CARNATION WILT DISEASES CAUSED BY FUNGI IN FINLAND E. A. Jamalainen and Laina Ruotsalainen Department of Plant Pathology, Agricultural Research Centre, Tikkurila Received August 20, 1961 The wilting disease of carnation (Dianthus caryophyllus L.) is caused by bacteria and fungi, among which the most often encountered are the Fusarium-tungi, Phialophora cine- rescens (Wr.) van Beyma (syn. Verticillium cinerescens Wr.), and the bacteria Pectobacterium parthenii Starr, var. dianthicola Hellm. and Pseudomonas caryophylli (Burkh.) Starr. & Burkh. (cf. Scholten 1955, Hellmers 1958, Pape 1964). For the carnation pathogenic form of F. oxysporum (Schl.) Sn. & H. has been given the name F. oxysporum (Schl.) Sn. & H. f. dianthi (Prill. & Delacr.) Sn. & H. Material In 1967—68 the Department of Plant Pathology studied the wilting disease of car- nation in Finland. Preliminary results have already been published (Ruotsalainen 1969). In order to find out about the occurrence of the disease and the fungi causing it, enquiry forms were sent to 120 carnation growers, and in addition, samples were collected from a number of nurseries. Samples were received from a total of 51 nurseries (Table 1). The fungi were isolated from the diseased plants by sterile cutting of samples onto oatmeal agar from the root, the base, and from a healthy looking part some 20—30 cm above the base and from the cut surfaces. From a total of 81 plants 177 isolations were made, and from these, 17 species of funcus were identified (Table 2). The Fusarium fungi, of which there were 10 species, proved to be the most commonly occurring in carnations infected with wilting diseases. The most common was F. oxysporum, which represented 31.1 % of the isolated fungi. Other spesies common were F. arthrospo- rioides, 7.3 %, F. avenaceum, 10.7 %, F. culmorum, 8.5 %, and Alternaria tenuis, 7.9 %, as well as Cladosporium sp., 9.0 %. Two samples of P. cinerescens, 1.1 %, were found. Some fungi of the Penicillium, Aspergillus and other genera occurred as epiphytes, and do not appear in Table 1. https://www.c-info.fi/en/info/?token=6W-lZ0fQr66GLPzS.z-zagcnCfngFvkcL0NPGIA.GGrKYP6lPPfUGE68JrLvoVhTIDhrwVWx3nv2PwcipaDWBDLgokUHXRDVHOSBnxE908KAcJKKlQBjvQQaSQoFINzT9oBzQknQRIOMB6BiNMy84pi1L9YixPJNA7-1Bz-ZRI7Y8u3bc6eZuq-jSElQf99QBd5zX9dxV-9lZ_ndIcP1joVwhAN-oY7qPOGRhY-1klF6pqs Table 1. Nurseries from which the carnation samples were taken, from 1967—68. Alternaria dianthi A. tenuis Botrytis cinerca Cladosporium sp Cylindrocarpon didymum Fusarium arthrosporioides F. avenaceum F. culmorum F. graminearum F. lateritium F. oxysporum F. „ var.redolens F. semitectum F. solani F. sporothrichioidcs Phialophora cinerescens Phoma sp. Rhizoctonia solani Rhizopus sp. Stemphylium sp. Nursery Locality 123 45 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Ahopellon puutarha Imatra 2 2 Bjomaan „ Helsinki 1 1 Aackas-tilan „ Helsingin mlk 112 2 111 1 Ekengrenin ~ Hamina 1 2 Elomaa Turku I 1 Holmberg Sipoo 1 Huhtamäen puutarha Laihia 1 Huhtasen „ Rauma 11 11 11 Huiskula Oy Maaria 2 Ilpoisten kauppapuutarha Turku 1 Jaalan puutarha Raisio 1 111 Kaarnikon kauppapuutarha Turku 1 1111 1 Kangaspuuta Helsingin mlk 12 1 1 1 Kempeleen puutarhurikoulu Kempele 1 1 1 Koski, Janne Kokemäki 1 1 1 Koskinen, Toivo Helsinki 1 4 Kukkolan puutarha Tampere 11 12 1 Lahtelan „ Kangasala 1 3 Lepolan kauppapuutarha Maaria 1 1 1 Liikkasen puutarha Hamina 1 1 Lindberg, E Kerava 1 Loimaan ev. kansanopisto Loimaa 1 1 Lyyvaara, Jali Turku 1 Mattila, Ensio Kangasala 3 3 Mattilan puutarha Orimattila 1 1 2 Naakan „ Anjala 1 Narinen, Matti