species on Finnish grasses

Kaiho Makela

Department of Plant Pathology, University of Helsinki. Viikki, 00710 Helsinki 71, Finland

Abstract. -The material (c. 2800 samples) for this study was collected from planted grassland or the borders of fields throughout the conutry in 1966- 1970. Rhynchosporium orthosporum Caldwell was observed to occur commonly on cultivated and wild grasses in many localities from Helsinki to Lapland. Spores of the were most abundant in the leaves of the grass in early spring and were least abundant in mid summer. R . orthosporum was the most common causer of leaf spot diseases on Dactylis glomerata L., during the growing season and in part also under the snow. It was also common on L., especially towards the beginning of the growing season. R. orthosporum also occurred commonly on Phleum pratense L., Huds. , L ., L. and L. On these grasses the significance of R. orthosporum was smaller than on the grasses first mentioned. In addition native spores of R . orthosporum were found sporadically on the following species of grass: L., A. tenuis Sibth., L., Calama­ grostis arundinaceae (L.) Roth., C. epigeios (L.) Roth., Deschampsia caespitosa (L.) PB., Lolium multiflorum Lam. and L. (Oud.) Davis was observed rather commonly on repens (L.) PB. and sporadically on Leyss.

Introduction LATCH & WENHAM 1959, LATCH 1966 ). A high degree of host specialization has been Rhynchosporium Heinsen is a genus of found within the species R . secalis (CALD­ M oniliales. Two species have been described. WELL 1937, ScHEIN 1958, KAJIWARA & IwATA R. secalis (Oud.) Davis is the causer of leaf 1963 ). blotch of , and certain grasses. . R. Rhynchosporium secalis (Oud. ) Davis, orthosporus Caldwell produced scald-like Trans. Wise. Acad. Sci. 20: 413, 1921; Syn. blotches on many wild and cultivated grasses M arssonia secalis, Oudemans, Konink. Akad. (CALDWELL 1937, SPRAGUE 1950). The fungi Wetensch. 6: 88, 1897; R. graminicola Hein­ are c:haracterized by a very sparse mycelium sen, Jahrb. Hamburg. Wiss. Anst. 18, 3: 43, which ramifies throughout the tissues lying 1901 ; (cf. LINDAU 1910 : 757 ). The fungus immediately belo·w the cuticle. The conidia has often been reported on grass species, e.g. are elongated and generally once-septate. R. on Agropyron repens , (L. ) PB. in Denmark orthosporum has cylindrical conidia which (LIND 1913 ), in Norway (J0RSTAD 1930, differentiate it from R. secalis, which has 1945, HANSE N & MAGNUS 1969 ), in Britain apically beaked conidia (CALDWELL 193 7). (OwEN 1952 ), in the USA (CALDWELL 1929, Both species thrive in humid, rainy and cool 19'31, 1937 ) and in New Zealand (BRIEN wheather (CALDWELL 1937, Sr<:oROPAD 1957, 1942 ), on Agrostis stolonifera L. in the Neth-

23 ported on this grass species e.g. in the USA (SPRAGUE 1950, ELLIOTT 1962 ), in Britain (OwEN 1952 ), in Denmark (SMEDEGARD -PE­ TERSEN 1970 ). in New Zeeland (LATCH & WENHAM 1959) and in Japan (KAJIWARA &

6 IwATA 1963). The fungus frequently attac'ks Lolium perenne L. in New Zealand (LATCH 1956 ) . It was recorded on this grass also in the USA (SPRAGUE 1946 ) and in Britain (FowLER & OwEN 1954). R . orthosporum was found on L. multiflorum Lam. in the 6 USA (SPRAGUE 1946 ), in Britain (WrLcox 1960) and on this species and on L. multi­ florum f. sp. westerwoldicum in New Zea­ land (LATCH 1966 ), as well as on Agrostis stolonifera L., Alopecurus pratensis L. and Calamagrostis canadensis (Michx.) Beauv. in the USA (SPRAGUE 1946 ). This study is part of a broad research pro­ ject dealing with spot diseases on grasses growing on leys, with the pathogens causing these diseases (cf. MAKELA 1970, 1971, 1972a) . The study has been in progress at the Department of Plant Pathology, University of Helsin'ki at Viikki ever since 1966. The pur­ pose of the present study is to clarify the occurrence of Rhynchosporium species on the mos•t important grasses.

