stems} petioles, leo! vcilzs, (Llld tl.'ndrils af Ni(/(ja1'(I, yr-ri'''' (Natllral sij::c.) ]'holo. Jlllle B} j<)07. '. again. A second \va\'e of deeper brown may pas~ across the spot hut sometimes it does not get entirely across a11(l tht1~ leaves a marginal band of a deeper brown than the centra] disc. Spots vary in size from I mm. up to 8 111m. in diameter, hut in general are 3 to 5 mm. On the European vine, Viala ('89) records the dia1llcter of spots as.4 to S em. or larger. Occasionally the. whoj~ leaf is destroyed but this (,89) Vial a, P. Dlle Mission Viticolc en Ameriqttc:\ Montpellier, r880,.1. c. 239.

13 is hy the m(llesccllcc of li1any spots. Whell till: spot ha~ attained full size. hlack ljurlie::;, Pycllidia (Plate II. Fig. f)), protrtlck from under the cuticle and either dot the entire surface of the sjlot with minnte ~pecks or are more often confined to a more or le~, concentric ring. The diltercnt shades of color are apparent on the unclei' side of the leaf 011 such varieties as hm"e lea\"es which are SI11<)0111 heneath. The pycnidia. however. hayc lle\'<:r hell seen on the tlll(ler,ide of the leaf in our varietic5. \. iab anc! Jb\'az ('88) show that the leaf spab of the various v<trictieq are really all caused by the same fungus, and abo stale that in ISS() (I. C..j<_)o, foot Hute :.!) they first called altentinn to the fact that the Laf sp(jt~ were collnected with the Wack Fat disease. 011 stems) IC1ldrils) f('dltllc/cs. pt'tiulcs and lcaf 7'c'iIlS (Figs. I,P and r~3,) The charilcter of the Black Rot lesiuns 011 stems is somewhat different from that on leaves. Its first appearance is a small darkened dcjlre~~iotl which soon!jecomes very blue),:, Un a cane the lesioll rarely extends J11ure than a quarter of the way round, while (JJ] a tendril or leaf petiole it may extend frol11 half to all of the way round. The lellgth of the ksioll~ "<try f rum 2 Illl11. up tn 2 em.) while in form they may vary frl1l11 circular to elliptical ur very much elongate(!. On' shoots, the lc;.;ion~ never extend 80 deep as to cut off the sap supply, but on leaf petioles this occa;;iollul1v F HI J. R. ro. I33.- ac l \01 l('s;mts happens. rarely so on pcdullcle~, all(1 '1111te Co1l1- on pedullcle of cllls!"y. manly so all pedides and tendrils.. Near the CNzll."- till' I'C11lllallt of (Ill I1Iftstcd 0/1 the berries (Figs , 135, T3G, 137 ) 1:f,:I/;II'ilZf:~:ioll l)~ccl;i:'~::i The' first indication of Dlack Rot 011 beforc the blossows otchcd, (.1\1 atural sft:('.) the berry is the apijearancc at su111e point Piloto. July IS, 1909, of a small circular hlanched.spot. The C. N. Jellsen. spot is scarcely I l11m. in diameter. and when of this size the blanching is so slight as to be detecte(l only hy careful observatioti. 1t rapidly hecomes more apparent and has a whitish appearance. Even vet " the contrast ls noi ('8S) Viala. P. et R:l.Yaz, L. Note sur Ie mack Rot (Laestadia bidwellii) Prog. Agr. et Vit, 9 : ler scmes\l"e.

