bluuebunny/crossref_metadata_2025 huggingface dataset:
Marquage par le 35S &d'Heterodera oryzae et &d'Heterodera sacchari et application à&l'étude de la compétition pour &l'infestation de la plante‐hôte1
Authors: Reversat G. , Bois J.‐F.
Published: April 2008

Par inoculation de plantes de riz, croissant sur un substrat contenant du Na235S04, on obtient des juvéniles marqués &d'Heterodera oryzae et &d'Heterodera sacchari. Par inoculation de mélanges de juvéniles non marques et de juvéniles marques, identifies ultérieurement par autoradiographie, on montre que les juvéniles &d'H. sacchari ont un pouvoir infestant supérieur àcelui des juveniles &d'H. oryzae, et que les juvéniles &d'H. oryzae issus de masses &d'ceufs et les juvéniles &d'H. oryzae issus de kystes ont un pouvoir infestant identique.
Caractérisation des pathotypes ďHeterodera avenae en France: influence de la période de culture slir le pouvoir discriminant de cultivars ďAvena sativa et différences dans la capacityéàfo̊rmer des femelles1
Authors: Rivoal R. , PERSON‐Dedryver F.
Published: April 2008

La caractérisation des pathotypes ďHeterodera avenae en France montre le rôle discriminant de plusieurs cultivars ďAvena sativa. Malgré un allongement de sa période de culture par un semis en automne (mois de decembre), le cultivar de type printemps Noire de Moyencourt est un hôte mediocre pour les pathotypes Fr 1 et Fr2 mais excellent pour les pathotypes Fr3 et Fr4. Cette relation entre les nématodes et le végétal paraît ďordre génétique, car les résultats sont confirmés par des données obtenues en conditions normalisées de culture et ďinfestation (plantes cultivées sur gélose en boîtes de Pétri et infestées par un nombre déterminé de larves). Nous avons également vérifiéqu'A. sativa cv. Prieuré de type hiver différencie Fr2 et Frl en multipliant fortement le premier pathotype et faiblement le second. ďautres études en conditions normalisées ont montré des différences dans la capacityé des pathotypes àformer des femelles sur diverses céréales. Le pathotype septentrional Fr4 se multiplie mieux sur les cultivars ďAvena que sur Hordeum ou Triticum. A ľopposé, les pathotypes méridionaux Frl et Fr2 se développent le plus sur Hordeum et sur Triticum. Les différences dans la capacityé chez ces pathotypes àse développer en femelles nous paraissent également génétiques;elles devraient être recherchées chez les entités physiologiques ďH. avenaeďautres pays.
Les cultivars ďorge, facteurs de discrimination des pathotypes ďHeterodera avenae1
Authors: PERSON‐Dedrwer F. , Pannetier D.
Published: April 2008

Les quatre pathotypes français Frl, Fr2, Fr3 et Fr4 peuvent être déterminés par leur capacityéàse multiplier ou non sur divers cultivars ďorge. Mais, ďune manière générale, les pathotypes méridionaux Frl et Fr2 se développent mieux sur les orges multiplicatrices, telles qu'Aramir, que les pathotypes septentrionaux Fr3 et Fr4. Les orges Siri et P 31–322‐1 sont résistantes àseulement trois pathotypes en France: Fr2, Fr3 et Fr4. ľhérédité génétique de la résistance de ces deux orges vis‐à‐vis ďHeterodera avenae est étudiée. Les résistances de Siri et de P 31–322‐1 vis‐à‐vis des pathotypes Fr2, Fr3 et Fr4 dépendent ďun ou de plusieurs gènes suivant le pathotype considéré. ľappartenance des quatre pathotypes français àla même espèce est vérifiée par ľétude de la descendance de leurs croisements.
Classification of Plants Resistant to Heterodera avenae1
Authors: Andersen K. , Andersen S.
Published: April 2008

Differentiation of barley plants resistant to Heterodera avenae is simple when they are completely without cysts and the number of cysts is high on a susceptible control cultivar. Problems with classification are discussed.
Resistance de l'avoine a Heterodera avenae. Methodes de selection et sources de resistance1
Authors: Clamot G.
Published: April 2008

Deux sources de résistance ont été utilisées pour la sélection de lignées &d'avoines résistantes àHeterodera avenae: CI 3445 et Nelson. Seules des descendances àrésistance intermédiaire (quelques kystes par plante) ont pu être sélectionnées au départ de CI 3445. En revanche, des lignées totalement résistantes ont pu être produites á partir de Nelson. Une méthode &d'évaluation de la résistance permettant &d' examiner rapidement un grand nombre de plantes s'est révélée discriminante pour les lignées hotes. Elle n'a pas permis de différencier les lignées totalement résistantes des lignées àrésistance intermédiaire. Cette méthode peut être appliquée au ≪ screening ≫ des lignées en cours de sélection. Elle doit être répétée pendant deux ou trois générations en raison du caractére bigénique et dominant de la résistance. Il est nécessaire, pour caractériser avec précision le degré de résistance des lignées en fin de sélection, de faire appel àune méthode plus normalisée, basée sur &l' utilisation de substrats artificiellement infestés et le dénombrement complet des kystes formés sur le système racinaire.
Variations in Cereal Yield Losses associated with Heterodera avenae in England and Wales1
Authors: Williams T.D. , Beane J.
Published: April 2008