Mussalo 1 1 Nyystilä, Arvo Toijala 1 Olsson, E Kymi 1 1 Pekonen Lahti 2 1 2 Peuralinna Helsingin mlk 1 Pitkäniemen sairaalan puut. Nokia 12 2 Poukan puutarha Laitila 12 1 Puutarhantutkimuslaitos Piikkiö 1 Pyhtään kauppapuutarha Pyhtää 1 1 Rapilan puutarha Laihia 1 2 1 Reitkallin puutarhakoulu Vehkalahti 1 1 11 Salmen puutarha Kivijärvi 1 Salmi, Esko Vanaja 1 1 Satakunnan parantolan puut. Harjavalta 111 1 1 Satoturve Oy Tuusula 1 1 Siikin puutarha Imatra 1 Sjöberg, Stig Helsingin mlk 2 1111 1 Sjölund, H. V. Helsingin mlk 1 1 Suutari, V. A. Karhula 1 14 14 1 Tiihonen ja K:ni Kausala 11 11 Tyynelän puutarha Punkasalmi 1 113 13 Uutela Helsingin mlk 1 1 Valkeaniemen puutarha Forssa 2 11 11 Vesan „ Oy Pori 1 I Tuntematon 1 1 14 10 16 4 13 19 15 3 155 1 1 3 2 2 1 9 4 3 253 The studied material revealed relatively few samples of P. cinerescens, the occurrence of which has already been established in Finland (Talvia 1964—1967). This fungus has been found also in many other countries. In Sweden P. cinerescens was very rare in 1968, while the Fusarium species have been common, in particular F. oxysporum (Söder- gren 1968, von Wachenfelt 1968). In Bulgaria, the main fungi causing diseases in carnation in recent years have been F. roseum Link (syn. F. graminearum Schwabe) and F. oxysporum Schl. f. sp. dianthi (Prill. & Delacr.) Snyder & Hansen (Aleksandrova 1968). In Holland there was widespread occurrence of F. oxysporum in 1966 (Scholten 1966). In cuttings and young growing plants the Fusarium fungi cause brown, wet and soft rot in the lowest parts of the stem. The roots are decomposed or not formed at all. The rot is generally confined to the base of the stem, but it may also spread well up to the top Table 2. Fungi isolated from carnation samples Samples % Samples % Alternaria dianthi Stev. & Hall. 1 0.6 F. oxysporum (Schl.) Sn. &H. var. A. tenuis Neerg. 14 7.9 redolens (Wr.) Gordon 1 0.6 Botrytis cinerea Pers. ex Fr. 10 5.9 F. semitectum Berk. & Rav. 1 0.6 Cladosporium sp. 16 9.0 F. solanti (Mart.) Sn. &H. 3 1.7 Cylindrocarpon didymum (Hart.) Wr. 4 2.3 F. sporothrichioides Sherb. 2 1.1 Fusarium arthrosporioides Sherb. 13 7.3 Phialophora cinerescens (Wr.) v. Beyma 2 1.1 F. avenaceum (Fr.) Sacc. 19 10.7 Phoma sp. 11 0.6 F. culmorum (W. G. Sm.) Sacc. 15 8.5 Rhizoctonia solani Kuhn 9 5.1 F. gramine arum Schwabe 3 1.7 Rhizopus sp. 4 2.3 F. lateritium (Nees) Sn. &H. 1 0.6 Stemphylium sp. 3 1.7 F. oxysporum (Schl.) Sn. & H, 55 31.1 parts of young plants. If infection has been weak, the pith in the cross section of the stem is brown, once infection has developed further, however, the whole stem becomes rotten and hollow. In older plants the rot is dry (Scholten 1955, Hellmers 1958). Wilting caused by F. oxysporum occurs together with collar-fusariosis caused by several other Fusarium species. In these instances it is difficult to distinguish between these diseases without pure cultures. In collar-fusariosis the base of the stem has rotted, while wilting caused by F. oxysporum is systemic. Both diseases bring about wilting and loss in yield. F. oxysporum is more destructive than other Fusarium fungi owing to the fact that it may penetrate the roots of the carnation in soil. Other Fusarium species penetrate the carnation only through the cut surfaces of the cuttings, through torn parts of older plants, through damaged places in roots and stems, and in particular through the surfaces where branches have been cut off or where the flowers have been cut or broken off (Pape 1964). Plants damaged by P. cinerescens wilt gradually. The