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1.
B. Román C. I. González Verdejo Z. Satovic M. D. Madrid J. I. Cubero S. Nadal 《Phytoparasitica》2007,35(2):129-135
Some species of the genusOrobanche are among the most devastating parasitic weeds, causing extensive damage in agricultural fields. Considering the difficult
control due to seed longevity in the soil, small seed size, high fecundity and a subterranean phase that allows them to parasitize
the host before they emerge and become evident, the development of diagnostic markers is highly recommended. In our study
we identified potential molecular diagnostic markers from the plastid genome in order to distinguish among the most importantOrobanche species attacking crops in Andalusia, the southern region of the Iberian Peninsula. The study has consideredO. crenata, O ramosa andO. cumana causing serious losses in legumes, solanaceous crops and sunflower fields, respectively, andO. minor that, although abundant in Andalusia, has to our knowledge not yet been found parasitizing agricultural hosts. We amplified
a non-coding region from the plastid genome, studied sequence differences among the amplified fragments and digested those
of the same length with selected restriction enzymes. Here, we propose a molecular protocol to distinguish the main parasitic
plants in crop fields of southern Spain. Different applications such as identification ofOrobanche seeds in soil or crop seed lots are discussed in order to offer right crop recommendations or to prevent new infestation
of parasite-free fields. Recommendations for further development of these diagnostic markers are also considered.
http://www.phytoparasitica.org posting Jan. 15, 2007. 相似文献
2.
向日葵列当是危害我国向日葵最严重的杂草。为明确我国向日葵田列当的发生危害情况及防治现状,采用对角线5点取样法对新疆、内蒙古、吉林和河北等主要向日葵种植区进行调查,对向日葵列当的寄生率和寄生强度等数据进行分析。结果表明,向日葵列当在向日葵产区广泛分布,严重危害向日葵的生产,其对食葵的寄生率高于油葵,对抗性品种的寄生率较低。在所有调查地区中内蒙古地区向日葵列当发生最严重,寄生率高达100%,寄生强度达到38.5,单株寄生数量最高,达118株;新疆地区的向日葵列当寄生率居中,吉林、河北向日葵列当发生相对较轻。通过实地调研结合文献报道,对目前国内外向日葵列当的研究进展进行了综述,研究结果为指导向日葵列当防治提供参考。 相似文献
3.
Sunflowers as a trap crop for reducing soybean losses to the stalk borer Dectes texanus (Coleoptera: Cerambycidae) 总被引：1，自引：0，他引：1
Larvae of Dectes texanus LeConte cause significant losses to soybean production in the American High Plains by girdling the stalks of mature plants at their base, causing them to lodge. The authors demonstrated that cultivated sunflowers can reduce rates of D. texanus infestation in adjacent soybean fields because adult females prefer sunflower over soybean for feeding and oviposition. Since females do not avoid ovipositing in plants already containing their own eggs or those of conspecific females, sunflower plants can accumulate multiple eggs, and subsequent larval combat typically results in the survival of only one. In west central Kansas, planting one half of a center pivot irrigated field to sunflower in 2004 significantly reduced infestation of soybean plants in the other half of the field within 200 m of the crop border. Beyond 200 m from the sunflowers, the rate of soybean infestation increased significantly. Planting sunflowers in the non-irrigated corners of a center pivot irrigated soybean field in 2005 reduced D. texanus infestation of soybeans by 65% compared with a control field without adjacent sunflowers. Surrounding a 0.33 ha soybean field with six rows of sunflowers in 2006 reduced soybean infestation to < 5% of plants, compared with 96% of sunflower plants. These results reveal that sunflowers can reduce D. texanus infestation in adjacent soybeans by acting as an 'ovipositional sink'. Further research is warranted to determine the optimum crop area proportions and spatial configurations that will maximize the efficacy of a sunflower trap crop to reduce soybean losses due to D. texanus-induced lodging. 相似文献
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5.