Many field experiments in England and Wales during the past 20 years have measured cereal yield losses and established regressions of yield on numbers of Heterodera avenae. Yield benefits from soil sterilants were greatest where most H avenae was present. Isogenic selections of barley and oats resistant and susceptible to H. avenae were extensively grown to assess the losses caused by this nematode alone. In some experiments these losses were identical with those measured by nematicide use, but in others (notably where broad spectrum biocides were used) losses were greater than those attributable to H. avenae and could be explained only by the known incidence of accompanying pathogens. Some yield loss may be due to migratory nematodes, e.g. Pratylenchus spp. occurring with H. avenae. Barley and wheat yields in the last 30 years have increased by 63 and 84 % due to improvements in cultivars and farming practice. Smaller percentage loss in a high yielding crop can be as costly as large percentage loss in poor crops grown on dry light soils. Many factors ‐ soil type, rainfall, nutrients, other pathogens etc. ‐ can greatly modify crop responses to similar popuiation levels of H. avenae.
Etude préliminaire sur les possibilityés &d'utilisation des champignons parasites comme agents de lutte biologique1
Authors: Cayrol J.C. , VELASQUEZ‐Dominguez M. , Levaux P.
Published: April 2008

Des études ont été entreprises pour tester &l'activité de deux champignons parasites des osufs: Verticillium chlamydosporium et Paecilomyces lilacinus respectivement contre Heterodera avenae et Meloidogyne spp. V. chlamydosporium apparait comme un auxiliaire intéressant bien que son pouvoir parasitaire soit limité par une incapacityé &d'attaquer les œufs dont le stade de développement embryonnaire excède trois blastomeres. P. lilacinus, considéré au Pérou comme un champignon très efficace contre les Meloidogyne, s'est révélé totalement dépourvu &d'interêt dans nos conditions expérimentales.
Cereal Cyst Nematode, Soil Heating and Fungal Parasitism1
Authors: Juhl M.
Published: April 2008

Experiments on winter heating of cereal cyst nematode‐infested soil have been carried out during 4 years on light loam in eight concrete pipes (l‐m diam.) dug into the soil. The soil in four of the pipes was heated to a temperature of 5oC during the winter periods. Temperature was measured at a depth of 5 cm. The heating was carried out by means of buried electrical cables. Soil temperature in the remaining pipes followed the natural fluctuation. The host plant was Sun II oats. Statistical analysis of the results for all the years together showed that the propagation of nematode populations was significantly lower in heated than in non‐heated plots. Investigation of soil samples in spring and autumn 1980 for eggs and larvae, as well as fungal parasitism of these, showed that numbers of eggs and larvae were significantly lower in heated than in non‐heated plots and the percentage of parasitized eggs and larvae was significantly higher in heated than in non‐heated plots. Verticillium chlamydosporium seems to be a main parasitic fungus.
Jectarow ‐ A Commercial Unit for Applying Low Volumes of Toxicants to the Seed Furrow of Row Crops1
Authors: Gurner P.S.
Published: April 2008

Jectarow was developed specifically to apply EDB at low volume into the cereal seed furrow for Heterodera avenae control. It has since been used successfully to apply a range of other toxicants. These include liquid formulations of the soil fumigants chloropicrin, and formalin, and emulsions of the fungicides quintozene and etradiazole and the insecticide chlorpyrifos. Suspensions of the powder formulations of captan and chlorothalonil have also been applied successfully using the microtube applicator. Other potential applications of Jectarow may include growth regulators, Rhizobium cultures, trace elements, fertilizers or nitrification inhibitors. Perhaps this machine offers the opportunity to inoculate antagonistic or competitive non‐pathogenic cultures into a required soil zone. Jectarow has the advantage that highly toxic compounds can be considered as being contained in a ≪ closed system ≫ Jectarow is a low cost machine that sells to the Australian farmer for $A 215–470 depending on the size of his cereal seed drill (16–120 rows). It is probable that in sophisticated agricultural systems several Jectarows could apply different toxicants on the same machine in the same crop simultaneously.
La prévision dee risques phytosanitaires. Approche agrométéorologique1
Authors: GERBIER N.
Published: April 2008

L'impact des facteurs climatiques et de leurs aléas sur les cultures est évident, et de ce fait l'agrométéorologie est un élément important dans la prévision des risques phytosanitaires. Les connaissances agrométéorologiques influent non seulement sur l'orientation de l'agriculture, notamment en comparant le climat et les exigences écoclirnatiques des cultures et de leurs parasites, mais sont importantes aussi dans le domaine phytosanitaire et lorsque doit être prise la décision d'une intervention. Les facteurs climatiques ont une incidence sur tous les niveaux de la production agricole, et partant, sur la santé des plantes. Dans cette optique, l'amélioration des systèmes pour recueillir les données, comprenant notamment la mise en place d'un réseau plus dense, pourrait être plus bénéfique à la prévision des risques phytosanitaires et à leur modélisation.
Caractérisation climatique locale: micro/mésoclimats1
Authors: SAMIE C.
Published: April 2008

