Leptosphaeria maculans (anamorph Phoma lingam) causes blackleg disease of oilseed rape. The teleomorph stage of the blackleg pathogen on oilseed rape in Hungary is reported for the first time. Airborne ascospores of the pathogen were monitored in the infected source area using a portable Hirst-type spore trap in different horizontal and vertical sampling points. Meteorological conditions influencing airborne spore dispersal of the fungus were analysed. Airborne ascospores of pathotypes A/Tox + and B/Tox 0 groups of L. maculans were identified using a modified germination test. A mixed population of L. maculans A/Tox + and B/Tox 0 groups were found in Hungary. The occurrence of the fungus on a wide range of its wild cruciferous hosts appears to be an important factor in the outbreak of the disease on oilseed rape. High relative humidity, rainfall, melting snow and moderate wind were the most important factors in the dissemination of the ascospores.

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We examined effects of UV and visible light irradiation on mycelial growth and sclerotium formation of Sclerotinia sclerotiorum. The irradiation with UV had no effect on the production of sclerotia. However it had strong inhibitory action on the growth of mycelia. In cultures of the fungus irradiated with yellow and green light more but small sclerotia developed mainly in the perimeter of culture at the time of irradiation and between this circle and the wall of Petri dishes. In cultures irradiated with red and blue light, a few, but large sclerotia developed.

Effects of habitat characteristics and climatic factors on the occurrence of reed pathogens were investigated in a four-year survey. While diseases caused by Puccinia magnusiana, Polythrinciopsis phragmitis and Stagonospora sp. started to increase as early as in August, the other species caused severe infection in September (Deightoniella arundinacea, Puccinia phragmitis) or even later in the vegetation period (Deightoniella roumeguerei). For the distribution of some fungal pathogens (Puccinia phragmitis, Deightoniella arundinacea, D. roumeguerei and Stagonospora sp.) weather conditions (especially precipitation) were profound, while the occurrence of others (Puccinia magnusiana and Polythrinciopsis phragmitis) depended more on the characteristics of reed stands.

A szerzők növénykórtani vizsgálatokat és felvételezéseket végeztek fűmagtermesztésben szerepet játszó fűfajokon és azok fajtáin Magyarországon (Keszthely) és Ausztriában (Irdning). Céljuk, hogy a két eltérő ökológiai tulajdonságokkal rendelkező termőhelyen meghatározzák a termesztésben résztvevő fűfajok és azok fajtáit károsító növénypatogén kórokozó gombák faji összetételét és dominancia viszonyait. Jelen dolgozatban csak a levélfoltosság tünettípust előidéző kórokozó gombákra helyezik a hangsúlyt, a rozsda-, lisztharmat-, és üszöggombák okozta károsítással nem foglalkoznak. Ismertetik többek között a Cercosporidium graminis, Ramularia pusilla, Drechslera spp., Bipolaris spp., Mastigosporium spp., Septoria, Ascochyta spp. és a Colletotrichum graminicola gombafajok által előidézett tüneteket, a fűfajokon történő előfordulásuk mértékét és jelentőségét a két mintavételi helyen.