SEEDLW‘QG. ”ESEASES OF _‘“ 'nesi; to: Degree ci H: 5:. i SUGAR BEETS ”—— »_- ._.— -——-—-—————-|—. »-v... V.._...- .. {F— -—- W S tew an: ,8? 3974 W W I. I‘ v a .. \w I . l, .I .o‘ O ' . a a . u I , \ ‘1‘ a. .E a 1 ~ . «i ,t‘ b r t ‘I \tl ar'l' K k If ‘ 9 IV ,. z )u ‘1'. . 4' 1111581: ; .Illll .llIliIu‘Ill- ;lllllur“ llllllllrllllli .1 f ,u‘u- a.- g M... n. E.E1.(IL L.. prur— ..:.‘L~K.... L51»? .tlplbn . SEEDLIUG DISEASES OF SUGAR BEETS. THESIS Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Michigan Agricultural College. Deweyn§jewart. 1924. ACIETC‘J’LE GLEN? "5 . The writer is indebted to Dr. E. n. Bessev and Dr. G. H. Coons for many valuable suggestions given during the course of the eXperiments, and for criticism and correction of the menu- script. \. 2' 7'2 "1 R.“ 400.4 i. 5139’ d m ' ')~'"‘ T1 .Lgi JJJ-:4' .3 COITTL‘ITT '3 . Introduction. Previous work on Seedling Diseases of Sugar beets. Symptoms. a Survey of Preliminary Experiments in Laboratory. in Greenhouse. Experiments Experiment $1 - On muck soil. the Vicinity of Lansing, Kichigan. EXplanation of Treatments in Table I. Discussion of Techni que . Experiment }2 - On Discussion of Table I. muck soil. Table II. Experiment $5 - On sandy loam. Explanation of Treatments in Table III. Discussion of Table III. EXDeriment f4 - On sandy loam. Discussion of Table IV. Esperiment f5. Discussion of Tables V and VI. Experiment f6. Discussion of Inoculation EXperiments. :zx-per iment $7 . Discussion of Summer I)" . Literature Cited. Table VII. Table VIII. SiIEDLIZTG DI:3:1~..3233 or .JL: .33‘3’23‘. I Introduction. The sugar beet industry is a very important rhese of Michigan agriculture. In 1925, 96,000 acres were planted to this crou which returned to the farmers an average of 572.00 per acre. In general, the area devoted to sugar beet culture is the central part of the Loner Peninsula. The soil type, for the most part, is sandy loam, however acme contain a large amount of humus and, in some localities, muck soil is used. The areas planted to beets are comaonly bottom or low valley lands, where tile drainage is necessary in order that agri- culture may be nracticed. Beets are commonly rrovn.in a four-gear rotation as the agriculturists connected mith the industry strongly advis against iollowir; beets with beets. In many sections it is planned to have beets follow clover, but in recent years beets have been used most successfully followinw cultivated crops. The croo is planted over a period ranging from very early Spring (April 20th) to late Spring (June 20th). Seed is sown very heavily in drills 24 inches apart and the young plants are cultivated frequently as soon as the: can be seen in the roxs. Tie plants are allowed to grow with no attempt at thinning until a decision can be made as to the stand. If soil and weatler conditions Lave been favorable and cultivation timely a stand profitable to work generally'results. If, on the other hand, intensive rains, low temyerature, or poor seed factors enter, the stand is poor. In such cases the field is dra fed up and either replanted to beets or some other croo. Some years as much as 25 percent oi the acreaze planted in some sections fails to show a profitable stand and must be regflanted t>beets or to some other crOp. It is obvious that the matter of a good s and is fundamental to successful sugar beet raising. The common cause of failure to get a stars is funrous attack which gives rise to the so-called "seedling diseases" of sugar beets. A general discussion of the nature of these diseases and their importance under Michifarxconditions has been given by Coons (3). In this article, the suggestion for some form of seed treatment as a means of control is made. This investigation has consisted in tests with'sugar beet "seed" under laboratory arm :aeenhouse conditions in an attempt to evaluate the various types of seed treatment which have been suggested. Previous work on Seedling Diseases of Sugar Beets. The ear y American.eXperiments to show that the death of sugar beet seedlings was caused by pathogenic organisms were conducted by Durgar and Stewart (5) in 1901. Their investi- gation proved that Corticium vajum B. a C. var.solani Burt. (called by them Rhizoctonia) was capable of killing sugar beet seedlings. Durgar (4) in New York, Pammel (9) of Iowa, and Selby (15) of Ohio had previously reported Rhizoctonia as causing a root rot in fields of mature beets. EurOpean literature for many years had contained more or less extensive studies on sugar beet diseases. In a series of reports between 1906 and 1911 Peters (10, ll, 12) and his co- workers (1, 2) went over this literature and from this and Q their own experiments concluded that Bytnium debaryanum Hesse, -5- Phoma betae fir. and sphanomyces leevis Dedy. are the organisms concerned in the production of seedlina diseases of sugar beets in Germany. They were unable to produce damping-off with Rhizoctonia violacea Tul. In 1915 Edson (6), working at Madison, Wisconsin, found Thoma betae, Pythium debarianum and Rhizoctonia sop., as tell as an organism uhich he later named Rheosporangium aghanidermatum Edson (7) as the principal organisms concerned sugar beets. Each oraanism produced a +5 in the seedling diseases 0 high percentage of diseased plants when introduced into the seed bed. Ddson also found fhoma present on all lots of seed balls examined from hmerica and Euroue, thus confirming previous results of Peters. Although Bhoma is constantly being introduced into sugar beet fields, fool and KcKay (15) have slmun that it does not live from year to year in the soil unless on frarments of suaa beets. however, Rhizoctonia and the Phycomycetes, Pvthium — l debaryanum, Aghanomyces laevis and Rheosuorangium aphanidermatum are common soil organisms as flzoun ey Jensen (6). The problem of controlling sugar beet seedling diseases was, therefore, concerned with the seed-borne fungus, Phoma and the numerous soil-inhabitina fungi. It is oovious that unless uninfested soil is available for use with disinfected seed, treatment of seed will, at most, be only partially effective. Besides this difficulty, it was found that treatment of seed ball (I) so as to eliminate Phoma betae as a factor was almost *‘1 impossible. Edson (6) in trying to find some means of freeing 'his inoculation experiments of rhoma tried strong solutions of hgdrochloric acid, concentrated sulphuric acid for one hour, -4- and 2; formalin solution for periods sufficient to injure the seedlings without materially reducin: the presence of Phoma. However, Teters‘ method of pasteurization at 60°C. for 10 minutes on two successive days gave one Phone-diseased plant in about forr hundred. Fdson states that this method is not practical for field use as the germination is reduced. In 1924 Kiss numbold (14) reported favorable results H. n sugar beet seed disinfection using formaldehyde and steam. This method has not as yet come into general use. Symptoms. f1 ihe diseases of sugar beet (jeta vulgaris L.) seedlings considered in this investigation