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Laser-Induced Fluorescence (LIF) from the S1 state of acetone and 3-pentanone was studied as a function of temperature and pressure using excitation at 248 nm. Additionally, LIF of 3-pentanone was investigated using 277 and 312 nm excitation. Added gases were synthetic air, O2, and N2 respectively, in the range 0–50 bar. At 383 K and for excitation at 248 nm, all the chosen collision partners gave an initial enhancement in fluorescence intensity with added gas pressure. Thereafter, the signal intensity remained constant for N2 but decreased markedly for O2. For synthetic air, only a small decrease occurred beyond 25 bar. At longer excitation wavelengths (277 and 312 nm), the corresponding initial rise in signal with synthetic air pressure was less than that for 248 nm. The temperature dependence of the fluorescence intensity was determined in the range 383–640 K at a constant pressure of 1 bar synthetic air. For 248 nm excitation, a marked fall in the fluorescence signal was observed, whereas for 277 nm excitation the corresponding decrease was only half as strong. By contrast, exciting 3-pentanone at 312 nm, the signal intensity increased markedly in the same temperature range. These results are consistent with the observation of a red shift of the absorption spectra (≈9 nm) over this temperature range. Essentially, the same temperature dependence was obtained at 10 and 20 bar pressure of synthetic air. It is demonstrated that temperatures can be determined from the relative fluorescence intensities following excitation of 3-pentanone at 248 and 312 nm, respectively. This new approach could be of interest as a non-intrusive thermometry method, e.g., for the compression phase in combustion engines.

In order to study perfusion effects of different liver preservation methods on liver structure, porcine livers were perfused with either Bretschneider's HTK (Histidine Tryptophane Ketoglutarat) solution, Euro-Collins (EC) solution or University of Wisconsin solution (UW) according to the respective recommended protocols. Subsequently, together with a group of unprotected livers, all organs were examined by light and electron microscopy including computer assisted morphometry. The width of the space of Disse, the continuity of endothelial cells and the ultrastructure of the hepatocytes were not impaired after cold perfusion with any of the 3 solutions. However, we found considerable differences between the groups with respect to removal of blood cells from liver sinusoids. Livers flushed according to the HTK-protocol had the lowest residual blood cell content followed by the livers of the EC- and the UW-group. Centrilobular regions of the liver lobules were generally better washed free of blood than periportal zones. Computer assisted morphometry did not reveal any significant difference between the size of hepatocytes of EC-, UW- and HTK livers. Only the hepatocytes of normothermic control livers (biopsy samples) were 10% larger than hepatocytes of cold flushed groups. None of the protective perfusion protocols showed structural signs of perfusion injury.

Triadimefon retarded the elongation of the upper internodes of shoots of tomato and cotton plants. The growth retardation was completely reversed by exogenously applied gibberellic acid (GA3). Growth of coleoptiles, primary leaves and roots of wheat and barley seedlings was reduced after seed treatment with triadimefon; application of GA3 did not completely counteract this growth retardation. Leaves of triadimefon-treated plants showed a darker green colour; leaves became lighter again when the growth retardation was reversed by GA3 application. When detached leaf sections were floated in triadimefon solutions or suspensions in the dark, senescence was delayed. The compound showed only a weak antagonistic effect on GA3-induced α-amylase synthesis in barley endosperm. Triadimefon strongly reduced the synthesis of gibberellin-like substances in Fusarium moniliforme. It inhibited the development of haustoria of Erysiphe graminis f. sp. hordei. Studies on its mode of action revealed that triadimefon blocked ergosterol biosynthesis in Ustilago avenae.

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1. Durch Grundungung mit Hafer, Senf oder Ackerbohnen kann der Befall der Baumwolle durchFusarium oxysporum f.vasinfectum in Gefasversuchen wesentlich vermindert werden. Die Befallsreduktion betragt bis zu 80%.

A few polyphenols (tannic acid and digallic acid), anthraquinone derivatives (rufianic acid and quinalizarin), and detergents (an alkylaryl sulfonate) proved to be especially effective inhibitors of pectolytic and cellulolytic enzymes of four phytopathogenic fungi. Some of these substances prevented the infection of tomato leaves withAlternaria solani. It appears, however, that inhibition of the germination of conidia was the crucial effect rather than inhibition of the enzymes. Alkylaryl sulfonate and rufianic acid were able to reduce the maceration of bean hypocotyls byRhizoctonia solani. Rufianic acid also counteracted tomato wilt, caused byFusarium oxysporum f.lycopersici, especially in the case of postinfectional application. On the other hand preinfectional rather than postinfectional application of rufianic acid had effect onVerticillium wilt of tomato.

