The article presents the studies about antagonistic influence of insect pathogenic fungi Beauveria bassiana (Bals.) Vuill. and B. tenella (Delacr.) Siem. against root rot diseases. The experiments were conducted in laboratory where the fungi were grown in Petri dishes. The results show that these fungi are antagonistic with each other. The used stem of B. bassiana was proved as strongest antagonist against all studied F.annosus.
The PDF contains a summary in German.
Two experiments were conducted in Punkaharju and Leivonmäki in the Central Finland in 1966-67 where the spread of the snow blight caused by Phacidium infestans Karst. was investigated in rows of excised branches from a ten-year-old stand of Scots pine (Pinus sylvestris L.). Ericaceous plants (Calluna vulgaris (L.) Hull and Vaccinium vitis-idaea L.) infected with snow moulds were used to determine their influence on the spread of snow blight.
The results show that significant inhibition of snow blight in Scots pine can be achieved with foliage of ericaceous evergreens. The mechanism of this inhibition is an object of conjecture. In healthy ericaceous vegetation it might be caused by saprophytic fungi living on surface of plants or by some constituent of the foliage. In the case of dead ericaceous foliage, the cause of inhibition seems to be the antagonism of other snow moulds. The antagonism of certain saprophytic organism is well known.
The observed inhibition suggests that ericaceous vegetation may be helpful for reforestation by offering a natural control of snow blight, when seedlings of Scots pine do not stand above the surrounding vegetation.
The PDF includes a summary in Finnish.
Unequivocal evidence on the antagonistic effects of endophytic fungi associated with woody plants against insect herbivores has been documented in only a few cases so far. Experimental evidence of the significance of needle endophytes to coniferous trees has remained scant because it is difficult to obtain trees with needles free of endophytes that could be used as comparable controls for trees infected with endophytes. Previously we reported a new methodology to get Norway spruce (Picea abies (L.) Karst.) saplings without needle endophytes and to inoculate them with a needle endophyte Lophodermium piceae (Fuckel) Höhn. Here we describe the first trial where spruce saplings with and without needle endophytes were provided as substrate for insect larvae. We transferred larvae of two sawfly species, Neodiprion sertifer Geoffroy and Gilpina pallida Klug, to the seedlings. Even though the main host of these sawfly species is not Norway spruce, but Scots pine (Pinus sylvestris L.), they are also known to occasionally feed on spruce. In this experiment the larvae did not develop to pupae with the provided spruce substrate but consumed measurable amounts of needles. No significant difference was found between the extent of needles consumed by either of the two sawfly species in inoculated and uninoculated saplings.