bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amélioration de la résistance du blé au piétin‐verse, Cercosporella herpotrichoides (Fron)1)
Authors: Vandam J. 
Published: April 2008

SommaireLa maladie du piétin‐verse, causée par Cercosporella herpotrichoides (Fron) est favorisée dans notre pays par des conditions climatiques particulières, jointes à la simplification des assolements céréaliers. De nombreux travaux ont permis de mettre au point des épreuves de résistance en serre, en chambre de végétation et en plein champ.Aucune variété de blé tendre n'opposant une résistance élevée à la maladie, les genres et les espèces voisins ont étéétudiés. Quelques lignées de Triticum monococcum et d'espèces tétraploïdes semblent présenter un certain intérêt. Au sein du genre Aegilops, A. ventricosa constitue une excellente source de résistance et son utilisation a déjà permis d'obtenir des résultats très encourageants.D'autre part, au cours des travaux de sélection, il est nécessaire de surveiller avec attention l'évolution de la virulence des souches du parasite.RésuméLa maladie du piétin‐verse causée par C. herpotrichoides revêt une importance croissante dans les cultures de blé. En Belgique, son extension est favorisée par les conditions climatiques et par la simplification des assolements céréaliers. De nomhreux travaux ont permis de mettre au point des épreuves de résistance en serre, en chambre de végétation et en plein champ. L'examen du matériel en cours de sélection exige l'utilisation d'une méthode indirecte d'appréciation des symptômes.Au sein de l'espèce T. aestivum, il ne paraît pas possible de trouver des géniteurs pouvant conférer une résistance suffisante à la maladie. Dans les genres et espèces voisins, quelques lignées de T. monococcum et des blés tétraploïdes semblent présenter un certain intérêt Parmi les espèces du genre Aegilops, A. ventricosa s'est révélé de loin le plus résistantL'évolution de la virulence des souches de C. herpotrichoides peut poser de graves problèmes aux sélectionneurs. Des études portant sur l'interaction souche hôte ont révélé la chute de la résistance d'A. squarrosa vis‐à‐vis de certaines souches isolées du parasite.L'amélioration de la résistance peut être basée sur l'utilisation de transgressions de resistance chez les blés tendres ou d'intergression des caractères de résistance provenant d'espèces voisines. Cette dernière technique a permis la création, en France, du géniteur VPM: (A. ventricosa T. persicum) T. aestivum cv. Marne 3 (Maia, 1967), qui semble le plus intéressant parmi les blés tendres.La réussite d'une sélection ayant pour but la création de lignées résistantes et de bonne valeur agronomique implique que des travaux soient menés simultanément en pépinière classique et en parcelles infectées artificiellement.
Effect of Foliar Application of Urea on Rhizosphere and Rhizoplane Microflora of Wheat1)
Authors: Vuurde J.W.L. van , Schippers B. 
Published: April 2008

AbstractThe effect of urea leaf treatment on plant growth and rhizosphere microorganisms was studied under controlled environmental conditions with spring wheat at 2 growth stages, and at 2 inorganic nutrient levels of the soil. The increase in dry weight of shoots and roots was inhibited by the urea treatment. Treatment of seedlings also resulted in a delay in the formation of tillers and nodal roots, especially in low fertilized soil. A temporary increase of rhizoplane bacteria was demonstrated after 7–9 days due to a stimulation of fast growing strains. A quantitative effect on rhizoplane fungi was only apparent, on day 9 after treatment of seedlings, as a decrease in total numbers and coincided with the increase in numbers of bacteria and actinomycetes. At this time the numbers of fungi known to be early root colonizers like Penicillium spp. and Mortierella spp. decreased after initially being stimulated, while numbers of late colonizers like Fusarium spp. and Trichoderma spp. increased after 9 days after initially being reduced in comparison with the control. Investigation of the rhizosphere effect (R/S) of wheat by the soil dilution plate method and fluorescence microscopy showed a 200% increase in total numbers of micro‐organisms in the rhizosphere soil when the former method was used, but a 10–30% reduction when fluorescence microscopy was employed.
Eyespot in Winter Wheat: Effects of Crop Rotation and Tillage, and the Prediction of Incidence1
Authors: Maenhout C.A.A.A. 
Published: April 2008

