Über die Zersetzung von Buchen- und Fichtenrinde unter natürlichen Bedingungen1

Natural degradation of bark of beech and spruce . In connection with the biological utilization of tree barks the degradation of bark of beech and spruce was studied by determining weight losses and the fungal flora of samples exposed in forest stands of the same species. The barks contained a considerable amount of easily degradable components.     

Untersuchungen über den Einfluß von Cuticularwachsen auf die Infektionsfähigkeit pathogener Pilze

The effect of cuticular waxes on the infection rate of pathogenic fungi. 1. Lophodermium pinastri and Botrytis cinerea . Spore germination and growth rate of germ-hyphae of Lophodermium pinastri and Botrytis cinerea are influenced by low concentrations of cuticular waxes, added to the germination medium. The stimulating effect increases with decreasing resistance of the species or race used for wax sampling. Generally the separately tested alcohol-, aldehyde-, ester-, fatty acid- and hydrocarbon fractions induce similiar but less pronounced reactions than total waxes. Exceptions occur. They led to suggestions in direction to single chemical components causing resistance. – Finally alcohol and hydrocarbon chromatOgrams of cuticular waxes for Pinus montana, P. nigra and Picea abies are presented for the first time.     

Untersuchungen über den Einfluß von Cuticularwachsen auf die Infektionsfähigkeit pathogener Pilze

The effect of cuticular waxes on the infection rate of pathogenic fungi. 2. Rhytisma acerinum, Microsphaera alphitoides and Fusarium oxysporum . Cuticular waxes of Acer and Quercus species stimulate germination rate and germ-tube development of certain foliar pathogens. The stimulation increases with host susceptibility. In the case of Rhytisma acerinum, the chemical composition of the leaf wax may be responsible for the host specificity of physiological races. Cuticular waxes showed a marked effect on Fusarium oxysporum also. In some cases, individual chemical components of different fractions seem to play a role in the mechanism of resistance.     

Über das Vorkommen von Rickettsien-ähnlichen Bakterien und Mykoplasmen-ähnlichen Organismen in Buchen aus Waldschadensgebieten

The occurrence of rickettsia-like bacteria and mycoplasma-like structures is reported from the roots and secondary phloem of beech trees from areas in Black Forests and Lower Saxony affected by forest die-back. The significance of the presence of these primitive organisms for the premature yellowing of leaves observed has still to be solved.     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst

Causes and criteria of resistancë to air pollution in Norway spruce. 3. Tolerance of toxic materials (“internal” resistance). Comparing relatively resistant and not resistant Norway spruce clones, an attempt was made to find differences by investigating the relation of needle colour and absorption of sulfur, needle pH-value and buffer capacity, sulphur distribution within several of their needle components and within the total plant, the ratio of organically fixed sulfur to total sulfur content of noedles, and content of sulfhydril groups, protein and chlorophyll of needles. Significant differences were shown only in buffer capacity of unfumigated needles, and in thc propornon of organically fixed sulfur before and after SO₂ fumigation.     

Untersuchungen über den Einfluß von Dimilin (Diflubenzuron) auf Wachstum und Konidienkeimung einiger insektenpathogener Pilze

Zusammenfassung Der Einfluß von Dimilin, einem Chitinsynthesehemmer, auf das Wachstum von 2 Deuteromyceten (Beauveria tenella, Metarrhizium anisopliae) und von 4Entomophthora-Arten (E. aphidis, E. culicis, E. sphaerosperma, E. thaxteriana) sowie auf die Konidienkeimung vonE. aphidis undE. thaxteriana wurde untersucht. Dabei konnte festgestellt werden, daß das Wachstum vonB. tenella und vonM. anisopliae bei praxisnahen Konzentrationen geringfügig beeinträchtigt ist, nicht jedoch jenes der geprüftenEntomophthora-Arten. Dieselben Konzentrationen stimulierten die Konidienkeimung und die Bildung von Sekundärkonidien vonE. aphidis undE. thaxteriana.

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Investigations on the influence of Dimilin (Diflubenzuron) on growth and germination of conidia of some insect pathogenic fungi

The influence of Dimilin, an inhibitor of the chitin synthesis, was tested on growth of two Deuteromycetes (Beauveria tenella, Metarrhizium anisopliae) and four species ofEntomophthora (E. aphidis, E. culicis, E. spaerosperma, E. thaxteriana) and on germination of conidia ofE. aphidis andE. thaxteriana. It was demonstrated that concentrations proposed for practical applications slightly impaired the growth ofB. tenella andM. anisopliae, but did not influence the growth ofEntomophthora species. The same concentrations stimulated germination of conidia and formation of secondary conidia ofE. aphidis andE. thaxteriana.

