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.
Authors:R. Bán, G. Fischl, A. I. Engloner and F. Virányi
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.