Instruments of the warning service for plant protection in Bayern (Germany)*

The warning service for plant protection in Bayern (Germany) obtains its information mainly from its own observations. The appearance of pests (including diseases and weeds) is investigated in cultivated areas and field trials. Weather data complementary to the pest enquiries can be made available from a measuring network of 116 field weather stations and is used to estimate the development of pests in relation to weather requirements. For several fungi and animal pests, computer‐based decision support systems (DSSs) and forecasting models are being used. The results are processed and passed on to farmers via circulars, branch reviews, public notices, telephonic announcement services, telefax services and the Internet.     

Collection,processing and transfer of weather data in the Agrometeorological Measuring Net of Rheinland‐Pfalz: a prior condition for using weather‐based forecasting systems*

The fundamental and most important condition for running forecasting systems successfully is the input of correct meteorological data. Rheinland‐Pfalz owns more then 30 agrometeorological measuring stations, which automatically collect data 24 h a day. This article describes how the data is managed (collection by modem, plausibility tests, filling blanks in the weather files), how the data flow from the Agrometeorological Measuring Net Rheinland‐Pfalz (AMN RP) to the adviser in the plant protection office is organized, how administration of data, sensors and service routines works and, finally, the conclusions and improvements that are made based on the results. This leads to meteorological data of high quality, which are necessary for weather‐based forecasting systems to guarantee a high standard of certainty when using the results of simulation in agricultural practice.     

Decision aids for apple scab warning services (Venturia inaequalis) in Germany*

Apple scab (Venturia inaequalis) represents the most serious pathogen and disease in orchards worldwide and has to be treated with a number of fungicides available on the market. In Germany, prophylactic application schedules have been banished in the past because of the availability of several commercial systems that forecast infection risk precisely. Experience with decision aids such as HP‐100, Welte, METOS and RIMpro in the Rheinland region of Germany in 1998/99 is presented and discussed. All systems serve as decision aids for forecasting potential infection periods, but do not provide a season‐long forecasting system based on data obtained 3–6 months in advance.     

Early warning system for grapevine in South Moravia (Czech Republic)*

South Moravia is a very important agricultural region with 12 000 ha of fruiting vineyards. The forecasting and warning service for vineyards in this region was created in 2000 as a PHARE Project which was part of a large‐scale programme ‘Cross‐border Cooperation between Czech Republic and Austria’. The aim of the project is ecological wine production. Forty automatic meteorological stations, located in the target area, create a network linked to a central computer. Meteorological data forecasts the development of Plasmopara viticola, Erysiphe necator and Botryotinia fuckeliana on bunches. The output can be used by growers to determine the time of fungicide application. The experiences and possibilities of improvement of the warning service are presented.     

Structure and development of decision‐support systems and their use by the State Plant Protection Services in Germany*

To ensure continuing work on decision‐support systems (DSSs) and the elaboration of new systems according to the needs of the Plant Protection Services of the federal states of Germany, these services have installed ZEPP (Central Institution for Decision Support Systems and Programmes in Crop Protection). At the national level, ZEPP guarantees a permanent supply of meteorological data, organizes and co‐ordinates trials, incorporates scientific progress into the existing DSSs and, in close co‐operation with universities and federal research stations, develops new systems for important pests. The PASO desktop system includes a data bank that administers all relevant meteorological files and field data. It allows for automated simulation runs and forecasts, serving as input for timely warnings by different media. Depending on the individual decision‐support modules, results are presented as tables and/or graphs.     

The status of warning services for plant pests in Italy*

A survey of the present status of warning services for plant protection in Italy shows the lack of a national project, so that the different regional governments approach the question in different ways. In spite of this, some common characters are present: (1) most of the regions manage the warning service directly; (2) everywhere, the warning service interacts with research institutes, farmers’ associations, agrometeorological networks and other warning services; (3)‘indirect warning’ is the prevalent model of organization; geographical areas are divided into homogeneous subareas, where information useful for producing advice is collected and elaborated; warnings are then disseminated by different means of communication, and farmers comply with them autonomously; (4) warnings are usually prepared by a team of advisers, who meet periodically, analyse available information and elaborate suggestions for crop protection; (5) available information comes from field monitoring, weather stations, insect and spore traps, forecasting models for pests and diseases; unfortunately, forecasting models are not widespread; (6) the content of warnings is rather uniform, including information on crops, pests and diseases, suggestions for control strategies and, frequently, meteorological conditions and forecasts; (7) different means are used to disseminate warnings to farmers; usually several methods co‐exist: bulletins published in local newspapers, sent by mail or fax, displayed on notice boards or available via the Internet; placards; telephone messages; surveys on local TV or radio.     

