bluuebunny/crossref_metadata_2025 huggingface dataset:
Viruses and virus diseases of grapevine in Tunisia
Authors: MAHFOUDHI N. , DIGIARO M. , SAVINO V. , DI TERLIZZI B.
Published: April 2008

Mature canes were collected from vines in the main grapevine‐growing areas in Tunisia (Cape Bon, Bizerte, Ben Arous), from commercial vineyards and mother‐plant plots, to assess the presence of virus and virus‐like diseases. Biological (mechanical transmission onto herbaceous hosts and grafting onto indicator woody plants) and serological detection (ELISA) methods were applied. ELISA showed that 96.4% of 669 vines tested were infected, most of them (88.1%) by at least two viruses. Grapevine leafroll‐associated 3 closterovirus (GLRaV‐3) was the most widespread virus (87.9%), followed by grapevine A vitiviras (GVA, 69.4%), grapevine fleck virus (GFkV, 51.9%), grapevine leafroll‐associated 1 closterovirus (GLRaV‐1, 36.8%), grapevine leafroll‐associated 2 closterovirus (GLRaV‐2, 19.1%), grapevine fan leaf nepovirus (GFLV, 18.2%) and grapevine B vitiviras (GVB, 14.8%). ELISA tests yielded negative results for grapevine leafroll‐associated 7 closterovirus (GLRaV‐7) and potato X potexvirus (PVX). The highest infections were found in Bizerte and Cape Bon regions (100 and 99.2%), and in vineyards aged over 20 years (98.5%) as compared with the younger ones (81.1%). Rootstocks in mother‐plant plots were practically free from all the viruses tested (1 plant infected out of 81), whereas severe infections were found in Vitis vinifera mother plants (67.4% of 341 samples), in particular table grapes (92.6%) compared with wine grapes (47.9%). In these mother‐plant plots, the prevailing viruses were GLRaV‐3 (41.3%), followed by GFkV (36.7%), GVA (27.9%), GLRaV‐1 (17%) and GLRaV‐2 (15.2%). GFLV and GVB were far more limited (1.5 and 0.6%, respectively). The presence of vein necrosis and vein mosaic was ascertained by transmission onto 110R and Vitis riparia indicators, whereas only GFLV was mechanically transmitted onto herbaceous hosts (from about 20% of the samples).
First record of Bursaphelenchus leoni in South Africa and comparison with some other Bursaphelenchus spp.
Authors: BRAASCH H. , SWART A. , TRIBE G. , BURGERMEISTER W.
Published: April 2008

Bursaphelenchus leoni was found in wood of a severely wilted pine tree (Pinus radiata) in South Africa. Morphological studies and morphometric measurements showed the South African population to be conspecific with B. leoni which is widespread in southern Europe and indigenous in the Mediterranean region. In addition, molecular biological tests (RFLP analysis of amplified ribosomal DNA) confirmed this diagnosis and allowed comparisons with other Bursaphelenchus spp. from pine and other trees, i.e. B. xylophilus, B. mucronatus, B. fraudulentus and B. sexdentati. This is the first record of a Bursaphelenchus species in South Africa as well as in the southern hemisphere. P. radiata is recorded as a new host for B. leoni.
Alternaria zinniae on Parthenium hysterophorus
Authors: SHARMA D. D. , GUPTA A. K.
Published: April 2008

Altemaria zinniae is reported for the first time on the weed Parthenium hysterophorus, at Udaipur, Rajasthan (IN).
Effects of active substances of plant protection products on biological control agents used in glasshouses
Authors: Plantenziektenkundige Dienst
Published: April 2008

Tables are presented classifying over 80 active substances for their harmfulness to natural enemies in protected cultivation, particularly parasitic hymenoptera, predatory mites and predatory insects. The categories used are: harmful, harmful under certain circumstances, not harmful. Results are given for different application methods in some cases. The duration of after‐effects is given for Encarsia formosa, Phytoseiulus persimilis and Neoseiulus cucumeris.
Protection of potatoes against pests in Ukraine1
Authors: LESOVOI M. P.
Published: April 2008

Potato production in Ukraine is now mainly in the private sector, and the phytosanitary state of potato crops leaves much to be desired. Control of Leptinotarsa decemlineata is generally well managed, but potato late blight (Phytophthora infestons) is out of control. Potato wart disease continues to cause problems in areas where it occurs because of the unavailability or unacceptability of resistant cultivars. Potato viruses and the losses they cause are little studied or taken into account. Other fungal, bacterial and insect pests are causing increasing problems in the field and in store. Integrated pest management systems are proposed by scientific institutions, including adequate forecasting of potato blight and use of certified seed potatoes of cultivars resistant to wart and cyst nematodes, but these systems do not adequately reach private growers. The range of plant protection products authorized for sale to the general public is very limited, and this is a serious obstacle to adequate plant protection in potato.
Good plant protection practice in potato1
Authors: ŽLOF V.
Published: April 2008

EPPO has identified the need for an appropriate assessment and management of plant protection products and is developing standards in areas such as efficacy evaluation and good plant protection practice. The EPPO programme on good plant protection practice (GPP) is presented and its purpose is explained. The EPPO standard on GPP for potato forms part of this programme. First published in 1994, it was designed for ware potatoes, i.e. potatoes grown for consumption or processing.
Efficacy of chemical plant protection products on potato in Ukraine1
Authors: MALAKHANOV Yu. A. , MEL'NIK P. A.
Published: April 2008