14 30U B U LLETI N 2~)3 great, but it hecomes more apparent by the appearance of a brownish line at the margin. The whitish centre increases in size and the brownish or reddish brown ring increases in diameter as well as ill width and is quite evident when the spot is in diameter. When the spot is 3 mm. in diameter the ring is one-half mm. in willth anel enough darker to giye a bird's eye effect (a light circular disc with an encircling darker barld). The sijot rapidly increases in size so that in twelve hours more it may be (j to in diameter, and the encircling band nearly in width. After five hours more, the spot is 8 or in diameter and there begins to appear an outer darker band and an inner lighter hro\\'n one which haye in some cases a mllch lighter line between them. The aureole is thus composed of two ur three ban(ls or rings. Eighteen hours latcr the spot is I CIll, or marc in diameter, is distinctly flattened, FIG. I34.-Black Rot 011 berries of Nili{fara (Jrap~. Successive stagl!s in the destnletion of the berry. (Natural si::;i:.) Photo. July I, Jt)oB. and numerous minute hrown specks appear on the white centre of the spot. In five hours more they are so numerous as to give a blackish appearance. The spot may not become any larger in size than this and in a few days.more.forms a thin black supedicial crust on the cheek of the berry. (Fig. I37.) Usually, however, it increases in size until the whole berry is involved. At about the same time that the hlackening appeari>, the berry begins to shrivel perceptibly,' and this continues until at the end of a week or ten days the herry is a hard, shriveled, and wrinkled l1mmmy. Viala ('89) has noted the superficiaj lesion and Prunet ('98) has figured it. Such lesions have been seen on berries of several varieties, and they are of cotnmon occurrence 011 the Agawam and Lindley. -..,..._... ('8g) Viala, P. Dne Mission Viticole en Amerique. 1. c. p. 24I... ('1)8). Prunet. A. Observations. et experiences sur Ie Black Rot. Rev. Vito 11: L c and

15 TUE BLACK ROT D1SE,\SE OP GRAPES 3 0t FIG. I35.- Black Rot in Niagara clttster. A few berries rotted by an early infection; most of them just tterning. browl! from -recent injections. The berry at tlte top on ttle l(!jt shows a spot not more than I2 hours old. (Natural si:::e.) Photo. Aug, I, I908.

16 J02 FlO Black Rat OIZ fruit of Niagara grapo. Ez'ory ber!'y in tlre eillste)' is illjected. CluSlc)' shows must (1f tlie illf('<' lifl1rs (If the sca.wii. The PSCIzidia show {,((rtlcula,'{y 1ucll. tnatlwal 8i:::I.'.) Photo. till[l. I, I908.

17 THE BLACK ROT DISEASE (IF GrUPES Fro. 13/'.- Black Ro~ OIl fruit of Niagara grape. S110ws (on tho right) the 'Ziarirms injections oj the smson. Nfal'ly every berry in the clustrr to the left is ii2jr:cled. Some are wrinkled while others arc. jltst beginlling to show spots 01' arr ~vrillk~ ling from trlc inlier side. On the rigttt s01lle of the s'uperjicial black cl'iisls can be see}!. (Natuml size.) Photo. Aug. 15,

18 BULLETlN 293 ETlDLOC;Y N amc of the parasite This disease is caused by the fungous parasite Guig/lardia bidwcllii (Ellis) Viala et Ravaz. Other specific and generic names have been given to the organism, as will be noted from the synonymy. This is due, ill part, to the polymorphic nature of the fungus, to a lack of uniformity of various mycologists in the system of nomenclature, as vvell as to difference of opinion regar<iing the structurl." and interpretation of parts of the fruiting hodies. According to the code of nomenclatttre adopted at the Brussels Internatiunal Dotanical Congress, the ahove name seems to he the correct one to apply to the Black Rot fungus. The writer has had no opportunity to examine type material of any of the forms concerned, and the following brief review of s),nonymy is made fr0111 au examination of the literature.. The first description of the fungus seems it} be that of Dr. Engelmann ('61). This was based on the spennogonia of the fungus. In case the first specific name applied to any stage of the fungus were retained, "amj>t:'licida n would seem to he the correct specific name as pointed out by Raze ('98). The date r850, sometimes cited for Phoma uvic(jla B & C, a. pycnidial st'lge of the fungus, is incorrecl; it should be Material was collected by Curtis in r850 and was sent to. Berkeley, who described it in Grevillea ('7.)), twenty-three years latcr, thus giving Engelmann's desc'i'iption twelve years priority. The ascosporous or perfect st'age of the fungus was discovered by Dr. Bidwell, and was namccl in his honor, by l'i'ir. J. B. Ellis ('80), Sph(tcria bidwellii. Accordillg to the Brnssels code the fil'st specific name applied to the perfect stage of an organism shall be the name of the species, in which case" bidwcllii" is the only specific name that can be. applied to the Black Rot organism. Saccardo (,82) trans-[crrcd the Black Rot fungus to the gcnu~ Pltysa losp0 1'a, thus placing it in a genus characterized as having paraphyses, while in his description of P. bid'lf.}cllii he writes, c, paraphy~iljus llullis," and then, "Hab. in bacds Vitis socia Phoma wvicola, quae Ol'te eius ('6r) Engelmann, Geo. Trans, St. Louis Acad. Sci. Jour, Pmc. 2: 165. r861.. ('73) Berkeley, J. M. Notiqes of North American FU1lgi. Grevillea 2: 82 j 187J, " ('80) Ellis, J. B. A new Sphaeria on Grapes. Bul. Torr. Bot. tlub 7: go p. ('82) Saccardo, P. A. SyI!oge FungofUn1. x: ('98) Roze, E. Qnel est Ie U'ome scit'ntifique a donner au Black Rot? Btl!. Soc. Myc, France 14: (}8,.

