bluuebunny/crossref_metadata_2025 huggingface dataset:
A method for measuring the level of sensitivity of Plasmopara viticola populations to cymoxanil
Authors: GENET J. L. , STEVA H. , VINCENT O. , CAZENAVE C.
Published: April 2008

A leaf‐disk bioassay was developed for monitoring the level of sensitivity of Plasmopara viticola populations to the fungicide cymoxanil. Grapevine leaf disks were treated with various concentrations of fungicide and inoculated one day later with a suspension of P. viticola sporangia. Fungal inhibition was strongest when the leaf disks had their upper side in contact with the fungicide solution and were sprayed on the other side with the same solution. The dose response was influenced by the level of disease on the untreated leaf disks and the date of evaluation which required standardization. Test‐to‐test variation was small but differences existed between laboratories where the assay was performed. There was good agreement between the results obtained in the leaf‐disk assay and those of a whole‐plant assay.
Potential role of almond in sharka epidemics: susceptibility under controlled conditions to the main types of plum pox potyvirus and survey for natural infections in France 1
Authors: DALLOT S. , BOUSALEM M. , BOEGLIN M. , RENAUD L. Y. , QUIOT J. B.
Published: April 2008

The changes in cropping conditions of almond and the development of efficient tools for the detection and characterization of plum pox potyvirus (PPV) populations have led us to reassess the potential susceptibility of this species to sharka disease and its role as a virus reservoir. The susceptibility of almond cv. Aï to nine isolates, representative of the known diversity among PPV populations, was assessed under controlled conditions. Most isolates were able to infect almond, by graft or aphid inoculation, causing generalized stable infections without any obvious sharka symptoms. These infected almonds were found to constitute a potential source of virus for aphid vectors, mainly in the case of M isolates. Surveys were carried out in the south of France, in foci of M and D strains of PPV, to evaluate the presence of natural infections of almond. No typical symptoms were observed and the virus was never detected. It can be assumed that the actual limited prevalence of PPV in France does not lead to a sufficiently high inoculum pressure to allow almond trees to be infected.
Viruses infecting almond trees in the region of Valencia (Spain) 1
Authors: LLÁCER G. , CAMBRA M. , CAMARASA E. , GORRIS M. T.
Published: April 2008

In the last 10 years, more than a thousand almond trees have been analysed by the DAS‐ELISA method in the Valencia region. The most frequent virus infecting unselected almond trees was prune dwarf ilarvirus (PDV) (62%), followed by prunus necrotic ringspot ilarvirus (PNRSV) (36%), apple mosaic ilarvirus (ApMV) (14%) and apple chlorotic leafspot trichovirus (ACLSV) (2%). Infection levels of selected trees were 26% for PDV, 15% for PRSV, 0% for ApMV and 5% for ACLSV.
Further observations of almond stem pitting 1
Authors: DI TERLIZZI B. , SAVINO V.
Published: April 2008

Two disorders of almond, know as 'stem pitting’and‘graft union necrosis (black line)', were described years ago from Puglia (southern Italy). The etiology of these diseases was uncertain, the causal agent unknown and reliable diagnostic methods were not available. Investigations were therefore carried out to identify Prunus species and/or cultivars as possible indicators for a quick and reliable diagnosis. In 1990, two different almond sources (cv. Filippo Ceo) affected by black line and stem pitting were budded onto seedlings of P. persica, P. cerasifera, P. amygdalus cv. Don Carlo, GF305, self‐rooted cuttings of GF677 (P. persica×P. amygdalus) and onto Don Carlo and GF305 seedlings that had been already grafted with almond cvs Genco, Tuono and Filippo Ceo. At least two inoculated plants were inspected each year for the presence of symptoms on the woody cylinder after removal of the cortex. Stem pitting developed on P. persica and P. cerasifera seedlings during the first year after graft inoculation. On the grafted plants that had been inoculated, pitting and grooving of the wood were much more pronounced in cvs Filippo Ceo and Genco, with a higher incidence when GF305 was used as rootstock. Clear symptoms were observed (from the first year in cvs Tuono and Genco), regardless of the rootstock, all along the junction line and often not associated with pitting of the rootstock and scion.
Union disorders of almond trees on plum rootstock 1
Authors: UYEMOTO J. K.
Published: April 2008

Almond scions growing on the plum rootstock Marianna 2624 (Prunus cerasifera×P. munsoniana) developed symptoms of deep pits in the xylem and necrotic bark tissues (almond brown line and decline – ABLD) or a mild etching (UME) in the woody cylinder at the union. Trees affected by ABLD decline rapidly while those affected with UME often recover and generally remain in remission thereafter. However, UME‐affected trees produce significantly less trunk growth and nut yields. Symptoms of ABLD can be induced by peach yellow leafroll phytoplasma. The etiology of UME is unknown.
Distribution of conifer beetles (Scolytidae, Curculionidae, Cerambycidae) and wood nematodes (Bursaphelenchus spp.) in European and Asian Russia
Authors: KULINICH O. A. , ORLINSKII P. D.
Published: April 2008