Use of geographic information systems in warning services for late blight*

One of the important aims of the German Crop Protection Services (GCPS) is to reduce spraying intensity as part of an environmentally friendly crop protection strategy. ZEPP is the central institution in Germany responsible for the development of methods with the goal of improving the control of plant diseases and, to this end, more than 20 meteorological data‐based models have been developed and introduced into practice. This study shows that it is possible to improve the accuracy of the results given by the models by using Geographic Information Systems (GIS). The influence of elevation, slope and aspect on meteorological data was interpolated with GIS and the results were used as input for forecasting models. The results will be presented as spatial risk maps on which areas of maximum disease risk are displayed. The modern presentation methods of GIS enable the results to be displayed in a more user‐friendly way.     

Incidence of pyrethroid‐resistant oilseed rape pests in Germany

BACKGROUND: Failures in pollen beetle control using pyrethroids since 2005 indicated pyrethroid resistance in Germany. Therefore, resistance monitoring using bioassays was established in Germany for oilseed rape pest insects. RESULTS: The spread and intensity of pyrethroid resistance of Meligethes aeneus increased from 2005 onwards, with no sensitive samples left in any region of Germany in 2011. Sensitivity also declined for the newly introduced actives bifenthrin, etofenprox (both class‐I pyrethroids) and tau‐fluvalinate; all three claimed to be less affected by resistance, although there was no clear cross‐resistance to lambda‐cyhalothrin (class‐II pyrethroid). In the German region with the longest tradition and high intensity of oilseed rape production, pyrethroid resistance of Psylliodes chrysocephala and Ceutorhynchus obstrictus, with resistance factors of up to 81 and 140 respectively, was detected. CONCLUSION: The intensive use of only one mode of action for many years is risky, because even pest insects with a low intrinsic resistance risk may develop resistance. Therefore, resistance strategies need to include several control options for pest insects needing regular treatments. Copyright © 2012 Society of Chemical Industry     

Hosts of Verticillium dahliae in Kriti (Greece)*

Naturally wilted cultivated and weed species were collected from several fields in Kriti (GR) over the years 1992/1997, and tested by isolation for the presence of Verticillium dahliae. The fungus was most frequently recovered from cultivated Solanaceae and Cucurbitaceae. Infection of many known Verticillium hosts was confirmed, and the fungus was found for the first time in Kriti in pistachio and grapevine and in several common weeds.     

Evaluation of an action threshold‐based IPM wheat model in Rheinland (Germany) in 1999/2001*

Under the specific agricultural and climatic conditions of Rheinland (DE), 48 field trials in three years demonstrated the practicability of the action threshold‐based fungicide strategy of the IPM wheat model. The underlying data for action thresholds and dosage of fungicides applied are outlined. The cereal pathogens concerned, predominantly Mycosphaerella graminicola and Puccinia recondita, were controlled in the early stages of epidemic development using reduced rates of fungicides. The IPM wheat model gave a high efficacy of control, in terms of disease incidence and disease severity, under both low and high disease pressure conditions. The yield levels resulting from this effective reduction in diseases were nearly the same as those of the disease‐free variant. Total yield increase varied between 15% and 30% with an overall average of around 20%, and resulted in monetary benefits of 50–100 EUR ha^?1 in the years considered.     

Computer‐aided design of improved warning systems – a case study for Botrytis control in flower bulbs*

Development and improvement of warning systems are often done empirically, relying on extensive field testing. As this approach is both costly and time‐consuming, there is a need for a more rational and efficient alternative. In a study to explore the options for improvement of a Botrytis warning system in flower bulbs, we applied a computer‐based approach to systems design. The approach consisted of the construction and evaluation of modified versions of the warning system using epidemiological knowledge, data sets of recorded and forecast weather and a simulation model of epidemic development and fungicide spray impact. Performance of modified versions was evaluated with regard to fungicide input, efficacy of disease control and sensitivity to the prediction error in weather forecasts. This approach can be more efficient than a purely empirical one, as it enables the designer to limit the number of alternative versions to be field‐tested on the basis of explicit performance criteria. It also has the advantage that it provides insight into the potentials for improvement of the warning system.     

Long‐term changes in weed occurrence,yield and use of herbicides in maize in south‐western Germany,with implications for the determination of economic thresholds

In 393 field experiments in Baden‐Württemberg region in south‐western Germany, herbicide efficacy, yield loss and crop tolerance of maize (Zea mays) were investigated between 1981 and 2011. The collected data served to determine changes in weed frequencies, in herbicide use, yield loss functions and economic thresholds (ETs). Over 60 weed species were reported. Chenopodium album and Galium aparine were the most frequent broad‐leaved weeds, the former becoming more frequent over time. Species of the genera Lamium, Polygonum, Veronica and Matricaria occurred in about every fifth trial. Alopecurus myosuroides and Echinochloa crus‐galli were the most frequent grass weeds; the former declining in frequency by 1.1% per year, the latter increasing by 1.5%. Results suggest a weed population shift towards thermophilic species. aceto‐lactate‐synthase and 4‐HPPD‐inhibitor herbicides became important in the 1990s. Pendimethalin and bromoxynil have been integral components of weed control since the 1980s. ETs, the point at which weed control operations provide economic returns over input costs, ranged between 3.7% and 5.8% relative weed coverage. Without weed control, no yield increase was found over 24 years. Yield increased by 0.2 t ha ^{? 1} year ^{? 1}, if weeds were controlled chemically. Despite intensive use of effective herbicides in maize, problematic weed species abundance and yield losses due to weed competition have increased in Baden‐Württemberg over a period of 30 years.     

