Reports of Plant Pathology Department of Agricultural Research Centre Tikkurila, Finland

REPORTS OF PLANT PATHOLOGY DEPARTMENT OF AGRICULTURAL RESEARCH CENTRE TIKKURILA, FINLAND

Maatalouskoelaitoksen kasvi- Meddelanden från Lancbruksför- tautiosaston tiedonantoja. söksanstaltens avdelning kir växt-

Tikkurila sjukdomar. Dickursby

No. 18 1956

THE PLANT PATHOLOGY. DEPARTMENT OF THE AGRICULTURAL RESEARCH CENTRE THE MOST IMPORTANT DISEASES OF CROP PLANTS IN FINLAND AND THEIR CONTROL

E. A. Jomoloinen

TIKKURILA 1956 THE PLANT PATHOLOGY DEPARTMENT OF THE AGRICUL - TURAL RESEARCH CENTRE

The present Plant Pathology De- partment of the Agricultural Research Centre began its activity in 1911 at Tikkurila, near Helsinki, as a Depart- ment of Plant Pathology of the Insti- tute of Agricultural and Economical Research. In addition to being a Re- ser,r,:h Institute of the State the In- sti'ute was, as an experimental sta- tion, subordinated to the Faculty of the University. In 1924 the Institute with its Departments was made a sep- arate Agricultural Research Centre of the State. The most important earlier a- chievements of the Department were researches on the smut diseases in Finland (17, 18, 19), and researches on the potato wart disease and its control (2), which were carried out under the direction of the renowned mycologist Professor J.1.1 ira, who held the directorship of the Department Boron deficiency diseases: (left) of Plant Pathology until 1937, in heart rot of sugar beet, (above addition to his professorship at the right) brown heart of swede, University. After him the directorshi p (below right) internal cork of was held by Professor A.J.Ra inio apples. until his death in 1944. The most important of his investigations were research on the Fusarium mould of for example in the middle of the oats (Fusarium roseum) (26), research 1930's instruction for controlling grain on the bacteria diseases of Gladioli diseases was arranged in cooperation (27) and a report on the potato late with the instructional organizations blight and its significance in Finland throughout the country. (28). Since 1925, when the Plant The research work carried out Protection Act became valid, the during the last two decades has Department has been responsible for extended to comprise besides diseases the statutes of the control of plant caused by parasitic fungi also non- diseases being observed. The Act has parasitic (physiogenic) plant diseases been widely applied in order to pre- and virus diseases. Of minor elements, vent the spreading of potato wart boron was the first object of research disease. Instruction in the field of at the Plant Pathology Department plant protection has continuosly been in Finland, and it was proved that on important part of the activities; the brown heart of swede is caused by a deficiency of boron (5); also ported in detail in the periodical other plant diseases caused by a Nordisk Jordbruksforskning (11). The deficiency of boron were found to following objects of research may occur in Finland, such as the heart deserve mentioning in this connection: rot of sugar beet and the internal the resistance of different varieties of cork disease of apple. Continued re- wheat to the stinking smut (6), the search on boron has shown that in Fusarium fungi in Finland (7), the wide areas in this country this element significance of potato virus diseases is a necessary nutrient for many plant in this country (8), and the fungus species (9). Other publications de- Sclerotinia borealis causing damage scribing the activity of the Plant in winter cereals and grasses (10). Pathology Department have been re-

PRESENT ACTIVITIES AT THE PLANT PATHOLOGY DEPARTMENT

At present (1956) the work of antsare Mr. Matti Haavisto, B. the Plant Pathology Department in- Agr. & Forest. and Mrs. Eeva cludes the following activities: 1) Tapio, 8. Agr. & Forest.; the research on plant diseases injurious Plant Protection Inspector is Mr . to cultivated plants, and their control Aarre Ylimäki, B.Agr. & For- methods, 2) experiments on the effec- est.; the Plant Protectants lnspector tivenes of fungicides, 3) inspection is Aulis Tinnilo B.Sc. (together duties in accordance with the Plant with the Department of Pest Inves- Protection Act and 4) instruction. tigation of the Agr. Res. Centre). The present Head of the Plant In addition the staff of the Depart- Pathology Department is Professor, ment consists of a junior research Dr. E.A. Jama loinen; the Senior worker, temporary research workers, Research Assistants are Miss., Dr. on office clerk, two laboratory as- Annikki Linnasalmi and Mr. sistants, two field assistants, and Jaakko Mukula, Lic. Agr & practising undergraduates. Forest.; the Junior Research Assist-