The objective of this paper is to compare, between regions of Russia, conifer beetles found in Scolytidae, Curculionidae and Cerambycidae. Of the 220 species of bark beetles which were found in Russia, 108 species are associated with conifers. Sixty‐three species of bark beetles are established in the European region of Russia and 94 species have been found in the Asian region. In Western Siberia 50 species are found. Eastern Siberia — 54 species, Russian Far East — 79 species. Forty‐nine species of bark beetles (such as Dendroctonus micans, Ips duplicatas, I. sexdentatus and I. typographus) are widely distributed throughout all Russian regions. There are 12 species of Pissodes found in all or various parts of Russia. Six weevil species (Pissodes gyllenhali, P. harcyniae, P. castaneus, P. pini, P. piniphilus and P. validirostris) are found throughout Russia and Western Europe. Five weevil species have only been found in the Asian region of Russia (Pissodes cembrae, P. insignitus, P. irrogatus, P. nitidus, P. nemorensis). Information concerning surveys of Russian conifer forests for wood nematodes, Bursaphelenchus spp., and their vectors is analysed. There is no evidence that B. xylophilus has ever occurred in Russia. Only B. mucronatus has been found. Six species of Monochamus beetles are found in Russia.
Monitoring of Ralstonia solanacearum in the Veneto region (Italy)1
Authors: TURCO P. , SACCARDI A. , PIAZZI E. , MARTINI G. , MELEGATTI A. , XODO E. , GAMBIN E.
Published: April 2008

Ralstonia solanacearum first appeared in the Veneto region in 1995 following the importation of seed potatoes from The Netherlands. An epidemiological study found a total of 25 fields to be contaminated and two cultivars involved (Primura and Liseta). The seed potatoes used to plant these fields all came from one Dutch producer. The disease appeared in a very serious form, indicating that the Veneto area is favourable to its expression. A description is given of the control measures adopted. Monitoring of the contaminated fields, the potentially contaminated fields and the surrounding areas in 1995 and 1996 did not reveal the presence of the bacterium in volunteer potatoes or in potato crops. Indicator plants cultivated in a contaminated field in the spring of 1996 showed no signs of the disease. The apparent lack of efficient sources of inoculum in 1996 may be explained by the effectiveness of the control measures adopted as well as environmental factors.
The situation and outlook for inputs of plant protection products and weed control in Polish agriculture
Authors: ADAMCZEWSKI K. , SKRZYPCZAK G. , WOZNICA Z. , BLECHARCZYK A.
Published: April 2008

This paper reviews the situation of Polish agriculture, as well as land distribution, privatisation, farm numbers and cropping patterns of the major field crops. The current situation of the market for plant protection products is presented, together with changes during the past decade in the degree of weed infestation.

Situation des apports de produits phytosanitaires et du désherbage dans l'agriculture polonaise, et perspectives
Microbiological, immunological and molecular methods suitable for commercial detection and quantification of the blackleg pathogen, Erwinia carotovora subsp. atroseptica, on seed potato tubers: a review
Authors: PÉROMBELON M. C. M. , BERTHEAU Y. , CAMBRA M. , FRECHON D. , LOPEZ M. M. , NIEPOLD F. , PERSSON P. , SLETTEN A. , TOTH I. K. , VAN VUURDE J. W. L. , VAN DER WOLF J. M.
Published: April 2008

Contamination of seed potato tubers by Erwinia carotovora subsp. atroseptica is widespread with the bacteria usually sited superficially in lenticels and suberized wounds. As seed contamination level is related to blackleg incidence, seed health is best assessed by determining the number of cells of E. c. atroseptica per mL of tuber‐peel extract. The relative specificity, sensitivity and ease of use of four recently developed microbiological, immunological and molecular methods to detect and/or quantify tuber contamination are discussed in relation to the testing of commercial seed stock. Sensitivities of all four methods are at or below the threshold level for blackleg development (< 103 cells mL‐1), but there are differences regarding their specificity and ease of use. Three of them allow enumeration of most live cells of the bacterium, using specific monoclonal and polyclonal antibodies against the predominant serogroup I: (a) immunomagnetic separation of E. c. atroseptica before viable count on a selective‐diagnostic growth medium, crystal violet pectate, (b) immunofluorescence staining and counting of colonies in pour‐plate medium in tissue culture plates and (c) enrichment of the bacterium in peel‐extract dilutions directly in microtitre plates prior to DAS‐ELISA. In the fourth method, both live and dead cells are detected, but not quantified, by PCR amplification of target sequences using specific primers for E. c. atroseptica regardless of serogroup.
First report on Corynespora cassiicola and its pathogenicity to soybean cultivars in Zambia
Authors: KAPOORIA R. G. , NDUNGURU J. , RONG I.
Published: April 2008

Off‐season volunteer soybean plants growing among the irrigated wheat during 1997–06/08 showed unfamiliar leaf symptoms in a farm east of Lusaka. The causal organism was isolated on potato dextrose agar and was identified as Corynespora cassiicola. Its identity was established on the basis of typical disease symptoms, characteristic colony features and distinct conidial morphology. Koch's postulates confirmed its pathogenicity to soybean and symptoms were noticed in 7–10 days following inoculation. The interaction between C. cassiicola and soybean cvs Hernon‐147, Kaleya, Santa Rosa and SCS1 was also investigated and showed that the lesions among the four commonly grown cultivars in Zambia ranged between small (1–2 mm) and large (4–6 mm) in size and the cultivars developed either few or many lesions. This demonstrated that Santa Rosa and SCS1 were moderately resistant/tolerant while Hernon‐147 and Kaleya were susceptible. This is the first report on the occurrence of C. cassiicola on soybean in Zambia.
First report of Pestalotiopsis guepini and Glomerella cingulata on blueberry in Buenos Aires (Argentina)
Authors: WRIGHT E. R. , RIVERA M. C. , FLYNN M. J.
Published: April 2008