Le chercheur, qui étudie l'action du climat sur la croissance et le développement d'une espèce animale ou végétale est entraîné vers une analyse de plus en plus fine des phénomènes bioclimatiques: il travaille donc à une échelle de temps et d'espace adaptée à l'organisme considéré. L'utilisation opérationnelle, en météorologie agricole, va imposer une transposition des résultats et la référence à un climat qui n'est généralement exprimé que grâce à des mesures normalisées, faites au moyen d'appareils déterminés, installés dans des conditions uniformes. Sans aller jusqu'à l'établissement de véritables fonctions de transfert liant le microclimat au mésoclimat, nous avons pu, grâce à la mise en œuvre de matériel de campagne, pendant des périodes assez courtes, mettre en évidence quelques relations entre les microclimats locaux et le mésoclimat défini par l'abri météorologique: influence de la végétation environnante (haie, clairière, lisière) et de la topographie en fonction des types de temps; ceci dans le cadre d'une étude de la représentativité des mesures de température sous abri dans le massif du Ventoux (Provence, France).
An Automatic Met Station for Agrometeorological Measurements1
Authors: WANNER R.
Published: April 2008

The design of a mobile met station for measurements of the temperature and wind profile up to 8 m above ground is presented. The data acquisition system is based on a desk top computer and allows display, print‐out and tape recording of data during agrochemical spraying trials.
Le réseau météorologique automatique suisse; expérience pratique1
Authors: CALAME F.
Published: April 2008

L'article résume l'expérience pratique en Suisse de la performance du réseau météorologique automatique. Les causes des pannes de 1978 à 1980 font l'objet d'une analyse détaillée, qui confirme enfin le rendement intéressant du réseau assurant 99.2% de l'information aux utilisateurs.
Evaluation of Samplers for Splash‐dispersed Fungus Spores1
Authors: FITT B.D.L.
Published: April 2008

Sticky glass cylinders, microscope slides under rainshields, funnels and a liquid impinger were evaluated as samplers for spores of the splash‐dispersed fungus. Pseudocercosporella herpotrichoides. Weekly spore counts for slides, funnels and the impinger showed a similar seasonal pattern. Funnels, as the largest samplers, generally collected most spores but the impinger collected more spores per unit area of sampling surface. Slides sometimes collected spores when other samplers did not.
Climatic Zoning and Plant Disease Potential – Examples from the Near and Middle East1
Authors: WELTZIEN H.C.
Published: April 2008

Actual plant disease and pest occurrence depends on many genetic and environmental factors, and frequently obscures the basic suitability of a given location to support or prevent epidemic development. In order to allow the demarcation of climatic zones related to the potential of disease or pest occurrence, we have used long‐term average climatic data, especially monthly average temperatures and monthly average rainfall. If applied to sugar beet leaf pathogens such as Cercospora beticola and Erysiphe betae in the Near and Middle Eastern region, some interesting zoning became possible, which could be verified by extended field studies. Other examples that have been analysed in the region are apple scab, Venturia inaequalis, and downy mildew of grapes, Plasmopara viticola. A recent and ongoing analysis of the factors controlling chickpea anthracnose caused by Ascochyta rabiei indicates that the same principle may be applied for very different pathogens. Large‐scale planning and control strategies as tried by the International Agricultural Research Centers should therefore be based on careful climatic zoning for plant pest and disease potential, to avoid waste of the limited genetic and financial resources available.
Crop Loss and Disease Incidence Classified by Climatic Parameters1
Authors: RICHARDSON M.J.
Published: April 2008

A method of analysing survey data, collected to obtain information on various aspects of cereal crop performance, especially disease incidence, plant population, and yield, has been developed to allow estimates of potential yield, and hence total loss, to be made. The method also allows the losses to be partitioned and the components attributed to different stages of the crop's growth ‐ establishment, tillering and grain formation. The farms used in the survey have been classified according to winter, spring and summer temperatures and rainfall. Attempts have been made to associate trends in disease incidence and losses occurring at different times of the year with the climatic parameters.
Aerial Transport of Pests and Pest Outbreaks1
Authors: JOYCE R.J.V.
Published: April 2008

Pests of arable crops tend to show a high degree of migratory activity. This is particularly so in northern Sudan where the variable rainfall produces habitats which are short‐lived and unpredictable in their frequency and location. Insects whose flight activity is adapted to enable them to move on the same wind‐system which produces the rains are frequently pests of the crops of these climates. Outbreaks of such pests are usually a function of the numbers which colonise the crops, and this in turn depends not only on the success of breeding in the source areas but also on increases in density which occur whilst they are airborne. The importance of the increases in airborne densities which occur within the inter‐tropical discontinuity and the cold‐air outflows ahead of convectional storms to pest outbreaks in the Sudan Gezira is described.
The Effect of Winter Weather on the Survival of Aphid Populations on Weeds in Scotland1
Authors: TURL L.A.D.
Published: April 2008

Since 1975 studies have been made in Scotland on the status of weeds as overwintering hosts for potato‐infesting aphids. The results show that Myzus persicae, Macrosiphum euphorblae and Aulacorthum solani can all overwinter anholocyclically on weeds or wild plants, and also suggest that the success of such overwintering depends on the relative severity of the winter. It appears that this overwintering success can be quantified and used in forecasting the potential for these aphids to colonise potato crops during the following spring.
Développement d'Adoxophyes orana en fonction de la température et conséquences pratiques pour la lutte1
Authors: CHARMLLOT P.J. , MEGEVAND B.
Published: April 2008