are those commonly known as "Black root", "Root sickness" and "Damping-off". No distinction can.be nude betueen these various names since they are used loosely to apply to death of seedlings from one cause or another. The comm n signs of this type of disease are a blackening of the hypocotyl and root. Th discoloration usually Shows above the surface of the ground before the seedling tOpples over. This killina may be fairly rapid or take place so slowly that the seedline seems to almost outarow the disease. The plants show great persistence as frequently a plant is seen entirely olalhened as far as the cot ledons, uhich, houever, mar be turgid and green. Examination of such seedlings shows cf- the vascular rerion as he onl; part not decayed. Another type of attack which is very common is a distinct wilting of the seedling. On removina such plants a brown, decayed region is 4'1 found on the rort. The central vascular region is discolored brown in advsnce of the external lesion. These lesions have I U". l a water soahod appearance a compared with the dry, black ,. C. appearance of the other tyre of attack. Qwenty four hours m Liter the first indications offuiltins the seedling is found to be almOst comyletely decayed. a seedling has never been Observed to recover afte" the onset of this type of disease. Another tyge of seedling disease not so distinctive in aopearance as tie others i the discoloration of the young leaves. In such 02 C V!) ses, seedlinrs make a slow growth and, in general, show evidence of malnutrition. Cn removinr the seedling the tap root is found decayed at the tip and the rootlets above the decayed region are functionin: and an arently attenmting to replace the primary root. To doubt many of these seedlings mould mature sects, but they would be of poor tyne. J. A Survey of the Vicinity of Lansing, michigan. Samples of sugar beet seed were secured from Kr. E. 3. Down of the U. 3. Department of Agriculture. These samples were from his isolated breeding plots in the vicinity of Lansing. rm inese seeds were hand cleaned and in general handled as care- fully as a person,would handle seed from breeding plots. :ais, in addition to the fa 0 't that they vere isolated, should have (D (U CD CD Cu 0 given almost a rhoma-fre “Samples of 5C: seed calls were planted in sterile sand in a moist chmnb er. .-‘.s the seedlings bee-in to die they mere examined for Ehoma. IhOma was determined by the character- istic worm-like coil of spores from a pycnidium when placed in water on a microsCOpe slide. Eifteen samples from different localities were used. 'homa betae was found in 10 samples -6- of the 15 regresenting all directions from Lansing and the College farm. Two samyles were ircm farms w ere poor stands due to disease were known to have occurred, and each sample showed fhoma in great amounts. E0 doubt if a diligent search had been made or new samples planted, Phoma betae could have been found in all lots. Ereliminary Experiments in Laboratory. The first tork undertaken consisted in studies to determine the best methods of eXperimentation. The nature of the problem can be seen by the follosin: brief test in the laboratory. The seed balls were treated with various disinfectants applied both as liquids and dusts. Moist chambers (15 cm. in diameter x e-o cm. high) were sterilized and the treated balls placed between moist absorbent paper. Seedlinrs germinated in this way soon became covered Lith hlternaria and Mucor. Also in this method certain “lemiccls such as mercurj bichloride leached from tle seed balls showed a harmful effect on the J roots. Tests were made in these same moist chambers using clean, sterile quartz as a seed beed. In this case the seedlings seemcd to die in a few €a,s after germination regardless of n 4 the treatment. This was thought to be due to the excessively moist atmosphere of the charmer. Batterg jars 25-30 cm. high covered with halves of mois chambers were substituted for the moist chambers, and sterile quartz used as before. This way the seedlings grew for many ays in asparently normal condition. The mercury treatments -7- which had shown injurious effect between moist paper now save the best germination and fewest diseased seedlings over a period of 12 days. Examination of dis ased seedlings from treated and untreated jars showed Phoma betae to be generally present in both. These treatments were made with mercury compounds, formalin and formaldehyde compounds, copper com- pounds, and furfurol, about 15 in all. These exseriuents made it evident that complete disinfection of seed balls was hardly to be obtained with the chemicals used. The small germinator type of experiment was taken to be of doubtful value for the purpose of the invest‘aation. Accordingly, attempts were made to grow beets under conditions approximating those in the field. Experiments in Greenhouse. ixgeriment $1 - On muck soil. The preliminary exyeriments in the laboratory had indicated that a partial control for Phoma betee and other fun i could be expected with certain chemical treat ents. Tests with soil were chosen because experiments conducted in this manner gave an opportunity to determine the value of the various treatments as a preventive against organisms arising from the soil as well seed-borne ones. In these experiments the seed balls were sown in soil and given careful attention. The bed used was 34" tide and 6” deep. The rows were 5" apart and had 50 seed balls per row planted 1" deep. Every third row was a check. The "seed" was American-grown, secured from the Holland-3t. Louis Sugar Company. The diseased seedlings were removed after records '“1 r-v l taken. rne records were taken at intervals of 2-; days over -8- r-v a period of 2: da,s, beginning with germination. Each treatment was in duplicate one half the length of the bed apart. Treatgent. 'ho. of seedlings. ' No. diseased ' Percent ' ' seedlings. ' disease. ‘Per row.‘ Total ' Per row.'Tota1.‘ I I “’ I I I 1. Chlorodhol ‘ 121 " ' l9 ‘ ' " ' 115 ' 254 ’ 17 ' 56 ‘ 15 I *' I I I I 2. Pythal ' 96 ' ' 15 ' ' " ' 98 ' 194 ' 10 ' 25 ' 15 I I I T I 30 Iii-9:019 ' ' ' ' ' illoCo ' 95 ' ' 10 ' ' " ' 95 ' 186 ' 24 ' 54 ' 18 I I j T I 4. "620" ' 88 ’ ' 11 ' ' " ' 90 ' 178 ’ 15 ' 24 ' 14 I I I I I 5. Cu304 +lime' 112 ' ' 29 ' ' " ' 112 ' 224 ' 21 ' 5O ' 22 I I I T 'I 6. CuCO, ' ' ' ' ' ( orona)‘ 95 ' ' l8 ' ' " ' 91 ' 184 ' 25 ' 41 ' 22 I 1— I I I 7. Cu005(Dow) ' 99 ' ' 44 ' ' " ‘ 89 ' 188 ' 6 ' 5O ' 27 I I I T I 8. Seed-C-San ' 72 ‘ ' 55 ' ' " ' 107 ' 179 ' 68 ' 101 ' 56 I W I I _I 9. Kalimat ' 75 ' ' 45 ' ' " ' 84 ' 159 ' 45 ' 88 ' 56 I I I r j 10. Formalin ' ' ‘ ' ' 1...:340 I 55 I I 28 I I " ' 46 ' 101 ‘ 29 ‘ 57 ' 56 T I I I T 11. Check ' ' ' ' ' (Av. 18 rows" 60 ' ' 24 ' ' _ " ' 60 ' 120 ‘ 24 ' 48 ' 4O 1 T I I I 12. 111005 ' '75 ' ' 55 ' ' " ' 85 ' 156 ' 59 ' 117 ' 75 1 I I I I ~— 13. Eurfurol 5,5' 57 ' ' :53 ' ' " ' 69 ' 126 ' l4 ' 47 ' 58 I I T 1 1 14. b’ur'furol 2,73' 42 ' ' 9 ' ' " ' 55 ' 95 ' 12 ' 22 ' 22 I I I— I T 15. Eurfurol 1,5' 75 ' ' 25 v ' " ' 72 ' 147 ' 25 ' 50 ' 54 Table continued on next page. Table I continued. Treatment. 