Blueberry is a relatively new crop cultivated in the provinces of Buenos Aires, Córdoba, Río Negro and Santa Fe (AR). In 1996, an unknown disease was observed. Plants ready to be planted near Buenos Aires and plants growing in a glasshouse in Buenos Aires, both imported from USA, had their stems blighted. Pestalotiopsis guepini and Glomerella cingulata were determined as causal agents of the symptoms.
Current situation and prospects of potato production in Ukraine1
Authors: KUCHKO A. A.
Published: April 2008

Total potato production has been maintained in Ukraine, but the share of production on private plots has recently increased from 65% to 97% and the efficiency of production has declined. Protection of the potato crop from pests has suffered particularly. Scientific institutions continue to breed new cultivars (particularly with resistance to wart and cyst nematodes), and the seed‐potato production system is being maintained and improved. However, these systems were designed for large‐scale production on collective and state farms and have to be adapted to the realities of private production.
Reduction of chemical residues in table potatoes in Ukraine1
Authors: KANONUCHENKO V. V. , KALITSKYI P. F.
Published: April 2008

A potato production system has been worked out in Ukraine to reduce the levels of chemical residues in table potatoes as much as possible. This is based on crop rotation and green manuring, mechanical weed control, use of resistant cultivars and optimum timing of any applications against Colorado beetle and late blight.
National control measures for Globodera spp.1
Authors: McNAMARA D. G. , SMITH I. M.
Published: April 2008

Potato cyst nematodes (Globodera spp.) are present in most potato‐growing areas of the EPPO region. Populations in infested fields are rather easily suppressed by crop rotation. Thus, further spread of these nematodes can be prevented by a national control campaign that prohibits the cultivation of potato on infested plots until the population has been shown by a standard soil test to have declined to a non‐detectable level. Alternatively, resistant potato cultivars may be grown, or early ware potatoes which are harvested before cysts mature, or the soil may be disinfested (ware potatoes only). Such rules are widely applied in European countries, but have been successful only in containing the pest (the infested area has not declined). There is now discussion on the application of more stringent measures for seed potatoes, and less stringent (or even deregulation) for ware potatoes. The Globodera spp. might accordingly be treated as regulated non‐quarantine pests.
Development of Globodera rostochiensis pathotype Ro1 in resistant and susceptible cultivars of potato1
Authors: PILIPENKO L. A. , SIGAR'EVA D. D.
Published: April 2008

Studies on the development of Globodera rostochiensis in potato cultivars with different levels of resistance have shown that both males and females of the nematode complete their whole cycle of development in susceptible cv. Svitanok Kyivskii in 61 days. In resistant cv. Vodograi, only males complete their development. Development of females is interrupted at the third larval instar, and mature females do not appear.
Definition and distribution of aggressive pathotypes of Synchytrium endobioticum in Ukraine1
Authors: MATSKIV T. I. , MELNIK P. A. , GOLIK I. V.
Published: April 2008

Aggressive pathotypes of Synchytrium endobioticum have been detected in Ukraine since 1963, mainly in the mountainous western part of the country. Potato crops are regularly surveyed to detect possible outbreaks. It has been observed that the aggressive forms attack the above‐ground parts of the potato plant, as well as the underground parts, and this can assist detection. Possible foci are investigated by planting a standard replicated test with a susceptible cultivar and a cultivar resistant to the common pathotype. The distribution of S. endobioticum in Ukraine is summarized. Outbreaks are particularly found in potato plots adjoining farm buildings.
Production and protection of seed potatoes in southern Ukraine1
Authors: BUGAEVA I. P.
Published: April 2008

In southern Ukraine, a double‐cropping system is used to multiply seed potatoes from microtubers to elite material in 3 years. Tubers are harvested early from a spring planting and immediately planted again to be harvested in autumn. This system saves costs and is increasingly supplying the needs of the region. The implications of this system for application of plant protection measures are discussed.
A laboratory study on accelerated multiplication of virus‐free potato material1
Authors: KHOMYAK M. V. , MEL'NIK P. A. , KHOMYAK V. V.
Published: April 2008

Various approaches have been tested for improving the production of usable microtubers in tissue culture propagation of virus‐free potato material. Cultures in which microtubers are spontaneously produced under conditions when only vegetative growth should occur are generally not usable, either for further propagation or for microtuber production. Feeding with supplementary sucrose solution has been shown to stimulate such cultures to produce adequate quantities of usable microtubers. Use of a liquid medium instead of a solid medium was another method used to increase microtuber yield. An attempt was also made to increase efficiency by placing more transplants in each culture flask. Improvements were obtained by making various adjustments in the density of plants and the volume of medium, with supplementary feeding if necessary. The density could best be expressed in relation to total surface area of growth chamber used.
Differential cultivars for aggressive pathotypes of Synchytrium endobioticum in Ukraine1
Authors: MALAKHANOVA E. L. , MEL'NIK P.A
Published: April 2008

