bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations concerning soil‐borne viruses in sugarbeet in Sweden1
Authors: LINDSTEN K.
Published: April 2008

Some experiments with soil‐borne beet viruses in cement tubes in a wire netting enclosure are described. It is confirmed that rhizomania (virus + vector) originating from German soil can survive and cause rhizomania in Sweden. Antisera produced in 1987 to one German BNYVV isolate and to one Swedish soil‐borne beet virus isolate, 86‐109, which is distinct from BNYVV, were used to check ELISA reactions in the tube beets. Positive ELISA was obtained not only for BNYVV but also for the 86‐109 virus from tubes with German inoculum. Beets from tubes with Swedish inoculum reacted only against 86‐109 antiserum. In 1988‐09, ELISA of 118 sugarbeet plants from Öland and 73 from Skåne, collected in 42 different fields with spots resembling rhizomania, showed no or weak reactions against 86‐109 antiserum, in contrast to plants collected in 1987. However, after transplanting the field plants into a warm glasshouse and using bait plants it was shown in ELISA and in transmission to Chenopodium quinoa that many of the bait plants became infected with the 86‐109 and ‘related viruses’ but not with BNYVV. Viruses of the 86‐109 type seem to be common both in Sweden and elsewhere but may escape detection, especially in mixed infections with BNYVV.
Serotypes of beet soil‐borne furovirus from FRG and Sweden1
Authors: LESEMANN D.‐E. , KOENIG R. , LINDSTEN K. , HENRY C.
Published: April 2008

Four virus isolates were obtained in FRG and Sweden from sugarbeet roots which had become infected via the soil. All isolates had rod‐shaped particles of four or five different lengths. Serologically they were unrelated to beet necrotic yellow vein furovirus and several other viruses of a similar morphology including two serologically distinct sugarbeet isolates from California (US). Our isolates were, however, serologically related to beet soil‐borne furovirus which has been described in England. They could be subdivided into two serotypes.
Present state and prospects of breeding for resistance or immunity to barley yellow mosaic virus1
Authors: FRIEDT W. , GÖTZ R. , KAISER R. , FOROUGHI‐WEHR B.
Published: April 2008

The BaYMV resistance of German cultivars like Diana, Franka, Gloria or Sonate is due to one recessive gene (‘German gene’), located on barley chromosome 3. This gene and the gene Ym1 are most probably allelic (or tightly linked). Resistance of the American cv. Anson barley is inherited independently of the ‘German gene’ and Ym1. The haploidy technique is an efficient means for approaching major breeding goals: (1) to improve quality characteristics of cultivars carrying‘German resistance' (2) to adapt exotic germplasm carrying the gene Yml to European growing conditions; (3) to broaden the genetic base of BaYMV resistance by incorporating additional ‘new’ resistance genes.
Investigations on potato mop‐top furovirus in Sweden1
Authors: RYDÉN K. , LÖVGREN L. , SANDGREN M.
Published: April 2008

Potato mop‐top furovirus (PMTV) was isolated for the first time in Sweden in 1985. During 1986 and 1987, soil samples from potato fields, mainly in the south‐west of Sweden, were tested for PMTV. The virus was detected in 49 out of 305 samples tested. PMTV was also found to be present in soil collected from potato riddles during potato grading in early spring. The soil samples were tested by using Nicotiana clevelandii and N. debneyi as bait plants in a glasshouse. Seven potato cultivars were grown in a PMTV‐infested field. PMTV symptoms in the tubers, i.e. external and/or internal brown rings and arcs (spraing), were observed in cvs Evergood, Provita, Saturna and Ukama but not in cvs Bellona, Bintje or King Edward. Very few, or no, PMTV symptoms were found in tubers of susceptible cultivars when examined 2‐3 weeks after lifting. In later examinations spraing appeared and increased. The increase was greater in tubers stored at 9°C than in those at 4°C, and in cut than in uncut tubers.
Infectivity, inoculum density and germination of Spongospora subterranea resting spores: a solution‐culture test system1
Authors: MERZ U.
Published: April 2008

Spongospora subterranea, causal agent of powdery scab of potatoes and vector of potato mop‐top furovirus, survives in the soil as balls of resting spores (cystosori). So far, the factors affecting longevity, germination and infectivity of cystosori have not been investigated. A rapid and versatile bioassay with tomatoes as bait plants has been developed to quantify the infectivity of cystosorus inoculum or infested soil. The intensity of root infection, as a measure of infectivity, was determined by evaluating the quantity of zoosporangia present in epidermal cells and root hairs of the whole, stained root system. A correlation was obtained between the intensity of root infection and the cystosorus inoculum density in nutrient solution. Sterile soil suppressed the inoculum potential of pure cystosori. Infectivity of untreated soil decreased with increasing time of storage. Root infection was not influenced by the pH level of the nutrient solution.
Cultivation factors influencing spraing in potato‐a statistical analysis
Authors: LOEVGREN R. L. , ERIKSSON K. B.
Published: April 2008