'Ho. of seedlings. ' No. diseased ' Percent ' ' seedlings. ' disease. 1Per row.‘ Total. ' Per row.‘Dotal.' T' I I I 1 l6. Lime ' 75 ' ' 9 ' ’ " ' 87 ' 160 ' l5 ' 22 ' 14 'I I I I I 17. Large secd' ' ' ' ‘ balls ' 68 ’ ' 20 ' ' " ' 75 ' 145 ' 10 ' 50 ‘ 21 I I I I I 18. Small seed' ' ' ‘ ' balls ' 24 ' ‘ 5 ' ' II I 29 I 53 I O I 5 I 10 Explanation of treatments in Table 10 1. Chlorophol is an organic mercury compound used at the rate of 1 gr. per gallon of water for 1 hour. 2. Pythal iszulcagwnic mercury compound sold by the Chicago Process Company, Chicago, applied in l/4fi solution for 1 hour. 3. HgClZ 1-1000 - treated an hour. 4. "620" is an.organic mercury compound applied far one hour. rurnished by Corona Chemical Co., Milwaukee, Wis. 5. CuSO4 + lime was a mixture consisting of equal parts dehydrated CuSO4 and dehydrated lime. 6. 011003 (Corona) furnished by Corona Chemical Co., hilwauuee, His. 7. CuCO5 (Dow) furnished by Dow Chemical Co., Kidland, Rich. 8. Seed-O-San is an erranic mercury compound applied in excess, in dust form. 9. Kalimat, a Formaldehyde compound furnished by Chicago Process Co., Chicago, Ill. 10. Formalin 1-240 applied ior 50 minutes. 11. Untreated, Ame‘icanegrown seed. -11- 12. Nickel carbonate dust in excess. 13. Eurfurol 5} applied for one hour in all concentrations. 14. Eurfurol 25 " " " " 15. 31:: furol 1,5 " n " n 16. Lime-hydr ted lime applied in excess. 17. Large seed balls were secured by sifting the ccmmercial seed through a screen 36 meshes per inch. Ehe seed bells remain- ing in the screen were considered large. 18. Small seed balls,- those seeds which sifted through above mentioned screen were considered small. Discussion of Table I. dichloride of mercury, Bythal, Chlor0ph01 and "620" all if ‘hos great reduction in disease with high total germination. O} This hows a superiority oifmercury and mercury compounds as a treatment. The cooper dust treatnents rave an.increase in germination and a decrease in qercentare of diseased seedlings. The "Dow" carbonate Rate a poorer stand than the ”Corona" although it has a hlPher percentage of copper. It is not around very fine and this Mill prooably eXplain its performance. Couuer com- pounds in the iorm of a dust show promise as a means of control as mellansnercmmycmrwounds. rormalin, Kalimat and Jeed-C-jan are of no value in pre— venting seedliny diseases after plants have emerged from the soil. -12- Nickel carbonate shoved an injurious effect and Eurfurol in general, for the concentrations used. was of no value. The effect of lime was somewhat unexpected. The germination was about that of the check but the disease, after the plants emerged, was reduced. It was thought cossible to eliminate the greater part of the rhoma by discardinr the small seed balls. The preliminary eXperiments in the laboratory had shown Jhoma betne on the larger seed balls, as tell as the small ones, end this indicates about that ustld be exsectcd from seed bills so separated as far as total germination and yercent of disease are concerned 1: thoma his present on neither. Technique. The aetiod oifplantirp:rwas<flu:nred for BXperiment f2, to insure uniformity as far as far as Space and depth of seed were concerned and iollomed for all iuture bed experiments in the greenhouse. A lath containing 50 holes 1 inch apart was placed across the bed, leaving a 4-inch margin on the back and 2-inch margin on the front. Thirty holes were made in the soil through tie lath. A seed hall was 97aced in each hole and forced one inch below the surface. The roms were exactly 5 inches a',.)::rt. All seed in iuture 2.03:1: \2’5s i‘romth sane see}: as used in preriment fl. hn average size‘ lot of 20 balls J 41 was counted out in each case before they were planted to insrre an avers e number of seeds per rovgso far as possible. A definite record as to date and rem number was kept for each dise sec seedlinr and the corresponding date was recorded ~13- for the oreanism found with it. Jach.diseased seedling was treated with H3012 l-lGCO for 1-2 minutes and rinsed in sterile water before plating on cornmeal sear. In determinin~ tie organism pert oi tie freuth was examined under the microscooe. Ho distinction was made betteen Eythium and its clcse relefiives. All were celled Bythitm. Experixent f2 - On muck 8011. In the first experiment no attempt was made to determine the organism associated with the diseased seedlinrs. This eXperiment is similar in all respects excegt for technique and organise determination. These data represent reed-ds taken at intervals of 2-; are over a period of 19 days after the O seedlings ap,esred. -14- Table II. Treatment. 'No seedlings. 'Uo. disetsed '% dis-' Organism. seeul1nr 'ea se. ‘Per 101"ot‘1“Per Iow'”ot 1' I I I I I I *demescn ' 57 ' ' 4 ' ' '“ythium " ' 53 ' 112 ' 4 ‘ 8 ' 7 '5ecteria T I I I I I CuCO5 (Corona)‘ 55 ‘ ‘ 18 ' ' '58 cteria " ' 54 ' 107 ' 7 ' 2b ' 23 'P"1hium I I I I I CuCOB (Dow) ' 44 ' ' 14 ' ' 'rzythium " ' 41 ' t5 ' 18 ' ' 5:72 ' 38 'P;~,th'1um “" I I I I I I Cu5C4+lime ' 41 ‘ ' 9 ' ' ‘Pytl ium " ' 39 ' bO ‘ 15 ' 24 ‘ 30 'Alternar is I I " I I I 1 Eurfurol 31 ' 55 ' ' l4 ' ' ‘Bythium " ' 5b ' 75 ' 10 ' 24 ' 53 'iythium I 7 I I I I Eurfurol lfi ' 50 ' ' 11 ' ‘ 'P71 inm " ' 27 ‘ 57 ' 15 ' 2o ‘ 47 Ascom;ceLG I ' - T..--_" h I I— ______’ I 1 -_._ Larre seed ' ‘ ' ' ' ' bull" ' 54 ' ' :2 ' ' 'PytLium " ' 5c ' 92 ' 15 ' 57 ' 4o 'Pythinm "‘”””’ " I ' I "" I I I T ~"" "'"“""" Small ~eed ' ‘ ' ' ' ' balls ‘ 16 ‘ ‘ 5 ' ' 'Pythium " ' 14 ' 52 ' 5 ' 6 ' l9 'fiacteria I “" I I I I I ya; e seed ' ' ' ' ' ' ball.‘£L lize ' 29 ‘ ' 10 ' ' 'ASQ 6311*111us " ' 50 ‘ 59 ' 9 ' 19 ' 52 'Ceih 101 eciwm I I I I I I Jmall -eed ' ' ‘ ' ' ' balls C lim ' 17 ' ' 2 ' ' 'Bo growth. " ' 15 ' 32 ' 5 ' 5 ' 16 'Bacterium I I 1— I I I Check (Av. 15 ' ‘ ' ‘ " ' rows.) ' 27 ' ' 10 ' ' ' t Pythium " ' 27 ' £4 ’ 10 ' 20 ' 38 ' l Jossllina ' ' ' ' ' ' 3 Eusarium ' ' ' ' ' ' 2 As erqi1lus *All treatmcn1 or;“<1nic mercury Nem01wr Co. '0' 8311110 It was as in Table I, except Semes C 0 mp ound furn i s he (1 b I. 4-‘ 74‘ bile 1.10 applied in dust form. an which is an duPont de -15- Discussion of Table II. \ I A new mercury compound, aemesen, was introduced which gave promising results both in the total germination and the percentage of‘disessed seedlings fou d. This is e powder A and can be used either as e licuid or as a dust treatment. In this case, the dus application was used. The 00 per compounds were as iced as before, hotever, the faults of the "Dow" preparation were mernified. "Corona" couper carbonate Les used entirely in future tests. rue tuo concentrations of Eurfurol used showed no control and were elimin ted irom future tests. The senervtion of tie seed bells gave no indication of a means of control. Although lime appeared very good before it proved worthless when applied to smell and large seed bells. Lime, excegt with cooper sulphate, was also eliminated from future tests. Formelin and formaldehyde compounds were not used because the; nod proved to'Mexnnyrymor and the mercury compounds were not repeated as they uould be given further test later. I". fie seedlings examined snore1 a arse majority of Pythium cultures. It is interesting to note that not a single culture of Phone or Rhizoctonia Les found. Why Phoma was not found can not be erydeined since it was so common in this lot of seeds. -15- Exocrin ent f5.