The principal potato pests controlled with plant protection products in Ukraine are Leptinotarsa decemlineata and Phytophthora infestons. Results are presented of trials of insecticides and fungicides against these pests. As a result, Sumi‐alfa 5% EC (a.s. esfenvalerate), Karate water‐soluble granules (a.s. lambda‐cyhalothrin) and Betabytroid 2.5% EC (a.s. beta‐cyfluthrin) were recommended for full‐scale testing against Colorado beetle in Ukraine. Sul'fokarbation and EKhR 19517 were recommended for full‐scale testing against potato blight.
Advances in biological control of Leptinotarsa decemlineata in Poland1
Authors: LIPA J. J. , SOSNOWSKA D. , PRUSZYNSKI S.
Published: April 2008

Results of research, and practical attempts at biological control of Colorado beetle (Leptinotarsa decemlineata), are reviewed. Attempts to introduce parasitic or predatory insects from North America and establish them permanently in Europe were unsuccessful. Studies conducted in Poland and Europe revealed 237 species of indigenous arthropod natural enemies of Colorado beetle (in North America only 61) and over 15 species of microorganisms (mollicutes, fungi, protozoa and nematodes). The combined action of indigenous natural enemies lowers density of Colorado beetle by 30–80%, but this is still above the economic threshold so that chemical control remains necessary. Under a cooperative project (Poland, Czechia, USA), it was demonstrated in Poland that three treatments with the biopesticides Mycotrol or Novodor provided a level of potato protection similar to that of two treatments with a synthetic pyrethroid.
Strategy of control of resistant populations of Leptinotarsa decemlineata in Belarus
Authors: BYKHOVETS S. L.
Published: April 2008

The development of insecticide resistance in Leptinotarsa decemlineata in Ukraine is reviewed, and current strategy for avoiding resistance is presented. The baseline sensitivity to new plant protection products is systematically checked, and possible appearance of resistance is constantly monitored. A sufficiently wide set of products should be available to allow an alternation strategy.
Phytopathological situation in potato in Belarus1
Authors: IVANYUK V. G.
Published: April 2008

The control of potato diseases in Ukraine is reviewed. Control of potato blight (Phytophthora infestans) has only been adequate for limited periods in the past (when resistant cultivars were available and when the systemic fungicides were introduced). Currently, the disease is in a new epiphytotic phase and control has failed again, probably connected with the introduction of new mating types and the existence of greater variability. Blight now occurs earlier in the season and in most years (instead of only years when climatic conditions are favourable). Control has now to be essentially preventive, rather than based on forecasting. The importance and control of other potato diseases is also considered (Alternaria spp., Rhizoctonia solani, Geotrichum candidum, Phytophthora erythroseptica, Sclerotinia sclerotiorum, Streptomyces scabies).
Mixed rots of potato tubers in Ukraine
Authors: POLOZHENETS V. M.
Published: April 2008

The pathogens involved in rotting potato tubers at harvest or in store have been identified in the forest and forest‐steppe zones of Ukraine. Fusarium spp., Phytophthora infestons, Erwinia carotovora and Ditylenchus destructor are the most important.
Quarantine pests of potato in Ukraine and requirements for their control1
Authors: MOVCHAN A. N. , MEL'NIK P. A.
Published: April 2008

Three principal quarantine pests (Phthorimaea operculella, Globodera rostochiensis and Synchytrium endobioticum) attack potato in restricted areas within Ukraine. Their biology is briefly presented. A complex of phytosanitary and plant protection measures is in place to prevent movement, multiplication and further spread of these quarantine pests.
Phytosanitary regulations of EPPO countries for quarantine pests of potato1
Authors: ORLINSKII A. D. , SMITH I. M.
Published: April 2008

An analysis is made of the phytosanitary requirements needed by EPPO countries for import of potatoes. General and pest‐specific requirements are summarized. This information is derived from the EPPO computerized system PRS, which also forms the basis of an EPPO publication ‘Summaries of the phytosanitary regulations of EPPO countries’.
Legislative measures to prevent the introduction and spread of Ralstonia solanacearum in the European Union1
Authors: WRIGHT A. J.
Published: April 2008

Since the outbreaks of potato brown rot (caused by Ralstonia solanacearum) in EU Member States in the mid 1990s, EU measures against this pest have been strengthened. Factors in the spread of R. solanacearum are reviewed: planting material, Solanaceous weeds, water, soil, waste, machinery and equipment. The Control Directive of 1998 aims to prevent spread and ensure eradication. It provides for the establishment of a demarcated zone whenever the pest is found, for measures to prevent spread from this zone and for measures to eliminate the pest within the zone.
Investigation and control of potato brown rot in Germany, especially in Bayern1
Authors: MÜLLER P. , PARUSEL R.
Published: April 2008

Ralstonia solanacearum has been found in Dutch potato production since 1995. For this reason, comprehensive laboratory tests on seed‐ and ware‐potato production have been carried out in Germany. The amount of tested potato lots has increased fivefold. In 1997, 10678 tests were carried out on seed potatoes and 2351 tests on ware potatoes respectively. In 1996, R. solanacearum was found in five lots in Bayern and in one lot in Brandenburg, and in 1997 only in two ware‐potato lots in Bayern. A thorough analysis was carried out to find the source of infection, but it was not possible to identify it clearly. The measures taken were based on the draft Control Directive for brown rot, which will soon be adopted by the Council of the European Union, and were very restrictive for the affected farms. Monitoring of a potato‐processing enterprise that had processed an infected lot without permit in 1996 established that R. solanacearum was present in wastewater. This paper discusses the measures taken in Bayern and the risks of further introduction.
Control methods for potato nematodes in Ukraine1
Authors: SIGAR'EVA D. D. , PILIPENKO L. A.
Published: April 2008

