Tuhosienien merkityksestä perunavarastojen turmelijoina Suomessa

Authors

• Laila Ollila Maatalouskoelaitos, Kasvitautiosasto, Tikkurila

DOI: https://doi.org/10.23986/afsci.71236

Abstract

This paper is based partly on the storing1 experiments carried out by the Department of Plan Pathology in 1931—1938, partly on the circulars sent to farmers by the Dept, in 1938, partly on earliee investigations. According to them the damage of stored potato on account of fungous diseases in Fin land is estimated at about 10 per cent of the total weight. The most serious potato disease during the storing time in Finland is the potato blight (Phytophthora infestans). About 70—90 per cent of sick, stored potato will have this disease as primary cause of rotting. The rest, 10—30 per cent, becomes decayed by bacterial diseases. The Fusarium-fungi on the contrary, isolated from stored potato, occur principally as saprophytes. Of that nature an Fusarium solani (MART.) APP. & WR., Fusarium sambucinum FUCH., Fusarium merismoides CORD/ and Fusarium avenaceuni (FRIES) SACC. Only the Fusarium coeruleum (LIBB.) SACC. is established as a parasitic fungus in a few cases, having no noticeable importance in the country. Likewise a number of saprophytic Cylindrocarpon-species (C. Ehrenbergi WR., C. Magnusianun WR., C. olidum WR. and C. radicicola WR.) occur on stored potato tubers. All the potato storing trials in Finland indicate that the keeping qualities of the potato varieties most susceptile to blight are quite insatisfactory. Therefore, the potato blight control which can be realized suitably by cultivation of the best resistant varieties is one of the most effective ways to prevent storing losses. The chemical preserving substances (Conservos and Karsan, p. 95) have not had any noticeable effect on the injurious storage diseases, blight and bacterial rot. Only the occurrence and development of some epiphytical fungi has been prevented by the use of those chemicals. 1 The potato in Finland is generally stored in root cellars and in pits.