6 ·-~· -· · 7" Oil ... ' """ " ""' ll "• 2 Materials and Methods

Fig. 1. Origin of the material. Grass samples were collected during the period between spring thaw and the first heavy snow-fall in autumn from 1966 to erlands (ANON 1951 ) and in the USA 197D. The grasses (c. 2800 samples were (SPRAGUE 1950), on Alo pecurus pratensis L. collected hom planted grassland and the in Norway (HANSEN & MAGNUS 1969 ), on borders of fields in many localities through­ Bromus inermis Leyss. in the USA (DRECHSLER out the country (Fig. 1). Conidia produced 1921, CALDWELL 1929, 1931, 1937, SPRAGUE in natural infestations were examined. The 1950), in Germany (MuHLE 1953 ) and in slides of the fungus material were prepared Norway (HANSEN & MAGNUS 1969 ), on B. from fresh grass leaves. The fungi on the mollis L. (BROOKS 19·29, OwEN 1952 ) and B. slides were preserved in lactic-acid and !acto­ sterilis L. (BROOKS 1928 ) in Britain, on Dac­ phenol solutions wit h trypanblue. The conidia tylis glomerata L. in the USA (DRECHSLER were also measured and photographed on 1921 ) and in Britain (BROOKS 1928, on Lo­ the sEdes. The fungus was not grown in lium multiflorum f. sp. westerwoldicum in pure culture. Britain (THORPE 1960 ), and on L. perenne L. in Germany (BARTELS 1928), and in the USA (HowARD et a!. 1951 ). Results and Discussion Rhynchosporium orthosporum Caldwel'l, J. Agric. Res. 55 : 184, 193 7. The fungus was In this study Rhynchosporium orthospo­ recorded on Dactylis glomerata L . in the rum was the dominant species on grasses. By USA for the first time (CALDWELL 193·1, comparison R . secalis was found in very small 193 7). Thereafter this fungus has been re- quantity and only on a few species of grass.

24 R. orthosporum was observed in a good 4. VIII. 1970; InL: Inari 13 . VI. 1969, 28. VII. 40 o/o o.f the grass samples that were collected 1969, 18. VI. 1970. throughout the country (c. 2670 samples). On Festuca pratensis Huds.: The fungus was most common on cocksfoot U: H elsinki, \ iikki ( 109 specimens), Tikkurila ( Dactylis glomerata), occurring in over 70 o/o (23 specimens), Hyrylii ( 1 specimen) ; \: Mietoi­ of the samples examined (c. 760 samples). nen (19 specimens); EK: Anjala (4 specimens); EH: H iimenlinna ( 5 specimens), Palkiine ( 4 spe­ On timovhy (Phleum pratense) and o-n mead­ cimens) ; St: Peipohja (27 specimens); ES: Mikkeli ow fescue ( F estuca pratensis) the fungus ( 14 specimens) ; PH: Laukaa ( 5 specimens) ; EP: occurred to a considerably lesser extent, in Ylistaro (6 specimens); KP: Toholampi (9 speci­ about 1/ 3 of the samples examined. For the mens ), PP: Ruukki (3 specimens); InL: Inari ( 2 specimens ) . other grass species (F estuca rubra, Lolium perenne, Poa pratensis) there were fewer On Festuca rubra L. : samples from fewer localities. Of these, R. U : Helsinki, Viikki ( 1 7 specimens), H yrylii ( 1 specimen) ; EH: Hiimenlinna ( 1 specimen) ; orthospoTUm was obser ed in 1/4-1/ 5 of St: Peipohja ( 1 specimen) ; InL: Inari ( 4 speci­ the samples. On meadow foxtail ( Alopecurus mens). pratensis) Rhynchosporium spp. occurred in On Lolium multiflorum Lam.: about 40 o/o of the samples (c. 170 samples) . U: Helsinki, Viikki 17. IX. 1968; PP: Ruukki Rhynchosporium orthosporum was further­ 24. IX. 1969, 16. II. 1970, 3. IX. 197"0, Apukka more observed sporadically in certain other 1. X . 