Control of Globodera rostochiensis in Ukraine depends on the use of resistant potato cultivars. In the last 2 years, the proportion of resistant entries in the official Ukrainian list has increased from 27% to 45%, and the number of Ukrainian‐bred resistant cultivars has increased from 3 to 12. It is now suggested that resistant cultivars are classified into the categories‘resistant and tolerant’ and ‘resistant but only relatively tolerant’. The choice of these cultivars should depend on the nematode population of the soil. Control of Ditylenchus destructor is also considered, on the basis of prophylactive and agrotechnical measures.
Variability of Synchytrium endobioticum in the Carpathian region of Ukraine1
Authors: MEL'NIK P. A. , MALAKHANOVA E.L.
Published: April 2008

The appearance of aggressive pathotypes of Synchytrium endobioticum in the Carpathian area of Ukraine is reviewed. An analysis is made of the factors that favoured their appearance in this area. Possibilities for distinguishing the pathotypes by characters other than their behaviour on differential cultivars are considered.
Detection methods for Synchytrium endobioticum1
Authors: ZELYA A. G. , MELNIK P. A.
Published: April 2008

Methods commonly used to determine the level of infestation of soil with zoosporangia of Synchytrium endobioticum are often laborious and call for complex equipment and costly and toxic chemicals. After comparative study of various existing methods, the authors propose a simple method based on centrifugation of soil residues in salt solutions of different density.
Seed‐potato production of cultivars resistant to Globodera rostochiensis in Poland1
Authors: KUCZYNSKA J.
Published: April 2008

Changes in the production of Polish seed potatoes of cultivars that are resistant to potato cyst nematodes have been followed. Over the period from 1972 to 1998, 35 cultivars resistant to Globodera rostochiensis (pathotype RO1) were introduced. Among them, one (Drop) was also resistant to Globodera pallida (PA3) and a number had multiple resistance to diseases and nematodes. Planting of seed potatoes of these resistant cultivars concerned only 0.4% of the total potato area. Against a background of much reduced seed‐potato production, the area planted with resistant cultivars fell by 47% over the years 1989/1997). However, the share of resistant cultivars in the total seed‐potato area increased from 16% in 1989 to 47% in 1997, the most important cultivars being Lawina, Orlik, Ibis and Irga. In 1992/1993, resistant cultivars occupied only 6–8% of the total potato area.
Production of seed potatoes in Ukraine1
Authors: SVERTOKA V. E.
Published: April 2008

The Institute for Potato Research is one of the major producers of healthy potato material in Ukraine. Under its leadership, an increasing proportion of elite seed‐potato production (about 70% at present) is based on healthy material propagated in vitro (mainly minitubers and vitro plants). The Institute is investigating the cost effectiveness of elite propagation based on different types of healthy starting material. Against the background of an overall fall in seed‐potato production, the Institute has an important responsibility to maintain its collection of healthy potato material, to sustain the national system for seed‐potato production, and to support the breeding of new potato cultivars.
Seed‐potato production and its protection in Kharkiv region1
Authors: MURAV'EV V. A.
Published: April 2008

Seed‐potato production is being renewed in Kharkiv region, in order to supply local growers and reduce dependence on imports from other countries or other regions of Ukraine. The continental climatic conditions of this region create particular problems for seed‐potato production. Early cultivars have to planted as early as possible, and harvested early. Control of Phytophthora infestons and Leptinotarsa decemlineata is critical.
EPPO certification scheme for seed potatoes1
Authors: GROUSSET F. , SMITH I. M.
Published: April 2008

A certification scheme is being developed by the European and Mediterranean Plant Protection Organization (EPPO) to cover the production of certified seed potatoes. The objectives and background of this scheme are given and its various stages are described.
Biotechnology of production of virus‐free seed potatoes in Bukovina (Ukraine)1
Authors: KHOMYAK V. V. , MEL'NIK P. A. , KHOMYAK M. V.
Published: April 2008

In the past, the Ukrainian Plant Quarantine Research Institute used to produce true‐to‐type virus‐free potato cultivars by in vitro propagation for its research on pathotypes of Synchytrium endobioticum and Globodera spp. Use of virus‐free seed potatoes has considerably declined in the 1990s as potato production has passed almost entirely into private hands. The Institute now has a role to fill in supplying virus‐free seed potatoes to local growers and has greatly increased its production in consequence. The techniques used for seed‐potato production in Bukovina are described.
Testing for wart resistance in Ukraine1
Authors: MALAKHANOVA E. L. , MEL'NIK P. A. , DMITRASHUK V. E.
Published: April 2008

