bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Control for Cereal Diseases
Authors: Parmentier G.
Published: April 2008

Application of the integrated control philosophy presupposes that adequate background research has been done: qualitative surveys involving the exact identification of the pathogens which actually cause financial losses, quantitative surveys involving estimation of populations and the threshold of damage that makes chemical control economically desirable. These surveys should be used as a research tool to determine and understand the role of different factors in the size of pathogen populations. The application of integrated control to winter wheat in Belgium is described.
Possibilités et limites de la monoculture en relation avec l'application de diverses mesures culturales1
Authors: Vez A.
Published: April 2008

SOMMAIRE

La monoculture du blé d'automne entraîn des baisses de rendement qui ne semblent pas dues uniquement à des causes sanitaires. Ces diminutions de rendement peuvent être atténuées par l'application de différentes mesures culturales. Un renforcement de la fumure azotée et, dans les parcelles exposées au piétin‐verse, un traitement au bénomyl au début de la montaison, constituent les mesures les plus efficaces. Les effets négatifs de la monoculture ont été plus marqués aprés labour qu'en semis direct.
Situation hivernale de Meloidogyne naasi Franklin et lutte par rotation culturale 1
Authors: Gooris J. , D‘Herde C.J.
Published: April 2008

SOMMAIRE

Le nématode des racines noueuses des graminées, Meloidogyne naasi Franklin, est à l'origine de dégâts surtout apparents sur betteraves, mais touchant également les céréales de printemps. Ce nématode ne développe qu'une génération par an. Il passe l'hiver sous forme de juvéniles J2 maintenus en quiescence dans les coques ovaires. L'éclosion simultanée au printemps est à l'origine des dégâts constatés sur les jeunes plantules attaquées. Les céréales d'hiver, telles que blé et escourgeon, ne paraissent pas subir de dégâts notables en raison de leur stade de développement au moment de l'attaque.
Biological Control of Take‐all by Phialophora radicicola Cain1
Authors: Deacon J.W.
Published: April 2008

Biological control of take‐all by Phialophora radicicola Cain and similar fungi is reviewed, and new evidence is presented on the possible role of hyper‐parasites, like Pythium oligandrum Drechsler, to augment this.

Phialophora radicicola var. graminicola Deacon is abundant in British grasslands. Its role in biological control of take‐all has been demonstrated in the glasshouse with natural soils and natural population levels of this control agent. Also there is much circumstantial evidence for its beneficial role in agriculture, especially in cereal monoculture following grass crops, and in natural and amenity grasslands. Some other similar fungi control take‐all in the glasshouse, but their roles in current agricultural practice are not known.

The take‐all fungus, itself, can reduce infection of roots by P. radicicola, so there is a dynamic interaction between these fungi. This is affected by host type, relative inoculum potentials of the fungi, and possibly by environmental conditions. By careful manipulation, therefore, it might be possible to control take‐all under a wide range of field conditions.

The chief role of P. radicicola and similar fungi is to delay establishment of severe take‐all early in cereal monoculture, rather than to combat an existing high disease level. It may therefore be desirable to combine different biocontrols, and hyperparasites like Pythium oligandrum may be important in this respect. This fungus was tested against varieties of Gaeumannomyces graminis Arx & Olivier and Phialophora radicicola in the laboratory; the host responses differed greatly, from marked susceptibility (P. radicicola var. radicicola) to almost complete resistance (G. graminis var. graminis). Hence, P. oligandrum might be used to alter relative population levels of these fungi in the field, but first its behaviour in natural soils must be studied.
Influence of the Conditions under which Seed Potato Tubers are Handled on Blackleg Infection1
Authors: Henriksen J.B.
Published: April 2008

Moistening of the seed tubers just before grading and presence of partly decayed tubers at grading increased the incidence of blackleg infection in the field. Blackleg infection was increased to a higher degree by moistening with extracts of healthy tubers than by moistening with water.
Laboratory Studies on Host Preference and Insecticide Resistance of the Cotton Bollworm, Heliothis obsoleta F.1
Authors: Moradeshaghi M.J. , Poormirza A.A.
Published: April 2008

Pupae of the cotton bollworm, Heliothis obsoleta F., from the northern part of Iran (Gorgan and Gonbad areas) were brought to the laboratory and used as the breeding source for bollworms. The larvae were reared on soybean plants for 8 generations under laboratory conditions of 60±5 % RH and 27±2 °C. To test host preference, the adults of both sexes were released into wooden cages where they were able to freely select their host. The females laid more eggs on soybean (before and at blooming) compared to cotton (before and after blooming) and maize (before and after stem extension).