1969; InL: Inari 12. VI. 1970. grass spc1es. On Lolium perenne L.: U: Helsinki, Viikki (28 specimens), Hyrylii (1 Material examined specimen) ; St: Peipohja ( 4 specimens); InL: Inari ( 2 specimens) . On Agrostis stolonifera L.: U: Viikki 24. XI.1967, 28 . III.1968, 17.V. On Phleum pratense L. : 1968, 9. IX. 1968, Hyrylii 29. V. 1970; EH: Hii­ U: Helsinki, Viikki ( 98 specimens), Tikkurila meenlinna 11. V. 1967, 31. V. 1968. ( 7 specimens), H yryla ( 1 specimen) ; \ : Mietoinen ( 5 specimens); EH: Hameenlinna ( 24 specimens); On Agrostis tenuis Sibth.: St: Peipohja (5 specimens); ES: Mikkeli (5 spe­ U: Viikki 30. VI. 1970, 12. X. 1970, H yrylii 29. cimens); KP: Toholampi (2 specimens); PP: V. 1970; EH: Juupajoki 17. VIII. 1970, Hiimeen­ Ruukki ( 11 specimens) ; InL: Inari ( 15 speci­ linna 3. IV. 1968, 25 . V. 1969; InL: Inari 28. II. mens) . 1969, 12 . VI. 1970. On Poa annua L .: On Alopecurus geniculatus L.: EH: Lepaa 4. IX. 1970; ES: Mikkeli 21. V. U: Viikki 21. I\. 1967, 6. V. 1970, 19. V. 1970; 1968; InL: Inari 1. IX. 1968, 22 . V II. 1969. St: Peipohja 15 . V. 1968, 27. V I. 1968. On Poa pratensis L.: On Alopecurus pratensis L.: U : H elsinki, iikki ( 15 specimens), Hyryla ( 4 U: Helsinki, Viikki (40 specimens), HyryHi (3 specimens) ; EH: Hiimeenlinna ( 3 specimens) ; sp cimens) ; EH: Hiimenlinna ( 4 specimens) ; ES: St: Peipohja ( 1 specimen); ES: Mikkeli ( 1 speci­ Mikkeli (2 specimens) ; InL: Inari ( 14 specimens). men); InL: Inari (5 specimens) . All the samples in the Collection of HPP, in On Calamagrostis arundinaceae (L. ) Roth. : 1966- 1970. U: Lohja 15. VIII. 1968. Rhynchosporium secalis was not positively On Calamagrostis epigeios ( L .) Roth.: identified on cultivated grasses at all. On na­ U: Helsinki, Viikki 28. VIII. 1969, Espoo 15. VIII. 1968, Nummela 15. III. 1968; EH: H ii­ tive grasses the fungus was observed rather meenlinna 23. VI. 1968; InL: Inari 22. VII. 1968. commonly on A gropyron repens (L. ) PB. In addition the fungus was found sporadically On Dactylis glomerata L.: on Bromus inermis Leyss. as follows: U : Helsinki, Viikki (322 specimens) , Tikkurila (21 specimens), Hyrylii (9 specimens) ; V: Mietoi­ On Agropyron repens (L.) PB.: nen (25 specimens) ; EK: Anjala (7 specimens); U: Helsinki, Viikki 17 . . 1967, 20. V. 1970, EH: H iimeenlinna (21 specimens) , Piilkiine (13 Kirkkonummi 15. VI II. 1968; EH: Lepaa 11. Y. specimens); St: Peipohja (40 specimens); ES: 1967, 17 .V. 1970, Hiimeenlinna 11.V.1967, 3. Mikkeli ( 49 specimens) ; PH: Laukaa ( 13 speci­ XI. 1967, 18. X. 1969, 4. II. 1970 ; ES: Mikkeli mens ); EP: Ylistaro (9 specimens) ; KP: Toho­ 21. V . 1968, 28. VI. 1968; InL: Inari 31. V II. lampi (13 specimens); InL: Inari (4 specimens). 1970. On Deschampsia caespitosa (L .) PB.: On Bromus inermis Leyss.: U: Helsinki, Viikki 4. VI. 1968; ES: Mikkeli U: Helsinki, Viikki 26. V. 1967, 28. V. 1970. 21. V . 1968; KemL: Pelkosenniemi 21. VII. 1970, All the samples in the Collection of HPP.