-Qn sandy loans To see if the tyge of soil was responsible for the common occurr cnce of farthium, and also to compare types of soil, a change of soil was made from much to sandy loam. This soil res irom the College Farm and had grown a crop of beans the year before. No record of it ever havinr sura beets on it can be found. In conformity to genera 1 practice among seel ana ;sts, a standard of two seedlings per seed ball has been set up in the followinr aml s as a sort of normal or ”ideal" germination .11ch mi ;ht be ex m3 ected from such seed if the disease factor did not enter. In the tables that follow, it vill be noted tha t two cases were fouiid uhere this stancard number was slightly eA ceeded. seed balls in sterile sand an d also those in sterile soil when siven the most effective of the seed treatments averaged about 1000 seedlin:s from 5C0 seed bells. Based upon this number a column showin? the percentage of seedlings emerging (commonly called germination) above the surface of the soil is given. Also the percentage of stand of apparently healthy seedlings after the last count was made, is simila rlv computed. The column of percent diseased is the actual percentage of disease amen? those appearing above the surface of the soil. In the other exoeriments it xas found that records taken every two or t was days mould not account for all the seedlings -17- or scne could not be accounted for. The slight variation in numbers from day to day is in nrrt due to this loss of individuals, and the “ame variation arises from delayed germination of the seed bells. Close observation showed that rapid killing and deca; of tie seedlings took place. f '21 his tyne of disease has already been described under symptoms. During this experiment records were taken every afternoon for thirteen days, starting immediately after germination. -15- Table III. Treatment 'Ho. diseased 'Healthy seed- 'Total no. seed-'Orsanism. ‘seedlinrs. 'linas at end ‘linfis emerging.‘ ' .1 ' Of €343” Jo . 1 ' ____ 1 ' 1Perfij’i‘otal‘ifo ‘Per 'Eotal' p 'Per‘i‘otalr p ' 'row.‘ ' 'row ' ' 'row.' ' ' 1 I I I I I W I I I 1.6emesan ' l5 ‘ ' ' 57 ' ' ' 72 ' ' 'l_fiucer " ' 9 ' 24 '18 ' 5F ' 110 '92 ' 62 ' 154 'll2 'l Pythium ' ' ' ' ' ' ' ' ' 'l hhizoctonia ' ' ' ' ' ' ' ' ' 'l hucor a Ens. I T T I I I I I I I _" 2.Usoulun ' lO ' ' ' 53 ' ' ' 65 ' ' 'l Queer ._ ” ' l4 ‘ 24 '19 ' 5C ' 105 '62 ' 64 ' 127 'lOb 'l Phoma I I I I I I I I I I 3 Pithium .._. ’I I 1 ‘f I f I I I I 5.HgClg ' 6 ‘ ' ' 5 ' ' ' 39 ' ' 'None. " ' 4 ' 10 ’ll ' 49 ' 62 '66 ' 55 ' 92 ' 77 'l Pythium I I I I T I I I I I 4.Dqunt $15' 7 ' ' ' 54 ' ' ' 4l ' ' 'l Rhizoctonia " ' 2 ' 9 '10 ' 47 ' El ‘”6 ' 49 ' 9O ' 75 '2 Bythium ' ‘ ' ' ' ' ' ' ' '23 lhu3or T I I I I 1' I T __‘ I 5.Pythal ' a ‘ ' ' 36 ' ' ' 59 ' ' ‘Ione " ' l6 ' 19 '21 ' 57 ' 75 ‘60 ' 55 ' 92 ' 76 'l Eythium I I I I I I I I' I I 2 1.111001. ' ' ' ' ' ' ' ' ' '1 Eusarium I I I I I I I I I I 6.Chloroohol' 6 ' ' ' 27 ' ' ' "5 ' ‘ '5 Bythium I I I I I I I I I I1 b‘usal‘ium I I I I I I I I I I1 1.11100 r " ' 6 ‘ 6 ‘10 ' 45 ' 7O '59 ‘ 43 ' 76 ' 65 '2 Pythium I I "I T I I I '. I I 7.Tillantin ' ‘ ' ' ' ‘ ' ' ' ' ' 4 ' ' ‘ 59 ' ' ' 45 ' ' 'Pythium " ' l2 ' 16 '19 ' 50 ' 69 '58 ' 42 ' 85 ‘ 71 'None I I I I I I I I j 1 8.011005 I I I I I I I I I I (Corona)' 5 ' ' ' 59 ‘ ' ' 44 ' ' '2 Pythirm I I I I I I I I I I1 131101718- ' ' ' ‘ ' ' ' ' ' 'l Eusarium " ' l4 ‘ 19 '16 ' 46 ' 67 '72 ' 62 ' 106 ' Lb"None r 1 I I I I I I I I 9.CuSO4+lime' O ' ' ' l9 ' ' ' l9 ‘ ' 'Hone " ‘ 6 ' 8 '16 ' lb ' 57 '51 ' 26 ' 45 ' 58 'Eone If I I I I I I I I I lO.Eormalin ‘ ' ' ' ' ' ' ' ' '1 Mucor 1’240 ‘ 6 ' P ' 19 ' ' ' 25 ' ' 'l Eusaritm " ' ll ' 17 '55 ' 12 ' 51 '26 ' 25 ' 48 ' 40 'l Pythium I 1 i 1 T I r T I " 1 11.Tillantin‘ ' ' ' ' ' ' I I I B' 8 ' ' ' 5 ' ' ’ l5 ‘ ' '2 Yythium " ' l7 ' 25 '57 ' l4 ' l9 'l6 ' El ' 44 ' 57 'l Pythium I ‘ I ' laole continued on next page. -19- Table III continued. Treatment 'No. d'seased 'Healthy seed- 'Total no. seed-'Organism 'seedlin s. 'linas a and 'linrs merging.‘ ' 'of exo‘t. ' ' ‘Per 'Totalrffif'rer“fotsl‘ fl 'Per"Totzd} ;6" 'I'Ovuo' ' 'I'OV.’.' ' '1‘0W.‘ ' ' I I I I I I I I I I l2.fasteur-' ' ' ‘ ' ' ' ' ' ' ization l.' 15 ' ' ' l4 ' ‘ ' 27 ' ' ‘l Bythium " ' 5 ' 18 '40 ' 5 ‘ 27 '25 ' 16 ' 45 ' 55 'None I I I I I 1* I‘ I I I l5.3asteur-' ' ' ' ' ' ' ' ' 'l Mucor. ization 2,‘ 7 ' ' ‘ 8 ' ' ' 15 ' ' 'l_Alternaria " ' 12 ' 19 "60 ’ 5 ' 15 '10 ' l7 ' 52 " 26 'None I I I I I T I I I I 14.95°C. ' 7 ' ' ' ll ' ' ' 18 ' ' 'l ngthium " ' l5 ' 22 '50 ' ll ' 22 '19 ' 26 ' 44 ' 57 'Uor e I I T' I I I I I 1 I l5.llO°C. ' 2 ' ' ' 2C ' ' ' 22 ' ‘ 'NOIm " ' l4 ' 16 '52 ' l4 ' 54 '28 ' 25 ‘ 5O ' 42 '2 PW! hium_ I I I T T I I I I I 15.L8IQB I I I I I I I I I I seed balls ' 9 ' ' ' 12 ' ' ' 21 ' ' 'None " ' 55 ' 44 '54 ' 24 ' 56 '50 ' 57 ' 76 ' 65 'l Yucor I I I I I I I I I I2 f.t‘__ irm I I I I T"' I I I I I I 17.329811]. I I I I I I I I I I seed bells ' 5 ' ' ' 5 ‘ ' ' 6 ' ' 'Uone " ' 6 ' 9 '60 ‘ 5 ' 6 ' 5 ' 9 ’ 15 ' 15 'l JVU’th I I I I I I I I I I1 l.'ucor I I ‘ I I I I I I I j lb.Hulled ' hone a11e(1ed above surface. II I I II I 'II I II I II I I I I ”—‘”' . I I I I II AI I I I T l9.Cieck ' ‘ ' ' ' ' ‘ ' ' '7 Pythium sv.2l rous' 6 ' ' ' l5 ‘ ' ' 25 ' ' '5 Riizoctoni: I I I I I I I I I I1 1335401115 " ' b ' 16 't5 ' l5 ' CO '26 ' 25 ' 46 " 4O ' 31 {la ne tion of treatments in Table III. I. Semesan was anplied in dust form in excess. 2. Uspulun - an organic mercury compound furnished by Fayer Company, Few York. Cne- fo rth _percent solution was applied for 1 hour. 5. HrClg l-lCLC - applied for 1 hour. 4. DuPont #15 - mercury compound furnished by 3. I. duPont de honours Co., Uilminrton, Del. It is a dust applied in excess. 5. Pythal - as in Table I. ~20- 6. Chlorophol - as in Table I. 7. Tillantin C - a mercury compound furnisned by H. A. Metz & Co., few York. 8. Cu003 (Corona) - as in Table I. 9. Cu304 + lime - as in Table I. 10. Eormalin 1-240 - as in Table I. ll. Tillantin B - cooper compound containing arsenic. Burnished by M. A. Ketz & Co., few York. 12. Easteurization l - ieed balls were placed in Water at 60°C for 10 minutes. 15. Pastenrization 2 - Seed balls were heated as in $12 but on two srccessive days. 14. 95°C. The seed balls were placed in an oven at 95°C for 10 minutes. 15. 110°C. The seed balls were placed in an oven at 116°C. for 10 minutes. 