The use of a internationally agreed standard differential set of potato cultivars to identify aggressive pathotypes of Synchytrium endobioticum is reviewed. In recent years, many new cultivars and hybrids have been tested in Ukraine for their reaction to the Carpathian pathotypes (11, 13, 18 and 22). Because of the specificity and stability of their reactions, and their availability, some of these potato cultivars are now recommended as part of a new differential set for use in Ukraine, especially with respect to the Carpathian pathotypes.
Dutch quarantine strategies applied to glasshouse pests1
Authors: Roozen N. J. M. , Cevat H. N.
Published: April 2008

The Dutch strategies to prevent the establishment of quarantine pests in glasshouse crops fall within the EU framework for preventing the introduction and spread of quarantine pests. Import inspections are mainly carried out at the place of destination of the consignment, thus enabling the inspection of unpacked consignments. There is an extensive monitoring programme for imported propagation material. Monitoring of places of production where imported material may be kept contributes to early detection of pests that are introduced despite import requirements and import inspections. Early detection is considered of major importance for eradication. Monitoring focuses mainly on plants for planting, as these present substantially higher phytosanitary risks than plants for consumption. On the initiative of trade and industry, a programme for accreditation of importers has been established, and insurance for importers and producers is under investigation. To be accredited and to be considered for insurance coverage, importers must comply with a set of measures aimed at minimizing the risk of introducing quarantine pests.
Situation en France des nouveaux ravageurs sous serre1
Authors: Maisonneuve J.‐C.
Published: April 2008

L'usage de la Protection Biologique et Intégrée (PBI) tend de plus en plus à se développer en France en cultures sous serre, légumières et ornementales. Du fait du mode d'action de ce procédé, il est possible à tout nouveau ravageur de s'installer rapidement en cas d'introduction accidentelle. De ce fait le suivi et le contrôle des cultures devienent primordiaux pour éviter toute nouvelle intrusion. Depuis plus de 6 ans, aucun nouveau ravageur n'a été signalé en serre en France et, de plus, des réseaux de piégeage ont démontré l'absence d'autres ravageurs. Ceci conforte l'idée de la fiabilité de la PBI, ainsi que des contrôles phytosanitaires aux frontières. Enfin il est clairement établi que Thrips palmi et Ceratitis capitata n'ont jamais été signalés en cultures sous serre en France.
Adaptation of spray dosage in stone‐fruit orchards on the basis of tree row volume
Authors: Rüegg J. , Viret O. , Raisigl U.
Published: April 2008

The tree row volume (TRV) model was adapted for use in stone‐fruit orchards. The number of leaves, leaf area and TRV were determined in apricot, peach, cherry and plum orchards in France and Switzerland. The number of leaves per tree ranged from 2500 to 25900, and TRV values ranged from 5400 to 28600 m3 ha−1. Trees were sprayed with a fluorescent tracer, according to TRV, in order to determine the quantity and distribution of tracer deposition in the crown of the trees. For large trees with TRV values above 15000 m3 ha−1, tracer deposits on leaves were lower in the upper half of the crown than in the lower half. The TRV formula developed for pome‐fruit trees was accordingly used for spraying stone‐fruit trees, but with a 15% increase in spray volume for large trees. Under these conditions, disease control was efficient, and residues of difenoconazole, penconazole and dithianon were below the maximum residue limit. The TRV method was thus found to allow adaptation of spray dosage and volume to the volume of the trees, on condition that sprayers are carefully calibrated and adjusted for each orchard. The TRV concept can be applied to a wide range of pome and stone‐fruit orchards and can help to harmonize registration protocols for fungicides and insecticides.
Influence of cropping practices on corn rootworm in Canada as a basis for assessment of the potential impact of Diabrotica virgifera in Germany
Authors: Schaafsma A. W. , Baufeld P. , Ellis C. R.
Published: April 2008

Monitoring of populations of adult corn rootworms (Diabrotica virgifera and D. barberi) in Ontario (CA), and surveys of insecticide use against rootworms, showed that populations declined in the last 10 years and that the proportion of the maize area treated with rootworm insecticide has fallen to <7%. This proportion was directly correlated with the percentage of cropping with continuous maize. The area of insecticide‐treated maize could be further reduced by educating livestock producers about the merits of crop rotation and the possibilities of alternative high‐energy crops, such as winter barley. Populations of rootworm adults and area of continuous maize are currently so low in Ontario that there is a good probability of success for an adult monitoring and insurance programme to replace the use of corn rootworm insecticides. In Germany (where D. virgifera is now absent but may potentially be introduced from the outbreak in the lower Danube basin), the four Federal Länder of Niedersachsen, Nordrhein‐Westfalen, Bayern and Baden‐Württemberg maintain a high frequency of continuous maize. If areas with more than 50% of arable land with maize are considered to be at high risk of rootworm infestation, about 348 000 ha of maize fall into this category. This is a third of the maize production area of the above‐mentioned Federal Länder and more than a fifth of the entire maize production area of Germany in 1995. On the basis of long‐term experience of insecticide use in Ontario, there is a potential for treatment of up to 111 000 ha with rootworm insecticide (terbufos) annually in Germany, at an added insecticide cost of 13 million EUR per annum. Without crop rotation or treatment, rootworm infestations could cost German maize producers 25 million EUR in crop losses each year. The experience in Ontario suggests that Germany should follow a strategy of changing crop rotation away from continuous maize, so as to reduce the potential for establishment of D. virgifera, the potential for economic loss and the potential for increased reliance on insecticides.
Etude de la gamme d'hôtes du sugarcane mosaic potyvirus et du sugarcane bacilliform badnavirus infectant la canne à sucre au Maroc
Authors: Nadif A. , Elyachioui M. , Elhadrami I.
Published: April 2008