L'établissement d'un modèle de développement pour la tordeuse de la pelure, Adoxophyes orana, basé sur les sommes de températures, est primordial pour l'avertissement Il permet à l'arboriculteur d'effectuer un minimum d'échantillonnages des populations aux moments les plus opportuns, afin de prendre les décisions qui s'imposent pour l'application de la lutte dirigée. Les essais effectués en laboratoire et à l'extérieur ont montré que le seuil de développement des œufs est de 10°C, celui des larves de la génération d'été se situe entre 7 et 8°C, alors que celui des larves de la génération hivernante est de 10°C. Le seuil de développement pour la phase nymphale est légèrement supérieur à 10°C. En admettant une vitesse de développement proportionnelle à la température, les durées des phases embryonnaires et nymphales sont de 90 degrés‐jours (dj) au‐dessus du seuil de 10°C. Le développement larvaire de la génération d'été est en moyenne de 430 dj au‐dessus du seuil de 7°C. Les implications de ce modèle pour l'avertissement établi par les services officiels ainsi que pour la stratégie de lutte contre la tordeuse de la pelure sont commentées dans ce travail.
Search for Climatic Models for Forecasting Microtine Outbreaks1
Authors: MYLLYMÄKI A.
Published: April 2008

Models for forecasting outbreaks of harmful Microtines are discussed in terms of the three most important types of rodent damage to agriculture and forestry in the European part of EPPO region: problems to field crops by Microtus arvalis and related species, to horticulture and forestry by M. agrestis and some other species, and injury to the underground parts of various crops by Arvicola terrestris. Two models were developed in parallel but independently for M. arvalis, one in the USSR, the other in France; the former approach included M. socialis. A joint Scandinavian project resulted in models for M, agrestis and Clethrionomys glareolus: the outcome is exemplified by the former case and a few comments are given on other types of model development. The probable mechanism of climatic influence through the food chain on the population dynamics of Microtine rodents is discussed and it is concluded that climatic models are a useful tool in planning rodent control strategies. The role of the EPPO Working Party on Field Rodents as a coordinating body in the development of rodent forecasts is also reviewed.
A Simulation Approach to Investigating the Response of a Coypu Population to Climatic Variation1
Authors: GOSLING L.M. , BAKER S.J. , SKINNER J.R.
Published: April 2008

The main environmental constraint on the population of feral coypus (Myocastor coypus) in eastern England is cold weather. This paper describes the use of population simulations to explore the effect of various combinations of cold and mild winters. Winter severity is defined‐using an expression that accumulates weighted sequences of freezing days. Descriptions of fecundity, recruitment to the adult sector of the population and mortality were obtained from dissections of over 20,000 coypus and from records of the control trapping operation between 1970 and 1982. These data were summarized in average years containing either cold or mild winters and used as inputs to a realistically constructed model of the population. The simulations presented show the seasonal consequences of cold and mild winters, the effect of continuous sequences of each type of winter, and the effect of random sequences of cold and mild winters occurring at the relative frequency (5:6) observed in recent years. The results give a quantitative assessment of the interaction between control trapping and cold weather and its effect in limiting the population. A simulated population curve over the 12‐year study was significantly correlated with the results of a continuous retrospective census over the same period.
Dix années d'utilisation de données sur les sommes de températures journalières pour la prévision des vols de Rhagoletis cerasi et d'Eupoecilia ambiguella au nord de la Suisse1
Authors: BOLLER E.F. , REMUND U.
Published: April 2008

Des expériences conduites en 1963 avec des pupes de Rhagoletis cerasi ont révélé qu'une température de base de 5°C et une somme de températures effectives de 430 degrés‐jours étaient nécessaires pour le début du vol. A partir des températures du sol (à 5 cm de profondeur) et des stations d'observation des pupes implantées sous les cerisiers, on a pu mettre en évidence une forte corrélation entre les dates de début de vol calculée et observée, et classer les principales régions de Suisse productrices de cerises en zones précoce, moyenne et tardive en ce qui concerne le développement de Rhagoletis cerasi. Utilisés avec le système de prévision mis au point au nord de la Suisse pour les vergers de cerisiers, les présents outils de prévision autorisent une estimation précise de la première apparition du ravageur et de la maturation du fruit dans les régions spécifiées. Quant au système de prévision pour Eupoecilia ambiguella, il utilise les sommes de températures maximales journalières à partir du 1er janvier. Il existe une bonne corrélation entre la date correspondant à 950 degrés‐jours et le début du premier vol. Les données obtenues au cours du vol de la première génération permettent de prévoir le début, le maximum et la durée probable du second vol, qui est d'une importance économique beaucoup plus grande.
Use of Meteorological Information for Forecasts of Pest Development based on Models and Computers1
Authors: VOLVACH V.V.
Published: April 2008

A computerized simulation model for the development of Leptinotarsa decemlineata is described. The model uses biological and meteorological data as input, and outputs the ecological reproduction coefficient. Calculated values correlate satisfactorily with observed reproduction coefficients. The model has been used to forecast these coefficients for average conditions in five zones in the USSR, and in 12 other European countries.
Forecasting the Incidence of Aphids Using Weather Data1
Authors: A'BROOK J.
Published: April 2008

Aphids have been trapped continuously at several heights at Aberystwyth (United Kingdom) since 1969. Relationships have been found between prior meteorological parameters (normally recorded at Agricultural Meteorological Stations) and numbers of aphids flying during both summer and autumn peaks, and with the first occurrence in the trap each year. Numbers of cereal aphids caught in the autumn are associated with previous winter and spring temperatures and particularly with summer rainfall. Cereal aphid numbers are also associated with the yields of their summer grass hosts which in turn are related to summer rainfall, thus providing a causal relationship. The value and accuracy of using meteorological parameters to forecast the incidence of aphids of agricultural importance is discussed.
Influence des facteurs climatiques, et plus particulièrement des mouvements atmosphériques turbulents de l'air sur l'envol migratoire d'une coccinelle aphidiphage, Somiadalia undecimnotata1
Authors: IPERTI G. , BRUN J. , SAMIE C.
Published: April 2008