Factors affecting the distribution and associated species of Malva parviflora in the Nile Delta,Egypt 
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下载免费PDF全文 Malva parviflora (little mallow) is a wild herb with agricultural importance in Egypt, where it is cultivated as a food crop. The main objective of the present work was to study the distribution and common associated species of the arable weed, M. parviflora, in the Nile Delta, Egypt. In addition, the diversity and behavior of the common species along the prevailing environmental conditions were assessed. Fifty stands, representing five common habitats (crop fields, orchards, canals, drains and roadsides), were selected. Eighty‐five species and one variety (50 annuals and 36 perennials) were recorded. Therophytes dominated the other life forms and biregional taxa contributed the highest chorological elements. Malva parviflora is a therophytic plant that has a Mediterranean distribution intermingled with Irano‐Turanian elements. Moreover, the highest coverage percentage of M. parviflora was recorded in the canal banks. Four vegetation groups that represented the distinct habitats were produced by the application of a two‐way indicator species analysis and a detrended correspondence analysis as a classification and ordination technique, respectively. Vegetation group C, which inhabited the crop fields, was the most diverse. A canonical correspondence analysis indicated that calcium carbonate, organic carbon, carbonate, potassium and the potassium adsorption ratio and electrical conductivity are the most effective soil variables on the distribution of M. parviflora and its associated species in the different habitats. It was found that M. parviflora was affected greatly by calcium carbonate, sand and magnesium. In addition, it was significantly associated with soil bicarbonate. Such a study could help in managing this important agricultural weed. 相似文献
6.
Globalisation and increasing trade have led to the introduction of alien plants that are highly competitive and difficult to control in agriculture in central Europe. Our study set out to analyse the invasion process and agricultural impact of the six emerging alien plants Abutilon theophrasti, Ambrosia artemisiifolia, Cyperus esculentus, Datura stramonium, Panicum schinzii and Sorghum halepense in Austria, based on a large distribution data set (694 occurrence records in crop fields). We found that all study species have increased in abundance and range, especially after the year 2000. The rate of spread was highest for A. artemisiifolia and lowest for C. esculentus. At present, records of the study species were largely associated with areas of high summer crop concentration in eastern, southern and north‐western Austria. Based on the CORINE land‐cover data set, we found that the agricultural area at risk of being invaded increased over time. At present, it ranges between 45 500 and 168 000 ha (approximately 2.4% and 8.7% of the total agricultural area) depending on the species. The invasion success of the study species is probably associated with frequent human‐mediated dispersal, specific crop‐dominated rotations and herbicide use. Our results suggest that the study species will successfully spread further. We conclude that these emerging alien species will cause substantial impacts on crops in Austria and probably in other countries of central Europe. 相似文献
7.
The Helianthus annuus taxon includes the wild (ruderal), weedy (agrestal) and volunteer biotypes, which may share space and time with the sunflower crop. The agrestal biotype is one of the most harmful weeds challenging the use of modern biotechnological tools in sunflower. The interference of the agrestal biotype was studied at a range of weed densities within a sunflower crop. The area of influence of one agrestal plant was estimated as a circular area of more than 2.5 m2. The agrestal biotype at 10.7 plants m?2 reduced the sunflower seed production by 66%, the seed weight by 41% and the yield by 80%. The agrestal biotype showed intermediate vegetative stage duration between sunflower and the ruderal biotype. The interference of the agrestal biotype would be due to its high initial growth rate, its larger leaf area and plant height. Some agrestal plants showed partial dehiscence at the sunflower harvest stage replenishing the soil seedbank with over 18 000 seeds m?2. The sunflower harvest operation and grain storage might be affected due to a fraction of agrestal plants remaining alive and moist when the crop reached harvest maturity. The results support the recommendation of preventing the entry of the agrestal biotype into crop production fields. 相似文献
8.
A total of 142 samples of plants showing symptoms of Turnip mosaic virus (TuMV) were collected from fields planted to Brassicaceae and non‐Brassicaceae crops in the southwest Marmora region of Turkey, during the 2004?06 growing seasons. Using enzyme‐linked immunosorbent assay (ELISA) TuMV was detected in the main brassica‐crop fields of Turkey, with an overall incidence of 13·4%. TuMV was detected in samples from Brussels sprouts, cabbage, wild mustard, radish and wild radish, but not cauliflower or broccoli. The full‐length sequences of the genomic RNAs of two biologically distinct isolates, TUR1 and TUR9, were determined. Recombination analyses showed that TUR1 was an intralineage recombinant, whereas TUR9 was a non‐recombinant. Phylogenetic analyses of the Turkish isolates with those from the rest of the world showed that the TUR1 and TUR9 isolates belonged to world‐Brassica and Asian‐Brassica/Raphanus groups, respectively. This study showed that TuMV is widely distributed in the Asia Minor region of Turkey. 相似文献
9.