Le sugarcane mosaic potyvirus (SCMV) et le sugarcane bacilliform badnavirus (SCBV) sont responsables des deux principales maladies virales identifiées sur la canne à sucre au Maroc à ce jour. L'étude de l'épidémiologie de ces deux virus a montré que le SCMV peut contaminer une gamme hôtes relativement large d'adventices et de plantes cultivées alors que le SCBV n'infecte qu'une gamme assez restreinte. Les plantes‐hôtes communes déterminées sont le panicum et le sorgho. Le milieu marocain est particulièrement propice au SCMV et assure parfaitement son maintien dans les conditions naturelles. Il offre une large gamme d'hôtes parmi les espèces les plus prédominantes et une abondance du vecteur potentiel Rhopalosiphum maidis. Le maintien dans la nature du SCBV serait dû essentiellement à la sensibilité et la pérennité des cannes nobles et sa dissémination serait assurée principalement par les boutures.
Adaptation progressive à la luzerne d'un isolat deVerticillium dahliae, originaire de la tomate
Authors: El Aissami A. , Lahlou H.
Published: April 2008

Un isolat deVerticillium dahliaeprovenant de la tomate s'est montré apte à vivre en parasite aux dépens de la luzerne connue par être attaquée uniquement parVerticillium alboatrum.Cette aptitude parasitaire ne s'accompagne d'aucune manifestation pathologique à la première inoculation. Des passages successifs de cet isolat chez la luzerne ont conduit à des lignées d'aptitudes parasitaire et pathogène nouvelles. Une réduction graduelle de son pouvoir pathogène à l'encontre de son hôte d'origine a été observée contrairement aux aptitudes parasitaires qui se sont maintenues. Les passages successifs sur la luzerne ont également entraîné des variations morphologiques qui ont touché la croissance radiale, le taux de sporulation et la forme de résistance. Des hypothèses sur la nature de ces variations sont proposées et les conséquences agronomiques de ces phénomènes sont discutées.
Occurrence of Puccinia sorghi on maize in Northern Ireland
Authors: Mercer P. , Gilliland T.
Published: April 2008

Maize rust, Puccinia sorghi was reported from Ireland for the first time in 1998. It seems likely that the inoculum source was wind‐borne spores, as there does not appear to be a common alternative host, and the disease did not recur in 1999.
Puccinia asparagi on Asparagus officinalis in Greece
Authors: Vakalounakis D.J. , Pavlou G.
Published: April 2008

The occurrence of a serious attack of Puccinia asparagi on Asparagus officinalis is reported for the first time in Kriti, Greece.
Putative virus disease of sunflower in Zambia
Authors: Ndunguru J. , Mwale S.
Published: April 2008

Symptoms of a virus‐like disease of unknown aetiology were observed in sunflower in five provinces of Zambia during the 1998 growing season. In the 20 surveyed farmers’fields, disease incidence was 80–100%. Yield loss in seed production as a result of the putative virus (or virus complex) was estimated at 60%. The virus was not seed‐borne in sunflower. The weed Tridax procumbens was found to be an alternative host of the virus, and the virus was transmitted by Aphis gossypii from the weed to sunflower. Serological analysis suggests that the virus (or virus complex) is closely related to luteoviruses. It is tentatively named sunflower yellow blotch virus (SYBV).
Natural occurrence of cucumber mosaic cucumovirus in Datura innoxia in India
Authors: Raj S. K. , Srivastava A. , Chandra G. , Singh B. P.
Published: April 2008

A natural disease causing green mosaic, leaf deformation and shoestring symptoms on Datura innoxia was observed in 1999. The causal agent of the disease was identified as a strain of cucumber mosaic cucumovirus (CMV), as evidenced by reverse transcriptase–polymerase chain reaction (RT–PCR) using primers specific to CMV coat protein and Southern hybridization tests with a probe derived from cloned cDNA of CMV. This is the first report of CMV in D. innoxia.
Weather information, site information and a system for dissemination of information on the Worldwide Web from a network of 52 automatic agrometeorological stations*
Authors: Sivertsen T. H.
Published: April 2008

The Norwegian Crop Research Institute runs a network of 52 automatic meteorological stations. The construction of a revised system for collecting meteorological data from the automatic stations and connecting the data to site‐specific information and biological information is outlined. The system for collection, validation and dissemination of information forms the backbone of the Norwegian Agricultural Meteorological Service. This system is geared towards the needs of agricultural research and extension service as well as the needs of farmers.
Prognosis of phenological stages of Vitis vinifera (cv. Riesling) for optimizing pest management*
Authors: Hoppmann D. , Berkelmann‐Loehnertz B.
Published: April 2008