Situation of the whiteflies Bemisia tabaci and Trialeurodes vaporariorum in protected tomato crops in Algarve (Portugal)*

Protected tomato is the most important horticultural crop in the Algarve (south of Portugal). However, the growing area has decreased by almost 48% since 1995, mainly as a result of the pests Bemisia tabaci and Trialeurodes vaporariorum and the epidemics of Tomato yellow leaf curl virus (TYLCV), a Begomovirus transmitted by B. tabaci. Both whiteflies are vectors of economically important viruses. Recently, Tomato chlorosis virus (ToCV), a member of the genus Crinivirus, transmitted by both B. tabaci and T. vaporariorum, was reported infecting tomato crops in Algarve. A study was carried out to evaluate the dynamics of whitefly populations on tomato crops in Algarve. Population counts of B. tabaci were high in the first months of autumn, then decreased until January, when numbers of T. vaporariorum became higher. Counts of B. tabaci then increased again.     

Incidence des maladies des cucurbitacées en France (melon,concombre, courgette,cornichon)*

Les principaux problèmes pathologiques des cucurbitacées en France sont essentiellement le fait de champignons telluriques rencontrés pendant la phase juvénile (Pythium spp., Rhizoctonia solani), puis pendant la phase de croissance végétative (Pythium. aphanidermatum, Fusarium oxysporum f. sp. melonis ou Phomopsis sclerotioides), des champignons à développement aérien (Sphaerotheca fuliginea et Pseudoperonospora cubensis) et de virus parmi lesquels les plus fréquents sont le cucumber mosaic cucumovirus et le zucchini yellow mosaic potyvirus. Dans le cas des champignons du sol, les efforts sont apportés sur la qualité des substrats, la rusticité des porte‐greffe, la recherche d'efficacité d'agents antagonistes. Dans celui des champignons aériens, le choix des cultivars, et celui des fongicides compatibles avec le développement de la production intégrée, ont pris ces dernières années une importance grandissante. Dans certains cas, une meilleure connaissance des phénomènes épidémiologiques permet de mieux cerner les risques encourus sous abri ou en plein air (bactériose du melon, mise au point de modèles). Les mesures prophylactiques, la protection physique contre les vecteurs potentiels et le choix des cultivars tolérants ou résistants sont des solutions partielles aux attaques de virus.     

Crop Rotation and Soil Pathogens — Trends in Germany

The need to cut costs has led to a simplification of crop rotation in several fields of plant cultivation. The results of Thormann, who has grown wheat continuously on parts of his farmland for 10 years, are discussed. Also, the preliminary results of our own experiments with increasing proportions of wheat and barley suggest that more wheat and barley may be cultivated in crop rotation than is allowed according to the conventional limits determined by the increase of foot rot diseases and cereal root eelworm. Even in successive crops of maize the problem of soil-borne pathogens can be tackled: the spread of blister smut is stopped by the control of the frit fly and by selection of tolerant varieties; root and stem rots of maize are overcome by the selection of appropriate varieties, too. On the contrary, the potato root eelworm is a serious pest in all sites of intensive potato production. Only an integrated control including the use of resistant varieties and the application of nematicides gives success. Much research work has to be done mainly to get more information on the biotical defence mechanisms of the soil.     

Characterization of potato Y potyvirus isolates from tomato crops in Islas Canarias (Spain)*

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 PVY^O/C or PVY^N 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.     

Intranet in Baden‐Württemberg (Germany) – using the technology of the Internet for internal information interchange within a State Plant Protection Service*

This article describes the new possibilities of an intranet for internal interchange of information within the plant protection service of a German federal state. In Baden‐Württemberg, the precondition is a closed internal network with central information servers and workstations at the local offices of agriculture. The intranet with information servers is based on the technology of the Internet and is a modern and user‐friendly tool for supplying advisers highly efficiently and economically with current comments, relevant notices, files, weather data and evalutions of computer aids for decision‐making. In the last 2 years, significant progress has been made in the automation of procedures for data request, transmission and evaluation of weather data for the warning service. In the plant protection service of Baden‐Württemberg, the most important data‐processing routines and evaluations of computer aids for decision‐making are running automatically as batch files. In order to save time in the preparation of regional warnings, the relevant information is available to the advisers via intranet at the beginning of their work. Compared with traditional procedures, the intranet with information servers is advantageous to the information supplier (Central Institute of Plant Protection) as well as to the user (advisers at the local offices of agriculture).