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 treat- ment 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 ob- tained 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.