Biologische Bek?mpfung des R��benzystennematoden Heterodera schachtii

The beet cyst nematode Heterodera schachtii is widely spread among sugar beet habitats with narrow crop rotation (especially in the warmer region of the Rhine Gorge). Without a consistent control management the economic efficiency of sugar beet cultivation under the current framework requirements is threatened. This problem is solved by the biological control using nematode-resistant oil radish or mustard which has been established during the last 25 years. Population of nematodes can be reduced up to 70% while maintaining the sugar beet yield on a high level. Big plot studies achieved a yield increase of 10?C15% thereby confirming the economic efficiency of nematode control measures using resistant undersown crops. Another starting point for problem solving lies within the cultivation of nematode-resistant sugar beet varieties. Currently, the sugar content and sugar yield of these varieties lie below the level of the standard varieties. Without nematode infection reduction in grain yield of approximately 10% must be accepted. Thus, cultivation is only economically reasonable in the infection areas. Heterodera schachtii is decreased by 60?C70%. Breeding of nematode-resistant sugar beet varieties has been the last step up to now. Already with low latent nematode infection these varieties clearly outbalance previous grain yields. A study series in 2009 showed an increase in sugar yield by an average of 10?C18% compared to the normal variety by cultivation of tolerant beet with latent nematode infection. Despite further developments in control management of tolerant/resistant beet, the culturing of resistant undersown crops remains up to date as these varieties, although only to a small degree, suffer from Heterodera schachtii.     

Alternative Bekämpfungsstrategien gegen die Kleine Weiße Rosenschildlaus Aulacaspis rosae (Bouché) (Hemiptera: Diaspididae) an Schnittrosen unter Glas mittels dem Einsatz von Leinöl

The rose scale Aulacaspis rosae has proven to be extremely difficult to control. For some years Hamburg flower producers have reported an increase in infestations in greenhouse grown rose crops. So far no pest management program, including natural, mechanical and chemical methods, have provided effective control. The rose scale feeds on parenchyma plant sap and is mainly found on the woody parts of roses. Under greenhouse conditions several generations may appear in a single year. Contact insecticides do not penetrate the protective covering of the scale insects and are most effective when applied on young larvae stages which are not protected by the shield-like cover yet. However due to long hatching periods the occurance of larvae overlaps with the hatching of the following generation. The outcome of this is a continuous presence of newly emerged larvae on the plants. Resulting in that pesticides need to be frequently applied which is both time consuming and impractical for the gardeners. Another problem is the limited coverage of the infested plant parts when pesticides get sprayed. The scale insects are well protected by both the leafage of the roses and also they tend to crowd together and stack in layers making it harder for contact pesticides to be effective. Systemic insecticides may be effective only on those scales infesting the leaves or those that are actively producing honeydew and showed no sufficient efficacy in practical usage against the rose scale. By searching for an adequate pest management method, linseed oil was tested as an alternative application agent. Linseed oil is a drying oil and polymerizes into a solid form by reacting with oxygen in air. Treatments on permanent rose crops infested by rose scales could decrease the occurance of larvae in a knock-down effect. Newly emerged larvae could be kept sustainably on a low infestation level. The results are showing a promising pest control with good efficacy.     

Erarbeitung eines Testverfahrens zur Bestimmung der Protektiv- und Kurativleistung von Fungiziden bei der Bek?mpfung des Erregers der Stemphylium-Laubkrankheit Stemphylium botryosum in der Spargelkultur (Asparagus officinalis L.)