16. Large seed balls r Same as $17 in Table I. 17. Small seed balls - Same as #18 in Table I. 16. Hulled - The seeds were hulled by pressing with a rotating motion between two blocks of wood. 19. Untreated American-grown seed. -21- Discussion of Table III. The average disease for the 21 untreated rows was 55 per- cent of those emerging having a stand of 26 percent.of what could have been if all factors causing loss of seedlings had been removed. The total number appearing above the surface was 40 percent. All mercury compounds showed decrease in the amount of disease and an increase in stand as well as an increase in the number of seedlings that should appear. Cepper carbonate gave results superior to those from most of the mercury compounds used including thlz l-lOOO for one hour. Cooper sulphate plus lime was not so good as the check. Tillantin 3, a cepper comoound containing arsenic, appears to be of no value. . Eormalin 1-240 for 1 hour gave about the same results as the average oi the 21 untreated checks themselves. Easteurization at sees. for lb minutes on one day or two successive da;s gave no indication of controlling seedling diseases. althDUgh Phoma betae may be eliminated to a great extent the seedlings seem helpless against the soil organisms. Dry leet at 95“C. or 110°C. for 10 minutes were of no value as a means of preventing the disease. The seoaration of the seed bells into lots of small ones and large ones seemed to be of no value, as in the previous test. an attempt was made to hull scme seed from the ball. None of these seeds germinated or appeared above the surface. This is ,robably due to injury done to the seed in hulling. -32- In seneral, it can be said that every treatment showing a disease control better than the checks was either a mercury compound treatment or copper carbonate (Corona) treatment. All disease seedlings occurring on the last six days of this test were examined as given for Experiment g2. The duplicate rous were one half of the dis ance of the bed apart or the dittos represent one end of the bed. B; this, it can be seen that the fungi causing the disease were well distributed throughout the soil. Bsyecially was this true of rythium. Seven cultures of shizoctonia were found and five rere on untreated rows. Three cultures of jhoma were found and one has from an untreated rev. Xueors, Frsaria and Alternaria were looked uyon as unavoidable sagmophgtes, however they may play a slight role in seedling diseases. Experiment 54 - Sandy loam. In order to repeat the same test and to see some of the effect of continuous cropping of beets the seedlings were removed and the soil well mixed. It was planted to siger beets immediately as before. Table I? shous results taken every afternoon over a period of 17 days after the seedlinns began to appear. -23- Table IV.: Treatment 'Uo. diseased 'Healthy seed- 'Total no. seed-'Organism. Iseedlinzs. 'lings at end 'linrs emergins.I ' 'Of GDCW‘to k, ‘ ‘ '-'“' ITer TTotal‘ fifiIIer 'Dotsl‘ fl 'ferg‘i‘otalT W* 1 Irow.’ I Irow.‘ I Irow.‘ I I 1‘ g I 1 ‘ I I I I 1 I 1.3emesan I 12 I I 57 I I I 49 I ' '3 Pythium a I I I I I I I I I4 Fusarium I I I I I I I I I '5 No erowth I I 11 I 25 I25 I so I 75 I62 I 47 I 96 I 80 '4 Phoma s I I I I I I I I “4 Eusariunl I I I I I I I I I I1 Pythium I I I I I I I I I '4 No growth ”~“‘ ’ 1 I I T 1 1 I *1 1 1 ” 2.Usuulun I 11 I I I 21 I I I 32 I ' '5 Pythium ‘ I I I I I I I I I I1 hucor I I I I I I I I I I5 Eusarium I I I I I I I I I '2 No growth " I 7 I 15 I25 I 52 I 55 I45 I 39 I 71 I 60 'Rhizoctonia I I I I I I I I I ' 2 1.7.11 001‘ I I I I I I I I I I2 Bacteria I I I I I I I I I I 2 NO 9‘1‘02‘.‘ 131"; I “I I I I I I I I I 3.HaClg I I I I I ' I ' I ‘2 Pythium l-lOQOI 14 I I ' 29 I I I 45 I I '4 Fusarium I I I I I I I I I '5 thcor I I I I I I I I I '1 Eenicillium I I I I I I I I I I ? Ifo growth I I 11 I 25 I50 I as I 55 I57 I 57 I to I 67 '“homa I I I I I I I I I '5 b‘usarium I t 3 I ' ' I I I ' 5 )‘ij‘khillm I I I I I I I I I 'Eilfiicor I I 1 —'I T I 1 I I T " —' 4.DuPontf13I 15 I I I 35 I I I 48 I I '8 Pythium I I I I I I I I I I3 Mucor I I I I I I I I I '1 Fusarium : I I I I I I I I '1 No growth " I 20 I 33 '55 ' 35 I 65 '56 I 55 '101 ' 84 I6*Pythium I I I I I I I I I ' 1 131.10 01‘ ' ' ' ' I I I I I I 2 No er owth ‘— I I I I I I I I I T \— 5.Pythal ' 5 ' ' I 05 ' I I 5 I I ‘2 Pythium I I I I I I I I I '1 Ho Growth n I 5 I 5 I14 I 15 I 49 I40 I 21 I 57 I 48 Il Bythium I I I I I I I I I I 2 Eusarium ‘ I ' I I I I ' I '2 No growth. -‘ T I I I I I I I I 1 6.Chlor09hfl‘ 2 I ' I 5" I I I 55 I I I1 Fusarium I I I I I I I I I I 1 17.1100 7. " I 6 I 8 I 9 I 44 I 77 '65 I 50 I 85 I 71 '5 Pythium I I I I I I I I I 'l hhizoctonia I I I I I u I I I I1 Ascomycete ' I I I t I I I ' I 1 TYO p.11 Ev-'th Table continued on next page. Table]? continued. Treatment 'No. diseased 'Healthy seed- 'Total no. seed-'Org‘nism. "seedlizes. 'lin s at end '1inrs emergin2.' ' 'Of exn't. ' 444' Ifer‘rTotul' p Tfer 'Total' fi:Per ‘Total' 5 ‘ ' I‘ 0‘“ o ' t t 1‘ UV! 0 ' ' r 0v; 0 ' ' ' j I I I I I I I I I 7.T111antin' ‘ ' ' ' ' ‘ ' ' '6 FusarLum C ' 715 ‘ ' ‘ 7 ‘ ' ' 2O ' ' '2 lhlcor I I I I I I I I I I2 Pythium I I I I I I I I I ' 2 170 9r owth n I 10 I 23 I41 I 25 I 35 '28 I 56 I 56 I 48 ‘4 Eusorium I I I I I I I I ' (3 1.1110 01‘ I I I I I I I I I ' 2 Pvthiwn I} I I I I I I I I T I 8.CuCO I ‘ ‘ ‘ ‘ ‘ ' ’ ' '6 Eusarium (Corona) ‘ 9 ' ' ' 29 ' ' ' 58 ' ' '3 nghium " I 15 ' 22 '52 ' 18 ' 47 '40 I 5 I 69 I 55 I5 Eueerium I I I I I I I I I '5 flucor I I I I I I I I I '7 Pwthium j T I I I I I T Y ‘ v 9. Cuso + I I I ' I ‘ ‘ ' ’ ' llme ' l ' ' ' 15 ' ' ' 16 ' ' '1 fiythium " ' 35 ' 54 '49 ' 21 ' 36 '50 ' 54 ' 7O ‘ 58 '6 ryuhium I I I I I I I I ' ' 6 1.1110 01‘ I I I I I I I I I '1 Phoma I I I I I I I I I '4 Eusarium I I I I I I I I I 11 Rhizoctonie I I I I T I I— I I I 10.30rmalin' ' ‘ ‘ ' ' ' ' ' ’1 Pythium 1-240 ' 5 ' ' ' 6 ' ' ' 9 ' ' '1 Mucor I I I I I I I I I '1 Fusavium " I 1 I 4 I44 I 1 I 7 I 6 I 2 ' 11 I 10 II No growth. I I“ I r I T I I I I ' 11.31113ntin ' ' ' ' ' ' ' ' '4 Pythium B I 12 I I I 10 I I I 22 ' I '4 Muoor I I I I I I I I I '2 TI"0.1:‘IIII‘im'n I I I I I I I I I '2 No growth " ' 7 ' 19 '60 ' 5 ' 13 '11 ' 10 ' 32 ' 27 'Ifrythium I II I I I I I I I '1 Alternaria I I I I I I I I I I1 Eusarium I I U I t ' ' I ' I 2 ITO gr OI. th —* I r I I I I F I —I I T x' ization 1, I 5 I I I O I I I 5 I I '1 Rhizoctonia I I I I I I I I ' '3 Euserium " I 7 I 12 '92 I 1 I 1 ' 1 ' 8 ' 13 ' 11 '2 Eusarium I I I I I I I I I I5 Pvathium . . . . I I I I I I1 Nb erovth ‘* I *1 I I I 1 J I I 1 I " 15.Basteur-' ‘ ' ' ' ' ' ' ' '3:Pythium ization 2. ' 8 ' ‘ ' 1 ' ' ' 9 ‘ ' ‘3 Mucor I I I I I I I I I '2 Eusarium " I 4 ‘ 12 '86 ' 1 ' 2 ' 2 ' 5 ' l4 ' 12 '3 Ensurium I I I I I I I I I I l fjtl'lium Table continued on next page. TableIV continued. -0" 5,0" Treatment 'flo. aiseesed 'Healthy seed-'Totel no. seed—'Orgenism 'see611ngs. '1ings at end '1inrs emerging.