Seven and 14‐day‐old larvae were treated with different doses of Supracide and Thiodan by topical application. Altogether, 3,000 larvae were used for this experiment and from the data collected, LD 50 values were calculated. It was found that, as the age doubled from 7 to 14 days, the LD 50 value for Supracide increased from 0.6 mg/g to 0.92 mg/g. For Thiodan, the corresponding increase during this period was from 0.52 mg/g to 1.50 mg/g. Fat body content was measured using Soxhlet apparatus and its correlation with LD 50 values was determined. Fat bodies represented 2.1 and 2.5% of the body weight in 7 and 14‐day‐old larvae, respectively.
Virus/Mycoplasm Diseases and Certification Schemes for Deciduous Fruit Trees1)
Authors: Posnette A. F.
Published: April 2008

Although the causal agents of several important fruit‐tree diseases have been identified, the aetiology of many remains unknown. Some prevalent viruses seem to have little effect on certain rootstock/cultivar combinations, while others reduce fruit yields and a few can make orchards quite worthless. Most EEC countries have 2 certification schemes; one requires only that plants are true‐to‐type and free from visible virus diseases, while to be eligible for the other scheme the plants must be propagated from virus‐tested scionwood trees and rootstocks. The use of virus‐free clones has resulted in better bud‐take, more even growth in the nursery and trees that will often be more productive in the orchard. Diseases, such as sharks (plum pox), that have insect vectors will be difficult to control in nurseries if the virus occurs in nearby plants.
Problems and Prospects in Plant Virus Identification1
Authors: Bos L.
Published: April 2008

Reliable identification is a prerequisite to the study and control of plant viruses and virus diseases. Viruses are now increasingly studied for their intrinsic properties, in addition to their variable biological properties. This has caused some degree of order to emerge from the intricacy of plant viruses. Ten « commandments » are listed which permit reasonably reliable diagnosis of plant virus diseases in the scientific laboratory. New viruses are still often discovered.

Routine tests for virus infection, carried out by plant protection, quarantine and especially certification services, never guarantee absolute freedom from viruses. A simple, but the least reliable of indexing methods, is that of visual observation. Infectivity tests are meant to trace the infectious agents with indicator plants. Using serology, one can detect certain viruses more directly and specifically. Electron microscopy allows the observation of the virus particles themselves.

The choice of test is always a compromise between efficiency and reliability. Through scientific research both are constantly being improved. With the increasing amount of information on plant viruses, diagnosis is tending to shift from mere visual observation to the more reliable study of aetiology.
Mycoflore des maïs humides: déterminisme de son évolution1)
Authors: Pelhate J.
Published: April 2008

Sommaire

La récente extension de l'aire culturale des maïs‐grains pose, notamment dans le nord et l'ouest de la France, des problèmes de récolte, de séchage et de conservation. Le stockage à l'état humide, compatible avec l'efficacité nutritionnelle, est alors préconisé.

L'anaérobiose, d'une part, et les stabilisants chimiques, d'autre part, représentent deux moyens de limiter la microflore dégradante des grains humides au cours de leur stockage. Les modifications de l'environnement se traduisent alors par un déplacement de l'équilibre biologique et une succession originale des cortèges floristiques. Cette évolution dynamique, établie par des observations répétées et confirmée par l'expérience, est transcrite sur un diagramme qui intègre les paramètres les plus déterminants: gradients d'anaérobiose, d'humidité, de température, de pH, seuil de tolérance vis‐à‐vis du stabilisant éventuel, sans oublier l'aptitude compétitive des espèces.

Dès lors, les relevés floristiques instantanés, mais replacés dans l'échelle temps, prennent une autre signification que l'inventaire statique; des extrapolations sont permises en amont et en aval de la présente étape. Ainsi peut‐on retracer, dans une certaine mesure, « l'histoire du lot » ou bien pressentir son comportement ultérieur. La première démarche tend à préciser la qualité biologique et nutritionnelle du substrat; la deuxième autorise des prévisions de conservation.
The Longevity of Resting Sporangia of Synchytrium endobioticum (Schilb.) Perc. in Soil1)
Authors: Pratt Margaret A.
Published: April 2008

Resting sporangia of the potato wart disease pathogen Synchytrium endobioticum (Schilb.) Perc. which persist in soil can be extracted from soil by a wet‐sieving and chloroform centrifugation method and counted. Soils from the sites of old wart outbreaks have been checked for resting sporangia. Sampling procedures, patterns and errors are being assessed.
The Relation Between Field and Laboratory Susceptibility of Potato Cultivars to Wart Disease1)
Authors: Pratt Margaret A.
Published: April 2008

Potato wart disease has been effectively controlled legislatively by the growing of resistant cultivars. The testing of new potato seedlings for plant breeders is undertaken so that susceptibles can be removed from the breeding program at an early stage.

In the laboratory, gradation of resistance and susceptibility is noted. The range of reactions is divided into 6 arbitrary groups, 3 with necrosis and 3 without (Hills, 1965), and Hille's infection patterns have been interpreted as a set of assessment keys. Susceptible cultivars show a variation in degree of susceptibility, but infections persist even though there may be a necrotic hypersensitive reaction of the host. With some less resistant cultivars, the fungus can become established in the host and complete its life cycle, but infected tissue mostly necroses and is sloughed off. These less resistant cultivars (intermediates) grow away from infection when grown on in pots. The cultivar Red Craigs' Royal showed no infection when inoculated in soil tanks (3 soil types) with heavy watering or when grown on infested land. All evidence collected gives indication that intermediate cultivars are field resistant and not affected to any measurable extent by Synchytrium endobioticum (Schilb.) Perc.
Crop Rotation and Integrated Control of Animal Pests1
Authors: Schuette F.
Published: April 2008

That crop rotation may be a valuable means of reducing pest populations has been shown in field‐grown rape. On an isolated area of about 800 ha, preliminary observations showed the beneficial effects in containing Dasyneura brassicae Winn. populations by substituting spring rape by winter rape. It appeared to be more difficult to control Meligethes aeneus F. and Ceuthorrhynchus assimilis Payk. through crop rotation but, with an improved trapping system and surveying of populations, the prospects are encouraging. Possibilities of combining crop rotation with integrated control are also examined.
Biology of the Gaeumannomyces graminis Arx & Olivier/Phialophora radicicola Cain Complex on Roots of the Gramineae
Authors: Deacon J.W.
Published: April 2008

Biological characteristics of the varieties of Gaeumannomyces graminis Arx & Olivier and Phialophora radicicola Cain are reviewed. They include: 1) pathogenicity to roots of cereals; 2) growth on living stem tissues; 3) type of fungal growth‐cessation structure formed on or in the host. Together, these provide a simple means of characterizing isolates and standard methods for assessing them are presented.