The development of potato wart testing at the Ukrainian Plant Quarantine Research Institute is reviewed from the first appearance of wart disease in the 1930s, through the period of breeding of cultivars with resistance to pathotype 1, to the detection of new aggressive pathotypes requiring further tests for multiple wart resistance, and finally to the operation of the Station in independent Ukraine. Wart testing in Ukraine involves two phases, preliminary laboratory testing (by standard methods) and official testing of cultivars in the field. The regulatory basis of wart testing in Ukraine is outlined. This includes testing of Ukrainian‐bred material and of material introduced, for research and breeding or for production, from other countries. The possibilities for breeding cultivars with multiple wart resistance are assessed.
Biochemical fingerprinting of the National Register of potato cultivars in Ukraine1
Authors: SOLOGUB A. S. , MEL'NIK P. A.
Published: April 2008

Isoelectric focusing of proteins from 37 Ukrainian‐bred potato cultivars showed that each could be characterized by a unique spectrum. This provides a method for biochemical fingerprinting of the cultivars on the National Register and for checking on trueness to type.
Potato breeding in Ukraine1
Authors: OSIPCHUK A. A.
Published: April 2008

The Institute for Potato Research of the Ukrainian Academy of Agricultural Sciences is breeding potato cultivars for high yield and starch content, and also for resistance to the most important pests (Synchytrium endobioticum, Phytophthora infestans, Fusarium solani, bacterial diseases, nematodes and Colorado beetle).
Biotechnological methods for developing pest‐resistant potato lines1
Authors: OLEINIK T. M.
Published: April 2008

Current work on potato breeding at the Institute for Potato Research of the Ukrainian Academy of Agricultural Sciences is reviewed. Somaclonal variation is being exploited to obtain new cell lines, from which promising potato material is being regenerated. Various methods are being used in an attempt to select for pest resistance in cell lines. Genetic engineering methods are being tested to introduce genes for resistance to potato X potexvirus, Leptinotarsa decemlineata and fungus diseases.
Appropriate measures for the eradication of unlisted pests1
Authors: Cannon R. J. C. , Pemberton A. W. , Bartlett P. W.
Published: April 2008

The number of quarantine pests listed in the Annexes of the EU Directive 77/93 is limited. However, many other unlisted organisms of phytosanitary potential are regularly intercepted by the EU member states, and new pests can confidently be expected to continue to appear. EU legislation provides the powers for certain actions to be taken to prevent the entry of unlisted pests into a member state. The initial action is often taken against a background of uncertainty, yet must be taken speedily in order to avoid pest spread and possible establishment. Emergency measures aim to eradicate the pest or contain the outbreak while detection surveys are carried out, and need to be sufficiently robust to meet possible threats. Such safeguarding measures may be modified as the uncertainties involved are minimized. The International Plant Protection Convention obliges contracting parties to recognize that phytosanitary measures should be technically justified, on the basis of pest risk analysis, as well as‘transparent’. In recognition of the uncertain and variable quarantine status of unlisted pests, the UK has adopted a systematic protocol to determine appropriate measures in each case. This approach is illustrated with reference to specific, unlisted invertebrate pests.
Control options for eradication campaigns against quarantine pests: what now?1
Authors: Cheek S.
Published: April 2008

Several important quarantine pests have been introduced into protected crops in the UK as a direct result of international trade, particularly in cuttings of ornamental plants. Such trade is increasing and diversifying, with a continuing risk of further pest introductions. Various control techniques are used as part of statutory campaigns aimed at the exclusion and eradication of quarantine pests in the UK, and these are outlined with reference to Liriomyza trifolii, L huidobrensis, Bemisia tabaci, Spodoptera littoralis and Opogona sacchari. The use of quarantine disinfestation treatments is highlighted as an important means of pest exclusion, and the integrated use of chemical, biological, physical and cultural options for glasshouse‐based eradication campaigns is discussed. Increasing restrictions on the use of plant protection products, particularly on edible crops, have led to a greater emphasis on the use of non‐chemical options. The development of biological control techniques against a number of quarantine species is discussed, outlining their integral role in many statutory eradication programmes.
Control of Frankliniella occidentalis and TSWV in capsicum crops in Hungary1
Authors: Zsellér I. Hatala , Kiss E.F.
Published: April 2008

In Hungary, Frankliniella occidentalis was first found on various cut flowers in 1989. It then spread widely in glasshouses within a short time and became the most abundant thrips pest of protected crops. Besides causing cosmetic damage to fruits, F. occidentalis acts as the vector of tomato spotted wilt tospovirus (TSWV) to many plants. Since its appearance in 1993, this virus has caused serious losses in protected vegetable and ornamental crops. Chemical control of F. occidentalis is very difficult because of its thigmotactic behaviour and tolerance to insecticides. Biological control using the predatory arthropods Neoseiulus cucumeris and Orius spp. provides adequate suppression of populations in capsicum crops. A decrease in TSWV infection was observed when light summer oils were applied to glasshouse capsicum crops in integrated pest management (IPM) programmes to reduce virus transmission by aphids. Further investigations are needed on the interaction of these applications with TSWV infection, because populations of F. occidentalis were not much reduced.
Results of the efficacy evaluation of biological control agents in glasshouses in the Czech Republic1
Authors: Navrátilová M.
Published: April 2008