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Mit 2 Abbildungen     

Endophytische Pilze in Blättern und Zweigen von Quercus petraea

Endophytic fungi in leaves and twigs of Quercus petraea . Surface sterilized leaf and twig samples taken in 1989 from sessile oak (Quercus petraea) in Austria yielded host-specific as well as unspecific ubiquistic endophytes. In leaves, Aureobasidium apocryptum and Apiognomonia quercina were the most frequent taxa, while Colpoma quercinum was the dominant species in twigs. The colonization rates of individual species were subjected to seasonal variation.     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst1

Causes and criteria of resistance to air pollution in Norway spruce, Picea abies (L.) Karst. IV. Recovery of injured needles, connections between forms of resistance and summary of results to date. Water potential measurement of resistant clones of Norway spruce treated with SO₂ showed that they recovered better than control clones or were at least not so permanently affected. From a variety of experiments on fumigation, it was concluded that reflexive and “internal” resistance were associated. The results of the series of papers so far are summarised.     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst1

Causes and criteria of resistance to air pollution in Norway spruce. 1. Morphological and anatomical resistance. Pollution resistance of selected visibly resistant clones is not due to environmental causes or to length of the growing season. Between the resistant and other clones there are significant differences in morphology and anatomy of the needles. The average length, width and weight of the needles of resistant spruce grafts arc greater than those of none resistant. The resistant grafts have more stomata and, at least in winter, lower permeability of needle tissue to gases.     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst.

Causes and critcria of resistance to air pollution in Norway spruce. II. Reflexive resistance . The different reactions of stomata of resistant and “normal” spruce grafts were investigated. Resistant grafts were shown to have a more sensitive reaction by measuring water potentials and by analyzing S content in SO₂ fumigated needles or F contents in grafts exposed to polluted air. Other tcsts involving gas permeability of stomata, clecrrical conductivity of needle cxtracts and watcr content of SO₂ fumigated needles were less effective.     

Über das Vorkommen von Armillaria-Arten und-Klonen in benachbarten Koniferenbeständen,Mischbeständen und in Laubwald1

Occurrence of species and clones of Armillaria in spruce stands, mixed stands and hardwood stands in close neighbourhood . From Armillarid rhizomorphs (collected around trees) and from spruce butt rots, isolates of the diploids were made. In pairings between the diploid isolates and haploid testers from the five (European) biological species (BULLER phenomenon) the mating reactions often were not clear enough to identify the diploids. So carpophores were raised from the isolates and single spore cultures were obtained. In pairings with the haploid testers Armillaria borealis, A. bulbosa and A. bulbosa were identified. Usually more than one Armillaria species and from each species more than one clone occurred in each stand.     

Über den Einfluß fluorhaltiger Fabrikabgase auf den Phenolgehalt von Fichtennadeln

The effect of industrial fluoride air pollutants on the phenolic contents of Norway spruce needles . Potted Norway spruce trees of two clones were exposed under natural conditions at various distances from an industrial fluoride source. The new needles were analysed periodically for their phenolic content. The group of trees closest to the fluoride source contained the highest amount of phenols.     

Eigenschaften und Verwendung des Patentbiegeholzes

Ohne Zusammenfassung     

Über die Eignung von Phosphatase- und Esteraseaktivitätsbestimmungen an Fichtennadeln und Birkenblättern zum Nachweis „unsichtbarer physiologischer” Fluorimmissionsschädigungen

Measurement of phosphatase and esterase activity in Norway spruce needles and birch leaves to detect “hidden” F-injury . Potted Norway spruce and birch were exposed at various distances from an industrial fluoride source. The needles and leaves were analysed periodically during a year for their enzymatic activities. In contrast to phosphatase, increased esterase activities were found to be a possible indicator of “hidden” F-injury to the trees.     

Endophytische Pilze in Blättern und Ästen gesunder und geschädigter Buchen (Fagus sylvatica L.)

Endophytic fungi in leaves and twigs of healthy and diseased beech trees (Fagus sylvatica L.). Endophytic fungi were isolated from surface-sterilized leaves and twigs of healthy and diseased trees. Three fungal species could be isolated frequently: Apiognomonia errabunda, Diaporthe eres and Bisporella sp. D. eres occurred in leaves of healthy trees more frequently, than in those of diseased trees. It has been hypothesized, that less capacity of water and nutrient uptake of diseased trees is responsible for this effect. A mutualistic symbiosis of A. errabunda and D. eres with beech trees is supposed and discussed.     

Über das Auftreten von Leucocytospora kunzei bei Pinus griffithii in Parkanlagen der Stadt Basel

Occurrence of Leucocytospora kunzei on Pinus griffithii in parks of the City of Basel. Leucocytospora kunzeii (Sacc.) Urban, the causal agent of a canker disease mainly known in North America, was found on Pinus griffitbii in several public parks of Basel.