In an attempt to study the effects of cultivation factors on the incidence of spraing in potato, on the presence of tobacco rattle tobravirus (TRV) and potato mop‐top furovirus (PMTV), and on the densities of trichodorid nematodes in field soils, a statistical analysis was conducted based on field records provided by a Swedish potato crisp industry. The factors studied were crop rotation, precipitation (irrigation inclusive), planting time, fertilization, plant‐available P, K and B, soil texture and soil pH. The data were collected for 1979‐1987, representing 50 farms (198 fields) in southern Sweden. A correlation was found between TRV infectivity in the autumn and planting time of the potato crop. Thus, late planting was correlated with lower frequency of TRV. By ANOVA test of 5 years of preceding crops, a possible spraing increase was indicated when numbers of potato or barley crops increased in the crop rotations. A possible spraing decrease was indicated when the share of wheat increased. High incidence of spraing, and high densities of trichodorid nematodes, were both correlated with low values of plant‐available potassium, KAL, in soil.
Transmission of tobraviruses by trichodorid nematodes1
Authors: PLOEG A. T. , BROWN D. J. F. , ROBINSON D. J.
Published: April 2008

Transmission of tobacco rattle tobravirus by Paratrichodorus and Trichodorus has been known since 1961. However many of the studies of these virus‐vector associations have been uncritical. Here we describe a system to study acquisition and transmission of individual tobravirus isolates by given species of Paratrichodorus and Trichodorus. Results from initial experiments in which this system was used suggest that different isolates of tobacco rattle tobravirus differ in vector specificity.
Tobacco rattle tobravirus: variation among strains and detection by cDNA probes1
Authors: ROBINSON D. J.
Published: April 2008

Because of their extreme antigenic variability, only a small proportion of tobacco rattle tobravirus isolates will be detected in serological tests with a single antiserum. Moreover, serological tests will not detect NM‐type isolates that do not produce coat protein, and would misidentify some natural recombinant isolates as pea early‐browning tobravirus. In contrast, nucleic acid hybridization tests with a probe to any part of RNA1 can detect all these different variants of tobacco rattle tobravirus.
Virus‐vector nematodes in cereals and fruit crops in Spain
Authors: ARIAS M. , ANDRÉS M. F.
Published: April 2008

Studies on nepoviruses and tobraviruses, and their relationships with their associated vector nematodes, are scarce in Spain. However, virus disease symptoms have often been detected and their nematode vectors are widespread in Peninsular Spain. Nepovirus vector nematodes (Longidorus attenuatus, L. coespiticola, L. elongatus, L. macrosoma, Xiphinema coxi, X. diversicaudatum, X. index, X. italiae, X. pseudocoxi and X. vuittenezi) have been found associated with fruit and cereal crops. All are also widespread in other crops and uncultivated areas, together with X. rivesi, which has not yet been found associated with fruit and cereal crops in Spain. Tobravirus vectors have been less studied in Spain. Of the five recorded species, Paratrichodorus minor and Trichodorus primitivus are present on maize and wheat respectively. The geographical and host distribution of these nematodes are given and their ecological characteristics are discussed.
Toxicité secondaire, en laboratoire, ďun rodenticide anticoagulant (bromadiolone) pour des prédateurs de rongeurs champêtres: buse variable (Buteo buteo) et hermine (Mustela erminea)1
Authors: GROLLEAU G. , LORGUE G. , NAHAS K.
Published: April 2008

Les pullulations de certaines espèces de rongeurs champêtres rendent nécessaire une lutte destinée à protéger des cultures; dans le cas du campagnol terrestre (Arvicola terrestris scherman) et des dommages aux prairies de montagne, celle‐ci se fait au moyen ďun appât ‘carottes en rondelles enrobées ďun concentrat de bromadiolone’ titrant 100 ppm de matière active pour la France, et ďun appât sec titrant 140 ppm pour la Suisse. Nous avons churchéàévaluer expérimentalement le risque découlant de ľutilisation de cet anticoagulant pour les prédateurs du campagnol terrestre, en choisissant comme modèles ľhermine (Mustela erminea) et la buse variable (Buteo buteo). Les campagnols terrestres, consommant de ľappât carottes durant 24 h et sacrifiés aussitôt, contenaient 6,5‐6,75 ppm de bromadiolone; ceux ayant consommé le même appât carottes durant 3 j consécutifs et sacrifiés à la fin du 3e j, en contenaient 8,72–10,93 ppm, tandis que ceux ayant consommé de ľappât sec, dans les mêmes conditions, n'en contenaient que 5,81 ppm (mais cet appât sec s'est révélé ne titrer que 102,5 ppm au lieu des 140 ppm théoriques). Si les campagnols ayant consommé durant 1 ou 3 j étaient sacrifiés 2 j après la dernière intoxication, le niveau des résidus était divisé, respectivement, par 4 et 9, tombant au‐dessous de 2 ppm. Chez les hermines (14 individus) consommant des campagnols intoxiqués durant 1 j, la mortalité est apparue (1/3) au bout de 5 j ďingestion; cependant, les survivantes ont été malades, même celles n'ayant subi que 3 j ďingestion. Chez les buses variables (108 individus), la mortalité n'est apparue que s'il y a eu répétition des ingestions durant 3 j consécutifs, que les campagnols aient eux‐mêmes été intoxiqués durant 1 ou 3 j ou, si après 1 ingestion et 10 j de nourriture normale, ces buses ont été soumises à une seconde intoxication unique. Le foie était bien ľorgane de stockage des résidus, chez les deux espèces de prédateurs, les reins en contenant presque exclusivement chez des animaux sacrifiés 24 h après intoxication ou ceux morts dans de courts délais. Une grande variabilité interindividuelle a été constatée. Le risque ďintoxication pour ces deux espèces de prédateurs, en fonction de la technique française de lutte contre le campagnol terrestre, semble peu élevé.
Citrus fruit flies of Sichuan Province (China)
Authors: YU‐AN ZHANG
Published: April 2008

