首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Actual plant disease and pest occurrence depends on many genetic and environmental factors, and frequently obscures the basic suitability of a given location to support or prevent epidemic development. In order to allow the demarcation of climatic zones related to the potential of disease or pest occurrence, we have used long-term average climatic data, especially monthly average temperatures and monthly average rainfall. If applied to sugar beet leaf pathogens such as Cercospora beticola and Erysiphe betae in the Near and Middle Eastern region, some interesting zoning became possible, which could be verified by extended field studies. Other examples that have been analysed in the region are apple scab, Venturia inaequalis, and downy mildew of grapes, Plasmopara viticola. A recent and ongoing analysis of the factors controlling chickpea anthracnose caused by Ascochyta rabiei indicates that the same principle may be applied for very different pathogens. Large-scale planning and control strategies as tried by the International Agricultural Research Centers should therefore be based on careful climatic zoning for plant pest and disease potential, to avoid waste of the limited genetic and financial resources available.  相似文献   

2.
Integrated Pest Management (IPM) has been widely implemented in apple orchards in various regions of Turkey. Between 1995 and 1999, in Central Anatolia and the Aegean Region, apple scab (Venturia inequalis) and codling moth (Cydia pomonella) were key pests, and implementation of pest control was based on forecasting and warning systems. During the project, orchards in which IPM was implemented and in which farmers applied conventional practices were compared. In nine provinces in which IPM projects were carried out in 1999, the damage due to codling moth was 0–1.3% in IPM orchards while it was 0.4–21.8% in nearby non‐IPM orchards. It is clear that damage did not reach the acceptable threshold level of 2% in any of the IPM orchards, while damage was much higher than the threshold in conventionally‐farmed orchards. The number of fungicide applications against apple scab decreased to 5–6 applications from 10–15 applications in the Eğirdir district of the Isparta Province in 1996 as a result of IPM implementation. No insecticides were applied against codling moth in IPM orchards in the Nigde Province in 1998 and 1999 because population levels of the pest were low and under the economic threshold. Apple producers received training and 1200 producers from Central Anatolia became experts in IPM for their own orchards, learning to make appropriate decisions about pest control. The Apple IPM Guideline was prepared and disseminated. In Turkey modern equipment for forecasting and warning systems was employed and, in the last decade, forecasting and warning networks have been improved. Computer‐based systems have increased the speed and accuracy of forecasting as well as decreasing its costs. A computerized national forecasting network in apple orchards now transmits data from the field to system headquarters automatically. The national forecasting network has been expanded and covered 12 208 800 apple trees in 34 provinces in 2006, using 115 electronic forecasting and warning stations.  相似文献   

3.
Recent research on the epidemiology of Fusarium ear (or head) blight (FEB or FHB) of small-grain cereals is reviewed, focusing on inoculum, infection and disease forecasting. Both conidia and ascospores have been shown to be important for causing FEB. For Fusarium graminearum, propagules from crop debris are the main source of initial inoculum. Inoculum production is critically dependent on rainfall although the precise relationship is not clear. Recent work on understanding the effects of climatic variables on FEB development has been based on field observations. These field-based studies confirmed that warm and moist conditions during anthesis are the key factors for FEB development. Several empirical models were derived from the field data and proposed for use in disease forecasting. However, these models may not be applicable to a broader range of areas because of the limited nature of the field data. Several areas are proposed for future research, focusing on the development of more generally applicable forecasting models and on understanding the relationships between disease severity, fungal biomass and the production of associated mycotoxins.  相似文献   

4.
 为了明确葡萄霜霉病菌对甲霜灵的田间抗药性水平发展态势,于轮换用药前后,采用叶盘漂浮法测定了河北、山西、河南3省葡萄主要种植区11个葡萄园试验地葡萄霜霉病菌对甲霜灵敏感性变化动态。结果表明:田间采集的葡萄霜霉病菌对甲霜灵抗药的菌株其抗药性可以稳定遗传;不同地区轮换用药后,葡萄霜霉病菌对甲霜灵的抗药水平变化态势因用药流程的不同而发生相应的变化。采用不同作用机制的杀菌剂轮换或混合用药进行葡萄霜霉病菌对甲霜灵的抗药性治理时,需制定合理的施药流程,并根据抗药性治理的效果不断完善治理措施。  相似文献   

