Beziehungen zwischen der Ausbreitung künstlicher Fomes annosus-Infektionen in den Stämmchen zweier Fichtenklone und einigen holzchemischen Eigenschaften

The spread of Fomes annosus from artificial infections of stems, in relation to the chemical characteristics of timber of two spruce clones . Differences in the spread of Fomes annosus in two spruce clones (Picea abies Karst.), which were found by DIMITRI, may be attributed to differences in the properties of the wood from the two clones, detected in laboratory tests. Wood meal from the more resistant clone R inhibited Fomes annosus in bioassays more than wood meal from the more susceptible clone A. Wood from clne A-trees showed a higher nitrogen content than wood from clone R-trees.     

Die Leitfähigkeit von Fichtenborken-Extrakten als empfindlicher Indikator für Luftverunreinigungen

The Conductivity of Bark-Extracts from Spruce, a Sensitive Indicator for Air Poilution . Bark of spruce is a useful and sensitive indicator for air pollution. The latter may be determined more precisely by electrolytic conductivity of bark extracts than by pH-value or sulphate level of foliage. By an additional simple sulphate analysis of bark extracts the effects of SO₂ may be distinguished from those of certain components in dust.     

Veränderung der Krankheitsdisposition von Forstpflanzen durch Herbizide1

Modification in discase-sensibility of forest plants by herbicide treatment. I. Field trials with Lophodermium pinastri. The effect of two herbicides TOP-KH (salt of 2,4,5-T) and Casoron G (Dichlobenil) on incidence of Lophodermium pinastri on Scots pine (Pinus sylvestrií L.) was investigated in field trials with potted plants. Treatment with TOP-KH led to increase in infection with higher herbicide concentrations and to higher numbers of severely infected plants in comparison with controls. Differences were greatest in spring. With Casoron G, however, smaller numbers of sevcrely infected plants were seen in spring and at the end of the growing season the damage was not much greater than in the controls. Possible reasons for changes in degree of infection are discussed as well as effects that could be expected on the epidemiology of pine needle cast.     

Hemmung einiger Ektoenzyme von Fomes annosus (Fr.) Cke. durch Holz- und Bastextrakte aus Picea abies (Karst.)

Inhibition of several ectoenzymes of Fomes annosus (Fr.) Cke. by wood and bark extracts from Picea abies (Karst.). Methanol soluble extractives of sapwood, heartwood and reaction zone from Norway spruce as well as acetone soluble extractives of spruce bark were tested at a concentration of 0.05 percent for inhibition of Fomes annosus enzymes cellulase, pectinase     

Das Keimverhalten der Konidiosporen von Fomes annosus (Fr.) Cke. bei Einwirkung verschiedener Standortfaktoren

The Influence of site factors on the Germination of Fomes annosus conidiospores . Cultures grown up on a source with an easily utilisable C-source produce conidia with a lower germination rate. An easily utilisable C-source in the medium promotes germination. Different strains vary individually in their germination behaviour in respect to temperature. Short-time-strains have an optimum between 12–28°C, longtime-strains have a peak at about 24°C. Some strains tend to suddenly alter their germination rate at a lower or higher temperature, thus increasing the plasticity of the fungus. Germination behaviour with regard to pH is strainspecific. The optima lie between pH 4,0–6,5. The pH influences the germination rate more than the nutrients status of the soil. The standard deviations in germination behaviour for some soils are large. Between the various origins of strains there are no significant differences.     

Early and late root formation in epicotyl cuttings of Pinus sylvestris after auxin treatment

Auxin stimulated rooting of epicotyl cuttings of Pinus sylvestris irrespective of the physiological stage of the plant from which the cuttings were taken. The epicotyl cuttings were divided into two groups, those that differentiated roots early (within 6 weeks after cutting) and those that differentiated roots late (more than 6 weeks after cutting). Auxin treatment significantly stimulated the frequency of early rooting of epicotyl cuttings, whereas it had no effect on the frequency of late rooting of epicotyl cuttings. The number of roots per rooted cutting was significantly higher after auxin treatment both on early and late rooted cuttings. Anatomical studies showed that most of the roots on both early and late rooted cuttings developed from wound tissue. However some types of rooting were found only after auxin treatment of early rooted cuttings, e.g., roots that developed from resin duct wound tissue or from vascular tissue or in the pith.     

Dünnschichtchromatographische und mikrobiologische Untersuchungen über den Hemmstoffgehalt einiger Pappelklone

Investigations of the content of inhibitory substances in some Poplar clones by thin-layer chromatography and the use of micro-organisms . Poplar leaves and stems (T 39 Wettstein Züchtung, T 213 PבForndorf’, T 217 Pבvernirubens’) from fertilized plots (P N K) and unfertilized plots were tested microbiologically and by thin-layer chromatography. Leaf extracts contained phenolic compounds which influenced the growth of Septotinia podophyllina Whetz. Stem extracts were found to contain other substances influencing the growth of Cryptodiaporhthe, populea (Sacc.) Butin. Fertilizing frequently influenced phenol production in bark extracts but only seldom in leaf extracts.     

Untersuchungen zum gegenwärtigen Stand der Insektizidresistenz bei der Stubenfliege (Musca domestica L.) in Süddeutschland

18 strains of the house fly (Musca domestica L.) were tested by topical application for resistance to cypermethrin, permethrin, lindane, trichlorfon and malathion; three of them were additionally tested to dimethoate, dichlorvos and bromophos. The strain WHO/IN served as control. No resistance against the two pyrethroids could be demonstrated in the most strains, some of them were more susceptible than the control flies. Only in one strain the resistance was almost 20-fold. All strains showed resistance to lindane, with R>100 in two, R between 2 and 20 in the other strains. The resistance level to trichlorfon and malathion was very high (R>500 to trichlorfon, R>80 to malathion). Also to dichlorvos (R ranged from 2- to 5-fold), bromophos (R ranged from 20- to 30-fold), and dimethoate (R ranged from 5- to 8-fold) the resistance level was increased.     

Die Wirkung von Monoterpenen auf das Mycelwachstum von Fomes annosus (Fr.) Cooke

The effect of monoterpenes on the mycelial growth of Fomes annosus (Fr.) Cke. Four monoterpenes, singly and in mixture, were tested for their effect on the mycelial growth of Fomes annosus. Inhibition was caused by all the substances, the severity depending on material and concentration. The inhibition was not maintained over the entire study period.