The fruit fly pests on Sichuan citrus include Tetradacus citri and T. tsuneonis (Diptera: Trypetidae), regarded as distinct species in China. Special attention has been paid to the former, which is a quarantine pest in China. It is distributed in 18 counties of Sichuan Province and has caused serious losses in citrus orchards. Its hosts are all the citrus fruits, especially orange and pomelo. T. tsuneonis is distributed in only two counties and attacks only tangerine, but it is a potential hazard to all citrus crops in the province. Both species have only one generation per year. The pupae overwinter in soil. Emergence of T. citri begins at the end of April. Before oviposition the adults need supplementary nutrients. Twenty days after emergence, copulation begins and 15 days later the adult begins ovipositing (peak period mid‐June to early July). The peak period for hatching is in early September. After three instars, the larva becomes mature in mid‐October. The peak period of pupation is from the end of October to mid‐November. Emergence of T. tsuneonis is about 15 days later than T. citri. The larvae bore the flesh of citrus fruits, causing great loss to citrus growers every year. Surveys are regularly conducted to check the distribution of the pests in Sichuan Province. Quarantine regulations enacted in 1982 and 1984 regulate the movements of articles that could spread the pests, with specified safeguards. Before female oviposition, spraying with trichlorfon in sugar solution gives satisfactory results in controlling citrus flies in orchards.
Occurrence of Microtus arvalis in Poland, 1969–19851
Authors: ROMANKOW‐ZMUDOWSKA A. , GRALA B.
Published: April 2008

In the years 1969–1985, the population density of Microtus arvalis in Poland varied depending on the area, the largest populations and the most frequent mass occurrence being noted in the southern part of the country. Mass occurrences of rodents were observed in 1971, 1978, 1981, 1983 and 1984. Differentiation in the occurrence of M. arvalis was caused by the sculpture of the landscape, soil structure and by the length of the growing season.
Simplified application of return gel electrophoresis for the routine detection of potato spindle tuber viroid
Authors: SCHROEDER M. , WEIDEMANN H.‐L.
Published: April 2008

The return gel electrophoresis method for the detection of potato spindle tuber viroid has been modified to simplify its use for large‐scale testing. The quantities of dissolvents for the extraction of nucleic acids were reduced and adapted to the use of disposable plastic tubes. The vertical electrophoresis system was replaced by a horizontal one, which was easier to handle. Migration distance for the separation of PSTV bands was shortened, saving time for the electrophoretic run. A single‐buffer system was used. The detection limit was estimated as 0.3 ng per slot. It was possible to detect both mild and severe strains of PSTV.
GUIDELINE FOR THE EFFICACY EVALUATION OF FUNGICIDES
Authors: Inaequalis Venturia , Pirina V.
Published: April 2008

This guideline combines EPPO Guidelines nos 5 and 42 for the efficacy evaluation of fungicides against Venturia inaequalis and V. pirina‐protectant applications and curative treatments, respectively.
Detection of quarantine viruses of potato by ELISA
Authors: SCHROEDER M. , WEIDEMANN H.‐L.
Published: April 2008

According to EC regulations, imported material of tuber‐forming Solarium spp. has to be tested for the absence of defined quarantine viruses. In order to allow an efficient and timesaving application of the quarantine inspection procedure, antisera have been developed and scrutinized for their use by the ELISA technique. The viruses concerned were Andean potato latent virus (APLV), Andean potato mottle virus (APMV), arracacha virus B oca strain (AVB‐O), potato virus T (PVT) and tobacco ringspot virus Andean potato calico strain (TRSV‐Ca). The results show that all viruses can be reliably detected by double‐antibody sandwich (DAS) ELISA. The detection limits were in the range ≤ 1–32 ng ml−1. The strain specificity by DAS‐ELISA of the antisera for APLV and APMV was overcome by mixing antisera from the different strains and strain groups, respectively. Strains C and Lm of APMV seemed to be serologically identical. A comparison of the suceptibility of several wild species of tuber‐forming Solanum with that of several cultivars of Solanum tuberosum showed a higher frequency of infection in the wild species.
A technique to detect Erwinia carotovora ssp. carotovora in lily bulbs1
Authors: SCORTICHINI M. , ROSSI M. P.
Published: April 2008

Erwinia carotovora ssp. carotovora can be detected very effectively in lily bulbs by anaerobic incubation of the bulbs followed by homogenization of the scales and plating of the diluted sap onto crystal‐violet pectate medium. This technique, compared with bulb treatments without preliminary anaerobic incubation, also improves the possibility of recovering E.c.carotovora overall at low storage temperatures in the long term. Differences among Lilium cultivars regarding the interaction with E.c.carotovora probably exist; the bacterium multiplied at a higher rate in bulbs of cvs Enchantment, Mont Blanc, Star Gazer and Yellow Blaze. The technique could allow inspection of lily bulbs before planting.
The effect of Cydia molesta on the incidence of Monilinia spp. on quince fruits
Authors: GARIĆ R. , STAMENKOVIĆ S. , ČANAK M.
Published: April 2008

A 2‐year study was performed on the effect of Cydia molesta on the incidence of Monilinia spp. on quince fuits. In Yugoslavia C. molesta regularly occurs in the Čačak area (western Serbia) and is a highly important pest of peach and quince. In Yugoslav conditions it develops four generations a year. The 1st and 2nd generations usually develop on peach and the 3rd and 4th on quince. The proportion of quince fruits injured by C. molesta can reach 78%, with up to 12 caterpillars per fruit. C. molesta had a great effect on the incidence of Monilinia spp. on quince fruits. Of the total number of fruits affected by fruit rot, 84 and 88% had been injured by C. molesta in 1987 and 1988, respectively. Timely control of C. molesta is the most effective measure against the incidence of Monilinia spp. on quince fruits.
Méthodes de diagnostic du bayoud du palmier dattier1
Authors: DJERBI M.
Published: April 2008