‘ ' 'of ex 't. ' ' 'Per ‘”ota1‘ éfi‘Fer_‘Tet21' N'Per TQotdI‘ N 5‘ Ira“; I I Irov‘l..I I Irowll I I I I I —I I “I 'I T W f 14.9500. ' 14 ' ' ' 4 ' ' ‘ 18' ' ‘1 rhona ' ' ' ' ' ‘ ' ' ' '4 Euserium I I I I I I I I I I 5 lmuc or I I I I I I I ' ' '4Pflmhm " ‘ 11 ' 25 '85 ' 1 ' 5 ' 6' 12 ' 50 ' 25 '2 Bytiium ' ' ' ' ' ' ' ' ' '4 EusoIium I I I I I I I I I I1 Phoma I I I I I I I I I I 2 1.1110 0 II ' ' ' ‘ ' ' ' ' ' '1 N0 erowth I I I I I I I I I I " 15.110°C. ' 3 ' ' ' 1 ‘ ' ' 4 ' ' 'l Alternaria I I I I I I I I I I 1 £171}? ium " ' 4 ' 7 '64 ' 5 ' 4 ' 4‘ 7 ' 11 ' 10 '2 Eythium I I I I I I I I I I l 1:110 or “r I I I F T I I "I I 16.Large ' ' ‘ ' ‘ ' ' ‘ ' '4 Pythium seed bulls ‘ lO ' ' ' l2 ' ' ' 22 ‘ ' '4 Euserium I I I I I I I I I I 2 ZEUCOI‘ " ' 12 ' 22 '55 ' 6 ' 16 '26' 16 ' 40 ' 23 '4 Euserium I I I I I I I I I I 2 lisf‘uhilun ' ' ' " ' ' ' ' ' '1 Rhizootonia I I I I I I I I I I l 1:17.001. I I I I I I I I I I 17,5m311 I I I I I I I I. I I seed 133.113 I O I I I 3 I I I 3 I I I " ' 1 ' 1 '17 ' 23' 5 ' 6‘ 5 ' (5' 5 '1 Racer. I I I 7* I I I I I I 16.3u11ed ' Hone aopeared above the surf oe of the soil. II I II ‘II II II II II II I’ I T I ‘ "I I I I I T 19. Check ‘x.7 ' ' ‘5.L ‘ ' ' b ' ' '25 Pythium (3r.21 rays) ' ‘ ' ' ' ' ‘ ‘ '6 Rhizootonie " "4.7 ' 9.4 '60 ‘5.. ' 6.6 ' 5' 8 ' 16 ' 15 '1 Ehoma I I I I I I I I I I 18 Irllc or I I I I I I I I I 'lb 117.3917] «arm I I I I I I I I I I9 Bacteri“ I I I I I I I I I I 5 1: O (:1. OIVII; tl‘ ‘ ' ' ' ' ‘ ' ' ' '7 Visoelleveons EXplanation of treatments nge as in Table III. {'3‘ -LU- Discussion of Table IV. fable IV is somewha similar to Table II, although the bad effect of planting beets after beets is apparent by a general reduction in the number of seedlings ampearinr above the surface of the soil. The 21 untreated rows shoued 15 percent emerged (based upon the normal or ideal germination) and 60 percent of these became diseased, leaving a 5 percent stand of good seedling‘. This 'shons a greater disease loss than shown in Table II, as the 21 untreated rows showed 40 percent emerged and 55 percent of these became diseased, leaving a 26 percent stand of good seed- lings. In comparin: Inble IV with Bable II it can be seen that the 53KB treatments have a similar rank in both when comoared with the average of their checks. file mercury cempounds in general are best with copper carbonate (Corona), comoaring well with HSClg l-lOOO as in Table II, and superior to some mercury treatments. All other treatments gave no indications of control, as before. A large number of Bythium cultures were found. In fact Prthium seemed to be as common on muck soil used in Table II. In few instances :homa and Rhizoctonia were found. Rhizoctonia was more common on the untreated rous. fythium was the most common of the tires. A large number of cultures oi Eusaria and Kucor mere found. They were very difficult to eliminate. ‘In fact some seedlings were treated with H;012 l-lOCO so long they produced no growth. ngeriment f5 - Sand compared with soil. The bed was divided into equal parts and the same soil ~27- worked into one bed. Clean sand was put into the other. This should give a comparison of the effect of the seed—borne organisms and the soil organisms. The soil had shown heavy infection and rhoma betae had been found common on the seed balls. The seed and te'hnique of planting were the same as before. Only tie best of the treatments were used. Pasteur- ization at 60°C. for 10 minutes on two successive da;s was used as this treatment had been reported to give seed balls fairly free of Ehoma betae. Table V represents a summary of records taken every afternoon over a period of 14 days after the seedlings began to apgear. -35- Table V. On Soil. 'No. diseased 'Healthy seed- 'Total no. seed-' . Treatment ‘seedlinas. 'linvs at end 'lines emerg1ng.'0rganism - ' . 'Of GKI‘t. ' ' ‘Irer Irotaif giIPer ‘Total' % Irer‘ITotal‘ fl ' 'rOVV. I ' ‘rO‘I‘J. ‘ ' ' 1a0\v.' ' 'A 1 I T" I I I I I I 1 Fg‘fhl um w'harium Semesan ‘ 12 ' ' ' 58 ' ' ' 5O ' ' '. EODETOWtRI n I 15 I 27 I 27I 35 I 75 ‘ 66‘ 50 ' 100 ' 83 'gfiPjthium I I I I I I I I ' ‘4 N0 growth I I I I I I I I I '2 Eusarium 1 1 1 1 11 I I I I 1 . DuPont E13 ' 4 ' ' ‘ 45 ' ' ' 47 ' ' '2 Pythium I I I I I I I I ' ' 2 Eusarium n I 9 I 15 I 14I 57 I 80 I 66' 46 ' 95 ' 77 '5 Pythium I I I I I I I I ' '5 Fusarium I I I I I I I I I I Chlorophol ' 7 ' ' ' 55 ' ' ' 40 ' ‘ ’2 Pythium I I I I I I I I I '5 N0 growth I I I I I I I I I I2 Bacteria n I 4 I 11 I 12I 45 I 78 I 65' 49 I 69 ' 74 '2 Pythium I I I I I I I I I ' 2 ITO .CI‘I' OW‘bh 1 I I I 1 I I 1' 1 1 ’ Uspulun ' 12 ' ' ' 52 ' ' ' 44 ' ' ‘8 Pythium I I I I I I I I ' '2 No growth " ' 17 ' 29 '56 ' 21 ' 55 ' 44' 58 ' 82 ' 68 '5’Fo gromth I I I I I I I ' ' ‘2 Rhizoctonia I I I I I I I ' ' '5 Eusarium I I I I I I I I ' '4 Pvthium I I I T I I I I I I d HgCl ' 10 ' ' ' 5 ' ' ' l5 ' ‘ '2 Fusarium 2 I I I I I I I I I '6 Pythium I I I I I I I I ‘ '2 No growth n I 6 I 15 I43 I 16 I 21 I 18' 22 ' 37 ' 31 'é’Fusarium I I I I I I I I ' '2 Pythium I I I I I I I I ' '1 N0 growth 1' I I I 1 1 1' I I I ‘“ CuCO_ ' 14 ‘ ‘ ' 15 ' ' ' 19 ' ' '1 Fusarium (Corona) II I I I I I I I I I2 Pythium ' ' ' ' ' ' ' I ' '1 Ho aromth " I 15 I 17 '32 I 21 I so I 50' 54 I 55 I 44 I11 rfiEhium I I I I I j I ' ‘ '5 Pythium CuSO4+1ime ' 6 ' ' ‘ 12 ‘ ' ' 18 ‘ ‘ '1 Eusarium " ' 10 ' 16 '40 ' 12 ' 24 ' 20' 22 ' 4O ' 34 'I rhoma I I I I I I I I ' '3 Pytruuun I I I I I I I ‘ ‘ '1 Eusarixnn I I I I I I I I I '2 NO QTOTWfl) 1 I 1 I 1 1 l ‘1 I I1 Ph053 Basteur'za-‘ 5 ' ' ' 4 ' ' ' 9 ' ' '4 Pythium tion £2 I I I I I I I I I Th P;t%' .‘ . _ a I nium ___" I 5 ' IO '40 I b ' 12 I 10' 13 I 22 ' 18 '5 Jusarium I ,— , .» . Check 4.4 ‘ ‘ ‘ ' a ‘ ‘ T’v.e' ' ‘29 Pythium " '4.4 ' 6.5 '45 ' 5 ' 10 ' 9' 9.4' lb.b' 16 ‘9 Fuserium (iv. 11 rows ' ' I ' ' ' ' ' '8 No growth I I I I I I I I I I2 jacteria All treatments are as in Table III. ~29- Table VI. On Band. - -1 II a ‘- I“ a . seed-' Ilfo. d;se::seé 'HUI’iltI’II‘] ”Bea 11.31321 no, IQ-Iwirism ' . "1""I~—‘ '1'11'10'3 at end '11nsa's er:;eI,;-_,ed. be» . Treatment seem lxxoo ' fa. I‘t , ~ I I o GKH . . t , pr 1,? “ I j." ~1j-‘j ’ ' 'fierfij’otal' m 'Ber ‘flotil' p“Be1 flotUL‘ m ’ Irnu;' I 'rou.‘ ‘ 'row.' I w .I I I ' ‘ ' t ‘ :1 M1" “ * I I 11oma -‘ _ _ I l I I 57 I ' ' 5b oemesan l I I” . I ; I 140 I116 ‘2 rhoma I Z I I Z- I 75 ' 10' 111 £42 4" *7 _ .. , II ' 1- ‘ 5 t i ' I I I I I I2 1‘0 $330th1 1‘ I I I I I ‘ ' ! 1 I I -. _ ,- I I 51 I I ' 51 ' _*____un- r) t ~1.0:) ' O b P ’ :- ' ‘1: . Du_8n , ’ b ' 5 ' 5 . 44 , 90 . ya] 47 I 92 1-51 12__:Lhoma _M I I “'“ I I I I __' ' ' rv I I "9 ' ' I ... I O I ' ' 09 t 0” ~ ;,.‘,‘Ax'n ChlglophOI . I 1 I 1 I 49 I e1 I o7I 43 I e2 I 55 I1 dactclla l 1 I 311' 1 I I I 1 ——""'-'—'" I I - . ' I I '1 Phone W I I I I 49 I ' ' bl fl ‘ ____:_ .-_- Uopulun 2 I » I I I A9 ' 98 ' 81' 55 ' 10b' 58 '4 Bhoma n I 6 E; L t 1 ' I , . I I 2 ITO wro‘th I I I . ’Ci _ y I I I I I ’T I ‘ 1 r I '5 Ihoma I I I I I ' ' .59 ' _ ch12 . 7 . . . 52 . . . . . '1 Io growth , - I OI ' I I 4 "6 Ehoma II I 6 I 13 I15 I 50 I he : 7..‘ 62 i 1011 551' g .i I I I '3 Phoma I r I I I 5 I ' ‘ 45 ' cu?0. ) . ° . . . 7 . . I . I I1 Ho grovth S rOHm I 8 I 14 I15 I 79 I 76 ' 64' 47 ' 90 ' 75 'b finoma ‘ g I I I I I I I I '2 H0 growtn I I I I I ' ' i ' 1 ' P Phoma .. I I P I I ' 39 ' ' 11 -_I.__ CuaO + lime' 12 ‘ g F, 1 , , -. . ‘homa "4 . m . 22 I... . . 