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Old-new disease is maize smut (Ustilago maydis)
43-46Views:216Corn smut disease (Ustilago maydis) is one of the most common maize diseases. In the previous years the disease lost some from its importance, however nowadays it turns into more and more important and widespread one. The control encounters great difficulties, therefore it should be emphasized the preventive and resistance-based protection.
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Irén Dobos horticulturalist-teacher plant protection engineer expert awarded by Antal Gulyás medallion for crop protection" in 2015 (laudation)
8-10Views:224The Public Utility for Development of Crop Protection Teaching (NOFKA) and The Hajdú-Bihar County Regional Association of Hungarian Chamber of Crop Protection Specialists and Plant Doctors established a joined Award Committee in 2011, which intend to serve as moral appreciation to prominent persons with excellent achievements by awarding the „Antal Gulyás medallion for crop protection” which are available for outstanding teachers, researchers, and practical crop protection specialists. In 2015 dr. Irén Dobos horticulturist- teacher and plant doctor has been decorated with the „Antal Gulyás medallion for crop protection” for her “excellence in integrated plant protection practical research activity and effective knowledge transfer”.
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Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth), a recently occured invasive weed in Trans-Tisza Region and a trial for control in maize
53-57Views:311To the effective control of invasive weeds are essential to prevent establish, if has already happened obstacle to massive accumulation, and promoting the efficient and rapid eradication, if it is possible. The Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) belongs to weeds which “hard to control” especially in corn. One of the difficulties of effective control is the prolonged emergence causing avoidance of several individuals the contact with pre-emergent herbicides. Another problem arises due to the intensive use of post-emergence herbicide products with short duration of action. To optimalize of timing of treatment is essential for successful control of later emerging weeds. The recently established Woolly cupgrass in Hungary shows resistance or reduced susceptibility to substantial portion of herbicides used in corn. The data collected from small-plot trials demonstrates that application of sulfonylurea or selective monoctyledonous herbicides can be effective against the Woolly cupgrass.
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Susceptibility of maize hybrids to corn smut diseas
39-42Views:189Corn smut disease is one of the most common maize diseases. In the previous years the disease lost from its importance, however nowadays it is becoming more and more important and widespread. The protection against it encounters great difficulties, therefore it is important to emphasize prevention and resistance based protection. The aim of the research was to investigate under laboratory circumstances the resistance of Hungary’s most commonly cultivated maize hybrids to corn smut disease. Twelve species were investigated. We distinguished two susceptibility groups within the hybrids based on the investigated parameters. The results are intended to assist the protection against corn smut disease and to make a suggestion for the farmers so that they could apply more environmental friendly and economical production.
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Allelopathic effect of invasive plants (Eriochloa villosa, Asclepias syriaca, Fallopia x bohemica, Solidago gigantea) on seed germination
179-182Views:317The aim of this study was to determine the allelopathic potential of invasive species woolly cupgrass (Eriochloa villosa), common milkweed (Asclepias syriaca), bohemian knotweed (Fallopia x bohemica), and giant goldenrod (Solidago gigantea Ait.) on germination crop (Lepidium sativum L.). Experiments were conducted under laboratory conditions to determine effect of water extracts in petri dish bioassay. Water extracts from fresh biomass (leaves and stem) of invasive weeds in concentrations of 4 and 8 g/100 ml were investigated. All invasive plants showed allelopathic effect on germination. In giant goldenrod stem water extract experiment, allelopathic effect was less pronounced.
The cress germination was greatly suppressed with the woolly cupgrass, common milkweed and the giant goldenrod. The experiment showed that the seed germination depended on the concentrations and the plant material used (leaves and stem).
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Changes of relative chlorophyll content at maize smut inoculated hybrids
55-58Views:285The leaf chlorophyll content analysis is important for several reasons. The natural or anthropogenic stressors directly effect on the chlorophyll content. Through the measurement of the chlorophyll content it is possible to obtain data concerning the physiological status of the plant, moreover the chlorophyll content is closely related to the nitrogen content, so it is linked to photosynthesis and the photosynthetic activity which determine biomass production.
One of the most common symptoms of plant diseases is the larger and smaller interveinal chlorotic areas. These might be local, or expand to the whole plant. There are multiply reasons of chlorosis such as reduction of chlorophyll content, unfavorable effects on the chlorophyll content,disorders regarding function of chloroplasts or ultimately destruction of the chloroplasts. Although such a chlorotic deviancy can contribute to significant losses in photosynthesis; however the underperformance photosynthesis of the sick plants is a more complex process.