Les méthodes de diagnostic de la maladie du bayoud du palmier dattier, provoquée par Fusarium oxysporum f.sp. albedinis, sont présentées et évaluées: symptomatologie, tests de pathogénicité, caractéristiques culturales du champignon, compatibilité végétative.
Why many phytophthora root rots and crown rots of tree and horticultural crops remain undetected1
Authors: TSAO P. H.
Published: April 2008

Of the approximately 50 recognized Phytophthora spp., more than half have not been reported to cause root rot or crown rot. Some well‐known phytophthora root and crown rots have still not been diagnosed in many regions or countries in the world. It seems likely that this arises mainly from use of inappropriate isolation media and diagnostic procedures. Thus, various root disorders of tree and horticultural crops have been attributed to other pathogens or to abiotic causes, and found to be due to Phytophthora spp. only when proper isolation techniques involving baiting and selective media were used. These special techniques, however, are still not widely used by many diagnosticians and pathologists today. It seems that most pathologists lack training and specific knowledge on Phytophtohora diseases and tools for their study. They are often unaware of the importance of these fungi in causing below‐ground infections, or of the unique nature of their biology, soil ecology and pathology in relation to root and crown rot development. It is hoped that wider use of special isolation techniques in routine diagnoses in the future will result in an increase in the frequency of reports of occurrence of phytophthora root and crown rots of woody perennials around the world.
Identification of Phytophthora species on fruit crops in Turkey by polyacrylamide gel electrophoresis1
Authors: ÇINAR A. , GÜNCÜ M. , BİÇİCİ M.
Published: April 2008

To identify 11 Phytophthora isolates obtained from lemon, peach and apple trees, and from strawberry plants, in the Mediterranean region of Turkey, protein, acetylesterase, peroxidase and catalose band patterns of these isolates and the same bands of 10 identified isolates of Phytophthora citrophthora, P. cinnamami and P. cactarum were compared. These 11 regional isolates were identified on the basis of the similarity of their protein and enzyme band patterns to those of identified Phytophthora isolates. It was concluded that protein band patterns could be used for identification of Phytophthora species. With enzyme band patterns, however, it may be possible to identify at species level but it is more practical to use this method only for identification of subspecies.
Profils isoenzymatiques et RFLP pour I'identification des Phytophthora du cacaoyer1
Authors: BLAHA G.
Published: April 2008

La mise en oeuvre simultanée des deux systèmes enzymatiques phosphoglucoisomerase (PGI) de malate déshydrogénase (MDH) semble pennettre une bonne reconnaissance interspécifique de Phytophthora palmivora (sensu stricto), P. megakarya et deux espèces proches respectivement de P. capsici et de P. citrophthora, parasites du fruit du cacaoyer. De plus, le nombre de bandes constantes et variables des MDH avec P. megakarya laisse supposer l'existence chez cette espèce d'au moins quatre populations. Avec P. palmivora, I'hétérozygotie des PGI et la ségrégation obtenue dans la descendance soultvent I'hypothèse d'un‘hybride naturellement sélectionnéà partir d'entités infraspécifiques ayant des relations privilégiées les unes avec les autres. En ce qui concerne le polymorphisme des longueurs de fragments de restriction (RFLP) de I'ADN nucléaire, les profils obtenus avec BAM H1 sont pour I'instant les plus distinctifs. Les mêmes analyses ont été faites sur d'autres espèces de Phytophthora, comme P. nicotianae var. parasitica, P. cactorum, P. cinnamomi, P. citricola, P. fragariae, P. infestans, P. megasperma et P. cryptogea.
The comparative genetics of Phytophthora1
Authors: SHAW D. S.
Published: April 2008

Mechanisms generating variation in Phytophthora are assessed. Patterns of inheritance are typically those of a diploid organism. The increasing availability of single gene markers is allowing the breeding system in heterothallic species to be defined. The genetics of virulence and fungicide resistance is summarized; somatic recombination and variation in chromosome number is discussed. Rapid advances in basic genetics, population genetics and evolution are expected through the application of the new techniques for manipulating DNA in vitro. The complexity of the problem is not underestimated.
Field effectiveness of fosetyl‐AI against citrus foot rot and brown rot1
Authors: DAVINO M. , GAMBERINI O. , AREDDIA R. , ALDARESI S.F.
Published: April 2008