The role of pigmented cells and tissues (growth‐cessation structures) in host penetration is questioned, since they are seldom associated with a progressive infection by G. graminis or P. radicicola. However, they are a taxonomic aid, especially as they are now known to form on cellophane overlying agar.

New evidence is presented on factors affecting conidiation by these fungi. Flooding colonies with distilled water induced formation of conidia by G. graminis var. tritici Walker, P. radicicola var. radicicola (British isolates but not the type) and P. radicicola var. graminicola Deacon, whereas none formed on corresponding unflooded agar plates. Conidia were usually much larger and germinated readily when they formed in response to flooding; many of these fungi therefore have 2 conidial types, distinct in both morphology and behaviour. Preliminary results suggest that biotin and the form of nitrogen also affect the type of conidium formed by P. radicicola var. radicicola.
Biochemical Testing Method for Determining Efficiency of Chemical Treatment on Quadraspidiotus perniciosus Comst.
Authors: Kolybine V.A.
Published: April 2008

Efficiency of chemical control of Quadraspidiotus perniciosus Comst. can be assessed, 3–5 days after treatment, by the use of a colour reaction relating to oxyreductase activity. The optimal conditions for this reaction are a 0.5‐1.5% solution of 2,3,5‐triphenyl‐tetrazolium chloride (pH 10.5) and time of 2–3 h. It is noted that use of a biochemical test for assessing mortality is possible for other insects, and is not dependent on the reasons causing their death.
Continuous Cereal Growing in Denmark; Experimental Results1
Authors: Jepsen H.M. , Jensen A.
Published: April 2008

In Denmark, results from 3 long‐term trials showed that yields from barley monoculture were satisfactory on clay soil provided that sufficient nitrogen was supplied. Root diseases, in particular take‐all (Gaeumannomyces graminis (Sacc.) Arx et Olivier), often stabilized at a rather low level after a period of decline. Mono‐culture of winter wheat gave poor yields compared with barley monoculture. Break crops of white mustard and oats in barley monoculture had a beneficial effect, especially on sandy soil.
Control of the Beet Weevil in Cyprus
Authors: Melifronides I.D. , Zyngas J.‐Ph.
Published: April 2008

During 1973, a severe attack by the Coleopteran Conorrhynchus brevirostris Gyll. was observed in a beet plantation near Morphou, on the north‐west coast of Cyprus (Melifronides, 1976). The larva of this pest penetrates the crown of the beet root and bores out galleries via which different root‐invading micro‐organisms find entry; such infested roots cannot be stored and have no commercial value.

For control of this pest, several granular organophosphorous and organocarbamate insecticides were tested during 1975 and 1976, and effectively reduced infestation and damage by the beet weevil.
Influence de l'humidité sur le développement des populations d'acariens dans les stocks d'oléagineux et de céréales
Authors: Fleurat‐Lessard F.
Published: April 2008

Sommaire

Les especes d'acariens Tyrophagus putrescentiae Schrank et Acarus siro L. se développent dans les stocks de colza du sud‐ouest de la France. Leurs populations sont réparties dans la partie supérieure des silos et décroissent rapidement avec la profondeur. La densité la plus forte est observée dans les zones où la teneur en eau est la plus élevée et où se développent les moisissures colonisées par ces acariens.

L'humidité relative de l'air joue un rôle très important clans la prolifération de la mycoflore de ces zones particuliérement exposées aux modifications de milieu: la multiplication des acariens ne peut s'effectuer qu'à partir d'un seuil d'HR voisin de celui du développement des moisissures et elle est soumise aux variations de ce même facteur. Une étude réalisée sur blé avec les 2 espèces citées confirme ces observations et permet de généraliser les résultats. La détermination des conditions de stockage appropriées permet d'énoncer des principes simples de limitation des risques d'infestation par les acariens.
Essais de fumigation des stocks de pruneaux d'Agen au bromure de méthyle (CH3Br) et au phosphure d'hydrogene (PH3)
Authors: Fleurat‐Lessard H. Cangardel et F.
Published: April 2008

Sommaire

En dehors des mesures classiques de prophylaxie applicables à toute denrée stockée, la lutte chimique par fumigation à pression atmosphérique ou sous bâche constitue aux Etats‐Unis une technique courante pour la désinsectisation des pruneaux stockés. L'expérimentation dont il est fait état ici se réfère à l'étude de l'efficacité du bromure de méthyle et du phosphure d'hydrogène sur les principales espèces d'insectes et d'acariens des pruneaux. Elle a été entreprise par le laboratoire de l'INRA, à Bordeaux, et concerne la fumigation expérimentale en chambre à pression atmosphérique, et des essais entrepris sous bâche, réalisés dans les conditions de la pratique.

