Zur Geschichte der Entdeckung des Reifungs-Anstieges im Gaswechsel von Obstfrüchten

Zusammenf assung Die Suche in der älteren Literatur nach bisher unbeachtet gebliebenen Beobachtungen über einen Reifungsanstieg im Gaswechsel von Kernobstfrüchten ergab:Der Reifungsanstieg im Gaswechsel von Obstfrüchten wurde bereits 1896 von Gerber für den Apfel dokumentiert aber übersehen, für die Banane jedoch auch beschrieben. Einige Jahre später beobachteten auch Müller-Thurgau & Schneider-Orelli (1908), daß das Ausmaß der CO₂-Ausscheidung von Äpfeln und Birnen im Verlauf ihres Wachstums bis zu einem Minimalwert absank. In diesem Zeitpunkt der minimalen CO₂-Ausscheidung gepflückte Äpfel und Birnen verstärkten im Verlauf eines ein- bis zweiwöchigen Lagerns bei Zimmertemperatur ihre CO₂-Ausscheidung auf etwa den doppelten Wert. Wurden die Äpfel erst einige Wochen nach dem Erreichen der Phase der minimalen CO₂-Ausscheidung gepflückt, so erfolgte der Anstieg der CO₂-Ausscheidung bereits auf dem Baum. Es wird geprüft, inwieweit die Autoren in diesen beobachteten Anstiegen der CO₂-Ausscheidung ein wesentliches, mit dem climacteric rise der englischen Forscher zu identifizierendes Reifungsphänomen erkannten.

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On the history of the discovery of the climacteric rise in gas exchange of pome fruits

In the older literature some observations concerning the gas exchange of ripening pome fruits have been found and discussed in this paper. These observations have been lost later on.The climacteric rise in gas exchange of apple fruits can be concluded from tables published by Gerber as early as 1896. Gerber himself did not recognize this phenomenon. In the case of the banana, however, he recorded and reported this rise in gas exchange during ripening.Some years later, Müller-Thurgau & Schneider-Orelli (1908), too, observed that the rate of the CO₂ output of apple and pear fruits diminishes to a minimal value during their growth period. Apple and pear fruits picked in this phase of minimal CO₂ output double the rate of their CO₂ output during the storage at room temperature for one to two weeks. If the apples are picked not before some weeks after having reached the phase of minimal CO₂ output, the rise in CO₂ output occurs already on the tree. Finally, it is discussed how far the authors have recognized that the observed rise in CO₂ output is an integer phenomenon of ripening for most of fleshy fruits. It is well known that this phenomenon is identical with the climacteric rise of the English investigators.

     

草莓新品种引种试验

对引进的74个国内外草莓新优品种进行栽培试验比较研究,筛选出鬼怒甘、公四莓、法兰地和麦特来4个优于主栽种丰香、适宜在我省推广栽培的品种。     

Control of seed-borne pathogens on legumes by microbial and other alternative seed treatments

Greenhouse trials were carried out in order to test the efficacy of different seed treatments as alternatives to chemicals against Colletotrichum lindemuthianum cause of anthracnose on bean and Ascochyta spp. cause of Ascochyta blights on pea, respectively. Resistance inducers, commercially formulated microorganisms, non-formulated selected strains of different microorganisms (fungi, bacteria and yeasts) and plant extracts were applied as dry or liquid seed treatments on naturally infested seeds. Seedling emergence and disease incidence and/or severity were recorded. Almost all seed treatments turned out to be ineffective in controlling the Ascochyta infections, which is in line with the literature stating that these pathogens are difficult to control. The only alternative treatments that gave some control of Ascochyta spp. were thyme oil and a strain of Clonostachys rosea. The resistance inducers tested successfully controlled infections of bean by C. lindemuthianum. Among the formulated microorganisms, Bacillus subtilis-based formulations provided the best protection from anthracnose. Some strains of Pseudomonas putida, a disease-suppressive, saprophytic strain of Fusarium oxysporum and the mustard powder-based product Tillecur also proved to be effective against bean anthracnose. However, among the resistance inducers as well as among the other groups, certain agents caused a significant reduction of plant emergence. Different alternative seed treatments can therefore be used for the control of C. lindemuthianum on bean, while on pea only thyme oil and a strain of Clonostachys rosea showed some effectiveness against Ascochyta spp.     

Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds

The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems.     

Histoplasma capsulatum Osteomyelitis in the Cat

Seven cats with osseous lesions as the primary manifestation of disseminated Histoplasma capsulatum infection were evaluated. The major clinical signs in these cats were related to the bony lesions and included lameness, bone pain, and soft tissue swelling of limbs and joints. Other clinical and pathologic findings were similar to previously reported forms of disseminated histoplasmosis in the cat. The radiographic appearance of the lesions was predominantly osteolytic; periosteal and endosteal new bone production was present in some cases. Infection occurred primarily in bones of the appendicular skeleton with a predilection for sites below the elbow and stifle joints.