The effectiveness of fosetyl‐A1 against citrus foot rot caused by Phytophthora citrophthora has been evaluated in a 25‐year‐old orchard of sweet orange cv. Tarocco, showing severe symptoms of the disease and in a 10‐year‐old orchard of the clementine‐type mandarin cv. Monreal, apparently healthy. All the trees were grafted on sour orange. In both orchards, three sprays at 200 g a.i. per 100 1 were applied in May, July and September for 3 years. The results were evaluated on the basis of yield and fruit quality. Trees of cv. Tarocco had yield increased by 25–44% whereas cv. Monreal yielded 3–16% higher than the unsprayed trees. Fruits of orange cv. Tarocco were collected from trees sprayed with fosetyl‐A1 and plunged in a water suspension of P. citrophthora. Fruits treated 11 days before inoculation showed an infection rate of 8.7%) whereas those unsprayed were 77% infected. Fruits inoculated 21 days after the treatment with fosetyl‐A1 were 32% infected whereas those unsprayed were 91%, infected. In other trials, trees of volkamer lemon were sprayed with a conidial and mycelial suspension of P. citrophthora at different times after application of fosetyl‐A1. The number of infected fruits and leaves in the unsprayed trees was very high (up to total leaf drop) and decreased sharply with the number of sprays (1 to 3).
Control of Phytophthora citrophthora by fentin acetate in laboratory experiments and by soil drench application in a lemon orchard1
Authors: ÇINAR A. , GÖKSEDEF M. , BİÇİCİ M.
Published: April 2008

According to the results of bioassay studies, 50 p.p.m. and higher dosages of fentin acetate inhibited the growth of Phytophthora citrophthora in situ. Zoospore movement of P. citrophthora varied between 3 and 15 min at 0.5, 1, 10, 100 and 500 p.p.m. fentin acetate. The fungicide also inhibited fruit infections caused by P. citrophthora zoospores at 5 p.p.m. concentration, and protected citrus seedling roots against infection by the fungus at 20–50 p.p.m. concentrations in water culture. Fruit infection was significantly lower in fentin acetate plots than in those without fungicide applications. Stem infection was 15.5 and 8.3% when fentin acetate was applied one or three times respectively as a soil drench in a lemon orchard, but reached 74.9%) in control plots. Fentin acetate treatment decreased inoculum potential to 1/2 and 1/128 in the root zone from the first to the third application.
Control of phytophthora brown rot of citrus fruits1
Authors: TUSET J. J. , PORTILLA M. T.
Published: April 2008

Control of brown rot of citrus fruits, using the new anti‐oomycete systemic fungicides, has been studied in the field and in packing houses under the climate conditions of Spain. In the field, in rainy weather and at the stage of colour‐break of the fruits, both with artificial inoculation and with natural infection by Phytophthora citrophthora, a single treatment with fosetyl‐A1 at 0.4% a.i. as a foliar spray provided good control of the disease. The highest fungitoxic effects were reached 14–21 days after treatment. Copper oxychloride + mancozeb at 0.3% a.i. showed moderate efficiency. In semi‐commercial experiments in the packing house and in the laboratory, fosetyl‐A1 at 0.3% a.i. strongly controlled infection with zoospores located in different layers of the fruit peel (flavedo or albedo). Fosetyl‐A1 also developed good efficacy in healthy fruits, protecting them from infection by contact. Metalaxyl at.0.2% a.i. also reduced infection by zoospores and contact. Oxadixyl, propamocarb and folpet (reference product) had poor activity against the brown rot fungus. All these data strongly support the value of fosetyl‐A1 for control of brown rot disease of citrus fruit in the field and in the packing house as a post‐harvest treatment. Metalaxyl may also be utilized for this purpose.
Phytophthora foot rot control in citrus with Myrothecium roridum1
Authors: TUSET J. J. , HINAREJOS C. , GARCIA J.
Published: April 2008

Foot rot is the most important disease in citrus in Spain. Phytophthora nicotianae var. parasitica is the major cause of this disease. Field treatments with classic contact fungicides have been extensively used for many years to combat stem and trunk Phytophthora diseases in citrus, while, more recently, foliar application of the systemic fungicide fosetyl‐A1 has been used with great success. It is now also possible to use a biological control method for foot rot disease. Myrothecium roridum, a cosmopolitan soil hyphomycete with high cellulolytic activity, produces toxins which are very active against Phytophthora fungi. Culture filtrates of M. roridum cultured in liquid medium with low sugar content strongly inhibit in vitro development of P.n. parasitica, P. syringae and P. capsici. In glasshouse trials employingcross inoculations of M. roridum and P.n. parasitica in stems of sweet orange and willowleaf mandarin seedlings, the bark lesions produced by Phytophthora were clearly stopped at 7 or 10 days after inoculation and the cankers subsequently did not show evident activity. In field trials, M. roridum inoculated into the roots of several citrus species limited development of cankers due to P.n. parasitica (artificial or natural infection). The good results open a new way for control of Phytophthora diseases in citrus.
The mode of action of the antifungal agent phosphite1
Authors: SMILLIE R. H. , DUNSTAN R. H. , GRANT B. R. , GRIFFITH J. M. , ISER J. , NIERE J. O.
Published: April 2008

Field studies have established that phosphorous acid (phosphite) is an effective control against a number of plant diseases. However, the mechanism of control is not known. We have used Phytophthora palmiuora to investigate the action of phosphorous acid as an antifungal agent. Phosphite is toxic to Phytophthoru in uitro, but concentrations which completely inhibit growth in vitro are rarely ever achieved in phosphite‐treated plants. Phosphite concentrations (1 m mol 1‐1) which do not inhibit fungal growth in vitro cause changes in the metabolism and cell‐wall components. We suggest that phosphite, when present in plants in concentrations too low to control fungi in vitro, may cause modification of the fungal cell surface in such a way that the plant is able to recognize it as foreign and respond by normal defence mechanisms.
Cloned diagnostic probe for Clavibacter michiganensis ssp. sepedonicus
Authors: FIRRAO G.
Published: April 2008