5.
In field trials against apple scab (caused by Venturia inaequalis) and powdery mildew (caused by Podosphaera leucotricha), improved control of one or other disease has been given by the newer systemic fungicides benomyl, triarimol and the thiophanates. However, in tests on apple seedlings in the greenhouse, biological evidence of translocation from individual deposits was generally limited to movement within the treated leaf. In greenhouse tests with cucumbers and marrows, using Oidium sp., there was again little evidence for movement of toxicant from a treated leaf, although effective disease control was readily obtained by root application of several compounds at low dosage. These results suggest that the systemic properties of the compounds evident when used as soil or seed treatments are of little account when they are applied as foliar sprays.  相似文献   

6.
Downy mildew, caused by Plasmopara viticola, is the most important disease of European grapevine (Vitis vinifera) in humid climates. On the basis of weather data the forcasting model “VitiMeteoPlasmopara” calculates the most important steps of the life cycle of downy mildew. A growth model for the simulation of leaf development is integrated in the pure forcasting model for downy mildew. “VitiMeteoPlasmopara” was elaborated by the Swiss Research Station ACW, Changins-Wädenswil and the State Institute of Viticulture and Enology Freiburg in Germany. Since 2003 the system is scientifically tested in Switzerland and Baden-Württemberg and applied in practice. Once or twice a day, the actual results of the forecasting system are visualised on the Internet. “Vitimeteo Plasmopara” is used to forecast downy mildew in Switzerland and in the south of Germany (Baden Württemberg), comprising approx. 42,000?ha of grapevine (15,000?ha CH, 27,000?ha D), and about 100 weather stations located in the area. The forecasting system is widely used by both advisory service and growers. It has proven a very useful tool to estimate the epidemiological situation and it allows the definition of spray intervals in relation with the epidemics. The open structure of the database allows the use and the integration of weather data into any other expert software moduls to forecast the development of other fungal diseases, pests or completely other models, for example irrigation models. “VitiMeteo Growth ”, a vine growth model, “VitiMeteo Insects”, a model for pests and “VitiMeteo DataGraph”, a software to analyze and present weather data, are already developed. The expert software moduls are summarized under designation “VitiMeteo Suite”.  相似文献   

7.
R. Hrubý 《EPPO Bulletin》2003,33(3):433-436
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.  相似文献   

8.
Adequate protection of apple trees during the primary contamination period is a cornerstone for management of apple scab. Correct timing of spring treatments is fundamental and thus, much effort has been devoted to forecasting ascospore release by Venturia inaequalis. Most models rely on degree‐day accumulation starting from a biofix date established yearly on the basis of biological observations. Here, the potential of using a single calendar date as a biofix and new types of time scales were explored, with the help of numerical optimization with field‐collected data. Using data acquired between 1996 and 2008, the daily rate of development for V. inaequalis primary inoculum was assessed by fitting generic time scale functions, a method that requires the smallest number of assumptions about the effect of temperature on the biological phenomenon. An optimal calendar biofix was established for Provence and use of non‐linear functions relating pseudothecial development rate to temperature for accumulating thermal time was compared with the usual linear response in standard degree‐day models. A model was then constructed using four additional years of data for validation. The predictive value of the model was further improved by adjusting the time scale with ‘accelerating rules’ to take into account the positive influence of rainy days on pseudothecial maturation prior to ascospore release. However, ‘halting rules’ inserted in the time scale to account for dry days during the ascospore release period strongly reduced the predictive value of the model for southern France, suggesting the possible occurrence of strains adapted to dry conditions.  相似文献   

9.
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.  相似文献   

10.
We have examined the effect of Pen, an aqueous extract of the dry mycelium of Penicillium chrysogenum, on plant–pathogen interactions. Pen controlled a broad range of pathogens on several crop plants under greenhouse and field conditions. Pen protected grapevine from downy and powdery mildew (caused by Plasmopara viticola and Uncinula necator), tomato from early blight (caused by Phytophthora infestans), onion from downy mildew (Peronospora destructor) and apple trees from apple scab (caused by Venturia inaequalis) to a similar extent as fungicides such as copper and sulphur or well-known inducers such as benzothiadiazole or β-aminobutyric acid. Pen had no major direct fungicidal effect and is thus supposed to protect plants by activating their defense mechanisms. The raw material for extraction of Pen was available in constant quality, a prerequisite for commercial application. Under certain conditions, Pen caused phytotoxic side effects. The symptoms mostly consisted of small necrotic spots or, more rarely, of larger necrotic areas. The development of the symptoms was dependent on several parameters, including concentration of Pen, the number of applications, the persistence on the plant tissue, the plant species and variety and environmental conditions. In grapevine, a partially purified fraction of Pen was much less toxic than the crude Pen extract, but protected the plants to a similar extent against P. viticola. Our data show that Pen has interesting and unique properties as a plant protection agent, but more research is needed to further reduce its phytotoxic side effects.  相似文献   