Despite modern weed control practices, weeds continue to be a threat to agricultural production. Considering the variability of weeds, a classification methodology for the risk of infestation in agricultural zones using fuzzy logic is proposed. The inputs for the classification are attributes extracted from estimated maps for weed seed production and weed coverage using kriging and map analysis and from the percentage of surface infested by grass weeds, in order to account for the presence of weed species with a high rate of development and proliferation. The output for the classification predicts the risk of infestation of regions of the field for the next crop. The risk classification methodology described in this paper integrates analysis techniques which may help to reduce costs and improve weed control practices. Results for the risk classification of the infestation in a maize crop field are presented. To illustrate the effectiveness of the proposed system, the risk of infestation over the entire field is checked against the yield loss map estimated by kriging and also with the average yield loss estimated from a hyperbolic model. 相似文献
10.
S. IREN 《EPPO Bulletin》1981,11(2):47-52
Cereal crop production is one of the most important projects in the agricultural improvement programme for Turkey. Overall, wheat represents 61 % of the cereal crop. While wheat production was almost 4 million tons in 1950, this reached a limit of 10 million tons in 1970. A number of diseases continue to afflict the crop from time to time, causing heavy losses. The most important of these are: bunt ( Tilletia foetida and T. caries ), loose smut ( Ustilago nuda ), rusts ( Puccinia strilformis, P. graminis f. sp. tritici, P. recondita f. sp. tritici ), leaf blotch ( Septoria tritici ), root and foot rots ( Fusarium spp., Drechslera sorokiniana, Pseudocercosporella herpotrichoides, Alternarla alternate, Sclerotium spp. and Rhizoctonia spp.). The diseases appear all over the country. Average losses due to rusts in epidemics are estimated at about 30–35 % in the whole country. Annual losses from covered smut are about 15–20 %, and from loose smut from 0.1 % to almost 20 % depending on the weather conditions of the year, on variety and on locality. Root rots have gained importance in some places, especially in Thrace in the last few years. In addition to the above diseases, several others occur occasionally but are of minor importance: powdery mildew ( Erysiphe graminis f. sp. tritici ), dwarf smut ( Tilletia contraversa ), flag smut ( Urocystis tritici ), take-all ( Gaeumannomyces graminis ) and a wheat mosaic virus (recently observed in a province of Central Anatolia). 相似文献
11.
EVANS ATUTI ATERA KAZUYUKI ITOH TETSUSHI AZUMA TAKASHIGE ISHII 《Weed Biology and Management》2012,12(1):53-62
Witchweed, Striga hermonthica (hereafter, referred to as “Striga”), is a major biotic constraint to cereal production in sub‐Saharan Africa. The parasitic plant is a socioeconomic problem that has forced some resource‐poor farmers to abandon their farms due to high infestation. This study was designed in order to elucidate farmers' perceptions of Striga control measures and to determine their potential adoption in two villages in western Kenya. Participatory rural appraisals and individual interviews were conducted in 2009 and 2010 in a sample of 128 and 120 households in Kaura and Kogweno‐Oriang villages in Homabay and Rachuonyo districts, respectively. The results revealed that crop production was the main occupation in most households. The farmers identified Striga as one of the major constraints to maize, sorghum, and finger millet production. According to the farmers, the most popular control measures were hand‐pulling, crop rotation, and intercropping, even though rotational systems might need a longer timeframe to reduce the soil seed bank of Striga. Although the level of Striga infestation and damage were increasing in the farmers' fields, the adoption of the control options was limited. The reason for the low adoption level of the control methods by the farmers is because they are “too risky” as there is no guarantee of a direct pay‐off in increased crop yield. Farmer‐led evaluation and adaptation of the various Striga control technologies in real‐life situations will facilitate the choice of appropriate options and facilitate their uptake. 相似文献
12.
Common ragweed (Ambrosia artemisiifolia) is an invasive annual plant with highly allergenic pollen. Its spread in introduced and native ranges often occurs on roadsides, where it builds stable and rapidly growing populations. The most sustainable way of controlling the population size of this species is to prevent seed production in order to deplete the soil seed bank. Populations on roadsides are submitted to regular mowing management, which can even exacerbate the situation by inducing resprouting after cutting or by accidentally spreading seeds along the road. The population density in the juvenile stages of development could play an important role in the success of cutting regimes, as it might influence the resprouting capacity of this plant. The influence of the juvenile population density and of seven cutting regimes, differing in the timing and frequency of cuts, on easily measurable reproductive traits was investigated in a glasshouse experiment. The cutting regimes had a strong influence on the reproductive success and on the phenology of the development stages of ragweed. The population density in the juvenile stages did not play a role in further phenological development, but did influence the reproductive traits. The reproduction of ragweed can be lowered by locally adapted combinations of the timing and frequency of mowing. As the optimal management option for the reduction of both the male and female flowers, the authors suggest a first cut just before the start of male flowering, followed by subsequent cuts every 3–4 weeks. 相似文献
13.