57 . I , 79.1.0010 I I I T I 1 I ' . I I I I I fig I I '5 Phomao Pasteoglza-: 3 : , , 50 I I I u I I I tion I“ I I I I an I 104 I béI 55 I 105 I 90 '1:0 growtn II 1 4 4 ‘JJ- ' t "1" ,‘q I I I I I I I I l :I‘LOLIc. I I I I I I ‘ ' ' t V“ ' '106 Phoma II . I I I ' 2 ' ' 'dé'5' - C(MLGCIIIC'], 11.5I I I 2 I I I I I '15 NO {‘1‘01’11311 a? I‘ V} r ”r. ,. ' 1 .. ' I UI11.5I 25 I25 ' 22 ' 44 ' o4'oc.5' 57 ' 50 4 BQCtella' I I I I I I I I ' '2 Alternarla I I I I I I I ‘ ' '” All treatments as in Table III. a 11,1111 m: -50- Discussion of Tables V and VI. In the soil (Table V) which had its third crOp of seed- lings, the mercury compounds still showed considerable control. Cucog again proved to be equal or superior to Hg012 l-lOOO for one hour. Cu504 + lime is not so good. The pasteurization treatment was about equal to the average of the eleven untreated r0ts. When the data from the soil and sand (Table VI) are com- pared scme very outstanding things are observed. First, the pasteurization whiciihad proven to be of no value in the previous soil tests now ranked second. The qualities of Semesan are as outstanding in that this chemical applied in a dust form was equal to pasteurization as a means of sterilizing the seeds. One row of,5emesan was exceptionally high in number of seedlings but with this reduced to that of the other rons Semesan.would Still YB as good as pasteurization. Also CuCO compares well 3 with H5012 as a means of freeing seed balls of Phoma betse. The average of the eleven untreated rows gives some idea as to the real importance of Ehoma betae. Thirty-three percent of the seedlings appearing above the surface of the sand became diseased, and with few exceptions Phoma was reSponsible for the disease. Three cultures of Pythium were found but they came from the buffer rOthearest the row of bricks sena- rating the sand and soil. Based Upon the number that should have appeared if Phoma had been eliminated 44 percent were killed below the surface, leaving a final stand of 54 percent healthy seedlings. No examination was made for Phoma in the sand before planting but it was direct from a sand pit and -31- there is every reason to expect Phoma to be absent. From this test as well as the previous experiments it is evident that the seed balls cannot be completely freed from Phoma betue by means of any of the large number of treatments tried. however, mercury compounds indicated a means of control. Coyper carbonate was very promising in that it is a dust treatment as well as being a cheap chemical compound. None of tlese treatments were a ccmplete ccmtrol for Phoma. With scme treatments, such as that with Chlorophol, no rhoma appe red, but in view of the failure of the other mercury compounds to control this entirely, this treatment also would not be expected to give complete control. Experiment #6. To determine if there was an effect due to the physical nature of the soil entering into the results reported in Tables V and VI, the following experiment was performed. Some of the soil and some similar sand were sterilized. New wooden greenhouse flats 5 inches deep and 16" x 20” were filled with this soil and sand, both sterilized and non-sterile. {34 Three rows of 30 see balls were planted in each. The middle row in each case was treated with Semesan. Twelve days after the seedlings began to appear the flats showed the following: I, Table VII. Total stand. Diseased. :Check 25 4 Sterile sand :Semesan 56 2 :Check 28 2 :Check 28 5 Sterile soil :Semesan 58 2 :CLeck 53 5 hon- :Check 27 5 sterile sand :Semesan 66 1 :Check 40 2 Non- :Check 2 O sterile soil :Semesan l6 1 :Check 1 O Discussion of Table VII. This table shows that the physical nature of the soil had no influence in the previous results. The results in sand (sterile and non-sterile) and sterile soil were similar. This was the fourth crop of seedlings for the unsterilized soil and the checks were completely destroyed. Inoculation Experiments. Experiment f7. To compare the pathogenicity'of the three principal was performed. .‘ ’mm strains of Phoma betae were used. One was isolated from a diseased seedlin: growing in sterile sand. The other was isolated from a sugar beet sent in from Colarado. The Rhizoctonia was from.a diseased seedling and also a strain from -53.- potato was used. The gythium deba yanum was isolated from a diseased seedling from the soil in greenhouse bed. About three weeks before planting the beets tlese organisms were started on 500 gr. of sterile cornmeal. 'i‘he sand was sterilized as well as the greenhouse flats. The cornmeal with a good 1ov-Jth of the funrrus Was thor ougl‘ily mixed \Lith the seed. The seeds were planted immediately in three rows across the flat containing 50 seed balls. The middle row was treated with den san dust in excess. The results were as follcns° - 54,1 .- .vv Table VIII. from spear seedlina. IWLOHML beet / rhoma fr on: Colorado. Rhisoctonia from seedling. hhizoctonia fIOL1530tatO. Mixture of Thoma, Pythium and Rhizoctonia, from seedlings. -5terile cmnuuueal. :Cluecl: :;3erne:3211 :Ckeck 3 ”.11 Check Check semest l 'emersed'dise 1 l O <10 COO 16 52 59 KO D3) C) Ordh' <10 00 ll 12 10 36' T , " 'W I 'lo. seedlin S I 7' l I lio- Oraanisms. ~\fi _ rnoma v'\‘ -x I'llOlhEl idiorza Lucor rhoma HHO) Rhizoctonia IO 5, ‘1 Rhizoctonia No arowth Alternaria Rhizoctonia {CHE-'1. Rhizoctonia hucor hhizoctonia Incor hhizoctonia Linc or n3%r00nmwx Rhizoctonia 3%.thi1un 1’1 1 o m a. Eythium Rhizoctonia I’ h 0 I518 Rhizoctonia CAHNNIYJHU‘I hucor Alternaria Bacteria Mucor Thoma Kucor Bacteria t—J QE'IZUHHHr'?‘ Table VIII continued. 'No. seellin s. ' **__* I Ifo. 4‘ Io. ' ‘emeryed‘diseased.’ Qrsmnisms. :Cneck 40 5 l Phoma sterile Sand : 5 Bacteria only. : l alterneria :semesan 44 0 :Check 40 l l Mucor. DISCLssion of Table VIII. Tythium was the most effective parasite, as not a single seedling soaeercd above the surface of the sand. However, on digging into the sand, seed bills could be found with the younr seedling attached which.was killed before it neachet the surface. In inoculation of this kind Semesan wvs not able to ward off the organism as previous soil tests had indicated. Ehpgg;betae was almost as effective as ”ythium. However, a fewseedlinqs came above the surface in each culture but beets were soon diseased. Rhizoctonia was quite different from the other two. A very POOd :rowth of the organism'was obtained before tie seedlings began to appear. In fact, the seedlings came through the surface colored broun with the fungus. The first twelve days indicated that Rhizoctonia, at least in these strains, was not a very im ortant organism. Twenty- four days after the seedlinrs began to appear the flats were destrOyed. Special attention was given the Rhizoctonia -55- inoculated flats and each seedling examined. It we" found that almost every seedling from the check rows in both flats had a decayed root tip. The Semesan rots were some better. The st ain from potato seemed to be as effective, if not more so, than the one from the beet seedlings. The root tip was more or less decayed and the plant had from 5 to 8 small rootlets just above this decayed region that seemed