wilting leaves turn yellow (straw coloured) and often curl up somewhat. A cross-section of the stem, taken 20—40 cm from the soil surface, shows a clear brown ring to have developed within the bark. The roots remain healthy and do not come off if the plant is pulled up from the soil (Scholten 1955, Hellmers 1958). The largest amount of fungi, totalling 15 species, was isolated from the base of the stem. There were missing Cylindrocarpon didymum, which is a typical root pathogen, Alter- 254 jiaria dianthi, which has been found higher up in the stem, and F. sporothrichioides and Phoma sp. which were revealed by cross-section of the stem. The species found in all parts of the plant were Botrytis cinerea, F. arthrosporioides, F. avenaceum, F. culmorum, F. oxysporum and Rhizoctonia solani. R. solani causes stem rot in conditions unfavourable for carnation -growing (Guba 1945, Pape 1964). The carnations had been infected by A. tenuis, B. cinerea, ■Cladosporium sp., F. oxysporum. F. sporothrichioides and Phoma sp. through cut surfaces. With a couple of exceptions, Fusarium fungi were found in all the greenhouses (Table 1). Inoculation trials Inoculation through soil. The rooted carnation cuttings used in the test were inoculated two weeks after planting with fungus suspension, with which the soil was sprayed. The trial comprised 36 carnation-plants. The results were as follows: Number of wilted plants after 8 weeks after 12 weeks Alternaria tenuis 0 0 Fusarium avenaceum 0 0 F. culmorum 0 0 F. oxysporum a 0 0 » b 4 6 Control 0 0 Two different isolates, a and b, ofF. oxysporum were used in the test. Of all the fungi used, only the b-isolate ofF. oxysporum was able to destroy the carnations through the soil and to cause their complete wilting within three months. Inoculation from the air. The carnations used in the test were 6 months old. After being cut to lengths of 0.5 m they were inoculated directly by spraying the ■cut surfaces with fungi suspension. The wilting appeared as shrinking of the stem, wilting and yellowing in the cut internodes, progressing in some branches downwards through several internodes. In healthy cut surfaces the stem was green and fresh. The results were as follows: No. of cut Wilting percentage after stems 3 weeks 6 weeks 8 weeks Alternaria tenuis 21 5 81 81 Fusarium avenaceum 24 4 83 88 F. culmorum 21 62 81 81 F. oxysporum 21 19 100 100 Control 41 0 15 29 All the tested fungi were able to penetrate the plants through their broken surfaces, ■or to cause in that way at least partial wilting. Most injurious was F. oxysporum. Even in the control, which had not been inoculated, wilting began to take place in 29 % of the ■cut stems. From these Rhizopus sp. was isolated. 255 Control trials The fungicide-sprays used in the control of the wilt disease caused by F. oxysporum were Dithane M-45 (mancozeb 80 %), Orthocide 50 (captan 50 %), and Pomarsol Forte (thiram 80 %). The soil had been inoculated as in the previous trial with the isolate F. oxysporum b. The first spraying was carried out two weeks after inoculation and was then repeated at fortnightly intervals. The following results were obtained (D = Dithane M-45, O = Orthocide 50, P = Pomarsol Forte); Sprayings Wilted % 22/7 5/8 19/8 9/8 23/8 D D D 50 100 O O O 50 91 P P P 41 91 D O D 45 86 D P D 59 95 O P O 59 95 D O P 68 95 Inoculated control 55 86 The sprayings had no effect and the treated plants wilted just as rapidly as the in- oculated plants that had not been treated.This is due to the fact that F. oxysporum penetrates the wood vessels and the