The prognosis of phenological stages of grapevine, linked with the assessment of leaf area development, is a valuable tool in support of timely plant protection treatments as well as optimum canopy management. Warm weather conditions from May to July combined with copious water supply may lead to an enormous growth in leaf area, so that volatile active substances have to be applied at shorter intervals than normally required. In addition, certain phenological stages are of special significance for the planning of appropriate plant protection measures. The expected phenological stages can be computed 10–14 days before their occurrence based on weather data, a 7‐day forecast and long‐term climatological data. In order to test the reliability of procedures aided by model approaches illustrated in the literature, a 30‐year observation series was used as a basis for this study. For the prognosis, mainly maximum and minimum temperatures, computed global radiation and daily precipitation totals were used. The computations were supplemented by long‐term daily mean values of these parameters.
Phenological forecasting model for Cydia funebrana*
Authors: Butturini A. , Tiso R. , Molinari F.
Published: April 2008

A simulation model of the phenology of Cydia funebrana (plum fruit moth) is presented. The Logan function was used to determine the temperature‐dependent developmental rates of the eggs, larvae and pupae; a linear equation was used for the ageing rate of females. The mean fecundity of females as a function of age was expressed by a modified Bieri's function. In order to simulate the stochastic process, a time‐distributed delay model was used. Results from the validation of the model in northern Italy (1995 and 1997) are reported. Catches of male moths in pheromone traps and oviposition activity were monitored in orchards of mid‐ and late‐ripening plum cultivars. The model was then run using temperature data from each farm. When the oviposition activity forecast by the model was compared with that actually observed in the orchards, good correlations between actual and forecast oviposition were obtained. The model is already available for technicians in Emilia‐Romagna and is a valuable tool in integrated fruit production; it gives an indication of the right moment to apply insecticides or to carry out further monitoring activity to assess the risk of C. funebrana damage (e.g. by sampling actual oviposition on just a single occasion).
Estimating the dynamics of airborne ascospores of Venturia inaequalis*
Authors: Giosuè S. , Rossi V. , Ponti I. , Bugiani R.
Published: April 2008

A system was elaborated to estimate the dynamics of primary inoculum of Venturia inaequalis in apple orchards. It separates the primary inoculum season into five periods with different risks: absent (ascospores not yet mature); potential (ascospores mature but not yet ready to be discharged); actual (ascospores can be discharged when favourable conditions occur); present (ascospores are airborne); exhausted (all ascospores have been ejected). These periods were determined by two mathematical models, which use meteorological parameters as driving variables. The first model estimates the development stage of the overwintering pseudothecia and then determines when the first pseudothecia contain pigmented and mature ascospores. A threshold of mature ascospores inside pseudothecia defines when the ascospores become ready for discharge. The second model estimates the proportion of the season's ascospores that are airborne on each discharging event, using temperature and leaf wetness, expressed as the degrees accumulated daily in the hours when leaves are wet. Estimates of absent and potential risk were verified by collecting data on the first ascospore discharge in the period 1991/1998 at Bologna and Modena (northern Italy), and they were always found to be accurate. To verify the estimates of actual, present and exhausted risk, the model outputs were compared with data collected by spore samplers at Modena and Bologna in 1997 and 1998: they were sufficiently accurate because the greatest part of the records from the spore sampler fell inside the confidence limits of the model.
An Internet‐based decision‐support system for insect pests of rape*
Authors: Morgan D. , Walters K. F. A. , Oakley J. N. , Lane A.
Published: April 2008

A decision‐support system (DSS) has been developed for the holistic management of the invertebrate pest complex of rape. Traditionally, management of one pest has been done in isolation from any other. However, the control tactics used for one may impinge upon the management of other invertebrates. At present, the DSS contains procedures for the concurrent management of five pests. An Internet version of the system has been developed using a combination of Java and Cold Fusion to facilitate the delivery of information.
Benefits and problems of the Nordic Internet Plant Protection Project – NIPPP*
Authors: Gröntoft M.
Published: April 2008

NIPPP (Nordic Internet Plant Protection Project) was started in 1996 in order to enhance cooperation between smaller groups in the Nordic countries. The problems encountered in the early stages of development are analysed, and recommendations are made for the successful continuation of the project.
Fungal pathogens associated with melon collapse in Spain*
Authors: García‐Jiménez J. , Armengol J. , Sales R. , Jordá C. , Bruton B. D.
Published: April 2008

Spain produces 43 200 ha of melons with a considerable export to European markets. In the last 10 years, melon cultivation in Spain has decreased more than 40% due mainly to collapse of the vines caused by soil‐borne diseases. Serious economic losses have resulted. In order better to understand the aetiology of this disease, a survey of 217 melon fields throughout the melon production areas of Spain was conducted from 1987 to 1996 to analyse the fungal population associated with roots. In addition, the presence of melon necrotic spot carmovirus (MNSV) was studied in 93 fields. This virus is present mainly in southeastern Spain. The predominant fungal species isolated from 82.5% of sampled fields with symptoms of collapse was Acremonium cucurbitacearum. Roots affected by this fungus show corky brown areas soon after transplanting. Small secondary roots and root hairs become necrotic, although there is continuous production of new rootlets. This process continues until the late stages of the disease. As the fruits approach maturity, the entire plant wilts and dies. Other fungal species associated with melon collapse are: Monosporascus cannonballus (isolated from 29.5% of sampled fields), Macrophomina phaseolina (32.7%) and Rhizoctonia solani (31.8%). Of these, the incidence of M. cannonballus isolated from diseased melons has increased substantially over the past 10 years. Melon collapse in Spain is complex because several fungi capable of causing collapse of the vines are prevalent and often isolated from roots in the same field. In addition, other minor pathogens, such as Rhizopycnis vagum and Plectosporium tabacinum, are frequently isolated from symptomatic vines and may also contribute to the death of the plants.
Genetic variation among Fusarium oxysporum isolates from cucumber
Authors: Vakalounakis D. J. , Fragkiadakis G. A.
Published: April 2008

