Die Wirkung wäßriger Streuextrakte verschiedener Waldbäume auf Mycelwachstum und Konidiosporenkeimung von Fomes annosus (Fr.) Cke.

The effect of water extracts of leaf and needle litter from different forest trees on the mycelial growth and the germination rate of conidia of Fomes annosus (Fr.) Cke. Litter extracts from various forest trees and stands have distinct effects on mycelial growth and germination rate of conidia of Fomes annosus. The effects depend on concentration of the extract, period of extraction and on date of collecting the litter samples.     

Einfluß niedriger SO2-Konzentrationen auf die Aktivität einiger Glykosidasen der Assimilationsorgane verklonter Waldbäume

Effect of low SO₂-concentrations on the activities of some glycosidases in the foliage of clonal forest trees. The aim was to find an early indicator of latent SO₂ injuries in a beech and a spruce clone. After exposure to 0.0, 0.05, 0.1 and 0.2 ppm for several weeks in outdoor fumigation chambers, the activities of β-glucosidase in the beech and β-galactosidase in the spruce clone and β-l,3-glucanase in both species were significantly raised. As the beech clone was very sensitive to SO₂, an indication of latent injury could be ascertained only in the 0.05 ppm treatment where the rise of the β-glucosidase activity appeared some days before necroses. Contrary to beech, the spruce clone was tolerant to all SO₂-treatments and the enzymatical changes could be used as early indicators of latent injuries.     

Die Wirkung der Dämpfe von Erdölbitumen auf Pflanzen1

The effect of vapours from asphaltic bitumen on plants . Asphaltic bitumen vapours escape from hot-mix asphalt plants and are deposited on leaves and shoots. Experiments were initiated to show whether such droplets cause injuries to plants. Results show that only certain sensitive plants develop symptoms, and then only when more than 3 mg of condensate are deposited per 100 cm² of leaf surface. Injuries caused by bitumen vapours and those caused by coal-tar vapours were closely related. They were both activated by UV-light and the symptoms were similar though milder in the case of bitumen. The differences are mainly due to the widely dissimilar content of aromatic hydrocarbons, the photoactivated agents common to the products.     

Simultane Messung der Chlorophyll Fluoreszenz-Kinetik bei verschiedenen Wellenlángen als rasches Verfahren zur Frühdiagnose von Immissionsbelastungen an Waldbäumen: Ozoneinwirkungen auf Buchen und Pappeln

Simultaneous measurement of chlorophyll fluorescence-kinetics at two different wavelengths as a rapid and an early detection method of air pollution damage on trees: Ozone effects on beech and poplar . A newly defined light adaption index A_P shows the stress influence already before the comparable and known vitality index R_fd and the appearance of visible ozone symptoms on foliage.     

Zur Wirkung von Nemacur- und Temik-Granulaten auf Wurzelgallen-Nematoden (Meloidogyne spp.) bei der Tomate

The susceptibility of the two single populations of root-knot nematodes invading tomato roots,Meloidogyne javanica andM. incognita acrita, in comparison with a mixed population of the two species was investigated to the granular nematicides, Nemacur and Temik. Root-gall indices ofM. incognita acrita were reduced more than ofM. javanica. In addition, root-gall indices of the mixed population and a single population,M. incognita acrita, were the same.     

Physiologische Reaktionen der Fichte (Picea abies) auf komplexen SO2- und Trockenstreß

Physiological reactions of spruce (Picea abies) on complex SO₂- and drought-induced stress. Part 3. Responses of SO₂-stressed spruces to subsequent drought-induced stress. SO₂-stressed spruces under drought-stress showed less reduced water content, less increased osmotical potential and less restricted photosynthesis compared to spruces without preceding SO₂-stress and thus seemed to be in a better physiological situation. Their ability to retain water (in cut-off twigs) as well as their ability to withstand a quick and strong water-loss in the needle-tissue without cell-damage were reduced. Reasons for the temporarily favourable effect of a pre-going SO₂-stress in surviving a drought-stress are discussed.     

Wirkung der Glasur von Reis auf die Vermehrungsfähigkeit von Vorratsschädlingen

The glazing of rice kernels with a coating of glucose and talc has a limited effect against infestation by some stored product insects. In the case of long kernel rice the development of te offspring ofTribolium castaneum, Tribolium confusum, Sitotroga cereallella andOryzaephilus surinamensis is significantly inhibited. In case of round kernel rice, a protecting effect againstTribolium castaneum, Tribolium confusum andOryzaephilus surinamensis is observable; whereasSitophilus granarius, Sitophilus oryzae andRhizopertha dominica have a greater number of progeny on glazed than on unglazed round kernel rice.     

Zur Wirkung von Milchsäure auf den Varroa-Befall der Biene

40% lactic acid was sprayed 3 times into each of two bee colonies. The rate of infestation was determined, before beginning the experiment and after each of the applications. The treatments showed a mean percentage reduction in the brood infestation byVarroa of 76,7% in the first colony and 85,2% in the second. These data indicate that it is possible to control the Varroasis by means of lactic acid successfully and without side effects.     