11.
The problem of protecting grapevine against diseases is an old one, but in the last few years new techniques have been developed to reduce cost to the farmer and damage to the ecosystem. These are based on mathematical models describing the state of the plant-parasite environment system. A model for forecasting development of grapevine downy mildew (Plasmopara viticola) is presented. The input variables are temperature, rainfall and leaf wetness (determining infection by sporangia), and RH and temperature (for incubation period). The model also takes into account the limited survival of spores. The output is expressed as %, disease progress. Field validation tests, performed in 1990, 1991 and 1992 in several vineyards in Toscana (central Italy) showed a good correlation between observed and simulated infections. The model allowed the number of treatments to be reduced without any increase in downy mildew damage. It could in future be integrated with grapevine growth and development simulation models in an expert system to determine infected tissue area and thus the economic damage threshold.  相似文献   

12.
The forecasting tool SOPRA has been developed with the objective of optimizing timing of monitoring, management and control measures of insect pests in fruit orchards in Switzerland. Applying time‐varying distributed delay approaches, phenology‐models were developed driven by solar radiation, air temperature and soil temperature on hourly basis. Relationships between temperature and stage‐specific development rates for relevant stages of the life cycles were established under controlled laboratory conditions for Dysaphis plantaginea, Hoplocampa testudinea, Cydia pomonella, Grapholita lobarzewskii, Cacopsylla pyri, Rhagoletis cerasi, Anthonomus pomorum and Adoxophyes orana. The implementation of body temperatures in the models is based on habitat selection and biophysical modelling of habitat conditions. In order to validate modelling, phenology predictions were compared with several years of independent field observations. On the basis of local weather data, the age structure of the pest populations is simulated and crucial events for management activities are announced. Through a web interface, the simulation results are made available to consultants and growers ( http://www.sopra.info ) and the latter can be applied as a decision support system for the eight major insect pests of fruit orchards in the alpine valleys and north of the Alps on local and regional scale.  相似文献   

13.
A dynamic model, called VenInf, was developed to forecast infection of pear leaves by conidia of Venturia nashicola. By simulating conidial infection processes following a rain event, the model estimates % conidia that successfully infected leaves at the end of an infection period. The model is mainly derived from logistic models developed from recent laboratory and glasshouse experimental results on infection of pear seedlings to estimate the rates of infection and mortality. It simulates the conidial infection process at 5 min intervals using temperature, relative humidity (RH), surface wetness and rainfall as input. The model was evaluated against pear scab in four unsprayed orchards in China over a 4-year period. In all orchards, all significant disease increases were associated with infection periods predicted by the model. In one orchard, in 2004 the incidence of leaf infection remained very low (<3%) during the entire season despite the model forecasting several severe infection periods. Results of orchard evaluation suggest that the model is able to identify all important potential infection periods. Thus, further field studies should be carried out to determine whether and how the model can be used in practice to assist farmers in making decisions on fungicide applications.  相似文献   

14.
Atypical scab‐like symptoms were reported for the first time in 2007 in the south of France on fruits of apple cultivars carrying the Rvi6 (=Vf) major resistance gene to Venturia inaequalis. With microscopic observations, nucleotide sequence data and pathological tests, it was shown that the causal agent was Venturia asperata. Scanning electron microscopy was used to compare its infection process and conidiogenesis to those of Venturia inaequalis on apple and Venturia pirina on pear. Venturia asperata produced fewer hyphae and fewer spores than the two other Venturia species, and resulted in weaker symptoms. This fungal species was previously described as a saprotroph on apple leaf litter. This is the first report of damage on apple fruits caused by V. asperata. Changes in host and cultural practices may have created a new context favourable for the emergence of this pathogen. It was also detected on symptomless leaves and on overwintered leaves on the ground. Pseudothecia developed on overwintered leaves and released ascospores over a 2‐month period from the end of March until the end of May, suggesting that the fungus is able to survive from season to season. However, it is not yet known if this new disease will establish over coming years and become an emergent disease.  相似文献   

15.
T. Rder  P. Racca  E. Jrg  B. Hau 《EPPO Bulletin》2007,37(2):378-382
During a three‐year project from 2003 to 2006, two models have been developed to predict leaf rust (Puccinia recondita and P. triticina) occurrence and to simulate disease incidence progress curves on the upper leaf layers of winter rye (PUCREC) and winter wheat (PUCTRI). As input parameters the models use air temperature, relative humidity and precipitation. PUCREC and PUCTRI firstly calculate daily infection favourability and a cumulative infection pressure index and, in a second step, disease incidence is estimated. An ontogenetic model (SIMONTO) is used to link disease predictions to crop development. PUCREC and PUCTRI have been validated with data from 2001 to 2005. Both models give satisfactory results in simulating leaf rust epidemics and forecasting dates when action thresholds for leaf rust control are exceeded.  相似文献   