Isolates of Fusarium oxysporum obtained from cucumber worldwide were classified into 3 groups by random amplified polymorphic DNA‐polymerase chain reaction (RAPD‐PCR). All isolates of f. sp. radicis‐cucumerinum fall into one group. Isolates of races 1 and 2 of f. sp. cucumerinum fall into a second group related to isolates of f. sp. melonis and niveum. Isolates of race 3 fall into a third group, related to f. sp. momordicae. Because f. sp. radicis‐cucumerinum has relatively recently been introduced into Greece, where it is actively spreading and very damaging, RAPD‐PCR may be valuable in monitoring populations of F. oxysporum.
Genetic diversity in Fusarium oxysporum f. sp. melonis*
Authors: Veloso M. M. , Melo E. M. P. F. , Jorge‐Silva M. L. , Bravo M. A.
Published: April 2008

Fusarium oxysporum f. sp. melonis is an important vascular wilt pathogen of melon. Races 1, 2 and 1–2 of this fungus have been identified in Portugal by pathogenicity tests with appropriate hosts. The aim of this research was to examine the relationships between different races of F. o. melonis of Portuguese and French origin through analysis of random amplified polymorphic DNAs (RAPDs). DNA fingerprint profiles were developed for all the accessions. Each isolate showed 5–10 DNA bands with each of the 16 primers employed. A total of 126 bands was obtained. The size of amplified DNA fragments generated with these primers ranged from 0.5 to 3.2 kb. A phenogram based on the Jaccard coefficient of similarity was computed by the unweighed pair group method using arithmetic averages (UPGMA). It was found that Portuguese race 2 is very similar to French race 1, while French race 2 is the most dissimilar being clearly separated from all other races. The genetic diversity of these isolates is also being studied for vegetative compatibility by using the nit mutant system.
Effects of isolate virulence and host susceptibility on development of early blight (Alternaria solani) on tomato*
Authors: Vloutoglou I. , Kalogerakis S. N. , Darras A.
Published: April 2008

Early blight of tomato (Lycopersicon esculentum) caused by Alternaria solani has the potential to become one of the most serious diseases throughout the tomato‐producing regions of Greece. Controlled environment experiments were conducted to study the virulence of A. solani isolates and the susceptibility of commercial tomato cultivars and hybrids to early blight. The isolates used, derived from naturally infected tomato plants during the period 1997/1998, differed significantly (P>0.05) in the rate of mycelial growth as well as in their ability to sporulate in vitro. No correlation (R2= 0.33) was found between mycelial growth and conidia production. Isolates of A. solani were virulent to young tomato plants (cv. Ace 55VF), although they differed significantly (P>0.05) in the intensity of symptoms produced on leaves, stems, petioles and flowers. Defoliation was linearly related (R2= 0.87) to the percentage of leaf area with symptoms. Twenty‐three tomato cvs. or F1 hybrids were evaluated for their susceptibility to early blight. The cultivars or hybrids were arbitrarily categorized as immune, highly tolerant, tolerant, moderately tolerant, susceptible and highly susceptible based on a percent disease index range: 0%, 1‐9%, 10‐24%, 25‐49%, 50‐74% and 75% or more respectively. None of the cultivars or hybrids tested was immune or tolerant to A. solani infection.
Characterization of potato Y potyvirus isolates from tomato crops in Islas Canarias (Spain)*
Authors: Abad P. , Jordá C.
Published: April 2008

A disease caused by potato Y potyvirus (PVY) affects tomato plantations with variable severity in Tenerife Island. Affected plants show diverse symptoms such as necrotic lesions or mild to severe mosaic in leaves and whitish spots in green fruits that remain after ripening. Tomato PVY isolates and few potato and capsicum PVY isolates have been characterized on the basis of biological, serological and molecular criteria. All PVY isolates reacted positively to monoclonal antibodies specific for PVYO/C or PVYN strains, and nearly 50% of tomato PVY isolates were recognized by both. Differentiation of PVY strains according to the response of inoculated experimental plants was confusing due to the variability of viral aggressiveness and symptomatology induced. RFLP analysis of the CP gene and 3’untranslated region (UTR) revealed high variability. In addition to mixed infection by different PVY strains, the biological and molecular properties of those tomato PVY isolates that react to both monoclonal antibodies could be explained as the result of RNA recombination between distinct PVY strains which infect the same host plant.
Epidemiology of tomato yellow leaf curl begomovirus in the Fayium area, Egypt
Authors: Aboul‐Ata A. E. , Awad M. A. E. , Abdel‐Aziz S. , Peters D. , Megahed H. , Sabik A.
Published: April 2008