Investigations and experiments

OVERWINTERING OF CEREALS, special attention has been paid to GRASSES, CLOVER, AND RAPE. parasitic fungi damaging young crops Though most of the cultivoted fields of cereals, grass, clover, and rape in Finland are given to overwintering during winter (15, 25, 29). As there plants - winter roy and wheat, is much snow in winter in Finland, grasses, clover, and winter turnip these fungi often play a very impor- rape (Brassica campestris v. oleifera tant part in poor overwintering. In f. biennis) - knowledge about the winter cereals and grasses, damage is reasons for poor overwintering has caused by snow mould (Fusarium earlier in many cases been very nivale), in many cases by the fungi insufficient. In Ole investigations of Typhula spp. and in central and carried out during the last ten years northern parts of the country by by the Piant Pathology Department, Sclerotinia borealis (10). In clover,

2 occurrence in different parts of the country and the damage caused by them; to discover the resistance of different strains of grasses and clover and that of the different varieties of winter cereals to winter damage; to examine the importance of seed treatment with chemicals in the control of snow mould; to find out the effect of chemicals in the treatment of overwintering plants (25). Last time teste were made with the PC NB -(pentach loronitrobenzene-) preparations used as dust in the autumn, very good results were obtained in the control ling of snow mould in winter cereals (25), clover rot (25, 29) and the fungi in winter turnip rape (25). FOOT ROT DISEASES OF SPRING CERALS. In a wide area in the western part of Finland, spring wheat Sclerotia of Sclerotinia borealis thrives poorly because the kernels on winter are scabbed (shrivelheads disease of wheat). Investigations have shown damage is often caused by clover rot (3) that one reason for this is fungi, (Sclerotinia trioliorum) and in winter in the first place Cercosporella turnip rape by Typhula sp. and herpotrichoides (causing eye spot Sclerotinia sclerotiorum. Different disease) as well as some species of variesties of winter cereals and Fusarium which cause foot rot disease . different strains of grasses and clover, In addition to this it has been estab- show great differences with regard lished that also a species of insects, to their resistance to damage caused Amblymerus graminum Hårdh, can be by fungi. At the Plant Pathology a cause of the shrivelheads of spring Department the object of the investi- wheat damaging the foot of plants. gations has been: to define over- Foot rot diseases of spring cereals wintering fungi; to find out their caused by parastic fungi are also common in other parts of Finland. DISEASES OF POTATO. Attention has chiefly been paid to the control of potato late blight (Phytophthora infestans) with chemicals and to the study of the control of storage losses (cf. investications in storage, p. 0). DISEASES OF VEGETABLES AND ROOT CROPS. In Finland vegetable and root crops suffer during the period of growth from several injurious diseases whose control is difficult. Of The effect of PCNB dusting on. these diseases the Department has red clover, left untreated, right investigated the following: onion virus treated in previous autum. disease (Allium virus 1) (12), downy 3 Cucumber varieties resistant against anthrachnose (Cladosporium cucumerinum).Above(left) Superb OE 48, Cavallius Orig., Muromsk (susceptible); below (left) Wisconsin SR 6, Highrnoor, Maine n:o Z. Photo Ingervo, mildew of onion (Peronospora destruc- - In the control of club root good tor) (12), antrachnose of cucumber results have been obtained by treating (Cladosporium cucumerinum), leaf the planting holes of the seedlings mould of tomato (C.fulvum),steak of with calomel preparation. tomato, late blight of tomato DISEASES OF FRUIT-TREES AND (Phytophthora infestans), club root of BERRIES. Of the diseases occurring crucifers (Plasmodiophora brassicae), in fruit-trees and berries, the Depart- Sc I eroti nia disease (Sc lerotinia ment has investigated the control of sclerotiorum), and damping-off (caused apple scab (Ventura inaequalis), by Pythium and Rhizoctonia fungi); brown root (Sclerotinia fructigena) the last mentioned disease systemati- American mildew (Sphaerotheca mors cally as well as biologically (21). uvae), and spur blight of raspberry So for the experiments with (Didymella applanata). In the control cemicals on the control anthrachnose of apple scab experiments using the of cucumber (20) and leaf mould of timing spray method have given reli- tomato have not yielded satisfaztory able results (4). A great number of results. A great number of experiments these experiments have been carried have been made with varietiesresistant out in various parts of the country to these diseases, and seed material since 1954 and 1955. The effec- from different countries has been tiveness of new substances against imported for the purpose. Some of apple scab has been tried out, and these varieties have, indeed, been of these particulorly the Captan found to have a resistance against preparations have been found to be the diseases in question, and have effective in conditions prevailing in been found suitable for this country. Finland.