Les normes de traitement sont calculées par référence au produit de la concentration du fumigant en mg/1 et du temps d'exposition en heures (CT). Afin d'écarter les risques inhérents aux résidus, les concentrations de fumigants ont été réduites au minimum, tout en prolongeant dans la mesure du possible le temps d'exposition.

) Fumigations expérimentales

Pour le bromure de méthyle, un CT de 144 mgh/l donne une efficacité totale sur les principales espèces suivantes: Carpophilus ligneus Murr., Plodia interpunctella Hbn., Nemapogon granella L. et l'acarien Carpoglyphus lactis L. Ce CT, qui représente le cinquième de la norme préconisée par la FAO (768 mgh/l) a été réalisé par une exposition au gaz de 18 h (8 mg/l × 18 h).

En ce qui concerne le phosphure d'hydrogène, le CT de 36 mgh/l (FAO: 180 mgh/l) assure une efficacité totale contre les principales espèces d'insectes. Une exposition de 72 h à la concentration de 0,5 mg/l s'est révélée satisfaisante. Contre les acariens, l'efficacité totale requiert un CT de 324 mgh/l (4,5 mg/l pendant 72 h). Cette dose est le double de celle recommendée par la FAO.

) Essais pratiques

Le bromure de méthyle émis sous bâche en plastique assure la mortalité de toutes les espèces d'insectes et d'acariens testés en 24 h, le CT étant de 384 mgh/l (16 mg/l × 24h).

) Résidus

Les analyses révèlent que pour les CT avec une longue exposition, les résidus sont demeurés, tant pour le bromure de méthyle que pour le phosphure d'hydrogène, inférieurs aux limites admises (CH3 Br: 6 ppm; et PH3: 0,003 ppm).
Perspectives d'utilisation des régulateurs de croissance contre les insectes nuisibles: premiers essais de lutte curative sur un lépidoptère et un coléoptère des céréales entreposées
Authors: Stockel J.
Published: April 2008

Sommaire

L'efficacité curative de 2 régulateurs de croissance ou analogues de l'hormone juvénile des insectes (Altosid et Altozar) a étéétudiée en laboratoire sur 2 ravageurs des céréales entreposées: Sitotroga cerealella Oliv. et Sitophilus granarius L. Les résultats ont été compareés à l'efficacité du malathion.

Les 2 substances testées n'ont qu'un faible pouvoir de pénétration dans le grain. Elles prolongent la période de développement postembryonnaire chez Sitotroga cerealella. Si l'Altosid est totalement inefficace chez cette espèce, l'Altozar en revanche entraîn une mortalité postembryonnaire d'environ 30 % de la population par troubles de la métamorphose et induit, chez 20 % des mâles qui émergent normalement, une stérilité par bloquage de la spermatogenese, sans affecter leur comportement sexuel (recherche de la femelle, copulation). Sur Sitophilus granarius, l'Altozar prolonge également la période de développement larvaire et nymphal, mais n'entraîne pas de diminution significative de la population.
Connaissances récentes concernant la faune des pruneaux dans les stockages traditionnels
Authors: Cangardel H.
Published: April 2008

Sommaire

L'étude faunistique des ravageurs des pruneaux stockés a permis de faire l'inventaire des différentes espèces présentes et d'établir une évaluation quantitative de leurs populations à partir de 2 méthodes de prélévement (piégeage, tri d'échantillons).

Par ordre d'importance on peut citer: les acariens: Carpoglyphus lactis L. (Glycyphagidae), les coléopteres: Carpophilus ligneus Murr., C. hemipterus L. (Nitidulidae) et Henoticus californicus Mann. (Cryptophagidae) et les lépidopteres Nemapogon granella L. (Tineidae), Plodia interpunctella Hübn. (Pyralidae).

Les ravageurs primaires s'attaquent aux pruneaux sains: ils sont responsables des principaux dégáts et comprennent Carpophilus ligneus, C. hemipterus et N. granella. L'autre groupe est formé des ravageurs secondaires, qui s'installent sur des pruneaux déjá attaqués par des insectes ou des micro‐organismes. On trouve dans cette catégorie Carpoglyphus lactis et H. calilornicus.

Les conditions optimales au développement de ces insectes et de ces acariens sont réunies, lorsque la teneur en eau de la pulpe du pruneau est égale ou supérieure à 20 %, la température ambiante clans l'entrepôt supérieure à 15°C et l'hygrometrie relative variant suivant Ies espéces entre 50 et 85 %.
Species, Cultivars, Rootstocks and Environment
Authors: Paunovic S.A.
Published: April 2008

World apricot production by no means meets the total need of the international market (fresh and processed fruits) and is far below the potential in view of the existing favourable geographic, climatic and agrotechnical conditions. The cause for this insufficient world production of apricots, particularly in certain countries which have favourable conditions for apricot culture and its expansion, should be investigated using scientific and technical concepts concerning the apricot decline syndrome (apoplexy, sudden wilting, withering of apricots). After the mutual assistance of research workers from different disciplines in investigating this complex disease, the economic security of apricot growing can be improved and apricot decline reduced to an acceptable level. Special attention must be paid to selecting appropriate cultivars, rootstocks or interstocks, locations and cultivation techniques.
Prunus Stem Pitting
Authors: Mircetich S.M. , Moller W.J.
Published: April 2008