The foilage of Asparagus officinalis L. has a large contact surface for different leaf diseases, which can lead to profits cuts, especially by the causal pathogen of Stemphylium leaf spot, Stemphylium botryosum. The maintaining healthy of the foliage is an important precondition to achieve an optimal harvest in the following year. Therefore, it is necessary to describe the efficacy of currently approved plant protection products against S. botryosum in order to optimize the fungicide applications. In the context of greenhouse trials with asparagus seedlings a method should be developed to evaluate the preventive and curative efficacy of fungicides. At the beginning, stable, repeatable and homogeneous infections of S. botryosum needed to be achieved. Ad hoc the factors plant age (weeks after sowing date), inoculum (density of conidia per ml and concentration of malt), infection conditions (period of high relative humidity) and day of rating, as well as their influence on the occurrence of the symptoms, were investigated. With the exception of the factor plant age, the other factors had a significant effect on the infection. For the trials to evaluate the efficacy of fungicides, the analysed factors were defined. The age of the seedlings was six weeks after sowing, the inoculum was composed of 1,00?×?10⁵ conidia per ml combined with an 0,5% malt concentration, as infection condition the ??tunnel system?? with periodically high relative humidity was chosen. 13 days past infection was the optimal day of rating. To apply the seedlings with the fungicides, the registered application rate was reduced to 1/5. The trials to evaluate fungicides were conducted with the fungicides Signum^®, Rovral^® WG and two different testing agencies. At four consecutive application days, the plants were covered with fungicides. In the following, the infestation degree of stems in percent was evaluated. Additionally, the used S. botryosum-Isolates were biomolecularly investigated and the QoI- and SDHI resistance state determined.     

Behandlung von Reis mit Neem und Diatomeenerde zur Bek?mpfung der vorratssch?dlichen Coleopteren Sitophilus oryzae und Tribolium castaneum

The commercial available diatomaceous earth Fossil Shield® and the neem product Neem Azal-T/S® are tested as single treatments and in combination as controls for the stored product pests Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). The diatomaceous earth, applied in concentrations of 0.5 g, 1 g and 2 g kg^-1 rice, reduced numbers of surviving beetles significantly (over a period of 3 weeks). A single treatment with the neem product, in concentrations of 0.01 g, 0.1 g, 0.2 g and 1 g azadirachtin kg^-1 rice, increased the mortality rate for both species significantly. The combination of neem and diatomaceous earth (1 g diatomaceous earth with 0.2 g or 1 g azadirachtin kg^-1 rice) was more effective than the single treatment in reducing numbers of surviving beetles.     

Behandlung von Reis mit Neem und Diatomeenerde zur Bek?mpfung der vorratssch?dlichen Coleopteren Sitophilus oryzae und Tribolium castaneum

The commercial available diatomaceous earth Fossil Shield® and the neem product Neem Azal-T/S® are tested as single treatments and in combination as controls for the stored product pests Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). The diatomaceous earth, applied in concentrations of 0.5 g, 1 g and 2 g kg^-1 rice, reduced numbers of surviving beetles significantly (over a period of 3 weeks). A single treatment with the neem product, in concentrations of 0.01 g, 0.1 g, 0.2 g and 1 g azadirachtin kg^-1 rice, increased the mortality rate for both species significantly. The combination of neem and diatomaceous earth (1 g diatomaceous earth with 0.2 g or 1 g azadirachtin kg^-1 rice) was more effective than the single treatment in reducing numbers of surviving beetles.     

Erfahrungen bei der bek?mpfung der wanderratte,Rattus norvegicus (Berk.) 1999 in Magdeburg

Data of a pest control business was used to study infestation with the brown, or Norway rat (Rattus norvegicus Berkenhout, 1769]) in the City of Magdeburg for the year 1999. Swarms of rats were found to live all over the territory of the city. Blocks of residential buildings erected during G. D. R. times and, more specifically, their basements were noted to be focal sites of infestation with rats. The problem of rats living in the sewerage system of the city turned out to be unresolved. Detailed reference is made to rodenticides and active substances as well as to control strategies. The priority given to economical issues over the application of scientific findings is considered to be the decisive factor which accounts for the needs in the extermination of rats.      