4 resistance of new varieties of wheat to stinking smut and on the resistance of new varieties of potato to wart disease. The results of these tests have been reported to plant breeding stations.lt has already been mentioned that in the investigations of the overwintering of plants, attention was paid to the resistance of different varieties of winter cereals as well as different strains of grasses and clover to fungi. In addition experiments have been carried out with varieties of The effect of chemicals on cucumber and tomato (cf.p. and stored carrots. Right untreated ; with different varieties of raspberry left, treated with TCNB prepar- resistant to spur blight (Didymella ation. applanata). OTHER INVEST1GATIONS. As INVESTIGATIONS OF STORAGE previously mentioned, the Department During the last few years the Depart- has earlier investigated the signifi- ment has investigated the effects that cance of boron on plant cultivation the fungi damaging plant products in Finland to find out to what extent in storage and other injurious factors it improves the quality of vieIds and have on the stored plants. Most increases them. At present the Depart- experiments were made with potato ment has continued the observations (24), carrot (23), onion (12) and of deficiency diseases of minor ele- apple (14). In addition, swede, cab- ments and their occurrence in field bage, and some other vegetable crops and garden plants. have been used for experiments. In The Department has investigated the storage of carrots good results the injurions effect on plants of such were obtained with the conserving, chemical substances that are used for (tetra chloronitrobenzene-) Fusarex- the conserving of the wooden parts preparation. Storage ot onion has been of greenhouses. on important problern, because espe - In order to control the fungus cially the set onion (Allium cepa diseases of coniferous trees experi- aggregatum) grown in Finland has ments have been conducted concerning shown a tendency to decay during the effectiveness of chemical sub- storage due to neck rot of onion stances against the Lophodermium (Botrytis allii). The experimentshave pinastri (Schrad.) Chev. and the thrown light on the effect of some Herpotrichia nigra Hartig. in the chemicals preventing the sprouting of control of the !atter fungus, which potato tubers, on the different ways causes damage in the nurseriesduring of storage, and on other facts con- overwintering, good results have been cerning the stored plants, and on the obtained with the PCNB compound storage resistance of different varieties (25). and strains. At the same time, some of the fungi found in the stored plants Virus investigation have been have been defined, and biological begun on potato, tomato, raspberry, experiments have been made with and other plants mainly in order to them. define the species of virus appearing RESISTANCE OF CROP PLANTS in them. TO DISEASES. The Department has Of the diseases affecting orna- made continuous experiments on the mental plants investigations have been 5 conducted on mildew of begonia (Oidium begoniae) and on carnation wilds (Verticillium sp.), and the effects of chemical substances on these diseases have been examined. The Department has continued its research on the Fusarium-fungi appearing in Finland (cf. oo).

Fusarium nivale (above) - Ca - lonectria graminicola below.