Frankliniella occidentalis, vector of the quarantine pest tomato spotted wilt tospovirus, first appeared in the Czech Republic in 1987. Further problems of crop damage appeared in 1991 with the quarantine leafminer Liriomyza bryoniae and in 1993 with Liriomyzo huidobrensis. Biological methods for the protection of glasshouse crops against these pests have been tested since 1993. The bioagents Phytoseiulus persimilis and Encarsia formosa have long been used (and also produced) in our country for protection of glasshouse crops against spider mites and whiteflies. The population density of thrips on vegetables, especially on glasshouse capsicum, has been greatly reduced after the introduction of the predatory mite Amblyseius cucumeris and the predatory bug Orius insidiosus. Introduction of another group of bioagents (Aphidius spp., Aphidoletes aphidimyza and Hippodamia convergens) has been shown to be effective against aphids. The protection system against leafminers based on Dacnusa sibirica and Diglyphus isaea is also sufficiently effective.
Occurrence and chemical control of introduced ornamental glasshouse pests in Poland1
Authors: Labanowski G. S.
Published: April 2008

Fourteen new pests were found in Polish commercial glasshouses on ornamental crops in 1982/1998 as a result of international trade with EU countries. They included: the insects Bemisia tabaci, Chaetanaphothrips orchidii, Frankliniella occidentalis, Lichtensia viburni, Liriomyza trifolii, Liriomyza huidobrensis, Opogona sacchari and Spodoptera littoralis; the mites Cecidophyopsis hendersoni, Polyphagotarsonemus latus, Steneotarsonemus laticeps and Tyrophagus neiswanderi; the nematodes: Paratylenchus besoekianus and Radopholus similis. The actual situation of these pests in Poland and recommended methods for their control are given.
Effectiveness of microbial and botanical insecticides in the control of Bemisia tabaci and Frankliniella occidentalis on ornamental plants1, 2
Authors: Labanowski G. S. , Soika G.
Published: April 2008

Results on the efficacy of a microbial insecticide (Paecilomyces fumosoroseus PFR‐97 WDG) and botanical insecticides (Neemix and SuperNeem 4.5) are presented. PFR‐97 WDG at three concentrations (0.1%, 0.2% and 0.4%), Neemix (0.4%) and SuperNeem 4.5 (0.04%) were applied as double sprays at 7‐day intervals against Bemisia tabaci on poinsettias. PFR‐97 WDG (0.4%) and SuperNeem 4.5 (0.04% and 0.08%) were also applied in a programme consisting of two spray treatments at 7‐day intervals against Frankliniella occidentalis on glasshouse roses.
Distribution of quarantine leafminers Liriomyza spp. in the Czech Republic, especially their occurrence and overwintering outside glasshouses1
Authors: Vlk R.
Published: April 2008

During 1994/1997, the population dynamics of the quarantine glasshouse leafminers Liriomyza bryoniae and Liriomyza huidobrensis were studied using yellow sticky strips in glasshouses at Tvrdonice (near Břeclav). There were usually three generations per growing season. An interval of about 28 days can be recognized between the peak periods for adults, which corresponds with the development time for these leafminers under the local temperature conditions. During 1995/1997, three polyphagous glasshouse Liriomyza spp. were recorded in the Czech Republic outside glasshouses: the native palaearctic species L. bryoniae in 17 samples (eight squares of grid map), Liriomyza strigata in 10 samples (five squares of grid map) and the originally nearctic and neotropical quarantine pest L. huidobrensis in five samples (three squares of grid map). The host plants were broad bean for Liriomyza bryoniae (three times), onion for L. huidobrensis and broad bean (three times) and poppy for L. strigata. Overwintering of puparia of L. huidobrensis outdoors in the Czech Republic seems barely possible.
Review of the status of glasshouse quarantine pests in EPPO countries1
Authors: Smith I.M.
Published: April 2008

The situation of Liriomyza spp. (L. bryoniae, L. huidobrensis, L. trifolii), Bemisia tabaci, Frankliniella occidentalis, Helicoverpa armigera, Spodoptera littoralis, tomato spotted wilt tospovirus (TSWV), impatiens necrotic spot tospovirus (INSV) and any other introduced glasshouse pests of current interest is presented for each of the 12 countries of northern and central Europe represented at the EPPO Conference at Pruhonice (CZ, 1998‐10‐13/15). These pests are in general established in the south of the EPPO region.
Determination of the tree row volume in stone‐fruit orchards as a tool for adapting the spray dosage
Authors: Rüegg J. , Viret O.
Published: April 2008

The tree row volume model is a method for adapting dosage and spray volumes to tree crops. The method can potentially facilitate the comparison of field efficacy trials and can contribute to fanners’effective and rational use of plant protection products. It has been developed and applied in pome fruit but not yet in stone fruit. Stone‐fruit orchards vary considerably in tree size, tree shape and distance between tree rows. Based on 700 detailed measurements of stone‐fruit trees in south‐eastern France, in southern Germany and in Switzerland, a multiple linear regression was computed that allows the calculation of tree row volume from the height and maximum width of the tree crown, and the distance between tree rows. Seasonal increases of tree row volumes in stone‐fruit orchards were most pronounced in May and June, and the increase was usually greater in young orchards than in older ones.
Guidance on resistance risk evaluation
Authors: van Gemerden J. F. , de Goey J. W. F. M. , Rotteveel A. J. W.
Published: April 2008