La température, l'humidité relative, la force et la direction du vent, l'intensité lumineuse ne représentent pas les seuls facteurs météorologiques qui influent sur le comportement migratoire d'une espèce de coccinelle aphidiphage, Semladalia undecimnotata. Aussi, la mise en place d'un dispositif appropriéà la mesure des composantes du climat a permis de prendre en considération le degré de turbulence de l'air représenté par l'indice de Richardson. Lors de l'interprétation des résultais obtenus, l'utilisation de la régression factorielle a rendu possible la mise au point d'un modèle prédictif du comportement d'envol des coccinelles où cette nouvelle donnée joue un rôle très important De plus, l'analyse de correspondance effectuée avec les différents paramètres temporels, physiologiques et climatologiques retenus a permis de mettre en évidence les conditions météorologiques nécessaires à l'obtention d'indices de Richardson suffisamment élevés pour faciliter surtout l'envol de la fraction la plus intéressante d'une population de coccinelles, celle des femelles.
Meteorology and Desert Locust Forecasting1
Authors: PEDGLEY D.E.
Published: April 2008

The now very considerable understanding of weather effects on breeding and movement by the desert locust has been used to prepare a forecasting manual. It is a two‐volume, 400‐page publication that describes, explains and illustrates the principles of modern forecasting, and includes not only much material on the biology and ecology of this species but also many new biogeographical studies of past locust developments that involved a variety of synoptic systems in some 60 countries of northern and eastern Africa and south‐western Asia. It can be useful to all who are concerned with the effects of weather on insect movement.
Disease Intelligence and its Role In Disease Forecasting1
Authors: GWYNNE D.C.
Published: April 2008

Disease intelligence information is received at Bristol by telex from plant pathologists in all regions of England and Wales. Weather information recorded at synoptic stations throughout the country is fed into the Meteorological Office computer at Bracknell, and from given parameters daily forecasts are issued for a number of diseases including apple scab, potato blight, barley mildew, barley leaf blotch, wheat septoria and wheat eyespot. All this information is collated, printed and distributed widely to plant pathologists in the advisory services, research establishments and various sections of commercial manufacturing and sales organisations. The report is broadcast on BBC radio, featured on teletext (BBC Ceefax), viewdata (Prestel) and Telephone Information Services (TIS), and published in a number of national and regional agricultural journals. Disease intelligence information aids in the interpretation of disease forecasts and equally disease forecasts aid in advising on the need for pesticide application.
Application d'un modèle à la lutte contre Botrytis cinerea sur vigne1
Authors: MOLOT B. , AGULHON R. , BONIFACE J.C.
Published: April 2008

Dans le cadre d'un groupe de travail «Modélisation du Botrytis» l'Institut Technique de la Vigne et du Vin en France a entrepris l'étude des réactions de ce parasite à des conditions d'humectation contrôlées. L'essai est réalisé sur une vigne adulte, sous abri plastique; il couvre 1600 m2 et permet, grâce à un dispositif de brumisan'on, l'étude comparative de 12 régimes d'humectation distincts. Après quatre années successives d'expérimentation, basée sur des protocoles évolutifs, les résultats mènent à des observations intéressantes, mais qu'il est toutefois prudent de ne pas étendre inconsidérément à l'ensemble des cépages ou vignobles. L'effet des humectations successives n'est pas obligatoirement additif, une longue période de sécheresse entre la floraison et la véraison aggravant considérablement les attaques à ce dernier stade. Une même durée d'humectation à la véraison ou 12 jours avant la récolte provoque des dégâts identiques. Les contaminations peuvent s'effectuer simplement en présence d'une humidité relative élevée, sans présence d'eau sous forme liquide; cette HR élevée est capable de créer et surtout d'aggraver fortement les foyers de B. cinerea. Les contaminations artificielles ont eu un effet significatif lors de la floraison. A la véraison l'effet est masqué par l'inoculum naturel. L'étude de la réaction de Botrytis cinereaà différentes durées d'HR élevée reste délicate, un seuil exact restant difficile à estimer vu le niveau de précision des appareils utilisés. En outre, le modèle mis au point par Strizyk a fait preuve d'une précision accrue au fil des expérimentations successives; il semble donc bien adapté au cépage méridional utilisé. La stratégie de traitement a permis de réduire de moitié le nombre d'applications de fongicides dans l'essai, l'expérimentation prouvant toutefois qu'une réduction supplémentaire était possible. Il apparaît donc que cette stratégie, basée sur le modèle Botrytis, est prometteuse mais nécessite encore quelques adaptations afin de la rendre encore plus performante. L'étude des réactions de B. cinereaà certains facteurs climatiques permet done, outre l'amélioration de la lutte contre ce parasite, une meilleure connaissance de ses facteurs d'évolution. Il est possible qu'à l'avenir le facteur humidité relative, alliéà l'hiumectation, procure une fiabilité optimale du modèle, et probablement de la stratégie de lutte en découlant.
Potentiel infectieux des sols ‐ concept et modèles1
Authors: BOUHOT D. , JOANNES H.
Published: April 2008