fungicides give the plants only surface protection. The healthy control plants and the non-inoculated treated carnations remained healthy throughout the trial. Since it was possible that systemic fungicides might protect the plants from the inside, a trial was arranged with these compounds. One batch of carnations was sprayed with fungicides 24 hours before soil inoculation with F. oxysporum, another batch 24 hours after. The systemic fungicides used were Benlate (l-(butylcarbamoyl)-2-benzimidazole carbamic acid, methyl ester 50 %), Plantvax (2,3-Dihydro-5-carboxanilido-6-methyl- - 1,4-oxathiin-4,4-dioxide),4-dioxide) and Vitavax (2,3-Dihydro-5-carboxanilido-6-methyl-1,4- oxathiin), and in addition the non-systemic fungicide Pomarsol Forte (thiram 80 %). The results are presented below (a = advance control, b = subsequent control): Wilting percentage 26/3 2/4 4/4 14/4 21/4 Vitavax a 0.0 21.4 67.9 82.1 92.9 » b 0.0 25.0 60.7 89.3 96.4 Plantvax a 7.2 78.6 96.4 96.4 100.0 » b 3.6 75.0 96.4 100.0 100.0 Benlate a 0.0 50.0 100.0 100.0 100.0 » b 3.6 28.6 85.7 92.9 100.0 Pomarsol Forte a 0.0 14.3 64.3 78.6 92.9 » b 0.0 14.3 57.1 78.6 96.4 Inoculated control 0.0 42.9 78.6 92.9 92.9 Non-inoculated control 0.0 0.0 0.0 0.0 0.0 256 The systemic fungicides had no effect whatever, and within less than two months over 90 % of the treated plants and the inoculated non-treated plants had withered. The non-inoculated control was at the time completely healthy. There were no differences between the trial plants that had been sprayed 24 hours before and those sprayed 24 hours after the inoculation of the soil. In another trial it was also planned to determine whether pre-planting treatment with fungicides would protect the cuttings from wilting disease. For this purpose rooted carnation cuttings were kept overnight in F. oxysporum suspension. Subsequently, some of the cuttings were placed in Benlate-solution and the other in Dithane M-45-solution for periods of varying length. After treatment, they were planted in the usual way. The following results were obtained: Treatment No. of No. of wilted plants plants 26/2 17/3 24/3 29/3 8/4 21/4 Benlate 10 min. 6 13 5 6 » 30 min 6 14 4 6 » 60 min 6 12 6 » 24 hours 6 0 0 0 0 3 5 Dithane M-45 10 min 6 0 4 5 6 » 60 min 6 0 0 0 6 » 24 hours 6 0 0 1 3 6 Untreated 11 0 11 In the trial, all the treatmentshad somewhat delayed the onsetofwilting. The untreated lot had wilted completely only one month after inoculation. At the time the plants that had received 24 hours’ Benlate treatment and those that had had 60 minutes ofDithane M-45 treatment were completely healthy. While the plants that had been treated with Dithane M-45 for 24 hours had wilted completely in two months’ time, of the plants that had been subjected to24 hours’ Benlate treatment, one half was still healthy. In conclusion, the spraying of rooted cuttings prior to planting with systemic fungicides and mancozeb- compound delayed wilting to a certain extent. Summary From 81 carnation samples collected in 1967—68 from nurseries in different parts of the country were identified 17 species of fungus, from a total of 177 fungus isolates. Among these, Fusarium oxysporum was most widespread, 31.1 %. Farthrosporioides, F. avena- ceum, F. culmorum, Alternaria tenuis and Cladosporium sp. occurred in considerable quanti- ties. The percentage of Phialophora cinerescens was 1.1 %. In the inoculation trials F. oxysporum behaved as a strongly pathogenic, infecting plants via the air through cut surfaces and via the soil by root-penetration. A. tenuis, F. avenaceum