Evaluation of the risks of the development of resistance by pests to plant protection products is part of the (re)‐registration process and is the subject of an EPPO standard. This standard indicates data requirements and the factors to be considered in evaluating resistance risk, but it does not show in detail how all these factors interrelate and should be considered in their relationships. This paper presents a decision scheme approach, providing guidance in the evaluation of the available evidence. It may also be of assistance in judging the need for optional data as indicated in the EPPO standard. The decision scheme is an aid for qualitative evaluation of resistance risks of applications of plant protection products by means of risk ranking. It recognizes six risk categories, which may overlap to some extent and should not be interpreted as absolute values. Expert judgement is called for in answering the questions of the evaluation key, which is also presented in three different flow charts. Expert judgement means, in this case only, that the evaluation should not be done in a‘tick‐box manner’, and does not imply that evaluation is for only the super‐specialist on resistance. The evaluation always concerns a given plant protection product used in a given way. It is not possible to use this guidance document for active substances only.
Highly sensitive detection of Ralstonia solanacearum in latently infected potato tubers by post‐enrichment enzyme‐linked immunosorbent assay on nitrocellulose membrane
Authors: Priou S. , Gutarra L. , Aley P.
Published: April 2008

A post‐enrichment enzyme‐linked immunosorbent assay (ELISA) on nitrocellulose membrane (NCM‐ELISA) is described for the detection of Ralstonia solanacearum in latently infected potato tubers. The polyclonal antiserum specificity was significantly improved by adsorption with cross‐reacting bacteria. The detection efficiency after enrichment was compared with those of nucleic acid spot hybridization (NASH), double‐antibody‐sandwich immunoassay (DAS‐ELISA) and plating on modified Kelman's medium. After 48 h of incubation of the tuber extracts with modified SMSA broth at 30°C, sensitivities of post‐enrichment NCM‐ELISA, DAS‐ELISA and NASH were similar. As few as 10cells mL−1 were detected in either inoculated or naturally infected tuber extracts. Of 255 field samples, no cross‐reactivity of NCM‐ELISA was observed. Post‐enrichment NCM‐ELISA thus provides a reliable and sensitive low‐cost method that is rapid and easy to use, making it suitable for assessing susceptibility of breeding lines to bacterial wilt, ecological studies and seed quality control in developing countries.
Fireblight (Erwinia amylovora) of pome fruits in Hungary: national phytosanitary measures and management of the disease
Authors: Németh J.
Published: April 2008

After the first detection of Erwinia amylovora in Hungary, as a result of an intensive survey started in spring 1996, it was concluded that the incidence of fireblight was highest in a zone 10–30 km wide and 200–250 km long near the southern and south‐eastern border. The disease was concentrated in the Békés, Bács‐Kiskun and Csongrád counties. Isolated infection foci were, however, also found in Baranya county. In 1997, further spread of the disease was recorded. Only three of the 19 counties could be considered as free from the disease. The disease attacked nine major host plants, but the majority of infected plants were quince and pear. During the eradication campaign in 1996, more than 60 000 trees were uprooted and destroyed across the country. Eradication was performed partly by special work teams and partly with the participation of growers. The pathogen most probably entered Hungary by aerial drift from Romania or Yugoslavia during the previous 2 or 3 years. In the interior of the country, introduction through nursery stock and possibly infested tools, as well as wind and insect movement, cannot be excluded. Major measures to control the disease are discussed.
Survey for Phytophthora fragariae var. fragariae in Finland
Authors: Pohto A
Published: April 2008

A survey for the possible occurrence of red‐core disease (Phytophthora fragariae var. fragariae) was carried out on 250 strawberry production sites in Finland. The fields were inspected visually. A total of 1080 samples of strawberry roots were taken in spring and autumn 1995 and examined visually, microscopically and by isolation in the laboratory. Root‐tip bait‐plant tests were performed in the glasshouse to look for the latent presence of the fungus. No red‐core disease was detected in any of the inspected fields or in the examined samples.
Occurrence and management of fruit flies in Cuba1
Authors: Vázquez L. L. , Pérez I. , Navarro A. , Casín J. C.
Published: April 2008

In Cuba, fruit‐fly control is traditional and is sustained by phytosanitary regulations. Recent surveys have shown that Anastrepha obliqua and Anastrepha suspensa attack various fruits, especially guava and mango, whereas Toxotrypana curvicauda attacks papaya. New host plants are reported for Cuba: A. obliqua on coffee, peach and Pouteria sapota and A. suspensa on Spondias mombin and S. ciruela. Their occurrence was only occasional, and neither of these species was found on citrus. Populations of A. obliqua and A. suspensa were relatively low on guava and mango, occurring mostly in the months of May to September. Five causes are suggested for the relatively low incidence of fruit flies in Cuba: efficient natural regulation by Bracanastrepha anastrephae; predation of larvae by ants in the soil; high mortality of pupae because of surface soil temperature and generalist predators; the cropping system; and the phytosanitary control programme (with preventive approach). The results of the control programme are presented, especially for areas intended for fresh‐fruit export.
Bacterial and fungal diseases in the major potato‐growing areas of Tunisia
Authors: Priou S. , Mahjoub M. El
Published: April 2008

In a two year survey of Tunisian rustic potato stores, the losses were nearly equally distributed between dry rots induced by Fusarium solani and watery wound rot or leak caused by Pythium aphanidermatum and P. ultimum. Symptoms of leak were different from those normally induced by Pythium spp. Surveys of the growing potato crop confirmed the prevalence of these pathogens, which caused wilt and internal vascular stem necrosis. Most rotted progeny tubers also exhibited leak symptoms caused by P. aphanidermatum. Hardly any Erwinia diseases were found in Tunisia. The incidence of diseased plants was significantly higher in fields with successive cultivation of solanaceous crops, which may be attributed to a high rate of soil infestation by wilt‐inducing pathogens such as Pythium spp., F. solani and Verticillium dahliae. The health of seed potatoes also played a significant role, affecting the incidence of rot in potato stores as well as in the soil before plant emergence. Therefore, Tunisian integrated management programmes for potato diseases should focus on soil disinfestation with appropriate crop rotation as well as seed quality and treatments.
Détection du sugarcane bacilliform badnavirus au Maroc par le test du Western blotting
Authors: Nadif  , Elyachioui M. , Elhadrami I. , Lockhart B.E.L.
Published: April 2008