AbstractEyespot in winter wheat is an important disease in the Netherlands. Symptoms can be found in almost every wheat crop. Italian ryegrass was shown to be a host crop and is able to maintain a high level of inoculum in the soil.In rotations with winter wheat every other year, ploughing compared with cultivating the soil in autumn resulted in a lower incidence of eyespot and a higher yield in the following wheat crop. A system of predicting the incidence at the beginning of May in order to indicate the necessity of chemical control is outlined.
La pourriture des racines de maïs causée par Fusarium moniliforme Sheldon1
Authors: Paul V. 
Published: April 2008

Fusarium moniliforme Sheldon, qui agit en tant qu'envahisseur primaire, provoque la pourriture des racines de maïs sans l'intervention d'autres espèces fongiques. Les hyphes du champignon se répandent dans les tissus par voie inter et intracellulaire. La lyse des parois de l'hôte par F. moniliforme entraîne évidemment la pourriture des racines du maïs.Résumé F. moniliforme forme des appressoria globuleux et pénètre ensuite dans les raciness de maïs en perforant directement la paroi des cellules épidermiques. Le mycélium se propage par voie inter et intracellulaire dans les tissus sous‐jacents. Dans de nombreux cas, les points de contact entre le champignon et la paroi de l'hôte sont marqués par des formations globuleuses riches en composés pectiques. Les hyphes pénètrent à travers des ponctuations dans des faisceaux conducteurs. La lyse des parois cellulaires de l'hôte par F. moniliforme entraîne évidemment la pourriture des racines du maïs.
Occurrence and Pathogenicity of Fusarium Species in Cereals in Finland1
Authors: Uoti J. 
Published: April 2008

AbstractSeveral Fusarium species occurred abundantly in spring cereal seed samples studied in 1966, 1968 and 1972 in Finland. A total of 17 species of Fusarium were isolated and identified. The most frequently isolated species were F. avenaceum (Fr.) Sacc., F. culmorum (W. G. Sm.) Sacc., F. poae (Peck) Wr. and F. tricinctum (Cda) Sacc. These species were found in more than 40% of the seed samples from 1972.The same 4 Fusarium species in addition to F. graminearum Schwabe were used in the pathogenicity test. Artificially inoculated spring wheat and barley seeds were grown in the field during the growing season of 1973. Of these 5 species F. culmorum was clearly the most pathogenic. This species significantly lowered the shooting percentage and the yield of both cereals. Foot rot assessment also revealed F. culmorum as the most damaging species. Natural soil‐borne infection obviously increased the foot and root rot, and thus the soil‐borne F. culmorum strongly affected all treatments. In the harvested seed F. poae dominated in all treatments, but F. culmorum still occurred most abundantly in the seed lot harvested from plots originally inoculated with this species.
Experience of Brown Rot Caused by Pseudomonas solanacearum (Smith) Smith in Sweden1
Authors: Olsson K. 
Published: April 2008

ABSTRACTBrown rot (Pseudomonas solanacearum [Smith] Smith) infection of 5% or less was found in potatoes from some fields in Southern Sweden at about 56° N in the years 1972 and 19732). The fields were irrigated with water from small streams. The pathogen has been isolated from a wild host, Solanum dulcamara, growing at the water's edge in one of the streams. The wild host is perennial and bacteria can overwinter in this host. Overwintering also occurred in artificially infected S. dulcamara at 59° N. No overwintering in soil has hitherto been demonstrated, in spite of experiments with artificially infested soil. Infections have probably originated from imported potatoes.
Experience of Ring Rot Caused by Corynebacterium sepedonicum(Spieck. et Kotth.) Skapt. et Burkh. in Sweden. Particularly Detection of the Disease in its Latent Form)1
Authors: Olsson K. 
Published: April 2008