Testing the effectiveness of plant protectants

in 1951 the Finnish Parliament trees, berries, and ornamental plants passed on Act and a additional 29, dusts for vegetable crops 2 , Statute for the Examination of Plant chemicals agains fungi injurious to Protectants. These came into force overwintering plants 8, soil disin- at the beginning of 1952. According fectant chemicals 6, conserving sub- to this Act only such chemical stances for plant products (incl. preparations as have been biolo- preparations for preventing the gically examined are allowed to be sprouting of potato tubers) 7, other sold. The preparations that have gone preparations 5. Examining the effec- through a thorough examination have tiviness of plant protectants does not their salepackages stamped according- only mean that preparations of differ- ly. Lists containing the names of the ent names are compared with one examined substances with corresponding another and compounds suitable for explanations are published at two-, use are recommended. In this work three- yearly intervals. the Department has also deliberately Tests to find out.the effectiveness searched among new preparations for of plant protectants have lately given such protectants as are necessary in the Department much work, because Finland for preventing damage caused several new chemicals have been sent by injurious diseases whose control is and are being sent to the shops for difficult. sale, and their suitability for use in Acts and Statutes passed on Plant this country has to be examined. It Protectants: may be mentioned that in 1955 the The Act on Plant Protectants, Plant Pathology Department examined April, 27, 1951, No. 261; the fol lowing substances and compounds The Statute on the Plant Protes- in connectionvvith various experiments: tants Act, June, 29, 1951, No. 399; seed treatment chemicals 14, sprays The Statute on Poisons, July, for potato, vegetable crops, fruit- 12, 1946, No. 555.

6 part of this activity and are conducted by the Plant Pathology and Pest In- vestigation Departments. The most important provisions concerning Plant Protection are as fol lows: The Plant Protection Act, June 5 1925, No. 202; The Decision of the Cabinet on the applic.ation of the Plant Protec - tion Act, June 5, 1925, No. 204; The Statute on Plant Destroyers, April 11, 1947, No. 309; The Decision of the Ministry of Agriculture concerning the conditions of the importantion and transit of potato, Printing; The Decision of the Ministry of Agriculture concerning the conditions of the Importation and transit of plants and parts of plants from Bel- gium and the Netherlands, May 13, Testing the effectiveness of fun- 1947, No. 395; gicides in the control of soil- The Decision of the Ministry of bor ne fungi by desintectans. Soil Agriculture concerning the conditions desinfected by steam, infested of the importation and transit of using pure culture of fungus, living plants and parts of plants , after that treated by different May 13, 1947, No. 396. fungicides.

Instructional activities in Supervision of plant the control of plant diseases protection Because of the numerous plant According to the Plant Protection diseases and the methods of controlling Act passed in 1925 and the statutes them the Department must devote much and decisions connected with it, the time to purely instructional work. The Plant Pathology Department must attend Department answers annually about a to measures control Ii ng dangerous plant thousand questions about plant diseases diseases. In this work attention hos sent by growers. Agricultural and chiefly been paid, as mentioned horti cu I tura I organi zations have greatly above, to the potato wart disease increased their instructional activities and its control (30). The inspection with regard to plant protection, and of plants tc be imported or exported the Department issuesdirections concer- is done by the Plant Pathology and ning plant diseases. Firms preparing, Pest Investigation Departments of the importing, and selling fungicides and Agr. Res. Centre. The Plant Path. plant protection equipment continu- Department examines the exported ously apply to the Department for plants and the imported potato information concerning the possibi I ities and gives the required certificates. of using these fungicides and equip- Inspections of garden nurseries, their ment in Finland. In cooperaiion with cultivations and stores, also form instructional organizations a campaign 7 for promoting plant protection in_ gation Departments of the Centre. gardens has been going on throughout For example the booklets containing the country since 1950. For this advice and information on the current purpose a Plant Protection Inspector activities in the field of plant is working under the supervision of protection was a result of this work. the Plant Pathology and Pest Investi-