Depuis la découverte du sugarcane bacilliform badnavirus (SCBV) au Maroc, plusieurs études ont été réalisées au niveau du Centre Technique des Cultures Sucrières en collaboration avec l'Université de Minnesota (US) afin d'améliorer son niveau de détection et renforcer les mesures de contrôle aussi bien au niveau de la grande culture qu'au niveau de la quarantaine. L'étude présentée dans cet article montre la possibilité de détecter le SCBV par la technique du Western blotting et permet aussi la comparaison entre les résultats de cette technique et ceux de l'ELISA.
First report of cucumber mosaic cucumovirus in banana from Pakistan
Authors: Khalid S. , Yasmin T. , Soomro M. H.
Published: April 2008

During regular surveys of banana plantations in the Sindh province of Pakistan for banana bunchy top nanavirus (BBTV), sporadic plants showing mosaic, chlorotic spots intermingled with a dark green area were observed at a few places in the districts of Thatta, Hyderabad and Nawabshah. The infected young plants were uprooted and grown in pots for 2 years to ascertain the cause of the disease. Apart from studying the development of symptoms, the infected plants were tested for the presence of BBTV, cucumber mosaic cucumovirus (CMV), chilli veinal mottle potyvirus (CVMV), tomato mosaic tobamovirus (TMV), potato X potexvirus (PVX) and potato Y potyvirus (PVY) by DAS‐ELISA. Virions were also partially purified. The infected plants developed typical symptoms of CMV. All tested plants were ELISA‐positive only for CMV, and a partially purified preparation revealed virus particles measuring 25–28 nm in diameter. Based on the characteristic field symptoms, serology and particle morphology, the presence of CMV in banana in Pakistan was established.
Two species of Mentha as new hosts of Corticium rolfsii
Authors: Singh A. , Chaturvedi C. , Kalra A. , Singh H. B.
Published: April 2008

Two species of Mentha were affected by collar rot and wilt in the Tarai region of Uttar Pradesh, India. The pathogen was isolated and identified as Corticium rolfsii, which is newly recorded on these hosts.
New diseases of ornamental plants in Brunei Darussalam
Authors: Sivapalan A. , Mariam D.K. , Omar P.G. , Junaidy Mohd Aslin Hj Mohd
Published: April 2008

During a recent survey, 21 new diseases were recorded for the first time on ornamental plants in Brunei Darussalam. These include two new species: a new variety and a new combination. In most cases, the pathogens were isolated from disease specimens, and Koch's postulates for pathogenicity were established.
Comparison of different diagnostic methods for detection of peach latent mosaic viroid
Authors: Loreti S. , Faggioli F. , Cardoni M. , Mordenti G. , Babini A. R. , Pollini C. Poggi , Barba M.
Published: April 2008

Latent mosaic is a widely distributed disease of peach caused by peach latent mosaic viroid (PLMVd). Some strains induce mosaic symptoms on leaves, delay in leaf emergence, flowering and maturity, calico and malformation of fruits with cracked sutures and enlarged pits, bud necrosis and, in more severe cases, early decline of the trees. To prevent the use of infected propagating material, international certification schemes provide for the absence of PLMVd from peach mother plants. Until a few years ago, detection of PLMVd was mainly based on cross‐protection tests on GF305 peach seedlings. Recently, improved knowledge of the PLMVd genome and optimization of molecular techniques applied to the diagnosis of plant pathogens have stimulated studies aimed at setting up diagnostic methods that are sensitive, reliable and less time‐consuming. A comparative trial among different Italian institutions has been set up to compare the sensitivity, specificity and reproducibility of the currently available diagnostic techniques that are routinely applied for the detection of PLMVd in peach germplasm. In this paper, we compare the results obtained in the diagnosis of PLMVd performed with biological indicators and molecular techniques (‘spot‐blot’ and ‘tissue‐blot’ hybridization using a non‐radioactive probe and reverse transcriptase‐polymerase chain reaction) starting from different organs (leaves, buds and bark) collected from infected and healthy peach plants and using two total nucleic acid extraction methods. On the basis of the results obtained, we suggest that a tissue‐blot hybridization assay using a PLMVd cRNA digoxigenin‐labelled probe and starting from bud tissue is a reliable diagnostic method for inclusion in quarantine or certification protocols that require the absence of PLMVd from propagating material of peach.
Sanitary status of stone‐fruit trees in East Anatolia (Turkey) with particular reference to apricot
Authors: Sipahioglu H. M. , Myrta A. , Abou‐Ghanem N. , Di Terlizzi B. , Savino V.
Published: April 2008