Prunus stem pitting disease was first described and recognized as a specific, infectious disease in 1967 and is now known to affect a number of Prunus species. Apricot trees affected by stem pitting show stunted terminal growth and chlorotic, drooping leaves that curl upward and lengthwise. The lower trunk may become enlarged at ground level or below with very thick, spongy bark. Removal of the bark from the affected lower trunk reveals pits and grooves on the woody cylinder. Wood pitting begins below ground, then gradually spreads into the roots and the trunk above ground. Stem pitting is caused by certain strains of the tomato ringspot virus. The causal agent is soil‐borne and also graft transmissible but is not uniformly distributed through infected trees. Naturally infected apricot trees may show a slow decline, or rapid dieback of the terminal growth. The severity of symptoms is determined by the cultivar and the strain of tomato ringspot virus. Control measures for Prunus stem pitting should include: use of propagation material from healthy trees and rogueing of pitted trees in nurseries and orchards. Repeated use of infested nursery sites for stone fruit nurseries should be avoided
Apricot Chlorotic Leaf Roll
Authors: MORVAN G.
Published: April 2008

Apricot chlorotic leaf roll is a graft‐transmissible disease, apparently a mycoplasm infection, which affects Japanese plum and sometimes peach. It is particularly important in Mediterranean areas.

First symptoms are a rolling and a yellowing of the leaves, often localized on some twigs. Later, various disorders, often localized on a part of the tree, are observed: proliferation of branched and slender shoots, growth of buds in autumn and winter. Leaf buds break before flower buds.

This growth in winter induces sensitivity to frost. Phloem tissues of affected branches are more or less damaged, taking on a brown discolouration. Some branches are destroyed, while on others, new shoots may develop. The presence of weak shoots with small leaves among normal shoots and irregularly distributed dried twigs on the branches is a characteristic aspect of the disease.

Symptom expression and evolution of the disease vary much according to environmental conditions, age and rootstocks.
Bacterial Canker and Dieback Disease of Apricots (Pseudomonas syringae van Hall)
Authors: Klement Z.
Published: April 2008

Bacterial canker and dieback (Pseudomonas syringae van Hall) of apricot is a widespread disease in Europe, except for the Mediterranean areas. Cankers usually develop at pruning wounds or other points of injury. Phloem and cambium become susceptible from just after leaf drop until budding. If the phloem necrosis does not girdle the branch or trunk, cankers develop by the middle or the end of summer. In early summer, the bacterium actually dies out in the infected tissue, and the tree remains resistant during the summer. During this period, the pathogen lives epiphytically on the surface of the leaves, without causing any symptoms. The extent of bacterial necrosis of the phloem depends on the severity of winter frost. Without winter frost, bacterial induced tissue necrosis does not occur. Necrosis is found only if P. syringae has enough time to proliferate before the onset of frost. The most effective method of control is to carry out spring rather than winter pruning.
Eutypa Canker and Dieback of Apricots
Authors: Carter M.V. , Moller W.J.
Published: April 2008

Eutypa canker and dieback of apricot trees, caused by the ascomycetous fungus Eutypa armeniacae Hansf. et Carter, has been recorded in Europe, North America, Australia and South Africa. Samples of diseased sapwood yield the imperfect Cytosporina stage in culture, whereas perithecia of E. armeniacae, immersed in a stroma, develop 2 or more years after death of a branch in high‐rainfall areas. The fungus is a wound parasite. Air‐borne ascospores, disseminated during and after rain, infect xylem tissues which have been freshly exposed by pruning. Cankers develop around the infected wounds; leaves on that part of the branch distal to the canker subsequently wilt and die during summer. E. armeniacae has been detected on a diverse range of host species, hence elimination of inoculum is not feasible; both biological and chemical approaches to wound protection and ultimate disease control are under investigation.
Monilia Disease
Authors: M.‐Sagasta E.
Published: April 2008

Monilia is a well‐known parasite of stone fruit trees. It normally attacks flowers, buds and fruits, producing the diseases known as “brown rot” and “mummified fruit”. In certain circumstances, however, Monilia can also attack older branches, producing chronic or acute symptoms. In the first case, the affected branches wilt after a certain time, while in the second, this wilting is extremely fast; these are the classical symptoms of dieback.

The parasite penetrates through wounds in the branches and first damages the phloem. If it reaches the cambium and girdles it, the branch dies from the area of attack to the tip. If there is no, or only moderate damage to the cambium, the tree can recover, or the disease may become chronic. The speed of disease development depends, primarily, on environmental conditions.
Apricot Decline Today and Tomorrow
Authors: Morvan G.
Published: April 2008

For many years, the causes of apricot decline have remained a matter of controversy. It may now be considered that this early destruction of trees is a result of the joint action of 6 different parasites, which particularly, if not exclusively, attack apricot: 4 fungi, 1 bacterium and 1 mycoplasm‐like organism. Each parasite, per se, is able to destroy trees in a good condition of growth. Some other fungi and some insects may also adversely affect apricot, as they do other fruit species. The development of each disease depends on particular agrotechnical and environmental conditions.

As no curative methods are available, control consists of preventive methods. These must be formulated and applied so as to avoid favouring the development of one parasite when preventing that of another.

