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91.
Wood Science and Technology - 相似文献
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以盆栽5年生云锦杜鹃苗木为材料,分对照、轻度胁迫、中度胁迫、重度胁迫4组,研究了土壤水分胁迫对云锦杜鹃叶片光合特性日变化的影响。结果表明:随着水分胁迫的加重,云锦杜鹃的光合日变化曲线由典型的双峰型逐渐转变为峰值很小的单峰型,峰值的降低在轻度水分胁迫下由气孔限制引起,而在中度和重度水分胁迫下则由非气孔限制引起。轻度、中度和重度水分胁迫对云锦杜鹃光合特性日变化的影响差异显著。经逐步多元回归得到了净光合速率日变化的回归方程。 相似文献
94.
Packaging foils made of cellulose actetate, cellophane, polyethylene, polypropylene, polystyrene, polyester, polyvinyl chloride, attacked byRhizopertha dominica F.,Stegobium paniceum L.,Tribolium castaneum Hbst. and larvae ofPlodia interpunctella Hbn. were examined with the scanning electron microscope (SEM). Because of the destruction marks made by the insects, it is possible to determine with the SEM the side of packaging material which has been attacked by the pests. Due to the shape and position of the mouthparts of the insects the gnawing marks are rather typical for the different species. By means of a standard of comparison it might be possible to determine the family and perhaps the genus or species of the insects involved. The influence of shape and size of the mouthparts as well as the position of the mandibles in relation to the anatomy and to the axis of the body on the gnawing ability of stored-product pests is discussed. The reasons for the insect resistance of packaging materials are discussed (smoothness of the surface, rigidity, thickness). 相似文献
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96.
Zusammenfassung Es wird über das Auftreten von 25 Vorratsschädlingen, darunter 17 Käfer- und 3 Mottenarten, in den Lägern der Bevorratungsabteilung des Senators für Wirtschaft und Arbeit, der sonstigen Großlagerhaltung sowie in den Vorräten privater Haushalte berichtet. Die häufigsten Schädlinge in der Großlagerei waren Brotkäfer (Stegobium paniceum L.) und Speichermotten (Ephestia elutella Hbn.). Für den Vorratsschutz interessante Fälle und besondere Arten werden ausführlicher behandelt. Außerdem wird ein Überblick über die Entwesungs- und Entseuchungsarbeiten gegeben, bei denen neben den Begasungsmitteln mit den Wirkstoffen Methylbromid, Phosphorwasserstoff und Blausäure auch Vorratsschutzmittel auf der Grundlage von Dichlorvos, Pyrethrum und Piperonylbutoxid in verschiedenen Anteilen eingesetzt werden.
Mit einer Abbildung und 3 Tabellen 相似文献
Stored products protection activities of the Plant Protection Office Berlin. Pests of foodstuffs and pest-control in warehouses from 1980 to 1986
It is reported about the appearance of 25 stored-product pests, within 17 species of beetles and 2 species of moths in warehouses of the Bevorratungsabteilung des Senators für Wirtschaft und Arbeit as well as in the other warehouses and private households. The drugstore bettle (Stegobium paniceum L.) and the warehouse moth (Ephestia elutella Hbn.) were the most common pests. Cases of special interest and particular species are described in detail. Also is given a survey about the pest-controlling measures carried out with poisongas as methylbromide, phosphine and hydrocyanic acid and with insecticides on basis of dichlorvos, pyrethrum and piperonylbutoxide.
Mit einer Abbildung und 3 Tabellen 相似文献
97.
It is predicted that dryland salinity will affect up to 17 Mha of the Australian landscape by 2050, and therefore, monitoring the health of tree plantings and remnant native vegetation in saline areas is increasingly important. Casuarina glauca Sieber ex Spreng. has considerable salinity tolerance and is commonly planted in areas with a shallow, saline water table. To evaluate the potential of using the nitrogenous composition of xylem sap to assess salinity stress in C. glauca, the responses of trees grown with various soil salinities in a greenhouse were compared with those of trees growing in field plots with different water table depths and groundwater salinities. In the greenhouse, increasing soil salinity led to increased allocation of nitrogen (N) to proline and arginine in both stem and root xylem sap, with coincident decreases in citrulline and asparagine. Although the field plots were ranked as increasingly saline-based on ground water salinity and depth-only the allocation of N to citrulline differed significantly between the field plots. Within each plot, temporal variation in the composition of the xylem sap was related to rainfall, rainfall infiltration and soil salinity. Periods of low rainfall and infiltration and higher soil salinity corresponded with increased allocation of N to proline and arginine in the xylem sap. The allocation of N to citrulline and asparagine increased following rainfall events where rain was calculated to have infiltrated sufficiently to decrease soil salinity. The relationship between nitrogenous composition of the xylem sap of C. glauca and soil salinity indicates that the analysis of xylem sap is an effective method for assessing changes in salinity stress in trees at a particular site over time. However, the composition of the xylem sap proved less useful as a comparative index of salinity stress in trees growing at different sites. 相似文献
98.
Zusammenfassung Nach einem kurzen Überblick über die gesetzlichen Grundlagen für die Durchführung der Pflanzenbeschau wird über die Ergebnisse der Kontrollmaßnahmen bei der Einfuhr von Pflanzenerzeugnissen (Getreide) nach Berlin (West) berichtet. Von 1980 bis 1985 wurden insgesamt mehr als 700 000 Tonnen Weizen, Braugerste, Roggen, Hafer, Sonnenblumenkerne, Hirse und Erdnüsse aus 12 europäischen, amerikanischen und afrikanischen Ländern eingeführt, davon mehr als 99% allein aus der DDR.Die Importe aus der DDR waren im Durchschnitt zu knapp 1% mit Vorratsschädlingen befallen, und zwar mit dem Reiskäfer (Sitophilus oryzae L.), dem Gemeinen Kornkäfer (Sitophilus granarius L.), Leistenkopfplattkäfern (Cryptolestes spp.), dem Amerikanischen Reismehlkäfer (Tribolium confusum Duv.) und dem Rotbraunen Reismehlkäfer (Tribolium castaneum Hbst.).
Mit 2 Abbildungen und 3 Tabellen 相似文献
Stored products activities of the plant protection office Berlin. The inspection of imported stored products from 1980 to 1985
A brief survey is given about the legal basis for the inspection of stored products (cereals) imported to Berlin (West). This follows a report about the results of those controls. From 1980 to 1985 more than 700,000 tons of wheat, barley, reye, oats, sunflower seeds, millet and peanuts were imported from 12 European, American and African countries, more than 99% of them from the GDR.On average about 1% of the imports from the GDR were infested by stored product pests; there were rice weevil (Sitophilus oryzae L.), grain weevil (Sitophilus granarius L.), grain beetles (Cryptolestes spp.), confused flour beetle (Tribolium confusum Duv.) and red flour beetle (Tribolium castaneum Hbst.).
Mit 2 Abbildungen und 3 Tabellen 相似文献
99.
通过分析不同森林类型采伐的经营特点,探讨森林采伐限额政策的适宜程度,形成对部分类型森林放开采伐限额的思路,分析评估放开采伐限额政策的风险,提出改善森林采伐限额政策建议。 相似文献
100.
Journal of Pest Science - Slugs are a serious pest of cereal crops, and recent emphasis in slug pest management has shifted from solely chemical towards integrated approaches. The objective of the... 相似文献