Bodenburtige Pflanzenkrankheiten sind nicht nur das Ergebnis einer Auseinandersetzung zwischen Wirtspflanzen und Erregern. Vielmehr greifen edaphische Faktoren, insbesondere die Bodenmikroflora, modifizierend in dieses Geschehen ein. Nahere Untersuchungen mitOphiobolus graminis Sacc. undCercosporella herpotrichoides Fron an Weizen sowieFusarium oxysporum f.vasinfectum (Atk.)Snyder &Hansen an Baumwolle haben gezeigt, das sich Grundungung auf alle 3 Komponenten des Krankheitsbefalls unmittelbar oder mittelbar auswirken kann. Hinzu kommt, das die einzelnen Organismen in verschiedenen Entwicklungsstadien durchaus unterschiedlich reagieren konnen. Im einzelnen wurden folgende Auswirkungen der Grundungung festgestellt: Die Gesamtwirkung einer Grundungung auf den Krankheitsbefall nachfolgender Fruchte ergibt sich als Resultante aus den Teilwirkungen. Sind diese uberwiegend positiv, so wird es insgesamt zu einer Befallsminderung kommen, wie sie fur die Schwarzbeinigkeit des Weizens(O. graminis) und die Baumwollwelke(F. oxysporum f.vasinfectum) beobachtet wurde. Aber selbst bei Vorherrschen befallssteigernder Einflusse, wie im Falle der Halmbruchkrankheit(C. herpotrichoides), konnen die schadlichen Folgen durch erhohte Toleranz der Pflanzen kompensiert werden.

Entomology and Phytomedicine This article represents a comment on the publication ofSchwenke (1974) in which phytomedicine is mentioned as to be a threat to entomology. With regard to this it should be stated that entomology and phytomedicine are independent fields of knowledge. The insect is standing in the centre of entomology, whereas phytomedicine is centred on the protection of plants from diseases and injuries. The relation of entomology to phytomedicine results from the fact that numerous insects belong to the most important organisms causing damage to plants. Specialized entomogists are qualified, within phytomedicine, mainly for such tasks as research and teaching. The practical plant doctor, however, who may be engaged in extension work, needs a broad phytomedical education; in so far entomology cannot occupy a special position within phytomedicine. From the standpoint of phytomedicine entomology, as a part of zoology, is a basic discipline similar to mycology, virology, etc. Entomology, therefore, is needed by phytomedicine, not threatened. Apart from this there are, of course, fields of activity in entomology which are outside of phytomedicine.

Of the compounds tested especially xanthene-9-carboxylic acid [I], applied via the roots (10−4M), strongly affected the morphogenesis of tomato plants. The leaves were deformed, the laminae reduced, the internodes shortened and the growth of axillary buds was stimulated. Geo- and phototropism of wheat and rye seedlings were disturbed. The observed effects are very similar to the influence of the structurally related derivatives of 9-hydroxyfluorenecarboxylic acid-(9) [II], known as “morphactins”.

DERIVATIVES of 9-hydroxyfluorene-9-carboxylic acid, known as Morphactins, have therapeutic effects on several diseases of tomato1. Apparently, there is no correlation between the morphoregulatory and therapeutic activities of these compounds. Davis et al.2 have shown that unsubstituted fluorene also has a certain effect on Fusarium wilt of tomato. This prompted us to examine several derivatives of fluorene for their therapeutic potencies against two vascular diseases (caused by Fusarium oxysporum f. lycopersici and Verticillium albo-atrum) and one leaf disease (caused by Phytophthora infestans).

In Kulturfiltraten vonCercosporella herpotrichoides, dem Erreger der Halmbruchkrankheit des Weizens, wurden folgende Enzyme nachgewiesen: Polygalacturonase, Pektinmethylesterase, Pektin-Lyase und Cellulase. Es wird vermutet, dass diese Enzyme, die in einigen Eigenschaften kurz charakterisiert werden, fur die Pathogenese von Bedeutung sind.