25 Fig. 2. Rhynchosporium orthosporum, A-G: lesions on leaves, H, I : the fungus growing in tissue of a leaf, A-D: on Dactylis glomerata, E: on Festuca pratensis, F: on Phleurn pratense, G: on Alopecurus pratensis, H, I: on Lolium perenne. A-G: x 1, H : x 100, I: x 1000. Occurrence of Rhynchosporium spec1es snow and for a time thereafter, leaves o.f during the growing season. grass containing conidia of R. orthosporum Rh.ynchosporium species were found were mainly dead (Fig. 2 B, E). The apical throughout the growing season. Different parts of the leave in particular were dead, grass species were quite similar in this res­ being light orange white - greyish orange pect. Conidia of the fungi were encountered in colour. On Dact·ylis glomerata in the dead in greatest abundance during the spring tissue there was often a white, granular months, i.e. from April to May, with moder­ coloration (Fig. 2 A ) . Below the light tip ate occurrence also in autumn. whereas they the tolour turned darker: mustard brown, were scarcest in midsummer. Via!ble conidia tobacco brown, bronze. On coc:ksfoot the were found in abundance even as early in colour was more reddish brown, on other spring as the time when the snow still partly grasses generally more greyish brown. When covered the leaves (even once in winter, on the grass started to grow, the siak leaves Jan. 13, 19·71 ) . Disease symptoms also were nearly disappeared ( cf. WILCOX 1960 ) . From found most frequently in early spring and the end of l\tlay to the end of June the grass in autumn. stands were clearly healthy ( cf. MAKELA & An important factor contributing to the ILONOJA 1971, MAKELA 1972a . Starting with frequent occurrence of Rhynchosporium spe­ the end of June the leaves, notably those of cies in thi material is e ·idently the Finnish Dactylis glomerata, began to be increasingly climate, its cool and humid spring and au­ tainted with spots caused by R. orthosporum tumn as well as its long and snowy winter (Fig. 2) . The most common ones were vague­ (cf. KoLKKI 1966, MAKELA 1972a) . Numerous ly-defined spots of different sizes which oc­ observations made elsewhere indicate that curred here and there on the leaf, often the diseases caused by fungi of Rh•ynchospo­ joining together and killing a major portion rium are important only in the cooler part of of the tissue of the leaf (Fig. 2) . Often the year (of. BROOKS 1928, J0RSTAD 1930, leaves of this sort were also dead at the tip. CALDWELL 1937, BRAVERMAN 1967 ). This has On Dactylis glomerata and Phleum pratense been the case on grasses (Lolium species, the spots were most often rust brown - oak Dactylis glomerata) in Britain (THORPE 1960, brown in hue, on Lolium and Festuca species, WILCOX 1960) and in New Zealand (LATCH tobacco brown - greyish brown - grey in & WENHAM 1959, LATCH 1966 ). colour. Of lesser occurrence were spots that were grey - bluish grey in the middle and Symptoms on grasses brown round the edges (Fig. 2 D ) (cf. CALD­ WELL 1937, OWEN 1952, SMEDEGARD-PETER­ Rhynchosporium orthospoTum caused on SEN 1970). The size of blotohes was on Dai ­ the leaves of grasses spots which varied in tylis glomerata (c. 1120lesions) (1) 16 (135- colour, ~hape and size even on the same 228) mm long, (1) 2.7 (7 ) mm wide and grass species .. The spots occurring on grass on Phleum pratense (c. 110 lesions ) (5 ) 27 were in general clearly distinguishable