Nahrungswahl der Honigbiene bei verschiedenen Zuckern und Wirkung der Zucker auf die Lebensdauer

A study was carried out on the preference to some types of sugars by worker honey bees, and their effect on bee longevities. Honey syrup was preferred as food by the bees, followed by inverted sugar, common sugar syrup, and molasses. Worker honey bees fed on honey had the longest life-span (13.7 days), while those fed on commercial glucose had the earliest deaths.     

Vergleichende Untersuchungen der Anziehungskraft von Weibchen und synthetischen Pheromonen auf Männchen von Lymantria monacha im Zusammenhang mit der Wirkung biophysikalischer Felder

Zusammenfassung Die Anziehungskraft von Weibchen-Fallen (Dyksche Fallen) und Disparlure-Fallen (0,1 mg) wurde an den Zahlen eingefangener im Freiland vorhandener Männchen vonLymantria monacha 1974–1978 und an den zurückgelegten Distanzen ausgesetzter Männchen zu den Einfangstellen 1975–1978 untersucht. Dabei ergab sich neben der Abhängigkeit der Anziehungskraft der Weibchen von endogenen Faktoren im Vergleich zum synthetischen Duftstoff auch eine wesentlich größere von den Witterungsverhältnissen. Während längerer andauernder warmer Perioden konnten Dyksche Fallen im gleichen Ausmaße Männchen einfangen wie die Disparlure-Fallen: in warmen gewittrigen Nächten konnte der Einfang bei ersteren auch höher liegen. Bei kühler Witterung waren jedoch die Männchenfänge stets zahlreicher bei den Disparlure-Fallen. Dies kommt vor allem dort zum Ausdruck, wo Weibchen und der synthetische Duftstoff miteinander in Konkurrenz standen. Es erwies sich ferner bei der Wahl der Fallenstandorte als wichtig, neben Windrichtung und Bestandesverhältnissen auch das Vorhandensein biophysikalischer Felder zu berücksichtigen. Biophysikalische Felder, d. s. mit der Rute abgrenzbare Reizzonen, wurden von den Männchen bevorzugt beflogen. Die Ermittlung der Anflugdistanzen ergab, daß bei diesen Versuchen Weibchen nicht weiter als 85 m anlockten, der synthetisierte Duftstoff jedoch bis 200 m (weiteste festgesetzte Entfernung) Männchen anzog.

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The ability of female moths of Lymantria monacha L. compared with this of synthetic pheromons to attract males in connection with influences of biophysical fields

The attraction of female traps (Dyk'sche traps) and Disparlure traps (0.1 mg) was proved by the numbers of captured males of the surrounding areas and by distances passed by males from the locations of releasing to the traps. The results showed, that attraction of females depended from various endogen factors and compared to this of Disparlure to a bigger extent from weather conditions. It was stated that the females could lure males in same numbers as the synthetisized Pheromon during warm periods, especially in warm nights, when thunderstorms happened. But during cool weather conditions always more males were captured by Disparlure traps. This can be seen particularly in such areas, where females and synthetisized pheromons are in competition with each other. By choicening the site for traps not only the same conditions for air movements and stands have to be taken in consideration. Furthermore it is necessary to find the same biophysical conditions. Biophysical fiels (these are Zones of earth radiations limited by rods) are preferred by swarming males. It has been found by this trial that females lured from distances as far as 85 m and synthetisized Pheromons as far as 200 m. (The limits applied during this investigation have been chosen at random.)

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Mit 4 Abbildungen

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Vortrag gehalten am Südtiroler Entomologentag in Dietenheim bei Bruneck am 30. September 1978.     

Zur Frage der Wurzelentwicklung von Kiefern auf Sand und auf Pseudogley

Von allen einheimischen Baumarten liegen über die Bewurzelung der Kiefer (Pinus silvestris) die meisten Untersuchungen vor (Liese, 1926;Hilf, 1927;Vater, 1927;Laitakari, 1929;Wagenhoff, 1938). Das Interesse hierbei galt bisher besonders der Wurzelentwicklung auf Sandböden. In jüngster Zeit erfuhren die Erkenntnisse eine wesentliche Vertiefung durch Arbeiten vonEhwald (1948),Köstler (1956),Wagenknecht (1960) undKreutzer (1961). Trotzdem sind die Vorstellungen von der Bewurzelung der Kiefer auf verschiedenen Standorten, ihrer genetischen Veranlagung und ihrem Wachstum noch lückenhaft. Die folgenden Ergebnisse stammen aus Untersuchungen, die im Rahmen eines größeren Forschungsvorhabens über die Wurzeltracht der einheimischen Baumarten, an dem im Münchener Waldbauinstitut gearbeitet wird, erhoben wurden.     

Modellversuche zum Einfluß der Nährstofïversorgung auf die SO2-Empfindlichkeit von Pflanzen1

Studies on the influence of nutrition on the susceptibility of plants to SO₂ . The mineral nutrition of plants is of great importance for their susceptibility to air pollutants. Substrate media with ammonia as nitrogen source, deficiency of potassium and low pH-values reduce the buffer capacity and the cation contents. Buffer capacity and cation contents play important roles for the detoxification of SO₂-borne products. Low cation contents and a reduced buffer capacity produce a severe increase of the SO₂-effects. Decreased sulfur nutrition results in a considerable delay of the beginning of the SO₂-injuries.