Les maladies dues à des micro‐organismes vivant dans le sol ne peuvent être caractérisées sans prendre en compte l'ensemble des composants du sol (physiques, chimiques et microbiologiques) où elles se manifestent. C'est pourquoi le concept de potentiel'infectieux du sol proposé se définit comme la quantité d'énergie pathogène stockée et disponible dans le sol. L'expression au champ du potentiel infectieux dépend des facteurs climatiques. Le potentiel infectieux du sol est mesuréà l'aide d'un test biologique appliqué en conditions standards. La relation obtenue entre la quantité de sol et le taux de mortalité sur la population de plantes est modélisée sur la base d'une compétition entre l'agent pathogène et la microflore totale du sol à partir d'un modèle de Lotka‐Volterra. Le test biologique et le modèle permettent de caractériser les sols, de déterminer la réceptivité d'un sol à un parasite, de prévoir certains risques de maladie, d'estimer le poids des facteurs climatiques sur la maladie et de prendre en compte les effets directs et indirects des pesticides.
EPIPRE: a Disease and Pest Management System for Winter Wheat, taking Account of Micrometeorological Factors1
Authors: RABBINGE R. , RIJSDIJK F.H.
Published: April 2008

EPIPRE (EPIdemic PREvention) is a cooperative project for supervised control of diseases and pests in wheat. It operates on a field by field basis. From every wheat field, basic data and field observations are stored in a data bank. Farmers send their field observations to the central team, which enters them in the data bank. Field data are updated daily by means of simplified simulation models. Expected damage and loss are calculated and used in a decision system, that leads to one of three major decisions: «treat», «don't treat», or «make another field observation». Exchange of information between farmers and central team is by mail. In 1978 EPIPRE started with Puccinia striiformis. Since then the number of pests and diseases which are considered have increased, so that in 1981 advice was given for P. striiformis, P. recondita, Erysiphe graminis, Septoria spp. and the cereal aphids, Sitobion avenae, Metopolophium dirhodum and Rhopalosiphum padi. For each of these pests and diseases predictive methods have been developed using explanatory simulation models as a tool. These explanatory models are based on knowledge of many input relations and some external factors (e.g. temperature) which govern most of the processes of the pest and disease population dynamics. On the basis of a sensitivity analysis with these models simplified decision rulés have been developed which are used in the advice system in which updating of the forcing variables is no longer needed.
Droplet Formation and Deposition1
Authors: BALS E.J.
Published: April 2008

At the EPPO Conference in Belgrade on 1970 the author reported on work showing that small, uniform, and non‐volatile droplets appeared to offer the prospect for greatly reduced dosages of pesticides by both providing a more effective deposit and by controlling drift. Three recent studies provide further evidence for this hypothesis, which questions the very principles on which our present spraying practices are based. However, the deposition of droplets by the external forces of wind and gravity imposes lower limits on the droplet sizes capable of being used. These are 30 μm for insecticides and fungicides (except in the case of flying insects) and 150 μm for herbicides, since the droplets require sufficient energy to impact themselves on the target. Electrostatic charging of droplets promises to free us from these size constraints by providing the droplet with a depositional force of its own, allowing it to impact on any surface. Electrostatics, however, is solely a force of deposition and thus must be balanced with the forces required for spray dispersion so that the droplets can penetrate the crop canopy and/or be transported to the target
Pulvérisation centrifuge à trèe bas volume: TG 4121
Authors: MOREL M.
Published: April 2008

Extrapolé des pulvérisations centrifuges portables utilisés en Afrique depuis plus de 10 ans, le GIROJET est une buse centrifuge qui se caractérise par son disque vertical. Cette particularité pennet de produire un jet plat comparable à celui d'un jet pinceau de qualité. Cette buse a permis de réaliser un pulvérisateur pour grande culture, porté de 4001, équipé d'une rampe de 12 m: le TG 412. Ce pulvérisateur permet l'application de volumes de bouillie à raison de 251/ha.
Design and Development of a Disc‐Windmill Atomiser for Aerial Applications1
Authors: SPILLMAN J. , SANDERSON R.
Published: April 2008

For greater efficiency in aerial applications of pesticides it is essential to get a greater fraction of the emitted formulation to the true biological target To achieve this and at the same time ensure that environmental pollution is a minimum requires the use of a narrow droplet spectrum of the correct mean size. The best atomisers currently made for aircraft use produce at best only about 40 % of the emitted volume in sizes within 25 % of the desired size and in many cases the percentage is far smaller. A simple spinning disc atomiser has been designed at Cranfield which operates in the filament mode of droplet formation at flow rates many times greater than the usual maxima for these devices. This improvement is achieved by using a high velocity radial airflow in the region of atomisation. This same air, arising from the forward speed of the aircraft, is used to rotate the disc by shaping it to be a high solidity windmill. Test results show that a 5 cm diameter disc will atomise up to 11/min into droplet sizes from 80 μm to 300 μm VMD, depending upon the chosen blade setting, and that, for any given blade setting, up to 80 % of the emission will be within ± 25 % of the mean size. It is anticipated that mass production of the atomiser will commence in 1983.
The Performance of Rotating Metal‐Foam Atomisers1
Authors: PARKIN C.S.
Published: April 2008

Prototype rotating metal‐foam atomisers, designed for aerial application, have been extensively tested both in the laboratory and under field conditions. Laboratory tests were carried out in a wind tunnel and field tests in a large‐scale aerial operation. The metal‐foam atomisers showed advantages in droplet‐spectrum control and vibration levels over currently available equipment, and, when used to spray 150,000 ha of cotton, four units required no maintenance. Rotating metal foam atomisers can operate safely at the high rotational speeds used for medium volume spraying of droplets with a diameter less than 50 μm (as in tse‐tse control).
Newly Developed Low‐pressure TeeJet Nozzles for Pesticide Application at Lower Water Volume and Reduced Wind Drift1
Authors: HAHMANN S.
Published: April 2008