Tomato yellow leaf curl begomovirus (TYLCV) severely invaded tomato plantations in Egypt (Lower and Middle Egypt) in 1989. This study aimed to discover the relationship between TYLCV and other epidemic‐associated factors in the Fayium area. The rate of TYLCV infection was inspected visually for three successive years (1994/1996) in the Fayium area. During the same period, whiteflies were collected for virus detection using bait‐plant and DNA hybridization techniques. DAS‐ELISA was used to detect mixed virus infections in tomato plants. TYLCV infection was prevalent (60–68%) and severe (2.1–3.0) in the Fayium fields. Cucumber mosaic cucumovirus (CMV) was found in some fields (5–28%) with moderate severity (1.0–20). Potato Y potyvirus (PVY) and potato leaf roll polerovirus (PLRV) were found in few fields (5–19% and 5% respectively) at very low severity. There was a negative correlation between TYLCV occurrence and distance from the source of infection, and a positive correlation (98%) between TYLCV intensity and percentage of viruliferous whiteflies in 1994 and 1995. There was no positive correlation between TYLCV and the total population of whiteflies caught during the same period. Five percent of viruliferous whiteflies, as proved by cDNA hybridization, led to 46% TYLCV infection. The same percentage of whiteflies, as shown by bioassay, led to 68% TYLCV infection. Monitoring of viruliferous whiteflies could be used for early prediction of TYLCV infection.
Detection and identification of seed‐borne pathogenic bacteria of imported tomato seeds in Egypt
Authors: Abdalla M. E.
Published: April 2008

Imported tomato seed lots of different cultivars were assayed for the presence of seed‐borne bacterial pathogens. The liquid assay method was used for detection of the bacteria, and seed extracts were plated on different semi‐selective media. Pseudomonas corrugata and Xanthomonas campestris pv. vesicatoria were detected in 14.7% and 12% of the seed samples tested respectively. These pathogens were identified by means of biochemical, physiological and pathogenicity tests as well as the Biolog GN Microplate System for X. campestris pv. vesicatoria. Both P. corrugata and X. campestris pv. vesicatoria were more easily identified on Tween B and CKTM media than on other media. This is the first report of the occurrence of these important pathogens on tomato seeds in Egypt.
Le chancre bactérien de la tomate en Algérie
Authors: Benchabane M. , Et A. Boutekrabt , Toua D.
Published: April 2008

Deux enquêtes, effectuées indépendamment en Algérie durant les campagnes 1988/1989 et 1997/1998, ont permis de détecter la présence du chancre bactérien dans les cultures de tomate du littoral algérois et de la plaine de la Mitidja. Les taux de contamination enregistrés étaient successivement de 15,3% et de 9,3%. Les isolements effectués ont permis de sélectionner 63 souches bactériennes appartenant à l'espèce Clavibacter michiganense subsp. michiganense.
Protocols for the diagnosis of quarantine pests*
Authors: Žlof V. , Smith I. M. , McNamara D. G.
Published: April 2008

EPPO member countries have recognized the need for a harmonized approach to detection and identification methods for quarantine pests. In 1998, EPPO started anew project to prepare diagnostic protocols for the quarantine pests of the EPPO region. The work is conducted by the Panel on Diagnostics, which is under the authority of the Working Party on Phytosanitary Regulations. The Panel consists of 10 experts in different fields. When necessary, expert groups on specific disciplines are called upon. The Panel agreed on a suitable common format for the protocols and a procedure for producing the best quality of diagnostic protocols. As there are about 325 quarantine pests for the region (listed in the EPPO A1 and A2 lists of quarantine pests and in the Annexes of EU Directive 77/93), it was necessary to decide upon a priority list of the organisms for which protocols should be developed first. At the moment, 52 protocols are at different stages of preparation.
Diagnostic protocols for organisms harmful to plants – DIAGPRO*
Authors: Harju V. A. , Henry C. M. , Cambra M. , Janse J. , Jeffries C.
Published: April 2008

DIAGPRO is an EU‐funded project to develop diagnostic protocols for 18 quarantine pests. Pilot test methods will be developed in the laboratories of the four partners in England, Scotland, The Netherlands and Spain. The methods will be ring‐tested at selected EU laboratories and published on the Internet for comment.
Classification and identification of plant‐associated bacteria by fatty acid profiling*
Authors: Weller S. A. , Aspin A. , Stead D. E.
Published: April 2008

This brief review is based on 15 years’experience of using fatty acid profiles to characterize, classify, and identify plant‐pathogenic and other bacteria. Fatty acid profiles are now well established for classification and identification of plant‐associated bacteria. Profiles are based on standardized culture, simple chemical extraction, and gas chromatographic separation of fatty acid methyl esters (FAMEs). FAMEs are identified and quantified to give a profile for each strain. Over 100 fatty acids, 8–20 carbon atoms in length, belonging to several classes, occur in bacteria. Most bacteria have between 5 and 25 of these acids. The types occurring are usually indicative of the class, family and genus. Many Gram‐negative genera have unique series of hydroxy acids. Gram‐positive genera usually lack hydroxy acids but are rich in branched acids. Acidovorax, Agrobacterium, Burkholderia, Clavibacter, Pseudomonas, Ralstonia, Rhodococcus, Xanthomonas and Xylophilus all have characteristic profiles. Profiles do not tend to support genomospecies within Pseudomonas syringae and Xanthomonas campestris but for most other species correspond well with DNA and rRNA homology. The relative amounts of individual fatty acids present often allow accurate differentiation at species, subspecies and sometimes biovar and pathovar level. However, pathovars in some species, e.g. Pseudomonas syringae, are often not well differentiated. Identification is facilitated by comparison with libraries of profiles produced under standard conditions. These can be produced in‐house or purchased. Accuracy of identification can be excellent.