THE MOST IMPORTANT DISEASES OF CROP PLANTS IN FINLAND AND THEIR CONTROL

During its period of activity the Plant Pathology Department of the Agr. Res. Centre has collected information on some 600 diseases occurring in crops, and about 100 of these diseases must be considered common and injurious. Of the diseases of c erea I s, smut fungi are common in Finland as in other countries. The most important of them is the bunt or stinking smut of wheat (Tilletia caries (DC.) Tul.) Test of winter wheat varieties which damages both winter and spring where the plants are damaged wheat. Other smut fungi to be found by Typhula sp. Photo April 17, in Finland are loose smut of barley 1948, Tikkurila. (Ustilago nuda (Jens.) Rostr.), loose smut of wheat (U. tritici (Pers.) Rostr.), covered smut of barley (U. hordei (Pers.) Lagerh.), loose smut of oats (U. avenae (Pers.) Jens.), and stripe smut of rye (Tuburcinia occulta (Wallr.) Liro). Increasing the seed treatment with chemicals, and the use of new varieties more resistant to smut diseases, have recentlydiminished the significande of smut fungi. Leaf stripe of barley (Helminthosporium gramineum Rabenh.) is common and injurious in some parts of the country. In Finland considerable damage in winter cereals is often caused by fungi, which were described earlier in this paper. The most important of them is snow mould (Fusarium nivale (Fr.) Ces.), and the fungi of Typhula spp. (T. idahoensis Remsb. and T. itoana Imai). Sclerotinia borealis Bulatik & Vleugel only occurs in central and northern parts of the country, often Eyespots (Gercosporella herpot- causing considerable damage. The richiloides) in straws of spring rust fungi of cereals (Puccinia graminis wheat.

8 Pers., P. glumarum (Schmidt) Erikss. clover are often due to an important Henn., and P. coronata Corda, P. disease, clover rot (Sclerotinia triticina Erikss., P. dispersa Erikss. trifoliorum Erikss.). & Henn., and. P. hordei Otth.)are Poor overwintering of winter relatively common in Finland. Con- wheat and clover is sometimes also siderable damage, however, is only the result of damage caused by the caused by them in certain years successive freezing and thawing of favourable for the occurrence of rust the soil, soil-ice needles, and frost, fungi (13). At present, the brown in districts and during winters with rust of wheat must be considered the little snow. most injurious of the rust fungi. Foot In the control of diseases in rot diseases (caused by Cercosporella grasses one of the most important herpotrichoides Fron and Fusarium measures is to cultivate resistant spp.) seem to be common, especially strains. Timothy has been found to in spring wheat. Ergot (Claviceos possess a strong resistance toinjurious purpurea (Fr.) Tul.) occurs in winter winter fungi, and it is one of our rye and barley. safest plants. On the other hand One of the most important means ryegrass (Lolium) does not flourish in of controlling diseases of cereals is Finland, except some strains of Eng- seed treatment with organic mercurials, lish ryegrass, due to the damage which, however, is not yet so common caused by the injurious winter fungi. in Finland as in some other countries. In the control of clover rot PCNB Approximately one third of the seed preparations are new beginning to be of oli the cereals is annually treated used. with chemical substances. Judging by In winter turnip rape damage is the experiments, especially the seed caused by the Typhula sp. (T. betae treatment of winter rye has consider - Rostr.) fungi and the Sclerotinia ably increased yields. In experiments disease (Sclerotinia sclerotiorum (Lib.) conducted during many years in be Bary). It is likely that PCNB different parts if the country (1) the preparations will be used for the increase in the yiels of winter rye control of s.hese fungi. averages 19 c>/. and of winter wheat The most injurious disease of the 6.5 %. These experiments have also potato is potato late blight resulted in considerable increases in (Phytophthora infestans (Mont.) de the yields of spring crops: wheat 7.3 Bary). In northern parts of the country %, barley 7.5-12.5 % and oats 11.6 %. the blight, however, cannot cause very much damage because of early In the attempts to control over- autumn frosts. Potato wart disease wintering fungi and rust fungi, chief (Synchytrium endobioticum (Schilb.) attention has been paid to cultivating Pers.) chiefly occurs in southern parts varieties resistant to these diseases. of the country where it has spread Recent results obtained with the especially in the neighbourhood of PCNB preparations seem to indicate some towns and other thickly popula- on effective means of controlling ted areas (30). Other fungus disease injurious winter fungi (25). - In the of potato are: Alternaria blight control of foot rot diseases it is, (Alterncria solani (Eli. & Martin) L. above ali, important to avoid growing R. Jones & Grant), Verticillium wilt spring wheat and barley continuously (Verticillium albo-atrum Reinke & in the same place. Borth), and sommon scab and powdery In grasses, winter injuries are scab (Actinomyces sp. and Spongospora caused by the same fungi as in the sp.). Virus diseases (streak, crinkle, winter cereals. Winter injuries of and mild mosaic virus) are found in