from (32-135 ) mm long, (1 ) 2.2 (6) mm wide. leaf blotch on barley, caused by R. secalis The spots which the Rhynchosporium ( cf. MAKELA 19 72rb ). On the other hand, on fungus caused on Alopecurus pratensis were many grass species (on Lolium spp., Festuca striking, particularly in early summer. In spp., Agrostis spp., and partly also on Phleum colour the spots were a vivid yellowish brown, pmtense ) the symptoms caused by R. ortho­ golden brown, tobacco brown chocolate sporum were similar to those caused by the brawn cocoa brown, sepia. Some of the spots H elminthosporium species ; the same applies went round the edge of the leaf, continuing to the spots caused by SpeTmospora spp. on to the sheath of the leaf (Fig. 2 G ). The Festuca rubra (cf. MAKELA 1971, 1972a). culm and the ear were also liable to damage. In this respect Dactylis glomerata a:nd Alo­ The size of lesions (about 70 ) was (2 ) 44 pecurus pratensis differed from the other ( 120) mm long, ( 1) 1.6 (1 0) mm wide. grasses. On ~hem symptoms caused by R. orthosporum were the most positively identifi­ Conidia able. Besides, very few H elminthosporium Conidia of Rhynchosporium orthosporum fungi occurred on both these grasses. were hyaline and generally two septa, though In early spring right after melting of the 3 ( 4) septa conidia occurred rather common-

27 Fig. 3. Conidia of Rhynchosporium orthosporum A-G and R. secalis H, I. A-D: from Dactylis glomerata, E : from Festuca pratensis, F: from Phleum pratense, G : from Alopecurus pratensis, H, I: from Agropyron repens. A: Helsinki, Viikki 10. VI. 1968; B: Mikkeli 21. II. 1969; C : Anjala 18. VII. 1969; D: Palkane 23. II. 1969; E: Mikkeli 21. . 1968; F: Hameenlinna 11. \ . 1968; G: Inari, Muddusniemi 14. VIII.1969; H: Helsinki 17. V. 1968 ; I : Tyrvanto, Lepaa 5. VII. 1970. A, c, I: X 2000 ; B, D-H: X 1000.

28 f G ~H~ ~ ~ r ~ u J~ ~ ~ ~

~~~~ ~8~ N 0

Fig. 4. Conidia of Rhynchosporium orthosfJorum, A-T and R . secalis, U -Y. A-E: from Dactylis glomerata, F-I: from Festuca pratensis, J-K: from Phleum pratense, L-M: from L olium peren­ ne, N-0: from Poa pratensis, P: from Agrostis stolonifera, Q from Calamagrostis arundi­ naceae, R-T: from Alopecurus pratensis, U-V: from Agropyron repens, Y: from Bromus iner­ mis. Helsinki, Viikki: A, 11. V. 1967; B, 23 . X . 1967; I, 5. VI. 1967 ; L, 28. III. 1968; R, U, 17. V. 1968; Y, 26. V. 1967. HyryHi: P, 29. V. 1970. Lohja: Q, 15. VIII. 1968 . H ameen­ linna: G, 11. .1968; J, 13.I\ . 1968; S, 23.VI.1968; V, 3. XI.1967. Peipohja: E, 15.X. 1968; M, N, 15. V. 1968. Mikkeli: F, 21. V. 1968. Inari, Muddusniemi: C, 28. I. 1968; D, 1. IX. 1968; H, 21. VII. 1968; K , 0 , T, I. IX. 1968.

29 Table I. Size of conidia of Rhynchosporium species on the different grasses.

Size of conidia, f.t 0 "0 :U ro ~ Fungus Grass .D ·~ ;:l length width E:-s ~ ;:l >:: ., Z8E mean range mean range

R . orthosporum Agrostis spp. 50 14.0 8- 23 2.2 1.0- 3.0 Alopecurus geniculatus 40 11.4 8- 15 2.1 1.8- 2.7 Alopecurus pratensis 50 1 13.3 8- 17 2.1 1.5- 3.0 -»- 470 2 13.3 8- 23 2.9 1.5- 5.0 Calamagrostis spp. 125 15.7 11-19 2.2 2.0-3.0 Dactylis glomerata 3300 14.7 6- 30 2.6 0.8- 4.0 (7 .0) F estuca pratensis 800 12.8 6- 22 2.4 1.0--4.0 Festuca rubra 40 14.2 7- 20 2.3 1.5- 4.0 Lolium perenne 360 13 .6 7- 24 (40) 2.2 1.0- 3.0 Phleum pratense 550 13.1 5- 26 2.1 1.0- -3 .5 Poa pratensis 120 12.1 10- 18 2.4 1.8- 3.0 Poa annua 35 11.4 