19 spermogonium; Vineland. New Jersey. America boreali (Bi<1well) An Laestadia?.'.' A few years later, Viala ct Ravaz ('R8 J ill a short note transferred the fungus to the genus Laeslariia, erected hy Aucrswald ('69). The same authors (\)2) substitute the name Guignard a for the species of Lacstadia, since the latter nallle is preoccupied by a composite genus of Kunth ('32 ). ' Apparently the name of the Black Rot fungus should he t7ltignardia. bid'wdlii (Ellis) Viala et Ravaz. But there seems to be some doubt concerning the valinity of the gcneric name C; zti[j11 ard ia. 1\ lagnlb ('93) ('C)..j.) points out that Dr. O. I" untzc recognized the fact that Laestadia as applied to a fungus is a synonym and su1jstituted the generic llame Cllrfia of Rabel1lwrst [857 for the species of LaL'stadill. Kuntze ('91 ) says* (free tran~lation) '. the composite gcllt1~ LaNtadia, Le~sing. is valid, so that the homonym of Ancrswald becomes a synonym; moreover, Carlia Rabh. is at all events older and on that account should be restored. The type is (arlia o:t"aliciis Rab. (Lllcsfadia O.l~. Sacc.) Bonorden named it correctly." He then transferred all of the listed species of Lacstatiia in Saccardo's Sylloge to the genus (arlill. Also, Saccardu (1. c. Vol. II, p. 289) in a foot-11ote says: "l\t agnus in Oesterr. bot. Zeitschr. 1894, no. 6 contends strongly and not without grounds that the name Carlia, Bonorden r864- (not Rabenhorst 1857), has the right of priority over Lacstadia Auerswald 1869 (not Lessing 1832)." But concerning the validity of the name Car/fa there seems to be some doubt. Lindau (',)7) in a foot-note states that Cariia of Rabenhorst *" Carlia Rabh. (J857) herb. vivo myc., ed. nov., cent. VI. Nr. 567 (cfr. Flora 18S7. p. 382.) Laestadia Awd. 186,) non Less... Klh." Die Composite Laestadia Less. gilt, so dass. das Humonym von Auerswald synonym wird; auserdem ist Carlia Rbh. 50 wie SL} iilter lind deshalh Z11 n:sl:turii'cll. Del' TYIlUS ist Carli a Oxalidis Rbh. (L:testadia ox. Sacc.)." ('32) Kunth. Lessing's Synopsis. Gencru11I Cmnpositaru111 p ('69) Auerswald. Lacstadia, nov. PerisporiacearUIll genus. I-Icdwigia 8: ('88) Viala, P. et Ravaz, L. Note sur Ie Black Rot. Prog. Agr. et Vie. 9: r888. rei' scmestrc. ('91). Kuntze, O. Reviso Gcnerum PlantarUIn. Pars. TI: I. ('92) Vinla. P. e.t Ravaz, L. Sur la dcnomitlation botanique dl! Black Rot. Bul. Soc. Myc. France, 8: ('93) Magnus. P. Sur Ie denomination hotanique des espec:es du genere Laestadla Awd. Bu!. Soc. Myc. France, 9: ('93) -~--. Einige \Vortc Ztt P. A. Saccardo's Kritik der von O. Kuntze in sein~r Revisio ctc. Hedw.. 32: ('94) Wie ist die Pilzgattutlg" Lacstadia jctzi Ztl bezcichnen? Oesterr. bot. Zeitschr. 44: 20J ('97) Lindau, G. in Engler twd Prantl, Die NaturJichen Pflanzcniamilien, I Theil, I abth. 1. c. 422.,.