History of introduction and distribution of common ragweed (Ambrosia artemisiifolia L.) in the European part of the Russian Federation and in the Ukraine 下载免费PDF全文
下载免费PDF全文 A. N. Afonin N. N. Luneva Y. A. Fedorova Yu. E. Kletchkovskiy A. F. Chebanovskaya 《EPPO Bulletin》2018,48(2):266-273
Ambrosia artemisiifolia L. (common ragweed) is an invasive alien plant (IAP) in the European part of the Russian Federation and in the Ukraine. Ragweed was introduced into the territory of Western Europe between 1860 and 1870 together with red clover seeds delivered from America, and has since spread and become a nuisance weed in agricultural land and disturbed habitats. This study presents a detailed overview of the history of introduction and distribution of this IAP in the territory of Russia and neighbouring countries. A map has been created to show species distribution dynamics in the European part of Russia and neighbouring countries from initial foci of introduction to date. A detailed map of current distribution in Russia and the Ukraine has also been created. The rate of expansion during the different time periods was calculated and compared with recent species distribution modelling allowing future spatial spread of ragweed to be forecast. In the European part of Russia, and in the Ukraine, the species has almost reached the edge of its environmental limitations and further expansion to the northern regions is expected to slow down. 相似文献
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15.
N Colbach L Biju‐Duval A Gardarin S Granger S H M Guyot D Mézière N M Munier‐Jolain S Petit 《Weed Research》2014,54(6):541-555
Weeds are both harmful for crop production and important for biodiversity, while herbicides can pollute the environment. We thus need new cropping systems optimising all cultural techniques, reconciling agricultural production, herbicide reduction and biodiversity conservation. Here, we show how to (i) develop models quantifying the effects of cropping systems on weed dynamics, (ii) integrate interactions between weeds and other organisms, (iii) predict the impact on production and biodiversity and (iv) use the model for multicriteria evaluation and multiobjective design of cropping systems. Among the existing weed dynamics models, we chose the one closest to our requirements to illustrate these different steps, that is, FlorSys which predicts multispecific weed dynamics as a function of cultural techniques and pedoclimate. We have illustrated the development of interaction submodels with the example of a crop pathogen whose propagation is increased when infecting grass weeds. To evaluate the weed flora impact, predicted weed densities were translated into indicators of harmfulness (crop yield loss, technical harvest problems, harvest pollution, field infestation, crop disease increase) and biodiversity (weed species richness and equitability, trophic resources for birds, insects and pollinators). Simulations were run over several years and with different weather scenarios (i) to optimise cultural techniques to control harmful weeds, (ii) to analyse the impact of changing agricultural practices (e.g. simplified tillage and rotations, no‐till, temporary crops) on weed density, species and trait composition and (iii) to evaluate cropping systems for their ability to reconcile agricultural production and biodiversity, thus identifying levers for designing sustainable cropping systems. 相似文献
16.
HIROAKI WATANABE 《Weed Biology and Management》2011,11(4):175-189
Since the introduction of rice production in Japan, lowland areas have been managed for rice production with the purpose of better rice growth, as well as lesser weed infestation. Rice is cropped every year in lowland fields by repeated cultivation of a single crop, with high yields and without soil sickness usually being observed in upland fields. This is probably because the irrigation water supplies various nutrients for healthy rice growth and the drainage washes out and removes harmful factors. However, until recently, the wet or flooded conditions of lowland fields in the Asian monsoon region never have allowed humans to cultivate useful summer crops, except rice or some aquatic plants. Therefore, the management of lowland areas in the Asian monsoon region has been significantly different from European field management, where crop rotation has been the traditional standard practice. Paddy weeds are aquatic plants or hygrophytes that have adapted to lowland fields. Traditionally, tillage and puddling were practiced seasonally in lowland fields on a regular schedule every year. Rice cultivation technology was developed and supported by regional irrigation systems that created stable environments for typical paddy weeds to complete their life cycle. After the introduction of chemical weed control, rice fields became very severe habitats for these paddy weeds, where they could not grow and reproduce without strategies for survival under herbicide exposure. Even so, many of the traditional paddy weeds survived because of their accumulated or uneradicated seed banks, although several aquatic plants were listed as endangered or threatened species. The important weed species changed, sometimes rapidly and sometimes slowly, depending both on their reproductive system and their biological response towards field management and weed control systems. Very recently, the level of perennial weeds, herbicide‐resistant weeds, and weedy rice has increased in paddy fields that are highly dependent on herbicide use. In addition, several hygrophyte species have invaded paddy fields. In order to address these issues, the improvement and application of integrated weed management methods are expected to be critical. 相似文献
17.