9 the potato fields of this country, but they are not of the some importance as in many more southern countries where the seed potato must be changed every two or three years . Leaf roll of potato is of minor signif-_ icance in Finland. Finland ought to have good possibilities of exporting seed potatoes which are free of virus diseases. - The most important of the diseases damaging potatoes in storage is potato blight. The second place is taken by the bacteria rotting potato tubers. Even dry rot caused by the Fusarium furgi (Fusarium coeruleum (Lib.) Sacc.) is found is stored potatoes. One of the most important means Virus disease of onion. of controlling potato diseases is the cultivation of varieties resistant to blight, and during the last decades farmers have increasingly begun to grow such varieties. During the last ten years spraying with chemicals to control the potato blight has been done in the southern parts of the country. In sugar-beet heart rot due to a boron deficiency used to cause damage, but with the greater preva- lence of the use of boron it is now of no importance. Damping-off can often great havoc in sugar-beet cultivations. The most important of the diseases affecting vegetable and roo t crops during the growth period are: damping-off (caused by Rhizoctonia solani Kuhn and Pythium debaryanum Hesse), the Sclerotinia disease (Sclerotinia sclerotiorum (Lib.) de Bary) especially on tomato, cucumber, pea and bean, Verti ci I I i um wi lt (Verticillium albo-atrum Reinke & Borth.), club root of crucifers (Plasmodiophora brassicae Woron), anthrachnose of cucumber (Cladospo- rium cucumerinum Eli. & Arth . ), downy mildew of onion (Peronospora destructor (Berk.) Casp.), the virus disease of onion (Allium virus 1), blossom end rot of tomato, streak of Sclerotinia disease on cucumber.

10 tomato, brown roots of tomato, potato Iote blight (Phytophthora infestans (Mont.) de Bary), leaf mould (Clad- osporium fulvum Cooke) on tomato, and anthrachnose of beans (Colle - totrichum lindemuthianum (Sacc. & Magn.) Bri. & Cav.). Of the diseases damaging stored plants may de mentioned the Sclerotinia disease Sclerotinia sp.) and grey mould (Botrytis sp.), black rot of carrot (Stemphylium sp.), and grey mould of onion (B. allii Munn.). The control of the diseases of vegetable crops presents difficult problems, as the protectants used against them have not always proved sufficiently efrective (vide p.). A more wide-spread desinfection of the soil is one of the most important tasks (22). Of the diseases of f r ui t-trees , apple scab (Venturia inaequalis (Cooke) Wint.) is common and injurious. Brown rot (Sclerotinia fructigena (Aderh . & Ruh I . ) Honey) often damages the yield of apples, as does also the internal cork disease (due to a deficiency of boron). The greatest damage on cultivations of fruits and berries is caused by frost. 60-70 % of the fruit-trees in Finland were destroyed during the severe frost winters 1939- 1942. Considerable frost injuries have °Iso occurred during many subsquent Stems of apple trees damaged by winter. Of other diseases of fruit — frost. trees may be mentioned crown gall (Agrobacterium tumefaciens (E. F. Sm. & Towns.) Conn.), pocket plums (Taphrina pruni (F uck.) Tul .), shot hole in plums and cherries, and silver leaf, In storage much damage is caused by the bitter rot of apple (Gloeosporium spp.). The following diseases occurring on cultivations of berries may be mentioned: American mildew (Sphae- rotheca mors uvae (Schw.) Berk.), spur blight of raspberry (Didymella applanata (Niessl.) Sacc.), yellowing of leaves and virus diseases of Gloesporium rot of apples raspberry, leaf spot of Ribes species 11 (Pseudopeziza ribis Kleb.), Septoria Diseases caused by fungi as well as leaf spot (Septoria ribis Desm.), rust physiogenic diseases are significant fungi (Cronartium ribicola J.E.Fischer, factors hampering the cultivation of Puccinia pringsheimiana Kleb., and P. these plants. The Plant Pathology ribis (DC)., leaf spot of strawberry Department has been accordingly (Mycosphaerella fragariae (Tul . ) giving growers some instruction Lindau), and grey mould (Botrytis sp.) concerning the diseases of ornamental in the berries of strawberry. plants, chiefly on the basis of The spraying of fruit-trees in information obtained from literature. order to control the parasitic fungi The Department has had only limited has lately become common in Finland. possibilities of investigating the dis- Plans for spraying fruit-trees and seases of ornamental plants. Among berries have been mapped out by the the mostharmful diseases of ornamental Plant Pathology ;-ind Pest Investigation plants the following examples may be Departments of the Agricultural mentioned: mildew of begonia (Oidium Research Centre. The timing spray begoniae Putt.), rose mildew (Sphae- system has begun to be applied to rotheca pannosa (Wallr.), Lev.), the conditions prevoiling in Finland. carnation wild (Vericillium sp .), The cultivation of orname n ta I Fusarium wilt of carnation, leaf p I on ts is at present of considerable scorch (Stagonospora sp.) and leaf economic value even in Finland. spot of Phlox (Septoria sp.).