and F. culmorum infected carnations only from the air through cut surfaces. In the fungicide trials against F. oxysporum, spraying the plants infected via the soil proved ineffective. The trials were made with the systemic Benlate (l-(butylcarbamoyl)- 2-benzimidazole carbamic acid, methyl ester 50 %), Plantvax (2,3-Dihydro-5-carbo- xanilido-6-methyl-1,4-oxathiin-4,4-dioxide), Vitavax (2,3-Dihydro-5-caboxanilido-6-me- 257 thyl-1,4-oxathiin), and with the non-systemic Dithane M-45 (mancozeb 80 %), Orthocide 50 (captan 50 %) and Pomarsol Forte (thiram 80 %). The dipping of rooted cuttings into Benlate and Dithane M-45 compounds to a certain extent delayed the process of wilting. Acknowledgements. Miss Annikki Hyvönen participated in the study in 1967 and Dr. A. Ylimäki was consulted as an expert in the determination of the isolated fungi. The authors wish to thank them for their help. LITERATURE Aleksandrova, 1. 1968. Bolesti po Karamfila Sim. Gradinarstvo 10(8): 18—21. (Ref. Rev. Appi. Mycol. 47: 628.) Cuba, E. F. 1945. Carnation wilt diseases and their control. Bull. Mass. Agric. Exp. Sta. 427: 1—64. Hellmers, E. 1958. Four wilt diseases ofperpetual-flowering carnation in Denmark. 200 p. Copenhagen. Pape, H. 1964. Krankheiten und Schädlinge der Zierpflanzen und ihre Bekämpfung, p. 333— 341. Berlin. Ruotsalainen, L. 1969. Neilikan lakastumistaudista. Puutarha-Uutiset 21:601—603. Scholten, G. 1955. Wilting diseases of carnations in the Netherlands. Reprinted from the Report of the XlVth Intern. Horticult. Congress, Netherlands 1955, p. 995—1002. —»— 1966. Vaatziekten in Anjers. Jaarverslag Proefstation voor de Bloemisterij in Nederland de Aals- meer, p. 32—34. Södergren, W. 1968. Om sjukdomar pä växthuskulturer 1967. Växtskyddsnotiser 33: B—l3. Talvia, P. 1964—67. Kasvitautien esiintyminen v. 1963. Maatal. ja Koetoim. 18(1964): 194—201. Kasvitautien esiintyminen v. 1964. Ibid. 19(1965): 232—238. Kasvitautien esiintyminen v. 1965. Ibid. 20(1966): 214 —221. Kasvitautien esiintyminen v. 1966. Ibid. 21(1967): 214 —223. Wachenfelt, M-A, von. 1968. Exempel pä svampsjukdomar i Mellansverige 1967—68. Växtskyddsnotiser 32: 64—72. SELOSTUS SIENTEN AIHEUTTAMA NEILIKAN LAKASTUMISTAUTI SUOMESSA E. A. Jamalainen ja Laina Ruotsalainen Kasvitautien tutkimuslaitos, Tikkurila Vuosina 1967—68 tutkittiin Kasvitautien tutkimuslaitoksella neilikan lakastumistautia Suomessa, josta on esitetty alustavia tuloksia (Ruotsalainen 1969). Tutkimusta varten kerätyistä 81 neilikkanäyt- teesta määritettiin 17 sienilajia, yhteensä 177 sienieristyksestä. Näistä oli eniten Fusarium oxysporumia, 31.1 %. Runsaasti oli myös F. arthrosporioidesta, F. avenaceurma, F. culmorumia, Alternaria tennistä ja Cladospro- rium sp;tä. Phialophora cinerescensiä oli 1.1 %. Infektiokokeissa saastutti F. oxysporum voimakkaasti patogeenisenä kasveja sekä maasta että ilmasta. A. tenuis, F. avenaceum ja F. culmorum saastuttivat neilikoita vain ilmasta haavapintojen kautta. Fungisidiruiskutukset eivät tehonneet F. oxysporumia vastaan tällä saastutetussa maassa kasvavissa neilikoissa. Kokeiltavina olivat systeemiset valmisteet Benlate (metyyli-l-(butyylikarbamoyyli)-2-bentsi- midatsolikarbamaatti), Plantvax (2,3-dihydro-5-karboksianilido-6-metyyli-1,4-oksatiini-4,4-dioksidi) ja Vitavax (2,3-dihydro-5-karboksianilido-6-metyyli-1,4-oksatiini) sekä ei-systeemiset valmisteet Dithane M-45 (mankozebi), Orthocide 50 (kaplaani) ja Pomarsol Forte (tiraami). Juurrutettujen pistokkaiden kastelu sekä Benlate- että Dithane M-45-valmisteella viivästytti jossain määrin lakastumista.