Forest Pathology

Mosseler, A. J.; Hubbes, M.

doi: 10.1111/j.1439-0329.1983.tb00127.xpmid: N/A

An attempt is made to determine the cause of a new canker and dieback disease affecting poplar hybrids (Populus spp.) growing in Ontario. Since the disease symptoms appear to be similar to those of a bacterial infection of poplars in Europe caused by Xanthomonas populi Ridé, bacterial species were investigated as possible causal agents of this new disease. Strains of Erwinia herbicola and Erwinia carotovora were associated with branch cankers on affected trees. The hypersensitive reaction on tobacco (Nicotiana tabacum var. Havana) resulting from artificial inoculations of strains of E. carotovora suggests the phytopathogenicity of these strains. Early results from inoculations into rooted poplar cuttings indicated that both strains may be capable of causing discolouration and decay of xylem tissues but these inoculations did not result in canker formation. Both of these opportunistic organisms may be potential pathogens of poplar under certain conditions.

Eckstein, D.; Aniol, R. W.; Bauch, J.

doi: 10.1111/j.1439-0329.1983.tb00128.xpmid: N/A

Dendroclimatological investigations on fir dicback. The dendrodimatological analysis of fir trees revealed that dry summers, in particular the summer 1976, did not cause fir dieback. As possible influencing factor, long‐term air pollution is taken into consideration.

Kiennen, L.; Schuck, H. J.

doi: 10.1111/j.1439-0329.1983.tb00129.xpmid: N/A

Investigation on the annual ring growth pattern of diseased Abies alba‐trees. Abies alba‐trees with symptoms of silver fir decline differ from healthy trees in the annual ring growth pattern.

Gellini, R.; Pantani, F.; Grossoni, P.; Bussotti, F.; Barbolani, E.; Rinallo, C.

doi: 10.1111/j.1439-0329.1983.tb00130.xpmid: N/A

Some italian pine‐woods on the Tyrrhenian coast (mainly Pinus pinea and Pinus pinaster) appear to have been deteriorating since nearly 20 years. From the experimental results of the present investigation, the main cause may be ascribed to the presence of both surfactants and salts in the sea‐spray which is deposited onto the pine needles by south‐westerly winds.

Spiers, A. G.; Wenham, H. T.

doi: 10.1111/j.1439-0329.1983.tb00131.xpmid: N/A

Laboratory studies established that poplar seed became contaminated with conidia of Marssonina brunnea during extraction from infected seed capsules. Contaminating conidia were loosely associated with the testa and were capable of initiating seedling infections. Examination of 23 imported Dutch seedlines showed that 20 were contaminated with viable conidia of M. brunnea. Ten seedlines produced infected seedlings when sown on blotters and in soil, confirming M. brunnea as a seed‐borne contaminant of poplar seed.

Rykowski, K.; Sierota, Z. H.

doi: 10.1111/j.1439-0329.1983.tb00132.xpmid: N/A

Some morphological traits of the crown (length and dry weight of needles, length of shoots) and chemical composition of the needles (content of nitrogen, phosphorus, potassium, calcium and magnesium) of a tree remaining in the middle of a Fomes annosus‐rot gap in a 55‐year‐old pine stand, were compared to the same traits from trees at the edges of the gap. The central tree (C) was intermediate in morphological traits. The lowest concentrations of N, P, and K were found in needles of the central (C) tree and, respectively, the highest ones in needles of the tree classified as weakened (I) and standing at the edge of the gap.

Butin, H.; Kowalski, T.

doi: 10.1111/j.1439-0329.1983.tb00133.xpmid: N/A

The natural pruning of branches and their biological preconditioning I. The fungal flora of beech (Fagus sylvatica). The paper deals with the species of fungi, on the basal part of dead branches of beech, associated with the natural pruning of these branches. Most of the species are Ascomycetes or Deuteromycetes.

Rudolph, E.; Halbwachs, G.

doi: 10.1111/j.1439-0329.1983.tb00134.xpmid: N/A

The bioindicator‐monitoring network “Inn‐Salzach‐area”– a border‐crossing network. The monitoring network for sulphur‐ and fluoride containing air pollutants, existing in Bavaria since 1975 and based on spruce trees (Picca abies) as indicators, has been extended to Upper Austrian territory. The results, which were obtained in the period between 1975 and 1980, are presented.

Gspiers, A.; Wenilam, H. T.

doi: 10.1111/j.1439-0329.1983.tb00135.xpmid: N/A

Marssonina brunnea infection of poplar seedlings was prevented by dusting artificially contaminated seed with benomyl, captafol, chlorothalonil, dodine, thiophanate and thiram applied as full strength formulated product and as a 1:1 mixture of formulated product and talc. Storage of seed dusted with a 1:1 mixture of fungicide and talc at ‐ 18°C. for 4 months did not affect seed germination nor seedling vigour.

Zhang, Shen; Holdenrieder, O.

doi: 10.1111/j.1439-0329.1983.tb00136.xpmid: N/A

Selective media for the assay of Heterobasidion annosum (Fr.) Bref. In fine roots. The behaviour of four Heterobasidion annosum strains on several selective media containing orthophenylphenol and antibiotics was recorded. The media were tested for selectivity by reisolation of the fungus from artificially infected and contaminated root segments. The following medium is recommended for the assay of H. annosum in fine roots: Orthophenylphenol 50 mg/l, Streptomycinsulphate 100 mg/l in water agar.