Erfahrungen bei der bek?mpfung der wanderratte,Rattus norvegicus (Berk.) 1999 in Magdeburg

Data of a pest control business was used to study infestation with the brown, or Norway rat (Rattus norvegicus Berkenhout, 1769]) in the City of Magdeburg for the year 1999. Swarms of rats were found to live all over the territory of the city. Blocks of residential buildings erected during G. D. R. times and, more specifically, their basements were noted to be focal sites of infestation with rats. The problem of rats living in the sewerage system of the city turned out to be unresolved. Detailed reference is made to rodenticides and active substances as well as to control strategies. The priority given to economical issues over the application of scientific findings is considered to be the decisive factor which accounts for the needs in the extermination of rats.     

Monitoringergebnisse der Schnellk?fergattung Agriotes (Elateridae, Coleoptera) in den Jahren 2008 bis 2010 in Rheinland-Pfalz

During the years 2008 to 2010 beetles of the genus Agriotes were monitored by means of pheromone traps in Rhineland-Palatinate. Each trap contained the female sexual pheromone of either Agriotes obscurus, A. sordidus, A. lineatus, A. sputator, or A. ustulatus. Beetles of these species could be caught, additionally also specimens of the species A. gallicus, A. acuminatus, and A. pilosellus. Specimens of A. brevis and A. proximus could not be caught, not even in traps with pheromones according to their species. The high frequency of A. sputator in the Upper Rhine Valley and mild river valleys was surprising. This might be an explanation for the increasing damages especially in potatoes during the past seven years. Also the species A. ustulatus occurred mainly in the Rhine Valley. The species A. obscurus was found predominantly in higher altitudes, A. lineatus and A. sputator appeared in the whole area, with varying frequencies. In all, we could determine the composition of Agriotes-species in 27 fields. In two fields traps were exposed in two subsequent years, in one field in three years. The changes in the populations are shown. The beetles collected in some fields were compared with the according wireworms.     

Agro-?koeffizienz im Maisanbau durch Selektion des Sortenmaterials und Ermittlung der Reifestadien von Siliermais (Silo- und Energiemais) – aus der Sicht von ?konomie und ?kologie

Data from silage maize variety trials of the years 1999?C2010 in the Central German dry region were subjected to a secondary analysis using methods of mathematical statistics: With the phenological ripeness indicators (grain dry matter content/TM of the residual plant) the differences in the ripeness dynamics of grain to residual plant and their effects on the economy and ecology compared to the current ripeness system with use-specific ripeness numbers are documented. This dependence on all directions of use in the maize of the environments and varietal types taking into account of the different plasticity of maize varieties is been quantified. The achievement of physiological ripening of the grain is the interface of all usage directions and at the same time basis for the comparable, agro-eco-efficient level of maturity (63% TM) in conjunction with the silage ripeness index (SRI of 2.8) by eco-silage maize crops. The specific characteristics of the usage directions are low and with regard to efficiency, environmental and consumer protection discussed. With the phenological stage indicator (SRI) can both replaced the DM content of the whole plant as a parameter to the harvest date of silage and energy maize as the usage-specific ripeness numbers to the variety choice for silage and grain maize. A classification of the varieties according to ripeness groups would fully correspond to the environmental maize production. In the preparation of production (breeding, approval, testing and type of election), the SRI serves as selection and during inventory management through differential ripening control in compliance with the environmental and field production conditions as ripeness index. The wide ripeness ratio between grain and residual plant is the phenotypic expression of maize varieties as indicator for the agro-eco-efficiency and multifunctional guarantee better plant health, the resource efficiency, as well as basic product safety and sustainability of the process of maize silage. A precise fixing of harvest time point (HTP) is possible only with the SRI. The correct HTP is in principle maximum possible SRI. This HTP differently from the silage optimum can be according to the environments and the type of election. Ideally a maximum high SRI of 2.9 and over to a high basic intake of ground feed when reaching for exclusive maize silage feeding ruminant more friendly, better structural efficiency and grain hardness for the bypass of starch in the small intestine. The variety and the harvest strategy are to focus their reasons of economy and ecology on a high proportion of stocks ripeness in the field of silage optimum (SRI >?2.6) reach. Standard for maximum efficiency of production process maize and its environmental and consumer protection in the field of view of social line is the reaching of the agro eco-efficient ripeness point (SRI of 2.8 at physiological ripeness of grain by 63%).     