As we unambiguously experienced during our investigations on common smut that the infected maize plants most common accompanying symptom was chlorosis on the leaves, so it is especially important to examine how the infection influenced on the chlorophyll content of different hybrids. -
Effect of the media on morphology of Cryphonectria parasitica (Murr.) Barr isolates and their Vegetative Compatibility Groups
38-42Views:176The most dangerous pathogen for the European and American chestnuts is the blight fungus Cryphonectria parasitica (Murrill) Barr. Short after its introduction a big number of chestnut trees were destroyed on the infested area. The control could be really complicated, because of the numerous vegetative compatibility groups of the fungus. There is a type that carries a mycovirus viz. hypovirus in the cytoplasm. We are able to control effectively this pathogen by using mycovirus-carrying strains (called hypovirulent fungal strains also). In laboratory it is easy to multiply the virulent and the hypovirulent strains of the fungus but do not easy to differentiate colonies visually on simple PDA medium. During our research, we tested different types of media, based on potato and chestnut bark extract respectively. It was observed that on potato medium the virulent strains produce more orange pigments. So it is more easy to differentiate virulent or hypovirulent isolates of chestnut blight fungus based on colony colour and morphology.
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Biological control of sweet chestnut on Pécsbánya, Hungary
77-81Views:250The supervision of plant hygiene of sweet chestnut grove on Pécsbánya (South Hungary) started more than four years ago. Hypovirulent strains were applied as a biological process to control Cryphonectria parasitica fungus which causes the chestnut blight disease. By now the performed interventions have shown obvious results, the vitality of the trees has greatly improved, the amount of harvested nuts is increasing, and the hypovirulent strain has been spreading within the area. During plant health inspection the galls of chestnut gall wasp (Dryocosmus kuriphilus) was found in the year of 2015, which is the obvious symptom of new occurrence of the pest. The pest was eradicated by destroy galls, which allows taking out of consideration the damage by now in this area.
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75 years of the chestnut blight fungus Cryphonectria parasitica (Murr.) Barr in Europe
82-85Views:236The chestnut blight fungus Cryphonectria parasitica is a native pathogen in East Asia and has been introduced into North America and Europe. Historical records and population genetic studies revealed at least three major introduction events from Asia into Europe.
Nowadays, chestnut blight is present in almost the entire distribution range of European chestnut, i.e. from the Iberian Peninsula to the Caucasus. The C. parasitica population in most countries has been studied in respect to the diversity of vegetative compatibility (vc) types and the occurrence of hypovirulence. The vc type diversity of the different populations varied considerably. Typically, a high diversity of vc types has been found in areas with a long history of chestnut blight and where sexual recombination between divergent genotypes commonly has occurred. On the other hand, newly established populations often showed a low diversity with only one, or a few vc types present.
Hypovirulence, i.e. the occurrence of C. parasitica isolates infected by Cryphonectria hypovirus 1 has been found widespread in Europe. Natural dissemination and active biological control applications have lead to a high prevalence of the hypovirus and to the recovery of many chestnut stands. Virulent cankers became hypovirus-infected within a short time and ceased expansion. There is concern that the diversity of vegetative compatibility types could increase in Europe through sexual reproduction between C. parasitica genotypes originating from different introductions. A higher level of vegetative incompatibility would not only hamper hypovirus spread within a population but could also select for lower virulence in CHV-1 and subsequently lead to an erosion of biological control. Recent studies, however, indicate that the vc type barriers are not so restrictive than previously assumed and that so far no evidence for an erosion of biological control system in high diversity populations can be observed.
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Chestnut tree: an appropriate choich for rural developement in Europe (review)
55-59Views:147In chestnut plantations or in associations many pathogens and pests can be found. They are causing more than a hundred year problem in chestnut protection, for example the blight fungus Cryphonectria parasitica. Lot of breeders hybridized the Castanea sativa and Castanea dentata with the tolerant asian species. Nowadays the presence of Dryocosmus kuriphilus seems to be the main risk. However, there are more and more chestnut plantations in Europe because of the extensive growth of needs. The food industry produces many products from chestnut, but the wood industry also use it more and more. In most of European countries the chestnut stands represent landscape aesthetics and touristic value, but probably the number of farmers inquiring the plantation will be increase in Hungary.
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Susceptibility of stem infected sweet corn hybrids to common smut disease
55-57Views:428The common smut of maize (corn smut, Ustilago maydis /DC/ Corda) can cause large economic losses in susceptible sweet corn hybrids as well. The protection against this pathogen is fundamentally based on prevention. Many methods to control corn smut have been recommended or evaluated, including crop rotation, sanitation, seed treatments, modification of fertility, and biological control. In spite of these frequently mentioned control strategies, the host resistance seems to be the only effective method to manage common smut in those areas where Ustilago maydis is prevalent.