ABSTRACTAs it is difficult to detect ring rot in its latent form as well as in badly decayed tubers and in potato haulm, a diagnostic technique has been developed. With the help of a Turmix blender and a little water, a suspension is made of the suspected material. The suspension is inoculated into eggplants. Gram‐staining of bacteria in sap from petioles of leaves showing symptoms is used to confirm the diagnosis. Some results obtained with this method applied on potatoes and potato haulm are described.
Field Observations on Blackleg in England1
Authors: Lapwood D.H. 
Published: April 2008

ABSTRACTInoculation of seed tubers with Erwinia carotnvora (Jones) Bergey et al. var. atroseptica (van Hall) Dye before planting resulted in early death (especially with sprouted seed), blackleg stems and decreased yields. Apical inoculations had most, and stolon inoculations the least, effect on growth and yield. Even plants without blackleg symptoms were more stunted and had fewer stems than plants from uninoculated seed. Rotting of seed tubers often stopped in dry weather and started again later, probably caused, or assisted by, insects breaching the wound barrier.Many other organisms can also rot seed tubers including Phytophthora erythroseptica Pethybridge (pink rot), Fusarium spp. (dry rot), Verticillium spp. (wilts) and Rhizoctonia spp. (black scurf).The bacteria have been shown to spread along rows underground and to different stocks within the same field, presumably in air, but season to season spread by the potato digger has not been demonstrated.
Plant Protection and Production in Modern Society1
Authors: Brader L. 
Published: April 2008

ABSTRACTMany currently existing agricultural production techniques have been developed in total reliance on effective chemical pest control. Today, however, it is becoming clear that chemical pest control has a number of limitations, and its ever increasing costs may well make it a limiting factor in agricultural production. This has already occurred in a number of cotton growing areas.The need for increased world food production will require improved pest control methods. If no special precautions are taken, we will undoubtedly end up in many other crops with a situation similar to that of cotton.In view of the reduced availability of new pesticides, those currently available should be used in the optimal way. At the present time, the integrated pest control approach is the best means of accomplishing this. The introduction of such programs will require official support through legislation or technical assistance.In the future, various new developments in pest control are to be expected. Greater reliance will be placed on the use of computer science. Further effort will be needed in areas such as crop loss assessment, stored product pests, technical assistance to farmers and pesticide selectivity. Closer international collaboration on plant quarantine matters and pesticide registration are essential for the future of pest control.
Economic Conflicts in Plant Protection: Individual Versus Social Decisions1
Authors: Regev U. 
Published: April 2008

ABSTRACTWe are becoming increasingly aware of the unintended harm caused by the use of chemical pesticides to man, crops, livestock, and the environment. The major side‐effects of pesticides are ecosystem disruption, increasing pest resistance and environmental pollution. Market structure (prices) does not include these effects and, for this reason, the individual farmer has no incentive to consider them in his pest control decisions.This leads to conflicting economic interests between the individual farmer who uses excessive pesticides to maximize profits, and society, which considers environmental quality and other external effects as part of the costs of pesticides, and thus desires lower levels of pesticides. A case study of resistance to pesticides by the Egyptian alfalfa weevil shows that the farmers' pest control decisions lead to faster development of resistance than would be deemed desirable by the society.Economic analysis of the costs of resistance serves as the basis for estimating needed investment in new pest control means, of which the most desirable ones are environmentally neutral: some form of biological control and/or host‐plant resistance.
Integrated Control for Cereal Diseases
Authors: Parmentier G. 
Published: April 2008

ABSTRACTApplication 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

SOMMAIRELa 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

SOMMAIRELe 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

ABSTRACTBiological 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

ABSTRACTMoistening 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

ABSTRACTPupae 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

AbstractAlthough 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

AbstractReliable 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

SommaireLa 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

AbstractResting 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

AbstractPotato 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.