The development of TeeJet flat‐jet nozzles in the 1960's has facilitated optimal herbicide application. The required accuracy of ± 15 % in transverse distribution was achieved by a nozzle spacing of 50 cm and a height above ground of 40‐60 cm. Two problems remained: 1) to reduce volumes; 2)to limit drift yet further. The development of the low‐pressure TeeJet has helped to solve these problems. The nozzle is constructed with a cylindrical tube which is ellipsoidal in cross‐section at the input end and which narrows symmetrically to the axis to a flattened oval orifice at the output end. By this means 1) the spray angle of 110° can be achieved with a pressure of 1 bar; 2) better distribution is achieved at the edges of the jet, by comparison with the standard TeeJet; 3) a greater proportion of coarse droplets is achieved by comparison with 110° or 120° nozzles (nominal pressure 3 bar). It is accordingly possible to apply herbicides at volumes lower than the currently used 4001/ha. Trials have shown that, with few exceptions, water volume can simply be reduced to 1001/ha without any increased risk of drift
New Atomizer Developments in the Hungarian Aviation Service1
Authors: PETTENKOFFER S.
Published: April 2008

In the practice of aerial application of chemicals in Hungary, the need arose in the mid‐70's to solve the spray atomization problem for the ULV range. First experiments were carried out with imported equipment, in view of the lack of Hungarian‐manufactured equipment. Unfavourable practical experiences impelled the Air Service in Hungary to develop and manufacture new spraying equipment, specially adapted to local requirements. The Unirot‐4 electrically driven rotary drum became the first successful atomizer, which was put into large‐scale operation in recent years. This multi‐purpose spraying equipment is now essential on helicopters used for ULV and LV applications. The X‐2 fan‐driven rotary drum is being developed for fixed‐wing aircraft.
Progress with an Electrostatic Device for enhancing the Selectivity of Herbicides in Cereal Crops1
Authors: TAYLOR W.A.
Published: April 2008

Apparatus is described that produces uniformly sized and charged drops that can be propelled to the target at a range of speeds. Results from the use of this equipment suggest that drop momentum, rather than just drop size, may have an effect on spray deposition. The magnitude of this effect is dependent on the characteristics of leaf surfaces. For example, spray deposition on cereal leaves is sensitive to changes in drop momentum but this is not the case for Raphanus sp. This factor, if exploited, could be the basis for altering selectivity between plant species.
L'humectation: une nouvelle méthode d'application des herbicides1
Authors: MOREL M.
Published: April 2008

On entend par humectation la technique qui consiste à déposer sur une plante une masse de bouillie par contact direct Ce mode d'application présente un intérét certain dans la mise en place d'herbicides polyvalents en culture. La sélectivité est dans ce cas assurée par la différence de hauteur entre les plantes cultivées et les adventices. Cette technique permet d'apporter une solution chimique rationnelle à des problèmes spécifiques de désherbage: 1) betteraves montées et sauvages en betteraves fourragères ou industrielles, 2) adventices (joncs, rumex, chardons, refus) en prairies. Les différents matériels utilisés comprennent: 1) la toile humectante alimentée par capillarité (Herbilame, Herbichoc); 2) les cordes alimentées par capillarité (Cordyl, Kapout); 3) les cordes en charge (Herbitec); 4) les cordes alimentées sous pression (Wedge Wick). Des résultats sont présentés sur les taux d'efficacité des différents matériels en prairies et sur betteraves industrielles en France.
The Kinetics of Spinning‐Disc Atomizers Applied to Seed Treatment Machinery1
Authors: GYÜRK I.
Published: April 2008

Spinning disc‐atomizers are widely used in seed‐dressing machines. They not only give an initial velocity to the droplet but deliver air as well, consequently the droplet enters a moving medium. Computer analysis shows the influence of this mutual motion in the case of linear, parabolic and hyperbolic air velocity decrease. The moving air exerts a significant effect on the ideal encounter zone of liquid and seed. This effect should be taken into consideration in designing the dressing chamber of seed treatment machinery.
Disinfection of Flower Bulbs by Pesticides in Foam1
Authors: BIJL A.S. , KOCH V.J.M.
Published: April 2008

Disinfection of flower bulbs is a very important operation for the grower. Traditional methods like spraying or drenching the bulbs with pesticide solutions is very environment‐polluting. To overcome the release of pesticides into the environment by dumping wastes, research has been undertaken into an alternative method of disinfection: administration of pesticides in a foam formulation. If applied properly this method avoids overdosing and prevents leakage of pesticides to the ground and drift of droplets. Several characteristics of the foam have been studied in relation to this method' of treatment. Other possibilities of application of this method are considered.
Control of Rosollinia necatrix by Deep Placement and Hot Treatment with Methyl Bromide1
Authors: SZTEJNBERG A. , OMARY N. , PINKAS Y.
Published: April 2008