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New occurence of woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) in Hajdúság area, East-Hungary
51-54Views:242Because of the globalization and global warming the emergence of invasive weeds in Hungary are more common. The woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) is published as an important invasive weed in Hungary. Woolly cupgrass is native in East Asia and it spreads into several parts of the World and causes difficulties in plant protection. It has been spreading extensively during the last few years,as the weed shows a very serious invasion potential.
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The specification of the growing temperature on PDA of chestnut blight pathogen (Cryphonectria parasitica (Murr.) Barr) to optimize timing for biocontrol treatments by hypovirulent strains
29-32Views:185The most destructive pathogen for the European chestnut trees is the blight fungus Cryphonectria parasitica (Murr.) Barr. The biological control is the only effective possibility to apply in situ biocontrol by hypovirulent strains against compatible virulent (wild) fungus strains. The infested bark tissues can inoculate by drilling holes surrounding and putting into agar discs interwoven by the appropriate vegetative compatible group (VCG) hypovirulent fungus strains. This latest can pass those virus-like particles (VLPs) by parasexual contact (called hypha-anastomosis)which responsible to hypovirulence. A laboratory experiment was made to find the optimal times to carry out the treatments. The intensity of growth of fungal colonies were analysed on different temperatures. The growth of the fungus on low temperature were rather slow,according to our expectations. On higher temperature the colony progress were the same as on the optimal 20–25 °C. These observations and the environment determine the date of the field applications under Hungarian weather conditions. It means the optimal treatment periods can be May or end of September to middle October in Hungary.
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Allelopathic effects of water extracts of pieces of wooly cupgrass (Eriochloa villosa) on the seedlings of field crops
167-170Views:182In Hungary, the woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) endanger row crops (i.e. corn, sunflower). Its fast spreading based on some reason viz. long-lasting emergence, reduced sensitivity to many kinds of herbicides, vigorous competitional ability and fast initial growth. Allelopathy, ability of many plant species to produce one or more biochemicals wgich is used tocompete with each others. In this experiment we examined, whether the woolly cupgrass possesses allelopathy, and if so, how influences on the development of cultured crops like maize, sunflower and lettuce.
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Sensitivity of maize hybrids to common smut under field artificial inoculation conditions
25-28Views:228Common smut disease of maize is one of the most frequent diseases of crop. In the last decades the importance of disease has decreased in feeding maize production, however its importance increasing again nowadays, especially at sweet maize hybrids. The aims of this work was to find hybrids possess of resistance, and to evaluate which ones are more or less susceptible under field artificial inoculation circumstances. Among feeding maizes the less susceptible hybrid was ‘P9578’, and the most susceptible ’NK Columbia’ hybrid, and differences in cob infection between them was significant (8.8%). At sweet corn hybrids the less susceptible was ’Prelude’, while the most susceptible was ’Jumbo’ with very high significant 74.6% differences.
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The role of production site isolation in the plant health situation of sweet chestnut (Castanea sativa)
79-82Views:168The most destructive pathogen for the European chestnut is the blight fungus Cryphonectria parasitica (Murr.) Barr. The spread of the fungus was very fast in Europe within a few decades in the second half of the past century. During the tree-health checking in the chestnut and
walnut plantation in Romania, Hargita county, next to Homoródkarácsonyfalva village, we especially concentraded on the signs of blight disease occurrence. The grove is laying on a western slope, under a pine forest. This favourable geographical space protects it not only from pathogen attacts, but it has a special, mild microclimate for nut and chestnut trees. The European chestnut could be a valuable member of local forests, opening a new perspective under conditions of climate changes. -
Laboratory diagnoses of the isolates of chestnut blight disease fungus Cryphonectria parasitica (MURR. BARR)
45-52Views:117Chryphonectria parasitica, the casual agent of chestnut blight, is one of the most important fungal pathogens of chestnut (Castanea spp.) in Europe and Hungary. In this study, we analyzed the ITS region of five Cryphonectria parasitica strains isolated from different location of Hungary. The differences among the Cryphonectria parasitica isolates were not insignificant because only two sites were considered as informative for the parsimony analysis. As the differences among geographically different isolates were insignificant, we mean that the evolutionary distance by ITS sequences within Hungarian Cryphonectria parasitica isolates is too small to get well based consequences for the phylogenetic relationships.