to be replacina the original tip. The hypocotzl was sound above the surface, however the leaves had a light green color. Very' few showed signs of tilting. No doubt in many cases the seed- ling would have won and produced a beet if given a chance. It seems that the strangled or forked beets so common in some fields can be exglained as a result of a combat between the .. fihizoctonia during its early staaes of growth, & seedling and rather than high water table or impervious subsoil as often suggested. The mixture was made by adding some sand inoculated with ghoma betae (seedling), Rhizoctonia (seedling) and Pvthium debaryanum (seedling) to a flat and mixing. The inoculum was not added in nearly as great quantities as in the other flats. Only a few cu tures of Thoma or Pythium.were reisolated from this flat. Rhiioctonia was the most common of the three, by far. This may seem stran e at first since Bythium and rhoma were so effective than alone. It can, no doubt, be explained by saying that the seedlings attacked by Phoma and Pythium were killed before they reached the surface as in the flats with Pythium or fihoma alone. This will also explain why Phoma Ch was so seldom found on seeds :rom soil when it war known to be common on the seed balls. One flat with cornmeal alone was used to see the effect of introducing the meal on which the organisms grew. The total number of seedlings were reduced but this is probably due to the cornmeal acting as a medium for organisms from the seed bslls. The sterile sand alone was much like the previous test on sand. Phoma was isolated from a diseased seedling. Summary. The sugar beet industry is an important phase of Michigan agriculture. Sugar beets are planted on sandy loa‘ soil as well as on much. The seed balls are planted heavily in drills but even this method of seeding fails to produce a stand. The common cause of failure to get a stand is fungous attack which gives rise to the so-called "seedling diseases“. Previous work rs have shown tha Phoma betae, 23thium debaryanum, dphanomgces lacvis, Rhizoctonia app. and gheosporangium aphanidermatum are the principal organisms 7" causing seedlina diseases oi sugar beets in surOpe and America. Phoma betfie has been found to be universally present on sugar beet seed balls. There are at least three distinct signs of seedling diseases. —. ’ 1 rhoma betae was found common on sugar oeet balls from isolated breeding plots in the vicinity of Lansing, Michiga . -5‘0- Best for seed treatments could not success fully be me de between absorbent paper or sand in moist chambers. @811 ha ttery jars containing sterile quartz were very good for test- ing small lots of seed balls. Experiments on much soil in greenhouse indicated that seed- ling diseases could be reduced by means bf mercury and cooper compounds applied to the seed balls. Pithium debarganum was found to be the most common organism associated with diseased seedlings from much soil. On sandy loam soil the results were similar to those on muck soil, as far a“ the disease has concerned. lasteuri'ation at 60° C. for 10 minu es on two successive da;s proved to be a very effective treatment mien the soil organisms were absent, but of no value in infested soil. Test in sand showed that 33 percent of all seedlinis may be killed by Ehoma betae after they appear above the surface, and tlat 54 pe Hcelt st 1nd of lealthy seeélin.:s is obtained in compai ison with Whit should be eXpecte:i for an ideal germination. Ho complete control was found. However, cepper carbonate and mercury compounds gave control. Jhe ph; 31 a1 npture of the soil did not influence the percent of diseased seedlings. Inoculation experiments showed that Pho a be“ tie and Pytiium debar"anum were v- rv strong and ragidl;-worhing para- sites. hhizoctonia is almost as effective in producing seed— liny diseases of sugar beets but slower in its action. r, 0. 0‘1 0 H C7. 0 Literature Cited. Busse Halter. Der Hirzelbrsnd der Rdben. 51. Sucker- ruoenoan. 15:297-LCC.1905. -— - -‘ *1" '\ -, Leo reters and I. C. von saber. Uber den der luckerrfiben. Hitt. k. Biol. Aust. f. till. I:€ft 4; o 1.3,“. lé-lt. 0 19L? 0 ‘ Coons, J. I. Soot 11s eo~e es of Sursr Beets. cects ibout jusar 15:15t-160. 1924. DP‘T‘l, J. K. Three immortent its us diseases of szmmr beets. E.Y. (Co1re11) . 3X0. its. Jul. 165:559-553. ———————————— and J. C. stewsrt. The sterile fun us “Hiuocuonis as a cause of slant dise ses in America. A. 1101'. (00.1.: 18.1.1.) “31‘. -J:::)o JJU I. 11111.. 1L0:5L§-610 19010 ston, n. u. seedlin: diseases of surer beets and their relation to root-rot and crohn rot. Jour. irr. “es. 4:135-166. 1915. ‘- .1 ‘yr . x .~\ . u' a ------- ---- theos OOTCfiDiUm somgnideimetum, a new er Us " t - " - ‘44'1' ~ ~\-- .-;.'- ' ~ ‘1‘ \‘,“-1 -\.'.-~ I LII-d S 9018-.» u; .L-l’A L.) “l QLULU 011 till. 1. U681“? 1:..LCl 11.:\:~—~:)-'~€‘L:). , I " T " ‘q l J \l‘. l.'..L. ...J~ o 40.19-13.53. 111-50 Jensen, C. 3. Sun us ilore of the soil. K.I. (Cornell) 11:31 0 Ill“: 0 3‘ :10 31110 1.15:415-CC‘20 191:3. w35.1.1'2e1, L. L. froliminar: notes on root rot disezse of Bu??? beets. loan Arr. 319. 3tr. sul. l5z‘ié- 51. 1L91. feters, Leo. Lur Le Itnis des fur: elorrIdes der Lucker- 1111080 .3640 4JC‘14U0 1.501400 “81583.1. 211.051-Cfl39. 19(00 -------- --- Der Hur"(1nnrno der Lucherrfiben. Umschuu. '1. . - . .- . -. -- --------- bber die firre on mes nur'elbrsrues. are. k. siol. inst. L nd-u. Borstu. 52211-259. 1911. e b_et e on the leaves of -17“? 0 1L 1:). 17001, I. 9'7 1d II. .5. I.IcII:..7‘. ___o - rsr beets. Jo.r. sgr. “cs. 4:16‘ $- Rumoold Caroline. Sufi r beet seed disinfection with 1 .L- 9 -.. fOan dehgde vapor end steam. Facts aoout Sugar 16:322-515. (10/ dbl. 3 lby, 1. D. 3uysr oeet 1u1est1© tions. Ohio 311. ste. dul. 126:165-174. 1900. Plate I. Seed treated and planted between absorbent paper. Showing effect of certain chemicals on the roots. (Preliminary experiment.) 1‘ filate II. Showing part 0: tLe bed 01 seedlings. Table I.) Plate III. 00mpering COpper carbonate (Corona) and check row. Table I. Plate IV. showing part of the bed of seedlings. (Table II.) :a ,N .> _ ‘77 __ '4- a»- —.._—. mist ' Plate V. Showing part of bed of seedlings. (Table III.) Plate VI. showing 'art of bed of seedlings. (Table III.) Plate VII. Showing portion of bed of seedlings. (Table IV.) Plate VIII. Showing a part of bed of seedlines. (Sable V.) Plate IX. Showing Dart of bed of seedlings. (Table VI.) Plate K. These seedlings were taken from bed.(Table VI.) Note each seedling shows Bhoma betee. Plate XI. Inoculated flats. (Table VIII). Flat 1%]. = Check. Elet #2 = Rhizoctonia from seedlinq. Flat $5 = Pythium from seedling. Flat f4 = Phoma from seedling. VIII.) (Table at. Sterile sand fl l’late XII o Rhizoctonia inoculated flat. (Table VIIIJ Plate XIII. Plate XIV. Typical Rhizootonia infected seedlings from flat shown in Plate XIII. Note the enlarged roots above the decayed region. ._.o.ld...)c.q(ll.w. .. \(1 .I1(( IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII (I(lull(«my(mm(VILWIMILIV(In