Salt restriction fragments of a highly conserved plasmid of Clavibacter michiganensis ssp. sepedonicus were cloned in pUC19. Five recombinant plasmids were selected and used in nonradioactive dot‐blot DNA‐DNA hybridizations. Results show that the probe hybridized specifically with the DNA of the pathogen and not with DNA extracted from other closely related organisms or potato‐associated bacteria. This safe, rapid and specific procedure may help in the diagnosis of potato ring rot, which is at present difficult and very time‐consuming.
STAR:
Authors: TOUZEAU J.
Published: April 2008

Le Service français de la Protection des Végétaux est chargé de missions à caractère réglementaire et de missions d'appui technique à la profession agricole telles que: les contrôles sanitaires des végétaux et produits végétaux à l'importation et à l'exportation; la surveillance phytosanitaire du territoire national; l'expérimentation et l'homologation des produits phytosanitaires; l'élaboration et la diffusion des Avertissements Agricoles. Depuis 1983, l'exécution de la plupart de ces missions est considérablement améliorée grâce à l'utilisation de l'informatique. Celle‐ci pemet notamment la saisie et le stockage en temps réel de toutes les données présentant un caractère d'urgence (résultats des contrôles en frontière, d'analyses de laboratoires, données météorologiques, biologiques…). Le traitement immédiat de ces données devient possible (analyses statistiques, modélisation, sorties graphiques, tris complexes…), ainsi que leur consultation permanente et décentralisée. Les informations sont diffusées rapidement (messagerie électronique, télécopie). La gestion administrative est accélérée (facturations, abonnements aux Avertissements Agricoles, fichiers d'importateurs, d'exportateurs…).
Computers as aids to agricultural extension1
Authors: AUSHER R.
Published: April 2008

Agricultural extension is helping the decision‐making process faced by farmers in managing and protecting their crops within changing environmental and economic conditions. Computer‐supported extension relies on the ability of computers to assist both processes of problem solving and those of the diffusion of information and knowledge. Crop protection programs could be either components of crop production models or independent modules. Microcomputer applications like database management of pesticides, expert systems for pest identification and control recommendations, spreadsheets for record keeping of field data, word processing for pest control publications, are the popular programs with extension specialists in crop protection. Problem‐solving models are either comprehensive or partial, process‐oriented or empirical. Israeli experience shows that empirical and partial models, developed with the participation of research, extension and farmers have the best prospects for early and large‐scale application as extension tools. With all the recognized limitations of computer support, there is no other technology in sight that offers greater potential to facilitate the transition of agriculture to more business‐management orientation. The potential embedded in computer‐supported extension could be fully exploited, if extension organizations will adopt it on a system‐wide basis. To this end a problem‐oriented, empirical and pragmatic approach is advocated‐one able to make the best decisions even when one does not have all the answers. Programs should be simple rather than conceptually elegant, and act with precision within a narrow range of operating conditions, rather than be of high generality.
L'informatique et les contrôles phytosanitaires francais1
Authors: ANDRIEU S. , DURAND H.
Published: April 2008

Des applications informatiques ont été mises en place, ou sont en cours d'installation au Service français de la Protection des Végétaux. Elles concernent: (1) l'amélioration du suivi phytosanitaire des filières à risque. Les informations collectées et analysées proviennent des contrôles effectués sur les produits importés et des contrôles effectués dans le cadre de la Surveillance du Territoire; (2) la diffusion des informations urgentes entre postes de contrôle par l'utilisation d'outils de communication; (3) l'aide aux contrôleurs par la diffusion d'une information plus accessible et la mise à jour périodique (réglementation, informations techniques…); (4) la réalisation de synthèses régionales ou nationales des principaux problèmes phytosanitaires à partir des diagnostics et des analyses effectués par le réseau des Laboratoires du Service de la Protection des Végétaux.
PPP: a plant protection program1
Authors: MAGNUS H. A. , SUNDHEIM E.
Published: April 2008

PPP is a data program that facilitates the recording and handling of plant samples sent to a diagnostic laboratory. The program can be used to retrieve help information from earlier advisory work to produce written replies to the sender. The letters are written both to files and to printers. The program may be used as a single user program or as a network program applying an internal communication program. A decision support system designed to help in advisory work may be used together with the PPP or as a stand‐alone module (CaSK Aid).
An expert system for diagnosis of post‐harvest potato diseases1
Authors: ADAMS S. S. , STEVENSON W. R. , DELHOTAL P. , FAYET J.
Published: April 2008

The Institut National de la Recherche Agronomique (INRA, France) has developed a LISP‐based computer program for diagnosis of post‐harvest potato problems (diseases, insect/nematode damage, and environmental/physiological disorders) which has been modified for use in USA production areas. This expert system simulates the behavior of a diagnostic consultant in interaction with a user. The system is composed of a knowledge base (called TUBERS) and an expert system shell (called MIRA). TUBERS contains the collective diagnostic expertise (encoded in the form of if‐then rules) of interviewed specialists in plant pathology, entomology, and agronomy. MIRA performs the reasoning and problem‐solving tasks (including searching TUBERS for applicable rules) while directing questions and issuing diagnostic reports to the user. The user simply responds to system questions with ‘yes’/‘no’/‘I don't know’ or any number of multiple choice responses. The expert system currently considers 35 disorders and we have verified that it accurately diagnoses each of those disorders when supplied with an appropriate series of user responses to system questions about observable symptoms. The system operates under MS‐DOS on IBM PC/AT/XT compatible machines fitted with an add‐on CL 1000 memory board and under Xenix‐SCO on most 80286 and 80386‐based microcomputers.
Utilisation de l'informatique pour le contrôle de la contamination par les pesticides des aliments d'origine végétale1
Authors: IMBROGLINI G. , CONTE E.
Published: April 2008