International co‐operative research is required to cope with difficulties in acquiring the necessary data, particularly in the field of disease resistance.
The Role of Biological Efficacy Evaluation and Methodology in Registration
Authors: Mathys G.
Published: April 2008

For both governmental agencies and industry, considerable advantages, especially from extrapolation of data within a country or between countries, can be derived from co‐ordinated action in the efficacy testing of new compounds. This has been recognized at an early stage in Europe, i.e. by France (1952) and the Federal Republic of Germany, where methods have been devised in a common agreement between official services and pesticide manufacturers.

The European Weed Research Council started work for international alignment on herbicide testing, whereas EPPO, in 1971, initiated collaborative studies on rodents1) (5 methods), fungi (5 methods), insects and mites (10 methods). These guide‐lines, having been approved by the 35 EPPO Governments, are already published or will be published in the near future; a further 29 methods are presently under study.

Since 197, contacts have been taken with the American Society for Testing and Materials in order to reach inter‐regional agreement on testing methods.
Le campagnol des champs (Microtus arvalis [Pallas]) en Europe1
Authors: Spitz F.
Published: April 2008

SOMMAIRE

Microtus arvalis (Pallas) a une histoire récente qui se rattache à celle des glaciations et de l'agriculture. Son écologie et son histoire sont liées et expliquent les particularités actuelles, entre autres le fait qu'il existe des zones presque dépourvues de campagnols et d'autres où ils pullulent régulièrement. Le présent travail résume nos connaissances sur la démographie de l'espèce. Après un rappel de quelques théories anciennes ou récentes, on évoque les principaux facteurs qui agissent sur les populations: la structure de l'environnement (les campagnols aiment les agrosystèmes peu intensifs et sont surtout affectés par l'importance des biotopes d'hiver disponibles), le climat et l'alimentation (qui déterminent leur rythme biologique saisonnier, et le modulent s'ils s'écartent de la normale), le comportement individuel et social (déplacements, compétition). Une synthèse est présentée de l'évolution de la situation des campagnols à diverses échelles (parcelle, région). Par référence à un exemple typique s'appuyant sur des éléments indiscutables, on estime qu'une pullulation «moyenne« (non aggravée par la sécheresse) amène des pertes largement supérieures à 120 FF/ha, ce qui justifie les investissements que l'on peut faire dans un système de prévision et dans une lutte préventive.
Outbreaks and Damage by the Field Vole, Microtus agrestis (L.), since World War II in Europe1
Authors: Myllymäki A.
Published: April 2008

The field vole, Microtus agrestis (L.), is a major pest in horticulture and forestry in all Scandinavian countries, and an important forestry pest in certain regions in central Europe. The most common type of damage is girdling trunks of cultivated trees, usually under the snow cover. In horticulture, the apple tree is the commonest subject of injury, while, in forestry, several deciduous and conifer species are attacked. In Finland and Norway, the garden industry has suffered most, while, in Sweden, the problems are predominantly in forestry. In central Europe, M. agrestis is a forestry pest only. Summation of all losses due to the field vole since World War II amounted to somewhere between 50 and 100 million US

Populations of M. agrestis normally undergo cyclic fluctuations. However, comparison of the periodicity of outbreaks in different areas reveals variations, 3 to 4‐year intervals dominating in the Scandinavian countries, while the interval in central Europe is generally somewhat shorter. No overall synchrony exists over the geographical range of the species. Present knowledge concerning the demography and habitat dynamics of M. agrestis is briefly reviewed.

Current possibilities for preventing damage by M. agrestis are much dependent on the individual value of the potential subjects of injury. High value stands, like apple gardens or seed orchards of forest trees, can be protected by means of mechanical guards. However, current means of combating damage in forest plantations are badly limited. Surface spraying with toxaphene and poison baits is practised in central Europe, while, in the Scandinavian countries (except Denmark), no chemical means are used today. Development of new compounds to be used as surface sprays, or specific baits for M. agrestis, is urgently needed. Research on bio‐control methods should also be intensified.
European Field Voles of the Genus Pitymys McMurtrie and their Damage in Agriculture, Horticulture and Forestry1
Authors: Santini L.
Published: April 2008

Research has been carried out to establish the actual incidence in European agriculture and forestry of damage by voles belonging to the genus Pitymys McMurtrie. Unfortunately, the great uncertainty remaining in the taxonomy of these voles and the practical difficulty of recognizing the species responsible for specific damage do not allow us to form, as yet, a complete picture of the situation.

Nevertheless, it has been shown that, in Europe, Pitymys voles which are responsible for damage to agricultural crops (irregularly and with varying intensities) can, essentially, be placed in one of the following fundamental species groups:subterruneus (de Sélys Longcharnps), savii (de Séys Longchamps) or duodecimcostutus (de Sélys Longchamps). Without doubt, greatest damage appears to be done by voles of the species group savii which, in a decidedly more southern distribution area, brings about serious damage, particularly to horti‐floricultural crops in the Italian peninsula. In Italy, where the Pitymys problem is perhaps more noticeable than anywhere else, the control methods used tend to be inefficacious and do not answer the problem. We hope, therefore, besides conducting a comprehensive biological study of this species group, to carry out adequate experimentation towards developing methods for testing the latest rodenticides as to their efficacy against Pitymys and to develop an adequate application technique.
The Common Hamster (Cricetus cricetus [L.]); a Review1
Authors: Nechay G. , Hamar M. , Grulich I.
Published: April 2008