20 DtlLLETIN 2()3 is a syllonym of Stifl/Jlartel Fr. and there treats it as such. Traverso C02) regarc1~ the type LJf Curlill (C. o.ralidis) as (me of the SlJhacrop;;iuaceae. perhaps a /{clldcrsoliia. Rabenhorst\; (Jri~illal description would learl one 1u think a" much.* l3ornonkn ('0-l) 1. c., p. r 52, unrler n ri,;puriacei writes: "6. Carli! Rahcnh., ]] erb. mycol"g., llyrcillis. gloljln;is, minimis, ostiulo sill1plici apertis; sp()ri~ [t!~if(jrllljllus, \'ci1trico~is, a:,c!:-l cnrtos, crassis., IJiesc C;attung \\"l.lnlc zncr:;t dur... h I(allenhurst ill l'incl' Species, Carlia Oxnl dis, ill delll lierb. myc.ologicul11 lliitgethcilt, ist aucb in der Fuckd'sL'hen Sal1l1l11ung cnthaltcl1-- "1. Carha O.ralidis 1<.al1.. pyrc:di" tligris, minilllb. gjoljosis, epidermide tecti.", prominuluc: ; ascis seso,ililms. curtis, Iallccnl"iis d hsciculatil11 colljunctus; spores fusiformibns, venirico::is, hyalink Hab. in foliis vivis... 2, Cwlia 1II11C1l1i/orlllis. Syn.: Splwcria III o cu lifo rjll is Fr. Syst. IT, p pyrcniis ljiinimis, etc. TaL. I. Fig Car/ill l.(1{'lil'jli ):011., pyrclliis gluhusis. cic,,---tah. I. Fig-, 23.", It will he lloticerl that this gencric descriptiun does not correspond at all with that of J\aIJl'uhorst Tilis ~t!cllls to have crm;-.ti!l1tefi an el11l'i1riation of the genlls and BUl1orrlCI1 ~hduld be cited as the uul11l1r. Hut Dr. G. Winter ('8i!) states that UpOIl cxrtl1linatioll of! he RalJcuhorstian specimen (ill herl). my col. edit. J I, no. 5()7) he finds it to he Sphaad/a dcta.'::cafol'mis, Tlll1~ i he species dted as type falls into synonymy. Uf the two remaining ~;pl'de,., listed 1JY ljulll)rriel1, which by some might Ill' taken as typ(\ \Villtcr ('S7) rciain,; illl' sccowl ill the Auerswaldian genus Lacstadia and trans[cr~ the third to the gclln~ Fhysa/os/,ora. \Vhether or not the 11ame Carlia is valid as a name for a gcm{~ of,11 ycosphuc'rd{,[c and whether it slwuld in,tlly \\':1)' he cul1l1edcrl with the namt~ of the I\lack Rot fungus ean he determined only lly a very careful monograph of this vc~'y larg~ and imperfectly t1nder~tood group. * Flnra 40:,~ Cadiu Raocnh, Mspt. S[lhal'riacC'arull1 noy. geuus Horll1 ll sporae Dc:\. afl1ne. P('ritlleda mlnuta subglnhosa e jll<lclila Jll'omilluia.. Spunw sphacrkae ioith> toruiqidicollcatcl~atal', ('pisjloriu cl'asso. hnmneu. Asd nulli. 567 C. Oxalldis l{ahcnh. p,erith. alris in Ilm<.:t11a fu>co"sl1hsphacc\ala.,jlll}'is millutisoi 1111S fusc'i s tornl oi dihlll->. '. ('64) Bonurden, H. F. :\I,handlungclI am clem Gcilictc dcl' Mykolngie, HaUe. 181)4.. ('86) \\"inl('f, G. Nachu';ig(' unci Derichtigungcn 7.11 Saccanlo', Sylloge FungOI'um V()ls. I. If. Hcdwhia 25: ro--!8. rs,q6.'. ('87) Wintf'r, G. In ]~ah(;'nlwrst, Kr~'pfngalllt'll.FIll1'a J. 2, 40.~ and 414, ('02) Tr,averso, J. B. Flora Italic:! Cryptogamia, 2: 375, ,