Field surveys were carried out in the main stone‐fruit‐growing areas of East Anatolia (Turkey) to assess the sanitary status of varietal collections, mother blocks and commercial orchards. The presence of virus and virus‐like diseases was ascertained by enzyme‐linked immunosorbent assay (ELISA), sap transmission to herbaceous hosts, graft transmission to peach cv. GF305 and molecular hybridization tests. A total of 1019 samples was tested by ELISA (859 apricot, 120 cherry, 21 almond and 19 peach). The sanitary status of apricot was extremely satisfactory, as the infection level was less than 0.3%. Cherry and almond, however, showed 21% and 33% infection respectively. The viruses identified were apple chlorotic leaf spot trichovirus (ACLSV), prune dwarf ilarvirus (PDV) and prunus necrotic ringspot ilarvirus (PNRSV). The commonest virus was PDV. Plum pox potyvirus (PPV), apple mosaic ilarvirus (ApMV) and the nepoviruses tomato black ring (TBRV), raspberry ringspot (RpRSV), strawberry latent ringspot (SLRV), cherry leaf roll (CLRV), arabis mosaic (ArMV) and tomato ringspot (ToRSV) were not encountered. Peach latent mosaic viroid (PLMVd) and hop stunt viroid (HSVd) were not detected either.
Evaluation de l'efficacité de traitements de semence vis‐à‐vis de Plasmopara halstedii
Authors: Achbani E. H. , Lamrhari A. , Serrhini M. N. , Douira A. , de Labrouche D. Tourvieille
Published: April 2008

Le mildiou du tournesol causé par Plasmopara halstedii est une maladie économiquement importante. Les dégâts sont particulièrement redoutés lors des printemps humides. En absence de cultivars de tournesol génétiquement résistants, seul le traitement des semences avec des produits systémiques est envisageable. Cette étude a été réalisée pour analyser, sous des conditions contrôlées (chambre de culture), et en plein champ, l'efficacité en traitement de semence de 11 formulations chimiques. Les expérimentations montrent que seules les formulations à base de métalaxyl ou d'oxadixyl assurent un contrôle appréciable du champignon. Celles‐ci peuvent assurer une protection totale, sans aucune phytotoxicité sur les plantes, à la dose de 2,5 g de produit commercial par kg de semence pour la formulation ‘10% métalaxyl+48% mancozèbe’ et à la dose de 3 g de produit commercial pour les associations: ‘10% oxadixyl+56% propinèbe’ et ‘8% oxadixyl+56% mancozèbe+3,2% cymoxanil’.
New plant protection information system in Hungary*
Authors: Pákozdi A.
Published: April 2008

Data on the occurrence and spread of pests has been supplied by the Hungarian Plant Protection Organization for over 40 years. Since the 1970s, this service has been operated by the central station and the 20 county stations of the Plant Protection Organization. Data recorded on pest occurrence and developmental stage of pests and plants has been used to run a forecasting system at local and national levels. However, because of significant staff reductions in the Plant Protection Organization and the disappearance of independent forecasting groups, the reliability of the system, which was based on very specific data, has decreased. It has become necessary to develop a more reliable and flexible computer‐aided system (Plant Protection Information System, PPIS), better adjusted to the political and economic changes that have occurred. A major element of the new system, introduced in 1997, is that excessively detailed recording was replaced by a more practical general approach with fewer subjective errors. Specialists from the county stations of the Plant Protection Organization monitor infestation levels of 73 pests in 20 crops using five qualification categories. The results obtained are input into the PPIS program, which processes them into user‐friendly charts and maps showing the plant health situation in each county and in the country as a whole, as a basis for taking decisions on plant protection measures.
A privatized crop warning system in the USA*
Authors: Thomas C.S. , Gubler W.D.
Published: April 2008

Over 1000 weather stations are operating in the western USA in a multistate disease warning system. They are operated by several private service‐oriented companies, including Western Farm Service, Wilbur Ellis, Terra Spase and Ag Unlimited. These companies work cooperatively with the universities to develop, validate and implement algorithms. The weather stations, manufactured by Adcon Telemetry, collect meteorological information in many crops, for many types of disease and insect warnings. The data is reported by radio from the weather stations automatically. At central data collection facilities, data is analysed to determine disease and insect risk as well as information for irrigation, planting, harvesting and nutrient timing. Information is then distributed daily to hundreds of farming operations by Internet, fax, proprietary Adcon server software or personal visit. This information is combined with remote sensing, GPS, GIS, weather forecasting and scouting technologies to make crop management decisions at the farmer or consultant level. Farmers pay a fee for a service‐oriented information subscription. This technology usually reduces at least one fungicide application and/or improves crop quality or yield by 10–50%.
Rational arrangement of a network for disease survey on a regional scale*
Authors: Battilani P. , Racca P. , Rossi V.
Published: April 2008

The forecasting and warning system of Emilia‐Romagna region (Italy) produces warnings for crop protection against diseases, using information from weather stations, biological surveys on a network of observation fields and simulation models. The network of field observations is crucial for the efficiency of the service but, unfortunately, the human and economic resources available for their management are usually less than needed. Therefore, the number of observation fields is insufficient to cover the entire territory uniformly, so that their geographical distribution increases in importance. In this work, a method for rational arrangement of observation fields on a regional scale is proposed. It uses models simulating crop growth and disease outbreak, both using meteorological data available on a 5‐km mesh, to draw maps showing homogeneous areas within the territory. For the main pathogens of winter wheat (Erysiphe graminis, Puccinia striiformis, Puccinia recondita and Fusarium subsp.), disease risk is calculated when host plants are susceptible to infection, and both static and dynamic maps are drawn. The use of maps is discussed in arranging observation fields and in timing field surveys.