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Molecular studies on Cryphonectria parasitica isolates from Carpathian-basin
76-80Views:105Chryphonectria parasitica, the casual agent of chestnut blight, is one of the most important fungal pathogens of chestnut (Castanea spp.) in Europe and Hungary. In this study we analyzed the diversity of 14 Cryphonectria parasitica strains isolated from different location of Carpathian-Basin. For the analyses we used the partial sequences of the translation elongation coding gene, tef1. Our results showed that the tef1 gene, contrary to other fungal species, is not suitable for the molecular analyses of C. parasitica. In the future, for the molecular studies of C. parasitica, we need to use other molecular markers like microsatellites.
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Studies of Cryphonectria parasitica (MURR.) BARR subpopulations on Quercus petraea in Ukraine
70-75Views:143Chryphonectria parasitica (Murr.) Barr, the casual agent of chestnut blight disease, which is one of the most important fungal pathogens of chestnut (Castanea sativa). The disease seriously affected the chestnut in Northern-America and in Europe as well. It is important to mention that the pathogen does not only infect the chestnut but oak species (Quercus spp.) also. In the Carpathian-Basin, the chestnut is endemic in the Mecsek mountains, in Zala, in Somogy counties but it also can be found in the Danube-Bend. In the Carpathian-Basin (outside Hungary) the chestnut is found in Slovakia, Ukraine, Romania. In our study bark samples infected by Cryphonectria parasitica were collected from Bobovyshche, Serednje and Rostovjatica (Ukraine). The rate of infected chestnut tree were higher than 90% around Bobovyshche and beside chestnut, the symptoms were detected on oak trees as well. We collected bark samples from chestnut and oak as well and then we isolated the pathogen Cryphonectria parasitica in the lab of University of Debrecen. Symptomatological observations, laboratory examinations on fungus morphology, as well as comparisons of ITS sequency homology were made and approved that the causal agent of new disease was Cryphonectria parasitica. Our results proved that the Cryphonectria. parasitica infects oak trees beside chestnut in the Carpathian-Basin. Further studies are needed to determine the VCG (Vegatative Compatibility Group) group of the Cryphonectria parasitica found on oak trees.
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Nutrient deficiency and effects of various nutrition technologies on crop health
109-113Views:295The impacts of climate change on crop production are increasingly noticeable. Extreme weather conditions – such as devastating droughts, which occur more often – have serious effects on crop conditions, thus damaging their defence ability against pathogens and pests. Therefore, in order to achieve high-quality and high yielding crops, it is urgent to elaborate new technologies that improve general condition of crops and prevent development of nutrient diseases. Those crops which suffer from the lack of certain nutrients are more sensitive and their tolerance against diseases are decreased. Nitrogen – as the most influencing macronutrient in yield – is also essential in maintaining crop health. Nevertheless, due to the complicated processes in soil (such as leaching, denitrification), the utilization of nitrogen is not nearly complete, therefore nitrogen stabilizers may be needed to maximize this factor. The use of these stabilizers can be promising where plants with high nitrogen content are grown, although further experiments are needed in which impacts of nitrogen stabilizers on crop protection aspects are examined as well, since there is a close correlation between exaggerated nitrogen fertilizing and sensitivity to pests. During my research I am going to examine the combined effect of foliar fertilizer and nitrogen stabilizer on crop health. Furthermore, my goal is to find clear correlation between pathogens and the different technological variants of nutrition.
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Screening of paprika (Capsicum annuum L.) varieties resistant to NaCl salt stress
105-110Views:176Salinity stress is one of the environmental factors that negatively affect the growth and production of pepper plants. The 100 seeds' weight was measured. The total fresh weight of five seedlings and the growth rate of one seedling of three paprika varieties were also measured under the influence of NaCl at a salinity level threshold of (3 dS m‑1). The proportion of tissue water content in three pepper cultivars was measured according to a mathematical formula at the end of the experiment. In terms of seed weight, the (Carma) cultivar outperformed other types greatly. Except for the superiority of both (Carma, and Bobita F1) over (Fokusz) variety in total fresh seedlings weight under sodium chloride as abiotic stress, there are no significant differences in the total seedlings' dry weight and the rate of seedling growth. The non-drought-resistant type (Bobita F1) loses water the fastest, at 89.61%, compared to drought-tolerant kinds, which lose water at a slower rate (Carma, and Fokusz). The results demonstrate the (Carma) variety's numerical vigor, particularly in the growth rate. More testing is needed to determine the selection of varieties that are resistant to abiotic and biotic stresses.