16.
Monoconidial strains of Venturia nashicola Tanaka et Yamamoto were isolated from Japanese or Chinese white pear trees which had never been treated with sterol demethylation inhibitors (DMIs) and their baseline sensitivities to fenarimol were determined by mycelial growth tests on fungicide-amended culture media. Strains were also obtained from Japanese pear orchards, which had been intensively treated with DMIs for several years and monitored for the shifts of fenarimol sensitivity in comparison with the baseline sensitivity. Results suggested slight shifts to lower fenarimol sensitivity in strains isolated from DMI-treated Japanese pear orchards. However, in inoculation tests on pear seedlings, fenarimol still provided adequate control of V. nashicola strains with reduced sensitivity to fenarimol in vitro, suggesting that the performance of this fungicide will still be maintained in the field. © 1998 Society of Chemical Industry  相似文献   

17.
EPIPRE (EPIdemic PREvention) is a cooperative project for supervised control of diseases and pests in wheat. It operates on a field by field basis. From every wheat field, basic data and field observations are stored in a data bank. Farmers send their field observations to the central team, which enters them in the data bank. Field data are updated daily by means of simplified simulation models. Expected damage and loss are calculated and used in a decision system, that leads to one of three major decisions: «treat», «don't treat», or «make another field observation». Exchange of information between farmers and central team is by mail. In 1978 EPIPRE started with Puccinia striiformis. Since then the number of pests and diseases which are considered have increased, so that in 1981 advice was given for P. striiformis, P. recondita, Erysiphe graminis, Septoria spp. and the cereal aphids, Sitobion avenae, Metopolophium dirhodum and Rhopalosiphum padi. For each of these pests and diseases predictive methods have been developed using explanatory simulation models as a tool. These explanatory models are based on knowledge of many input relations and some external factors (e.g. temperature) which govern most of the processes of the pest and disease population dynamics. On the basis of a sensitivity analysis with these models simplified decision rulés have been developed which are used in the advice system in which updating of the forcing variables is no longer needed.  相似文献   

18.
In intensive viticulture, the distribution of the principal meteorological elements depends principally on aspect, slope and altitude. The present research aims to examine microclimate modelling in vineyards, by connecting local atmospheric conditions with macroscale meteorological conditions as reported by the standard meteorological networks. To study the effect of topography on crop microclimate, vineyard temperature has been measured with an infrared thermometer, and phenological, allometrical and yield measurements have been made in vineyards located close to the Chianti Classico hills (IT). The climatic and pathological data has been used to verify mathematical models simulating microclimatic conditions and to protect grapevines from downy mildew (Plasmopara viticola). The models allow a reduction in the number of treatments against the disease, lightening at the same time the damage to the ecosystem and the cost for the farmer.  相似文献   

19.
V. GUTSCHE 《EPPO Bulletin》1993,23(4):577-581
PROGEB integrates forecasting models for the main pests of potatoes and cereals in Germany: PHYTEB for Phytophthora infestans, SIMLEP for Leptinotarsa decemlineata, SIMCERC for Pseudocercosporella herpotrichoides, SIMERY for Erysiphe graminis. All models follow the same philosophy, and have been implemented on PCs following a uniform design. The system is illustrated by the example of P. infestans control.  相似文献   

20.
A. MYLLYM KI 《EPPO Bulletin》1983,13(2):177-182
Models for forecasting outbreaks of harmful Microtines are discussed in terms of the three most important types of rodent damage to agriculture and forestry in the European part of EPPO region: problems to field crops by Microtus arvalis and related species, to horticulture and forestry by M. agrestis and some other species, and injury to the underground parts of various crops by Arvicola terrestris. Two models were developed in parallel but independently for M. arvalis, one in the USSR, the other in France; the former approach included M. socialis. A joint Scandinavian project resulted in models for M, agrestis and Clethrionomys glareolus: the outcome is exemplified by the former case and a few comments are given on other types of model development. The probable mechanism of climatic influence through the food chain on the population dynamics of Microtine rodents is discussed and it is concluded that climatic models are a useful tool in planning rodent control strategies. The role of the EPPO Working Party on Field Rodents as a coordinating body in the development of rodent forecasts is also reviewed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号