Rosellinia necatrix, the cause of white root rot in fruit trees, was efficiently controlled in an infested avocado orchard soil, by applying methyl bromide by deep injection (up to 90 cm) of cold gas and by surface application of hot gas, at a dosage (for heavy soil) of 1500 kg/ha and 1000 kg/ha, respectively. Efficiency of control was evaluated: 1) by testing pieces of naturally diseased avocado roots buried in the soil before treatment at different depths up to 100 cm; 2) by planting avocado and almonds in the treated field and in soil samples; 3) by burying avocado leaves in the soil samples. All the evaluaton tests showed that both treatments of methyl bromide were effective in controlling R. necatrix completely up to the depth of 100 cm, immediately and 9 months after treatment.
Matériels pour l'application des produits agrochimiques1
Authors: BOURNAS L.
Published: April 2008

Les progrès récents dans la conception des pulvérisateurs ont porté sur la précision des applications, en particulier pour les herbicides, l'augmentation du rendement horaire, la facilité de mise en ceuvre et les traitements en localisation. En ce qui concerae la precision des applications, on constate le développement et le perfectionnement, notamment à l'aide del'électronique, des systèmes de régulation à débit proportionnel à l'avancement. La suspension des grandes rampes, allant jusqu'à 24 m pour des pulvérisateurs portés en cultures basses, est constamment perfectionnée pour assurer une meilleure stabilité. Par ailleurs, la tendance à réduire les volumes par hectare entraîne une nouvelle étude des circuits de bouillie, notamment de la filtration. II est recouru aux buses à fente de petit calibre, pouvant travailler à basse pression (parfois moins de 2 bar), et la stabilité du rideau de pulvérisation sous rampe à bas volume par hectare est examinée de même que les organes de pulvérisation centrifuge permettant de descendre à moins de 50 l/ha. Les pulvérisateurs arboricoles et viticoles sont dotés de ventilateurs plus puissants et des souffleries sont étudiées pour un meilleur rendement à moindre bruit. Parmi les autres progrès on remarque le développement des systèmes de localisation pour les traitements de la vigne. Quant à la distribution des microgranulés phytopharmaceutiques, elle a fait l'objet de nombreuses adaptations, en particulierd'épandeurs d'engrais pneumatiq'ues ou de semoirs. Ainsi, des gammes de pulvérisateurs portables ou manuels, à pression liquide ou centrifuges, plus pratiques et légers, ont été développées.
Plant Protection Equipment Developed and Used in Norway1
Authors: NORDBY A.
Published: April 2008

The Norwegian Institute of Agricultural Engineering has developed spraying equipment for particular uses, based on the adaptation of ordinary crop sprayers. Tractor‐mounted sprayers are described for spraying brassicas and carrots against Delia spp., strawberries against mites and Botrytis cinerea, and for making regular applications on blackcurrant plantations. A special « boat‐shaped » sprayer has been developed for use in forest nurseries, both to apply insecticides against beetle attack and to apply herbicides. Nursery plants can alternatively be insecticide‐sprayed before planting in a specially‐designed spray chamber.
The Direct Injection Technique for Preparing the Spray Mix ‐ A Method for Reducing Safety and Hygiene Problems in Plant Protection?1
Authors: SCHMIDT M.
Published: April 2008

In the past, industry and research institutes have produced a number of technical proposals to improve sprayer technique, and development in this area has been very successful. The «closed sprayer‐system», the pesticide flushing system, flow regulation systems and updated stirring arrangement are examples of many different practicable improvements. A completely new approach to improving application technique is the « direct injection of pesticides »: contrary to normal practice the tank of the sprayer is filled with pure water only. The pesticide is introduced in concentrate form into a separate tank and injected into the water flow produced by the equipment pump during the application process. The advantages of this technique include no direct handling of the active substance concentrate; no problems with liquid‐stirring; no pesticide residues. A commercial sprayer equipped with a metering device prototype and a newly developed constant pressure fitting is described as an illustrative example of prospective design of a « direct‐injection » system. A number of other technical possibilities exist for putting this method into practice. The advantages of this technique have to be paid by an additional capital outlay but they offer the chance to reduce safety and hygiene problems in chemical plant protection.
Control of the Olive Moth in Cyprus
Authors: MELIFRONIDES I.D. , ZYNGAS J. Ph.
Published: April 2008

Damage caused by larvae of Prays oleae has great economic impact for the olive growers in many of the chief olive‐growing areas of Cyprus. P. oleae has three generations per year affecting successively the flowers, the fruit and the leaves. The fruit generation is the most destructive, the larvae living inside the stone of the fruits and the attacked fruit falling prematurely from the tree either in late June of in late August. The trials reported in this paper were aiming to find the best time to spray for more effective control of the fruit generation. Olive trees were sprayed four times at weekly intervals using the insecticide formothion. The treatments which started on 25 May were completed by 16 June 1976. The best period was found to be that particular stage of fruit growth at which the fertilized fruit started to grow normally and they can easily be distinguished from the non‐fertilized. Having found the best time to control the fruit generation in 1976, three insecticides were tested in 1978. These were cypermethrin, formothion and triazophos.
Interception of Colorado Beetle In England and Wales, 1978‐1982
Authors: BARTLETT P.W.
Published: April 2008

The policy of the British Government continues to be to maintain total freedom from Colorado beetle by preventing its introduction and eradicating any breeding colonies which are found. During the years 1978‐1982, no breeding colonies have been found and there is no evidence that the Colorado beetle is established anywhere. Interceptions on imports during this period are analysed by country of origin and also by means of introduction. Total confirmed reports of live beetles are compared with those in previous reports; 286 were found in 1978‐1982, 257 for the previous 5‐year period and 563 of known origin for the 20‐year period previous to 1978.