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The potential of biological control on invasive weed species
73-75Views:100Sorghum halepense is one of the invasive species in Europe. This study was made to identify the morphology of fungi on invasive weed species samples on the roots of Sorghum halepense. The samples were collected in the region of Debrecen. The experiment was conducted under laboratory conditions to determine the microscopic form of fungi. The samples were put on PDA and for identification of fungi is based on the morphological characteristics of the features and colonies of conidia that were developed in Petri dishes.
The examination of the culture revealed that the fungus from the root of Sorghum halepense was Aspergillus niger. Pathogenicity and the relationship between the fungus and Sorghum halepense are still uncertain so in the future pathogenicity tests and re-isolations from plants are very important steps.
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Correlation analysis of relative chlorophyll content and yield of maize hybrids of different genotypes
211-214Views:153In 2021, correlation between relative chlorophyll content and yield in three maize hybrids of different genotypes was examined. The data were collected at the Látókép Experimental Station of the University of Debrecen located on the Hajdúság loess ridge in Hungary. The soil of the small plot field strip plot trial, which was set up in 2011, was calcareous chernozem. Apart from the control treatment (without fertilisation), N fertiliser is applied in the form of base and top dressing. The base fertiliser containing 60 and 120 kg ha-1 N of nutrient applied in spring was followed by top dressing containing +30–30 kg ha-1 N in V6 and V12 phenophases. SPAD values measured at different phenological stages of the growing season increased by an average of about 28% up to 10 leaf stage for all three hybrids. In the pre-silking period (Vn), the relative chlorophyll content decreased by 8% on average. After an average increase of 14% in the tasselling and silking period, SPAD decreased by an average of about 29% at full maturity (R6).
For the different fertiliser treatments, higher N doses resulted in higher yields. In the basal fertiliser treatment, the A 60 N dose resulted in an average 34% increase in yield, and the A 120 N dose resulted in an average 94% increase in yield compared to the control. The 60 kg ha-1 N basal fertiliser (A60) increased in the V6 phenophase with an additional 30 kg ha-1 N resulted in an average yield increase of 26%. When 120 kg ha-1 N of basal fertiliser (A120) was increased by an additional 30 kg ha-1 N in the V6 phenophase, only the Merida hybrid showed a significant yield increase (7%). No further yield increase was observed when V690 and V6150 treatments were increased by an additional 30 kg ha-1 N in the V12 phenophase. The yield of the Armagnac hybrid decreased by almost 20%, the yield of Fornad by 3% and the yield of Merida by 1%.
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Biological potential of plant pathogenic fungi on weeds: A mini-review essay
59-66Views:166The invasion of weeds into productive areas has substantial negative effects on native ecosystems as well as agricultural production systems globally. Consequently, the task of maintaining or restoring these systems will become increasingly challenging without consistent, ongoing management efforts. The intensifying emergence of herbicide resistance in numerous weed species, coupled with the unintended pollution caused by synthetic herbicides, underscores the growing necessity for alternative, environmentally friendly, and sustainable management techniques, such as the utilisation of bioherbicides. Plant pathogenic microbes play an important role in biologically management of weeds, with the utilization of plant pathogenic fungi emerging as a promising area of study for novel research trends aimed at weed management without reliance of herbicides and to mitigate environmental pollution. A potential solution to decreasing pesticide usage involves the development of bioherbicides containing fungal active ingredients. Among the most commonly utilised fungi in bioherbicides are genera like Alternaria, Colletotrichum, Cercospora, Fusarium, Phomopsis, Phytophthora, Phoma, and Puccinia. Increased weed resistance to herbicides has influenced new strategies for weed management, with some fungi from genera such as Colletotrichum and Phoma already employed for weed control. Nonetheless, it is evident from reviews that further research is imperative in this domain, with particular emphasis on analysing the efficacy of each plant pathogenic fungi.
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Preliminary test: Evaluation and selection of tomato (Lycopersicon esculentum Mill.) varieties resistant to drought and powdery mildew
33-37Views:144Powdery mildew (Leveillula taurica) and (Oidium neolycopersici) are two harmful fungi that invade the tomato (Lycopersicon esculentum Mill.) plant and grow in dry conditions. Under the influence of polyethylene glycol 6000 at a concentration of 12%, the total seedlings fresh weight, total seedlings dry weight, seedling growth rate of one seedling, seedling length, and tissue water content percentage for three tomato varieties were assessed. Despite the superiority of the (Mobil) tomato variety in terms of numerical values, the results revealed no significant differences between varieties. As a result, (Mobil) has greater vigor under environmental drought stress of lower osmotic stress than other tomato varieties. More work is required to evaluate the research selection of varieties resistant to biotic stresses in dry areas, such as powdery mildew disease.