21 307 A!ist of the more important llamc,; applied to Lhis tt1l1gns i;-; as follows; Guignardia bidwelhi (Ellis) Viala ct Ravaz. nul Soc. ;\[yc. France, 8: (;3. r8sj2. Splwt'l'ia bidw<'llii Ellis. Dul. Torr. L\ut. ClulJ 7: ~)O. r880. Plzysa/ns/,ora I>id1l'cllii (Ellis) Sacco Syllor;(: Fll11!:;:(lntlll I: -I-P. 11)82. L(l('stlldin hit/,c'cllii (Elli~) Viab d Ravaz. l'rog..\gl'. d \ -it. 9:.t9C~--1-(j3 188i:l. COl'lia bij,l'l'llii (Eili~) :-,1 agnus. eul. SOl'. }_] ye. FralWl.!): [;-4 Ig<J3 Glli(/Ilaniia (ljili'tlicida (Engelmann) Raze. nul. Soc. ~\iye. Fram~c. 14: ). 18l)~;, Xacl/los/'ora am pc!icija Fnge1munJ1. Trans. St. LOllis.\cad. Sci.,.Iunr. jlme. 2: IllS. PllOlIl(l 1!1 'ic() la. Jlcrkdey & Curti:'.. Grevillca 2: PII,)111 a llstula/lljil Berkeley :l.nj Curtis. Grcyillea 2: I'ho/lla w.:-icola val'. /abmsc(lc von Thilmen. Die Pilzc dt.:s \\'einstockes. r87t:1. p. It;. ISS!. Dt'Pa.~ ea /aurltscac Engelmann. Trans. St. Louis.\cad. Sci., Jour. f'rue. 3: ccxv l'hyllosticta 't'ifiro/a yon Thiill1en. Die f'ilze ues Weinstockes. IRiS. p l'hyllosticta labrltsca,' von Thi.1mell. Die Pilze d(~s W c:instochs. rrif;, p. l8<). Phyllo.rticta (/111/'clupsidis Ellis & 1fa1'tin. Ellis' North.-\mcrican Fungi. No, rro0 Life history -l'l'l'itlzccia The variuus manifestations of thi~ polymorphic fungus make a ':'turly of its life history exceedingly interesting'. Tile ob;;e1'vations recorded here have ueen takm as they occur naturally under most favorable conditions, a11(l observations have exlended over two seasons, the entire time being devoted to this onc particular factor. Upon entering, early in the spring. a vineyard whieh has hac! Hlack Rot the year previous, one finds that most of the ll1t1il11tlicu clusters of

22 the previous year are lodged on the g-rotu]fl, having he en broken loose from the vine a11!1 dropped there at the time of trimming and pulling the hru5h. (Fig. 138.) Careful examination of such mummies with the unaided eye shows the presence of very numerous minute elevations which are th~ fmiling conceptac1es or perilhecia of the fungus. A slight perforation or rupture at the apex, -"careely visible to the naked eye, is the ostiole. At first, the writer had expected to find the best pel'ithecia for stndy un or ncar the side of the berry in contact with or imhedded ill the.~nil. A fter frequent examinations, he fonnd that FIG. 13l:l- MUIH1II icd cluster of yraj'es cliayihg to the wire and forming a eente,' of. illjectioii. (Natll1'ai size.) Photo. July r, the perithecia in such locations were usually han'en and that it was on the upper, exposed side,. where outwardly the mummy appeared to be very dry, that these developt:d best. From this observation, he was led to examine more closely niu111mies which cling to the wires. 'While. peritheda on them were not mature so early in the season, there was a. greater abundance of' them in a living condition than when 011 the ground. On making a thin section throt1gh a region bearing perithecia, au sorts of conditions are to be found (Fig. 139.and Plate II, Fig. 7) -

23 TJ-IE I\LACK ROT DISEASE OF GIUrBS ascigcr<1ns perithecia in all stages of developmeilt, pycnidia and spermogonia containing pycllospores, and spermatin from the previous season. On April :l3. I 1)08, c1tl~ters of Dlack Rot mummies were collected at Lake Ridge, N. Y. Examination ~howed that at this time no development had taken place. The!'c mummies were placed in a stender dish, ami although overrun with C c plla! otheciwn roscii11'i, continued to de "dop. and 011 May 16 the writer fonnd asci with spores that were apparently mature. On this latter date a clu~ter of ll1tl1lltnies was picked frum the wires at Ithaca an(1 examination "howe,l that the perithecia FIG. I39.- Cross sectiull th)'ou.q/! a peritheciuih s!zowiuy developi/ly asci alld asco.fpores. Outlined wilh a,amem lucida. \vere just beginning to clevelop. Some of the internal cells were slightly elongated. Under natural conditions tlevelopment had beeil retarded. On March 27, I907, 1l1t1mmiecl clusters were sent to Ithaca by Mr. G. G. Lansing, Romulus; N. Y. These were kept in a stender dish with moist cotton about them. On April 25 an examination was made jt1st prior to discarding the whole lot, when mature asci with spores were found. On June 13, 1907, the writer's first examination was made for asci developed under field conditions, and an abundance of them were found at that time. The spring had been exceptionally cold and wet,