L Molinero‐Ruiz A B García‐Carneros M Collado‐Romero S Raranciuc J Domínguez J M Melero‐Vara 《Weed Research》2014,54(1):87-96
The parasitic weed Orobanche cumana (sunflower broomrape) constrains sunflower production in eastern and southern Europe and in the Middle East. Although genetic resistance is the most effective control method, new parasite races evolve overcoming sunflower resistance. In this work, highly virulent populations of O. cumana were analysed for pathogenicity and genetic diversity. The virulence of 11 populations from Hungary, Romania, Spain and Turkey was assessed and compared after infection of sunflower inbred lines to differentiate races of the parasite under glasshouse conditions. Molecular diversity among and within 27 parasite populations was studied by RAPD‐PCR, UPGMA and amova analyses. Highly virulent race F was identified in Hungary, Spain and Turkey. The most virulent race (G) was also found in Turkey. The molecular analysis among highly virulent populations of O. cumana identified four molecular clusters, respectively, grouping populations from Central Spain, Hungary, South Spain and Turkey. The genetic homogeneity within parasite populations was confirmed, since no molecular divergences were found within them. This work constitutes the first geographical study of O. cumana together with pathogenicity and molecular traits inherent to each geographical group, and provides useful information for possible phylogenetic analyses of O. cumana. In addition, molecular markers associated with geographical origin could be developed and used as diagnostic tools to track new broomrape introductions into areas free of virulent races where they might represent a threat to sunflower production. 相似文献
18.
Simulation study of the competitive ability of erect, semi-erect and prostrate cowpea (Vigna unguiculata) genotypes 总被引：1，自引：1，他引：1
Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterised, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower than companion field experiments for the competition of cowpea and purslane. The validated simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habit on final biomass production of cowpea and sunflower. The model suggested that erect growth habit was more competitive than semi‐erect and prostrate growth habit, when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass. Our simulation approach is suggested as a method for crop breeders to gauge the likely success of selection for competitive crops before undertaking expensive long‐term breeding experiments. 相似文献
19.
A.-C. WALLENHAMMAR 《Plant pathology》1996,45(4):710-719
During 1986–87 the presence of clubroot in soils sampled from 190 fields was assessed using a bioassay method, based on baiting the soils with Brassica campestris spp. pekinesis cv. Granaat. Clubroot was detected in 148 (72%) of the fields investigated and, on average, 49.2% of the plants were infected according to the bioassay. Subsequent testing of fields in 1990 and 1992 (54 and 81 fields, respectively) where no further Brassica crops had been grown indicated a significant decrease in the degree of infestation to 7.1% in 1992. Clay soils showed, on average, the highest degree of infestation, and high infestation was recorded for a wide range of pH values (5.2–6.6). The highest degree of infestation was recorded on fields where oilseeds were grown five times during the period 1965–85. The results presented show that, in a field with 100% infestation, the level of infestation declined to below the detection level after a period of 17.3 years. The half-life of the spore inoculum was determined to be 3.6 years. During the sensitivity testing of different Brassica species and cultivars, it was found that Chinese cabbage showed a low percentage of infestation in two soils, whilst some oilseed rape and spring oilseed turnip rape cultivars showed high degrees of infestation in these soils. 相似文献
20.
外来入侵物种三裂叶豚草(Ambrosia trifida L.)及其风险分析 总被引：8，自引：0，他引：8
外来入侵物种严重威胁着农业生产、生态安全及人类健康,已成为世界各国广泛关注和研究的热点。本文对外来杂草三裂叶豚草(Ambrosia trifida L.)的起源和分布、生物生态学特性、经济和生态影响及其控制管理措施等进行了系统综述。根据生物生态学特性、潜在风险及管理控制的难度等指标,初步建立了外来杂草的风险评估体系。应用该体系对三裂叶豚草进行了风险评估,得出其风险值为83,属高度危险的检疫性有害生物。 相似文献