Untersuchungen zur überlebensf?higkeit und Entwicklung der Larven zweier Herkünfte des Schwammspinners Lymantria dispar L. (Lep.: Lymantriidae) in Abh?ngigkeit von der Fra?pflanze

The polyphagous gypsy moth (Lymantria dispar) is able to feed on about 400 different woody plant species. In general, oak species are preferred – on the other hand some other groups of plants are avoided on account of the presence of toxic substances. These unfavoured hosts are, for example, most of the Papilionaceae, like locust (Robinia pseudoacacia). We compared survival rate and development of two populations of different origin with long-term habituation to oak and locust, respectively. Larvae from the population habituated to oak proved unable to develop on locust food. There must be a lack of detoxification systems to modify the toxic alcaloids and flavenoids produced by Robinia pseudoacacia. On the other hand, larvae isolated from an locust stand were able to feed on oak leaves without problems in larval development or eclosion of adults. Gypsy moth larvae specialized on locust as host showed increased mortality (up to 27%) in the early larval instars, but the surviving animals, especially female individuals, reached significantly higher pupal weights and showed better fecundity: 40% higher egg numbers/egg mass compared to those feeding on oak. These results indicate that the gypsy moth population originating from the locust forest had achieved a high level of metabolic adaptation to this host plant and formed a 'biotype' of Lymantria dispar with optimal reproductive conditions in this special habitat.     

Untersuchungen zur überlebensf?higkeit und Entwicklung der Larven zweier Herkünfte des Schwammspinners Lymantria dispar L. (Lep.: Lymantriidae) in Abh?ngigkeit von der Fra?pflanze

The polyphagous gypsy moth (Lymantria dispar) is able to feed on about 400 different woody plant species. In general, oak species are preferred – on the other hand some other groups of plants are avoided on account of the presence of toxic substances. These unfavoured hosts are, for example, most of the Papilionaceae, like locust (Robinia pseudoacacia). We compared survival rate and development of two populations of different origin with long-term habituation to oak and locust, respectively. Larvae from the population habituated to oak proved unable to develop on locust food. There must be a lack of detoxification systems to modify the toxic alcaloids and flavenoids produced by Robinia pseudoacacia. On the other hand, larvae isolated from an locust stand were able to feed on oak leaves without problems in larval development or eclosion of adults. Gypsy moth larvae specialized on locust as host showed increased mortality (up to 27%) in the early larval instars, but the surviving animals, especially female individuals, reached significantly higher pupal weights and showed better fecundity: 40% higher egg numbers/egg mass compared to those feeding on oak. These results indicate that the gypsy moth population originating from the locust forest had achieved a high level of metabolic adaptation to this host plant and formed a 'biotype' of Lymantria dispar with optimal reproductive conditions in this special habitat.     

Effektive Kontrolle des Braunrostes (Puccinia recondita f. sp. secalis Rob. ex Desm.) in Winterroggen mit Fungiziden unterschiedlicher Wirkstoffgruppen – Auswertung der Ringversuche der L?nder Brandenburg, Sachsen-Anhalt, Sachsen und Thüringen

To investigate different control measures against the diseases in winter rye several trials were done in the German federal states. As a result from these trials the brown rust,Puccinia recondita f. sp.secalis, was the disease with the most negative influence on the yield. The brown rust occurrence at different times on the top three leaves depend on the winter and spring weather. It should be verify whether the protective use of fungicide mixtures with the new carboxamides active ingredient benefits the curative use (disease onset) in terms of achieved efficiency againstP. recondita. It can be stated that the action threshold does not need to be changed when using fungicide mixtures with carboxamides. Regarding the duration of the fungicide efficacy againstP. recondita an order in increasingly levels of efficiency could be determinate. The order is, from lowest to highest, azole fungicides, strobilurin-azole compounds, azole carboxamide compounds, and azole-carboxamide strobilurin mixtures. Due to the variability in the values of the individual test sites in the experimental series the tendency could be confirmed, however, no statistical significant differences between the various mixtures could be determined. The new carboxamides enrich the possibilities of targeted anti-resistance strategy againstP. recondita in winter rye. These trials results are introduced into recommendations for agricultural practice.     