Taxonomy, distribution, biology, population dynamics, economic importance and control measures regarding Cricetus cricetus (L.) are reviewed on the basis of available data, including recent developments and some unpublished work. The common hamster is a significant pest in central and eastern Europe and, supposedly, modern agricultural technology provides favourable conditions for it. Besides field crop losses, other types of damage and hygienic hazards are also conspicuous when the hamster occurs at peak densities. At present, the best method of control is fumigation, e.g. the use of hydrogen phosphide. There is a lack of information about this hamster and more research is needed confirming its ethology, population dynamics and some methodological problems. Control techniques which are suitable for simultaneous application on large surfaces and which are innocuous to the environment are urgently needed.
Damage Caused by the Rodents Gerbillidae to Agriculture in North Africa and Countries of the Middle East1
Authors: Bernard J.
Published: April 2008

The author reviews the problem of damage by Meriones spp. in agriculture in North Africa, especially M. shawi (Duvernoy). This species is subject to outbreaks like those of microtine rodents in Europe.

The importance of M. libycus Lichtenstein and M. crassus Sundevall in North Africa and M. persicus (Blanford), M. tristrami Thomas and M. Vinogradovi Heptner in the Middle East is discussed. The 3 latter seem to have become of greater importance in Iran, following changes in agricultural practices.
Développement d'un modèle de prévision des pullulations du campagnol des champs 1
Authors: Spitz F.
Published: April 2008

SOMMAIRE

Le présent travail est fondé sur les résultats démographiques et écologiques recueillis en Vendée de 1959 à 1968. On a étudié principalement les corrélations entre le climat et certains éléments de la démographie d'où ont été dégagées un certain nombre de règles simples pour calculer les taux de diminution ou d'augmentation de la population et pour prévoir la date du début de la reproduction. Les densités dangereuses peuvent alors être prévues suffisamment à l'avance (en févier ou en mars). Le protocole de piégeage est précisé.
Population Dynamics of the Field Vole (Microtus agrestis [L]): a Model1
Authors: Stenseth N.C. , Hansson L. , Myllymaki A.
Published: April 2008

The basic hypothesis underlying a population dynamics model for the field vole (Microtus agrestis [L.]) in central Scandinavia is described and discussed. The hypothesis is that most aspects of population dynamics of the field vole may be understood by analyzing the nutritional (energy and matter) balance of individual animals and their differential allocation of available nutrients. Digested nutrients are assumed to be utilized for maintenance cost, M; growth, A S; reproduction, R; and dispersion behaviour (including dispersal), D. The simulation model whose main ideas are described verbally is being developed at present. The model is intended to simulate density, age structure, reproductive activity of different categories of the population and spatial distribution; grazing impact apportioned among the most important potential food species (or group); interaction with sympatric rodents, their predators and parasites. Special emphasis is placed on the spatial heterogeneity of the landscape. The population dynamics model is of the Monte Carlo type and considers the realization of a series of events by calculating average probabilities and “drawing” random numbers. The model simulates individual animals in a large heterogeneous area.

Qualitative predictions based on our basic hypothesis are discussed and compared with available field information.
Five‐year Surveillance of Small Mammal Abundance in Scandinavian1
Authors: Myllymäki A. , Christiansen E. , Hansson L.
Published: April 2008

A large‐scale surveillance system was established in 1971. It was based on the practical needs for information on the fluctuation in numbers of harmful rodents and the desirability of forecasts. The sampling method used was the Small Quadrat Method (SQM). The annual surveys covered about 50 localities in Norway, Sweden and Finland, the total number of SQ's being over 2,000, and the total number of specimens caught approaching 18,000.

In terms of numbers, the dominant rodent species were Microtus agrestis (L.) and Clethrionomys glareolus (Schreber), the former clearly dominating in Finland, the latter in most regions of the other 2 countries. In southern Sweden and Norway, Apodemus species were also relatively abundant, as was Sorex araneus L. in certain regions. During the 5‐year period under study, the numbers of M. agrestis peaked twice (1972 and 1975) in Finland but only once in Sweden and Norway. The peak years of C. glareolus mosdy coincided with those of M. agrestis but, in some areas, were slightly earlier. Fluctuation in numbers of Insectivora did not seem to be correlated with that of the rodents. The usefulness of the SQ indices as a basis of short‐term forecasts is apparent, while criteria for long‐term forecasts require further analysis.
Monitoring Musk‐rat Control in the Netherlands1
Authors: Troostwijk W.J. Doude Van
Published: April 2008

Musk‐rat control in the Netherlands is carried out by means of various types of traps, operated by government employed trappers. The results of their efforts are affected by a number of factors, most of which are variable. Simple models can be constructed by which the influence of these factors on the net results is shown.

For each separate working area, and for larger areas as well, the models allow us to present: a) a prognosis with regard to the probable results to be expected in the forthcoming year, b) a statement on the results of past year(s), and c) an assessment of the present situation.