8-14 2.1 1.8-3.0 R. secalis Agropyron repens 160 13 .7 10- 19 3.4 2.5- 4.5 Bromus inermis 50 15.1 12- 22 3.4 3.0-4.0 conidia without an apical beak 2 conidia with an apical beak ly on Dactylis glomerata ( cf. SPRAGUE 1950 ) . Spores of the Rh·ynchosporium species were There were rather small differences in the unobservable. Only when gro"'ring in highly size of the spores between the different spe­ favourable circumstances could the spores be cies of grass (Ta:ble 1), though the spores seen growing in thick groups on the leaf growing on D. glomerata and on Calama­ surface. Conidiophores were not visible at all grostis species were relatively longer, whereas and mycelia of fungi were extremely scarce those growing on Poa species were relatively (Fig. 2 H, I) (cf. BROOKS 1928, CALDWELL shorter. The shape of the spores varied some­ 1·937). what depending on the species of grass and Acknowledgements. - I express my sincere the growing conditions (Figs. 3, 4 ). thanks to Mrs. Eila Metsapelto, M. Sc., Mrs. The spores of R. secalis were generally Aino Hanhilahti, Agr., Miss Riitta Lahtinen fatter two septa with a short apical beak and Mrs. Hilkka Koponen, and also to many (Figs. 3 H, I, 4 U-Y). other persons for their technical assistance, In all the samples gathered from Alopecu­ e.g. in analysing plant specimens and meas­ rus pratensis there were spores similar to uring spores. I am thankful to Mr. Pentti Hei­ those of both R. orthosporum and R. secalis nanen for photographing my microscopic (Figs. 3 G, 4 R- T ). In size, notably in slides and leaves of grasses. My thanks also width, they were closest to spores of R. ortho­ to the Experiment Stations of the Agricultu­ sporum. The same phenomenon has also ral Research Centre and the Plant Breeding been observed by SPRAGUE (1950). Institute of Hank:kija as weU as to late Prof. In the present study the size and form of Otto VaHe for research materials. I am conidia of Rynchosporium species were same grateful to the University of Helsinki and as m many other materials. ( cf. CALDWELL to my late husband Dr. Aarne Makela for 1937, OwEN 1952, 1958, LATCH & WENHAM their financial assistance. 1959, SMEDEG,\RD-PETERSEN 1970).

REFERENCES

ANON. 1961. Jaarboek 1961. Versl. Pl-Ziekt. Dienst BRAVERMAN, S. W . 1967. Disease resistance in cool­ Wageningen 136. 248 p. (ref. Rev. Appl. season forage, range, and turf grasses. Bot. Myc. 42: 295- 296) . Rev. 33: 329-378. BARTELS, F. 1928. Studien iiber Marssonina grami­ BRIEN, R. M. 1942. First supplement to 'A list of nicola. Forsch. Gebiet Pfl.krankh. Immuni­ plant diseases recorded in New Zealand' . tat Pfl.reich 5: 73- 114. N.Z.J. Sci. Tech., A, 24: 62- 64.

30 BROOKS, F. T. 1928. Observations on Rhyncho­ diseases of cocksfoot (Dactylis glomerata sporium secalis (Oud.) Davis, leaf blotch L. ) in the Manawatu. N.Z.J. Agric. Res. of barley and rye. New Phytol. 27, 4: 215- 2: 544-551. 219. LIND, J. 1913. Danish fungi as represented in the CALDWELL, R. M. 1929. Preliminary results from herbarium of E. Rostrup. 650 p. Copen­ cross inoculation and culture studies upon hagen. the fungus Rhynchosporium secalis (Oud.) LINDAU, G . 1910. Fungi imperfecti: Hyphomycetes Davis causing scald of cereals and other in Rabenhorst, L. Kryptogamen-Flora ·on grasses. (Abstr.) Phytopathol. 19: 104. Deutschland, Oesterreich und der Schweiz. 