Literature

ELOMAA, A. 1952. Viljan peittauskokeiden tuloksia vuosilta 1928 - 1950. Summary: Results of cereal treatment experiments with disinfectants during the years 1928-1950. Valt. maatal. koetoim.tied. (Rep. Finnish State Agr. Res. Board) 226:1- 43. HILLI, A. 1932. Perunasyövän (Synchytrium endobioticum (SCHILB.) PERS.) leviämisen syistä Suomes- sa ja ulkomailla. Abstract: The reasons of the spread of potato wart (Synchytrium endobioticum (SCHILB.) PRES.) in Finland and abroad. Valt. rnaatal. koetoim. julk. (Publ. Finnish State Agr. Res. Board) 46: 1 - 249. Dissertation. HÄRDH, J.E. 1953.Kevätvehnän kahutähkäisyydestä sekä sen syistä Suomessa. Referate: On the shrivelheads of spring wheat and their causes in Finland. Ibid. 140:1-152. Dissertation. 1955.0menarupi ja sen torjunta Suomessa. Referate: Apple scab andits control in Finland. Ibid. 144:1-43. JAMAL.AINEN, E.A. 1935. Tutkimuksia lantun ruskotaudista. Referat: Untersuchungen tiber die "Ruskotau- ti"-Krankheit der Kohlrtibe. Ibid. 72:1-117. Disseration. - 1941. (Jber die Steinbrandanfälligheit verschiedener Weizensorten in Finland. Ibid. 115:1-27. _u_ 1943 a.nd 1944. Uber die Fusarien Finnlands, 1-111. Ibid. 122, 1943:1-26 (I); 123, 1943:1-25 (II) ; 124, 1944: 1-24 (III). - 1946. The significance of potato virus diseases in Finland. Maatal. tiet. aikak.(j. Sci. Agr.,Soc. Finland)18: 134-146. - 1949. Boorin puutteesta aiheutuvista kasvitaudeista ja boorin merkityksestä maamme kasvinvil- jelyssä. Summary: On boron deficiency diseases and on the role of boron in the Finn- nish plant cultivation. Valt. maatal. koetoim. julk. (Publ. Finnish State Agr. Res.Board)130: 1-48. -"- 1949. Overwintering of Gramineae-Plants and parasitic Fungi, I. Sclerotinia borealis Bubåk & V1eugel. Maatal. tiet. aikak. (J. Sci.Agr.Soc. Finland) 21:125-142. -"- 1950. Den växtpatologiska litteraturen om kultur- växterna i Finland under de senaste halvtan- dra decenniet. Swedish. (The literature on the field of plant pathology in Finland during the last 15 years). Nord. jordbr. forskn. No . 1, 1949/1950:12-29. 13

JAMALAI- 1.952. Sipulin tuotantoon haitallisesti vaikuttavista NEN E.A. tekijöistä ja sipulin viljelyn edistämistoimen- piteistä. Summary: On factors hampering o- aion productionand on measures for promoting onion cultivation. Valt. maatal. koetoim.tied. (Rep. Finnish State Agr. Res. Board) 225: 1 - 45 -"- 1953. Black rust and occurrence of Berberidaceae in Finland. Maatal. tiet. aikak. (J. Sci. Agr. Soc. Finland) 25:47-53. -"- 1953. Suomessa viljeltyjen omenalajikkeiden säily- vyydestä varastossa. Summary: On storage qu.alities of varieties of apple grown in Fin- land. Ibid. 25:136-146. 1954. Overwintering of cultivated plants under snow. FAO Plant Protection Bull.11:102-105. 1955. Fusarium species causing plant diseases in Finland. Acta agr. fennica 83:159-172. KITUNEN, E.1922. Tutkimuksia kauran nokisienistä ja eri kau- ralaatujen alttiudesta nokitartunnalle.Referat: Untersuchungen tiber den Haferbrand und die Brandanfälligheit der verschidenen H afer- sorten. S. maanv. tai. koel. tiet. julk. (Publ. Inst. Agr. and Econ. Res.) 15:1-126. Disser -