24 BULu,:nx 2')3 but ~IS has hetll pointed ont I)), I'runet \ '97 ). pcritltecia wil] ri(~\'dup at a vcry lui\" tl'lllperature if c.ufficient l11oi:;tllre i,s present.,\t frc(jut:l1t inicltals throughout the SUlllmer ex.lminatiol1s were made to Sl'e ju"l how IOllg the a~ci per~isted. From the observatiljn:; of Scrihncr and \' iab ('88), which haye been copied wielely. the writer h,((1 expected them to disappear carly ill the season. \\'hen he found asci with spurcs that were immat11re in August, 1907, he thought it was prulwhlr due to the wry dry summer which vve had experience(l. \Vhe11. however, Ill: fouml on October 2, I~o7, an abundance of asci with spores \\'hleh genninate(l re;ulily in tap water after sixty hours. he was COI1- yim:erl that the,lscigerot1s stage was not so eval1lsccnt as he har1 been ll:d tll Lelieve. J1ata obtained in 1908 confirmed this ouservatio11. On.lui}' 2I, lllttlllj11ies containing quantities of asci, both immature anri matnrt" w~re enclosed in a piece of wire cloth and buried in the grml11d to,l depth of ahuut six inches. On Clctohcr 2+, these were taken up ami ex<llllinccl. 1\0 evidence of spores of any kiwi was fot1nd, and in fact many of the mtllilluies WC1'e completely disintegrated. \11 l'vcil more conclu::iive experiment on thi:-; subj ~ct was terminated July 16, In a particular section of a r\iagara vineyard where no fmit hat! he en picked in 11)06 because of the great all11nclalll'e of Black [{ot, the whole rutted mass went onto the ground and was plowed uncler early in!'i I a..'-. _'\s many vineyardists., plllw back," the writer decided to se~! whether this would be advisable in ~uch a rot-infested section. ('on~eqt1ent1y, a few rows were plowed 1);wk in the u:-,ttal way. The writc't' then made a search for mummies hut much to his surprise was not able to fmcl an.\'. An occasional remnant was foullfl. lklieving that the plo\\' had not gone deeply enough. a spade was hrmtg;ht into usc. 'Vith this,,,\-ell after continued search. only all occasional mummy was found. A microscopic examination of SUch 111ummies showed them to be in an ad\'<mcecl stage of disintegration and entirely voill of spores. This, too, had. taken plaee in a season which had been reladyely dry. Jt therdore seems quite certain that, although spores may be formed. in peritheda during mo~t of the summer, under normal conditions they nrc de"troyecl in a few weeks (six or eight) if hnricd under n. few inches of soil. Galloway ('8')) has shown that the same thing holds true if the mummies arc covered in the autumll. This is of considerable. ('88) Scrilmcr. F. L. and 'Viala, P..Black Hot. U. S. D. A., Sec. Veg. Path.. Bul. 7: 1. c. :2:2. rr88.. erg) Gallo\yay, D. T. )\scosllores of the B1flck Rot Fungus as affected by coveting with earth. Jour. Myc. 5: I 88!)... ('97) Prun~l. A. Les formes cit! parasite dll Black-Rot, de l'automne au prmtemjjs (1).. Prog. Agr. et Vito la7: I. c