Zum Auftreten der Robinien-Miniermotte,Phyllonorycter robiniella (Clem.) und der Ro?kastanien-Miniermotte,Cameraria ohridella Desch. & Dim. (Lep., Gracillariidae) in Südtirol

Zusammenfassung  An 2 Gracillariiden,Phyllonorycter robiniella undCameraria ohridella, wird gezeigt, wie rasch importierte Sch?dlinge sich ausbreiten k?nnen: Die RobinienblattmotteP. robinella wurde in Südtirol erstmals 1991 festgestellt und trat 1996 bereits in Massenbefall bei Brixen an Robinien auf.—Die Ro?kastanienminiermotteC. ohridella war hier erstmals 1992 im Pustertal bei Toblach festgestellt worden (Butin & Führer, 1994). Neueste Untersuchungen im Herbst 1997 zeigen, da? sie nun bereits im gesamten Eisacktal zwischen Franzensfeste und Bozen an Ro?kastanien (Aesculus hippocastanum) verbreitet ist (Tab. 1); hingegen wurde im Etschtal südlich und westlich von Bozen bisher noch kein Befall festgestellt.

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On the occurrence of the robinia-leafminer,Phyllonorycter robiniella (Clem.) and the horse-chestnut- leafminer,Cameraria ohridella Desch. et Dim. (Lep., Gracillariidae) in South Tyrol

The examples of two species of Gracillariidae,Phyllonorycter robiniella andCameraria ohridella, show how fast the expansion can take place: The robinia-leafminerP. robiniella was first noticed in South Tyrol in 1991 and an outbreak occured on False Acacias near Brixen, already in 1996.—The horsechestnut leafminerC. ohridella was first noticed in the Pusteria Valley near Toblach-Dobiacco, in 1992 (Butin & Führer, 1994). The latest research, of autumn 1997, shows that they are now distributed on Horse Chestnut Trees (Aesculus hippocastanum) in the whole Isarco Valley, between Fortezza and Bozen-Bolzano (Tab. 1), whereas in the Adige Valley at south and west of Bolzano no occurrence could be found as yet.

     

Untersuchungen über Fichtengallenl?use, Dreyfusia spp. (Hom., Adelgidae) und deren Predatoren in der Nord-Türkei

In the East Pontic mountains at Giresun (Black Sea shore) three species of the genus Dreyfusia have been established: D. nordmannianae Eckst. and D. prelli Grosm. on Abies nordmanniana Link. and Picea orientalis Link. and Dreyfusia nov. spec. on A. nordmanniana. The latter species, earlier known from Greece and the Balkans, but not yet described is most probably unholocyctic on fir.In the Zigana mountains between Trabzon and Gümüsane a species producing plenty galls on young P. orientalis trees and closely resembling D. merkeri Eichh. has been observed. Further investigations are necessary to evaluate whether or not it lives unholocyclic on spruce.In the West Pontic mountains near Bolu D. nordmannianae was intensively studied in twig infestations on A. bornmülleriana Mattf. The pattern of attack differs greatly from the one experienced in central Europe in that almost exclusively the current year's shoots are attacked whereas the leader and the older twig axis remain free of attack. In Europe all parts of the trees are colonized.Considering the known facts about generation- and morph sequences, morph determination and phenological behaviour of D. nordmannianae the characteristics of their population dynamics in Turkey and the interactions of the curious mode of attack and the extraordinary efficiency of their special predators have been completely evaluated.