Le Ministère italien de l'Agriculture met actuellement en place un réseau de contrôle du degré de contamination des denrées agricoles par les pesticides appliqués en conformité de la bonne pratique agricole. L'Institut Expérimental de Pathologie Végétale de Rome assurera la coordination du contrôle et mettra en service l'Unité Informatique. Une fois complètement lancé, le système permettra d'analyser au moins deux types de matière active sur 50000 échantillons des cultures choisies chaque année. Pour chaque échantillon analysé, il faut connaître les époques et les modes des traitements, le délai d'emploi avant la récolte, la zone de provenance et l'exploitation agricole productrice. Le contrôle s'appliquera ainsi à des échantillons de produits arrivant sur les marchés de gros, et servira à détecter, le cas échéant, les utilisations de pesticides inadéquates ou non déclarées. Un troisième contrôle est prévu pour les produits importés, les prélèvements étant faits directement sur le lieu d'arrivée. Le classement de l'échantillon sur fiches, la transmission des données et leur traitement seront assurés à l'aide de l'informatique. Le traitement des données par ordinateur permettra de savoir quelles cultures, et combien, ont été soumises au contrôle, les zones de provenance, les traitements appliqués, le respect ou non des seuils fixés par la loi pour les résidus. L'examen critique des données sera transmis aux autorités compétentes en vue des décisions à prendre.
L'informatique dans l'aide à la décision à la parcelle: EPICURE—système d'optimisation des traitements fongicides du blé1
Authors: PROJETTI F. , BENIZRI E.
Published: April 2008

L'évolution de l'agriculture française dans les prochaines années va modifier profondément les circuits de l'information phytosanitaire et provoquer une demande en outils de prise de décision utilisables au niveau de l'exploitation agricole. Les agriculteurs auront ainsi à leur disposition une information complète, actualisée et adaptée aux contraintes locales, leur permettant de prendre des décisions optimisées techniquement et économiquement. Le Service de la Protection des Végétaux expérimente depuis 1981 un système d'optimisation des traitements fongicides du blé. Ce système est une adaptation du modèle néerlandais EPIPRE, son objectif étant de conseiller les agriculteurs sur les traitements à réaliser dans leurs parcelles pour lutter contre les maladies du feuillage du blé. A partir d'une notation des attaques et des caractéristiques agronomiques de chaque parcelle, des équations propres à chaque maladie permettent de prévoir leur évolution ainsi que les pertes à la récolte. Les conseils de traitements, déduits en comparant ces pertes au coût de l'intervention, ainsi que la période optimale d'application, sont communiqués aux agriculteurs. Un prototype, baptisé EPICURE, a été utilisé pendant trois années avec satisfaction dans le Sud‐Ouest de la France. Le Service de la Protection des Végétaux étudie actuellement la possibilité de développer un système plus général qui pourrait être diffuséà l'ensemble des agriculteurs.
Plant diseases and pests in Sweden: a data base for the advisory services, education and research1
Authors: GRÖNTOFT M.
Published: April 2008

Regular field observations on pests and diseases in cereals, rape, peas and potatoes in Sweden are recorded in a data base, created using Fourth Dimension on Macintosh. These data can be analysed, and presented graphically, in multiple ways, in relation to factors such as geographical area, cultivar, crop rotation, soil type etc.
Towards a reduction of chemical haulm killing in potato growing in The Netherlands1
Authors: KOOISTRA T. , VAN HALTEREN P.
Published: April 2008

The official Netherlands government policy to reduce the volume of chemical plant protection products, that will be laid down in a policy document later in 1991, includes the reduction of chemical haulm killers in potato growing. Although the prospects are promising, the reduction of chemical haulm killers has to be introduced gradually, thus enabling farmers and industry to meet the demands for reliable and effective mechanical equipment. Introduction of mechanical haulm destruction techniques has to go hand in hand with adaptation of alternative growing and harvesting techniques, choice of cultivar, etc., which have to satisfy phytosanitary and profitability requirements. During a transition period, at least one efficacious chemical compound must be available in case of emergency, where mechanical equipment cannot be brought into action for climatic reasons.
Plant parasitic nematodes as pests of potatoes in Poland1
Authors: KORNOBIS S. , STEFAN K.
Published: April 2008

Only two plant parasitic nematode species have practical importance in potato crops in Poland. They are Ditylenchus destructor and Globodera rostochiensis pathotype Ro1. Control of D. destructor is done permanently by the elimination of infested seed potatoes and sowing of cereals in the infested fields. Damage to potatoes is observed rather seldom. G. rostochiensis is widely distributed throughout Poland. It is controlled by non‐host crops and by resistant potato cultivars. Chemical control of potato nematodes is not put into practice in Poland.
Integrated control of potato late blight (Phytophthora infestans) in Switzerland: concept and first results1
Authors: GUJER H. U.
Published: April 2008

A project has been undertaken in Switzerland to reduce the number of applications of fungicides to potato by a reduction of late blight incidence and disease pressure as well as by providing reliable and precise spraying recommendations against blight. We try to achieve this aim by combining different elements: (1) to delay and to impede disease progress, it is planned to promote less susceptible potato cultivars and to reduce the number of primary foci by advising seed potato growers to protect their crops more carefully; (2) the data of about 20 weather stations are utilized to test different forecasting systems; (3) these (theoretical) indications on the appearance of the disease are complemented by extensive monitoring of real late blight occurrence in the field; (4) the late blight susceptibility of all cultivars grown in Switzerland is being assessed by special trials. From the combination of all this information, spraying recommendations will be formulated according to regions and cultivars.
Bacterial diseases of potatoes in the major potato‐growing areas in Turkey1
Authors: BENLIOČLU K. , ÖKTEM Y. E. , ÖZAKMAN M.
Published: April 2008