This paper deals with the construction of such models, the evidence for the usefulness of a), b) and c), as well as the best way to obtain, process, store and distribute the required data. This way of monitoring is very useful because it provides an insight into the optimum way of spending the State's budget for musk‐rat control (about F1 2,000,000) and into the progress made in reducing musk‐rat populations.
Consumption by and Agricultural Impact of the Common Hamster, Cricetus chcetus (L.), on Cultivated Fields1
Authors: Gorecki A.
Published: April 2008

Energy flow through a hamster population and the impact of this population on field crops were estimated on the basis of population dynamics, rhythm of activity, metabolic rate, and consumption and utilization of natural diets.
Population Dynamics of Small Rodents in Farm Buildings and on Arable Land1
Authors: Rowe F.P. , Swinney T.
Published: April 2008

Live‐capture/recapture data on house mice caught in buildings on a single farm in England over a 1‐year period showed that the populations were essentially unstable, being characterized by constant changes in size and composition. Less than 50% of the mice were recovered 8 weeks after they had been first captured. Although there was considerable individual variation in the movements of male and of female mice within particular buildings, movement between isolated populations was rare (6/439 animals; 1.4%). The house mouse was also found to be present in hedgerows near and distant to the farm buildings, albeit in low number. Movements of out‐door living mice into farm buildings were not extensive, but could be important in relation to the re‐invasion of cleared premises. The most abundant small rodent in the hedgerows was found to beApodemus sylvaticus(L.).
The Use of Confined Colonies of Wild Mice (Mus musculus L.) in the Evaluation of Rodenticides1
Authors: Rowe F.P. , Bradfield A.
Published: April 2008

Experimental studies have been conducted using penned families of wild house mice (Mus musculus L.) treated with different rodenticides and subjected to various poisoning regimes. The results showed that such investigations on rodents can provide valuable post‐laboratory information on the relative merits and the best mode of application of rodenticides prior to their examination under field conditions. Pen population studies also permit closer study of feeding activity, bait acceptance, social behaviour and other factors that can affect rodenticidal efficacy.
Methods for Laboratory Testing of Rodenticidal Dusts1
Authors: Davis R.A.
Published: April 2008

A method is described for a laboratory comparison of the relative amounts of various inert dust bases that are picked up by laboratory mice of a standard weight group in given times of exposure. Related to this work and arising from it, determinations are made of the median lethal dose for mice of various toxicants formulated in dusts. Data on the effectiveness of various anticoagulant poisons are also given. The insecticide DDT is shown to be relatively ineffective, while the toxicity of BHC (benzene hexachloride) is shown to be increased by the addition of anhydrous calcium sulphate (plaster of Paris) to the formulation. Apparatus that will enable the methods to be extended to wild rats and mice is being designed.
Testing Rodent Chemosterilants1
Authors: Marsh R.E. , Howard W.E.
Published: April 2008

This paper presents some recommended procedures and test methods for evaluating rodent chemosterilants, including laboratory test procedures to determine acceptance and efficacy of such compounds, the kind of test animals to use, safety measures to adhere to, and methods of evaluating the efficacy of potential rodent chemosterilants in pen and field stations. Emphasis is on the Norway rat, Rattus norvegicus (Berkenhout).
A Program for Control of Damage by the Field Vole, Microtus agrestis (L.), in Seed Orchards of Forest Trees1
Authors: Myllymäki A.
Published: April 2008

For providing high‐quality seed for forest nurseries, a large‐scale seed cultivation program, including laying down 3,790 ha of seed orchards of pine, spruce and other forest trees, was established in Finland in the early 1960's. In particular, pine grafts are extremely vulnerable to damage by rodents, especially the field vole, Microtus agrestis (L.). An integrated rodent control program for all the existing seed orchards was established in 1969. From that time, rodent populations were surveyed every year according to a common scheme based on the Small Quadrat Method (SQM). Short‐term forecasts and specific control instructions were issued shortly after the survey. Earlier, the principal method of controlling voles was surface treatment with endrin. At present, the bulk of grafts is protected by mechanical guards round the stems. Investments in guard materials, as well as labour costs of preparing and installing the guards, constituted more than 90% of all control costs from 1969 to 1976, and amounted to about 5 million Fmk. Total costs of rodent surveillance and supervision of the program were about 6% of control costs. Since the establishment of this integrated control program, the absolute numbers of grafts destroyed has considerably decreased, even though the area of seed orchards had more than doubled; thus the large investments in vole control have already been recovered.
Mechanized Control of Muridae in Isolated Foci1
Authors: Hamar M.
Published: April 2008

Rapid mortality resulted when kernel baits treated with zinc phosphide were used; baits were applied by different types of drills. Pre‐planting treatment of the seed with heptachlor emulsion (40%) + TMTD had a highly repellent effect and considerably reduced rodent attack. Factors underlying the appearance of murid invasions are discussed.
Integrated Plant Protection in Austria: Scientific Principles, Practical Application, Present State
Authors: BERAN F.
Published: April 2008

Although numerous types of intégrated plant protection programs have been elaborated and, in many areas, also effectuated, reports on the actual results and effects of the application of integrated plant protection are scarce. The author attempts to examine the results of integrated plant protection activities in Austria by means of a structural analysis of the use of plant protection products. It is concluded that the efforts of plant protection scientists have been successful both in developing a plant protection method that does not adversely affect the environment and in integrating non‐chemical and chemical methods of pest control. As a consequence of the refined techniques used in forecasting and warning services, application of chlorinated hydrocarbon insecticides and the total use of insecticides are diminishing. On the other hand, the use of fungicides is moderately increasing and that of herbicides has doubled over the preceding decade.