25 3! l interest and importance from the practical standpoint, for if rotted duskr,; a1'<': remuved from the arms and dropped on the ground at trimming time a11(1 then cov(;re(l with the p1u\v, these soun:es of infection will Le climinaiccl. at the asclts (Plate I, Figs. I-6.) Origill alld dc~'cl(}tmcllt The writer had hoped to make a critical study uf thb point as there arc many illterc~iing bio]ogieal considerations connected with it. Howeyer, he soon found that snch a study was, alone, suliicient material for a major problem. and that part of it would have to be left until another time. One of the chief difliculties 111et with is the extreme minuteness of the nuclei. l~p(lll examination of well-stained microtome sections of perithecia taken June IG to 22, 1907, ane! in various stage" of development, it is easy to find ones in which there is practically no development f rom the winter condition. Such perithecia are sun'olmde(l hy the t1~ltal thick, black, pseurloparenchymatol1s covering. This pseudoparcnchynm hecomes thinner walled inwardly, so that the whole interior of the peritheciul11 is filled with it. Tn the stained sectiol1s there are scattered here and there, ncar or a little helow the centre of the pcrilheeiull1. little dots of much deeper staining quality, \"hich in well-hleached preparations are seen to be individual' cells when examined with an immersion lens. From a series of successive stages which are readily nbtaina.hle, it seems dear that these cells which stain more intensely are a!'cogcllotls ~'el1s, the rema~ni11g' cells serving purely as nurse cells. Each individual cell has a nucleus, but nuclei in these deeply staining cells retain the :;tain much 1110re tenaciously than the others. \Vhen activity hegins, the ascogel1otts cell elongates by pushing its way upward, th'jugh at the very first it seems to take the path of least resistance and m;ly grow in a longitudinal directinn for some distance. (Plate I, Figs. I and 2.) When the ascogenous cell is half the length of a maturc ascus, one can sometimes sec a single large nucleus in the centre of the cdl or somcwhat distad of the centre. (Plate I, Fig. 3.) The apex of the cell, which up to this time has been somewhat acute, now becomes ohtusc as the cdl enlarges at the. tip a11(1 ljecol11es clavate. The writer has noticed that at this stage the protoplasm in the ba"e of the ascogenous cd! seems to recede a little distance and sometimes apparently lays dowll a wall, leaving a small empty cell at the foot of the asctls,. \Vhatever take:;; place now, does so very rapidly. The '\'riter has been unable to get tran!iitiol1 ~tages between the n;1inurleatc condition and one ill which all of the spores are more '0r less clearly outli11ed and

26 3I2 DtJLLETIN 293 each possessing one to four nuclei, usually two or three. (Plate I, Fig-s. 4 and s ) There are a number of these ascogenous cells in a perithccium, generally fifty to one hundred o.r even more. As has been pointed out above, they do 110t mature synchronou:-.ly, and when several asci are found in a perithecium it is very evillent that much of the pscudo~ parenchyma has gone. The writer is of the opinion that these cells are absorbed by the r1eve10ping asd. Now, early in the season when the vcry first asci are developing, 110t nearly all of the pscudoparen~ chymat(lus l11as~ has disappeared, and when crowder! together by the development and exljam:ion of two asci situated rather close together, often, in poorly stained preparations, give~ the impressioll of paraphyses between the asci. The writer is satisfied, however, that there are no true paraphyses developed here as there are in the case of so many discomycetou" fungi, as,yell as other P}'rclImnycctcs. In this con1)cction Scribner ('8Ci) inscrts the following foot note: "l\1r. Smith (Erwin P.) in his investigations above referred to, found the ascosporous form very frequent in the berries examined" after May 10. He discovered asci in all stages of development from very small imlmihtre ones to perfect ones containing well developed ascospores. lj1 il1[jlcd with the asci 'l.vcre the usual paraphyses." Price ('92) figures some bodies which he records douhtfully as paraphyses: The writer has oft.en seen about the mouth of the peritheciu111 short chains of moniliform cells tapering' toward the ostiole which look very much like the ones figtued by Price, b1.1t these are auached to the periphery of the perithecium and near the upper part. The writer has usually designated them as periphyses. He has never seen such cells intl'fmingled with the asd nor any cells which he could inierpret as paraphyses. (Fig. I39.) The spring rains furnish moistul'e conditions which favor the development of asci. \\Then an asctls is mature, and this, depending on tile season, may be at any time after the mid<1le of May, it is a long clavate body with a very hyaline but thick wall which is a little thicker at the apex than at any other place. (Plate V, Fig. 26.) It contains elght spores placed in a single series and ttsually all having a similar orientation. The size of the ascus varies with the method of observation. If the section is made dry, the ascus measures 62 to 80 by 9 to I2 microns j ('86) Scribner, F. L. Report on the Fungous Diseases of the Grape Vine. U. S. D. A., Bot. Div., Sec. Plant Path, Bul. 2: 1. c ('9~) Price, R. H. Black Rot of the Grape. Texas Agr. Exp. Sta. Bul. 23: , 1893.'..