LEHTOLA, V.B. 1940. Untersuchungen tiber einige Brandpilze der Gattung Cintractia CORNU. Acta agr. fennica 42:1-136 Dissertation. LIRO, J.L. 1924 and 19g8. Die Ustilagineen Finnlands I - UI. Ann.aad. sci. fennica. 1924, A 17:1 - 626 , and 1938, A 42:1-720. LINNASALMI, ANNIKKI 1947. On the control of cucumber scab (Cladosporium cucumerinum ELL. &ARTH .). Maatal. tiet. aikak. (J. Sci. Agr. Soc. Fin- land) 19:124-128. -"- 1952. Damping-off on herbaceous vegetables and ornamental plants. Ann. bot. soc. "Vanamo" 26, 1:1-120. Disseration. -"- 1955. Maan desifiointi. Finnish.(Desinfection of the soil.) Puutarhavilj. Liitto (Union of Horti - culturists) 11:1-46. MUKULA, J. 1950. Säilytysaineiden käytöstä. porkkanan varas- toimisessa. Summary: On chemical preven- tion of storage rot of carrots. Maatal. tiet. aikak. (J. Sci. Agr. Soc. Finland) 22:86-92. -"- 1953. Perunan varastoimistappioista ja niiden ehkäi- semisestä. Summary: Storage loses of potatoes and their control. Valt. maatal. koetoim. julk. (Publ. Finnish State Agr. Res. Board) 137:1-39. Overwint e ri ng of plants and experiences in the chemical control of winter-injuring fungi in Finland.

(Authors L.A.J.AMALAINEN, AARRE YLI- MÄKI and M.HAAVISTO). Valt. maatal. koetoim. julk. (Publ. Finnish State Agr. Res. Board). Printing. RAINIO, A.J. 1932. Punahome Fusarium roseum LINK, Gib -- berella Saubinetii (MONT.) SACC. ja sen aiheuttamat myrkytykset kaurassa. Referat: Fusarium roseum beim Hafer und dadurch hervorgerufene Vergiftungen. Valt. maatal. koetoim. julk. (Publ. Finnish State Agr.Res. Board) 50:1-39. RAINIO, A.J.1936.Tutkimuksia Gladiolus-kasvien bakteeritau- deista (Pseudomonas marginata Mc. Cl., Ps. gummisudans Mc. Cl., Bacillus omnivorus Hall ja B variegatus nov. spec.) ja niiden torjuminen. Referat: Untersuchungen iiber Bakterienkrankheiten der Gladiolen (Pseudo- monas marginata Mc. Cl., Ps.gummisudans Mc. Cl., Bacillus omnivorus Hall und B. variegatus Rainio nov. spec) und ihre Bek- ämpfung. Ibid. 84:1- 1 02 . -"- 1937. Perunaruton aiheuttamat tuhot Suomessa ja sen esiintymiseen vaikuttavista tekijöistä.Re- ferat: Die durch der Kartoffelschimmel ver- ursachten Schaden in Finnland und iiber die auf sein Auftreten einwirkenden Faktoren.Ibid. 95:1-47. YLIMÄKI, AARRE 1955. On the effectiveness of penta and tetrachloronitrobenzenes on clover rot (Scle - rotinia trifoliorum Erikss.). Acta agr. fennica 83:147-158. -"- 1955. Perunasyövän levinneisyys ja torjunta Suo - messa. Zusammenfassung: Verbreitung und Bekämpfung von Kartoffelkrebs in Finnland. Maatal. tiet. aikak. (J. Sci Agr. Soc. Finland) 27:199-220.