1931. Host specialization and parasitism of 1, 9, 983 p. Leipzig. the genus Rhynchosporium. (Abstr.) Phyto­ MAKELA, K. 1970. The genus Mastigosporium pathol. 21: 109- 110. Riess in Finland. Karstenia 11: 5- 22 . 193 7. Rhynchosporium scald of barley, rye, 1971. Some graminicolous species of Hel­ and other grasses. J. Agric. Res. 55: 175- minthosporium in Finland. Karstenia 12: 198. 5- 35. DAviS, J. J. 1919. Notes on parasitic fungi in Wis­ 1972a. Disease damage to the foliage cul­ consin VI. Wise. Acad. Sci., Arts, Letters, tivated grasses in Finland. Acta Agr. Fen­ Trans. 19: 705-727. nica 124, 1: 1- 56. DRECHSLER , C. 1921. Occurrence of Rhynchospo­ 1972b. Leaf spot fungi on barley in Finland. rium on Dactylis glomerata and Bromus Acta Agr. Fennica 124, 3: 1-23. inermis. (Abstr.) Phytopathol. 11:42. & lLONOJA, P. 1971. Effects of nitrogen ELLIOTT, E. S. 1962. Disease damage in forage fertilization on disease damage to foliage grasses. Phytopathol. 52: 448- 451. of silage leys. Act<. Agric. Scand. 21: 237- FowLER, A. M. & OwEN, H . 1964. New or un­ 248. common plant diseases and pests. Rhyncho­ MuHLE, E. 1953. Die Krankheiten und Schadlinge sporium orthosporum on perennial ryegrass. der zur Samengewinnung angebauten Fut­ Plant Pathol. 13: 94. tergrasser. 167 p . Leipzig. HANSEN , L. R. & MAGNUS, H. A. 1969. Leaf spot OuDEMANS, C. A. J. A. 1897. Observations Myco­ fungi on barley in Norway. Norwegian Plant logiques. Kunk. Akad. Wetensch. Amster­ Protec. Inst. Div. Plant Pathol., V ollebekk, dam 6: 86-92. Rep. No 42. Forskn. forsek landbr. 20 : OwEN, H. 1952. Leaf blotch of cocksfoot. Plant. 95- 105. Pathol. 1: 122. How.\RD, F . L., RowELL, ]. B. & KEIL, H. L . ScHEIN, R . D. 1958. Pathogenic specialization in 1951. Fungus diseases of turf grasses. Bull. Rhynchosporium secalis. Phytopathol. 48 : R. J. Agric. Exp. Sta. 308. 56 p. 477-480. ]0RSTAD, I. 1930. Beretning om plantesykdommer SKOROPAD, W . P. 1957. Temperature and humidity i land- og hagebruket. VI. Sykdommer pa relationships in securing infection of barley korn- og engvekster. 84 p. Oslo. with Rhynchosporium secalis (Abstr.) Phy­ 1945. Parasittsoppene pa kultur- og nytte­ topathol. 47: 32- 33. vekster i Norge. I. Sekksporesopper ( Asco­ SMEDEGARD-PETERSEN, V . 1970. Drechslera poae mycetes ) og konidiesopper (Fungi imper­ and Rhynchosporium orthosporum recorded fecti ) . Medd. Stat. Plant Pathol. Inst. 142 as pathogens on grasses in Denmark. Horti­ p. Oslo. cultura 24: 38- 46.

KAJIWARA, T. & !wAT.\, 1 Y. 1963. Studies on the SPR GUE, R . 1946. Rootrots and leafspots of grains strains of the barley scald fungus,· Rhyncho­ and grasses in the Northern Great Plains sporium secalis (Oud.) Davis. Bull. Nat. and Western States. Plant Dis. Reptr. Suppl. Inst. Agric. Sci. Tokyo, Ser. C , 15 : 1- 73 . 163 : 195, 202. (ref. Rev. Appl. Myc. 43 : 132--133.) 1950. Diseases of cereals and grasses in KoLKKI, 0. 1966. Tables and maps of temperature North America. 538 p. New York. in Finland during 1931- 196'0. Suppl. Me­ THORPE , I. G. 1960. New or uncommon plant teorol. Yearb. Finland 65, !a: 1- 4'2. diseases. Rynchosporium secalis on Wester­ LATCH, G . C. M . 1966. Fungious diseases of rye­ wolths ryegrass. Plant Pathol. 9: 111- 114. grass in New Zealand. N .Z.J. Agric. Res. WILCOX, H . J. 1960. New or uncommon plant 9: 394- 409. diseases. Rhynchosporium orthosporum on & WENHAM, H. T. 1959. Fungal leaf-spot Italian ryegrass. Plant Pathol. 9: 111- 114.

31