In 1988 and 1989 bacterial diseases of potatoes in Central Anatolia were investigated by utilizing the EC method for the detection of ring‐rot bacterium (Clavibacter michiganensis ssp. sepedonicus) and using selective medium. 91 samples containing 200 tubers from commercial and farmers’ stores in Central Anatolia were tested for the presence of C.m.sepedonicus and about 50 tubers of each sample were also tested for the presence of soft‐rot erwinias. Five different bacteria that cross‐reacted with C.m.spedonicus antisera were isolated from heel‐end extracts. All cross‐reacted bacteria differed from C.m.sepedonicus morphologically and none of them was pathogenic on eggplant. C.m. sepedonicus was not detected, but Erwinia carotouora ssp. carotouora and Erwinia carotovora ssp. atroseptica were present in 7 and 17% of the samples respectively.
Toxicity of sodium fluoroacetate and zinc phosphide wheat grain baits to Microtus guentheri and Meriones tristrami
Authors: MORAN S.
Published: April 2008

Whole wheat grains impregnated with 0.02, 0.05 and 0.2% sodium fluoroacetate, and 2% zinc phosphide, were offered to series of single caged individuals of Microtus guentheri and Meriones tristrami. In most cases the sodium fluoroacetate treated baits were well accepted by both species. The acceptance of the zinc phosphide‐treated bait was partial in all the series tested. The approximate LD50 ranges of sodium fluoroacetate are between 0.24 and 0.43 mg kg−1 for M. guentheri, and, perhaps, for the jirds too, and for zinc phosphide—between 32.6 and 58.8 mg kg−1 for M. tristrami, and a similar value, more or less, for M. guentheri.
Problems of potato cyst nematode pathotypes in the Czech Republic
Authors: POTOČEK J. , GAAR V. , PERLOVÁ V.
Published: April 2008

During 1983–1989 about 1,200 infested plots in the Czech republic were investigated for the occurrence of new pathotypes of the potato cyst nematodes (PCN) Globoderu rostochiensis and G. pallida. Only eight populations of the pest were suspected of containing another pathotype than Ro1. Glasshouse pot trials were performed with those eight natural populations, two populations of Ro1, 10 potato cultivars resistant to Ro1 and 10 cultivars resistant to more pathotypes, G. pallida included. The multiplication rates (Pf/Pi) showed that four of the PCN populations were probably mixtures, with pathotype Ro1 prevailing. Three populations were suspected of containing G. pallida, but their morphological characters corresponded only with G. rostochiensis. One population corresponded with pathotype Ro5. The extent of the occurrence of pathotypes or virulence groups different from Ro1 can be estimated at 0.3–0.4% of infested plots.
Relevance of physiologic races of plant pathogens to quarantine
Authors: CHANDRASHEKAR M.
Published: April 2008

The concept of physiological specialization as used in plant pathology has limitations for consistent use in plant quarantine. Some details of the concept and its application in quarantine are discussed. A structured approach is developed and proposed for evaluation of variations in pathogens as a valid scientific argument in quarantine decision‐making.
Present problems of meteorological services for plant protection in the Czech Republic1
Authors: HRBEK J.
Published: April 2008

Agriculture in the Czech Republic and its supporting services have been influenced during the last four decades by: (1) heavy pollution of the environment; (2) structural changes in the agricultural sector, i.e. collectivization in the fifties and privatization in the nineties; (3) global climate changes. Further destruction of the environment must be avoided, and methods of integrated plant protection, including biological methods, must be used whenever possible.
Le Réseau d'avertissements phytosanitaires du Québec1,2
Authors: LETENDRE M.
Published: April 2008

Le Réseau d'avertissements phytosanitaires est un programme de formation et d'information visant à rendre les producteurs agricoles du Québec plus efficaces et responsables de la protection de leurs cultures. Le programme a pour objectif également de promouvoir l'utilisation rationnelle et sécuritaire des pesticides, de même que l'adoption de la philosophie et de la pratique de la lutte intégrée au sein de la communauté agricole. En se basant sur des modéles bioclimatiques de prévision et des programmes de suivi au champ, le Réseau informe régulièrement les producteurs et les conseillers agricoles de l'évolution des ennemis des cultures dans leurs régions, de la stratégie d'intervention la plus appropriée, compte tenu des risques et des mesures préventives disponibles, et de la période optimale pour une telle intervention. Il existe actuellement des programmes de prévision pour une quinzaine d'insectes et de maladies des plantes; ces programmes sont alimentés par des données recueillies chaque jour au niveau de 110 stations météorologiques. Le service est offert gratuitement par le Ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec à l'ensemble des producteurs agricoles. Les producteurs horticoles (légumes, petits fruits, pomme de terre, pommier, cultures en serre) reçoivent l'information par la poste, alors que dans le cas des grandes cultures (céréales, maïs, graminées et légumineuses fourragéres, soja) les communiqués sont publiés dans la presse agricole. Certains communiqués sont de plus diffusés par Radiométéo Canada, par des stations de radio locales ou par des répondeurs téléphoniques.