No. 71 (2017)
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Articles
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Examination of the plum psyllid (Cacopsylla pruni Scopoli), a vector of European Stone Fruit Yellows (ESFY) phytoplasma in the countryside of Boldogkőváralja (Hungary)
5-11Views:211European Stone Fruit Yellows(ESFY) phytoplasma disease on apricot was identified by molecular methods for the first time in 1992 in Hungary. Currently, the pathogen is known as’ Ca. Phytoplasma prunorum’. Since, the pathogen become wide-spreaded and manyof the apricot-plantations had to be eliminated. In 2009 and 2010 in the countryside of Boldogkőváralja the infection of the apricot-plantations was about 77%. As the disease spreading and causing large damages, we studied the roleo fpossible vector,the plum psyllid (Cacopsylla pruni Scopoli) in the areas of Boldogkőváralja, North-East-Hungary. Studies were done in the year of 2016, monitoring the behaviour of the psyllids in four different areas, and caught 41 them for further examination. We collected plant samples from those apricot trees, on which the plum psyllids were caught.
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Herbicide tolerance of maize genotypes in the wet 2016 year
13-18Views:145The herbicide tolerance levels of 49 Martonvásár inbred parents were examined in Martonvásár in a herbicide susceptibility trial in 2016. The normal dosage recommended in the permit documentations and double dosage were used for the 12 small-plot herbicide treatments performed in two repetitions. Spraying of early post-emergent herbicides was carried out in the 1–2-leaf stage, while post-emergent treatments were applied in the 7–8-leaf stage of maize. The extent of phytotoxicity was scored for the early post-emergent herbicides two and four weeks after treatments and for the post-emergent herbicides two weeks after treatments, respectively. Some of the herbicides examined are not approved in seed production; however it is important to know the reaction of maize parent genotypes for every type of herbicides. The active agent topramezone was withdrawn from the market in 2015, but it was included in the trials as its usage was allowed until stocks run out in 2016. The herbicide agents were examined as follows: mesotrione + S-metolachlor + terbutylazine; isoxaflutol + tiencarbazon methyl + cyprosulfamide; isoxaflutol + cyprosulfamide; mesotrione + terbuthylazine; tembotrione + isoxidifen-ethyl; mesotrione + nicosulfuron; prosulfu ron; nicosulfuron +prosulfuron + dicamba; bentazone + dicamba; nicosulfuron; topramezone; foramsulfuron + isoxadifen-ethyl.
Among early post-emergent herbicides, isoxaflutol + cyprosulfamide caused the less phytotoxic damage in the genotypes. The large amount of precipitation during the spring facilitated the infiltration of the active ingredient S-metolachlor, used regularly and successfully also in seed production, into the root zone, resulting in phytotoxic symptoms on susceptible inbred lines at the time of the first inspection. These genotypes recovered by the end of the vegetation period. The spring weather was cooler than usual, retarding the development of maize and thus led to the slower fermentation of herbicide active ingredients, accordingly, all of the post-emergent herbicides caused visible phytotoxic symptoms on some of genotypes. The most severe damages were generally caused by the double dosage of nicosulfuron + prosulfuron + dicamba, nicosulfuron, and foramsulfuron + isoxadifen-ethyl. -
An unimportant insect pest with characteristic symptoms: Halticus apterus (Miridae)
19-23Views:166Halticus apterus, a tiny mirid bug with jumping hind legs has not been taught in agricultural entomology courses in Hungary. However, the most detailed agricultural entomology text book, the “Handbook of Agricultural Entomology” briefly presents the pest. Although, it is common in Hungary, its damage is insignificant because of the low density; it can cause quality loss in feed crops only. Nevertheless, its special symptom – spottedness – is worth taking into consideration. The author has been studying pests and natural enemies of alfalfa for a long time (at least ten years), so he focused attention on this species. Occurrence of H. apterus was only sporadic in the alfalfa field, but it showed characteristic and frequent symptoms at a density of averagely three individuals per alfalfa plants in mixed plant associations at the studied field edge. By presenting the damage appearance and form, it was possible to make a more accurate description of H. apterus’symptoms, and with evaluating relevant European references, also the detailed entomological characterisation, economic importance and assessment of future risks have been achieved. As a difference to former descriptions, the special leaf spottedness of H. apterus does not consist of homogenous round spots but rather of spherical conglomerations of tiny whitish dots caused by the piercing and sucking mouthparts and the injected saliva
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Sensitivity of maize hybrids to common smut under field artificial inoculation conditions
25-28Views:188Common 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 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:161The 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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In memory of József Vörös mycologist (1929–1991) on the 25th anniversary of his death
33-37Views:140Twenty five years ago died professor József Vörös, internationally recognized mycologist, phytopathologist. On the field of microscopic fungi research, especially on taxonomy of plant pathological conidial fungi (Deuteromycetes, Coelomycetes, Hyphomycetes) gained imperishable reputation during his more than 40 years research activity. As author of 17 fungus taxa and publisher of numerous mycological data J. Vörös took place in the history of mycology.
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Distribution of the American grapevine leafhopper (Scaphoideus titanus Ball 1932) in surroundings of Nagyvárad (Oradea, West Romania) and Debrecen (East Hungary)
39-44Views:159The first European appearance of american grapevine leafhopper (Scaphoideus titanus), which is the vector of Grapevine Flavescence Dorée phytoplasma (‘Ca. Phytoplasma vitis’), were detected in France in 1924. The leafhopper has been distributed since 2006 in Hungary and now it occurs in the whole country, while the first record of the phytoplasma was published in 2013.
We studied the distribution of the leafhopper in surroundings of Nagyvárad (Oradea, West Romania) in 2015 and surroundings of Debrecen (East Hungary) in 2016. During the studies 17 sites were sampled. The leafhoppers were found in six Romanian places with relatively low abundances while it occurs in all studied Hungarian sites and two of them showed extremely high frequenncy. -
Occurence and spreading of box tree moth (Cydalima perspectalis Walker 1859) on the North-East region of Great Hungarian Plain
45-50Views:156Box tree moth shows (Cydalima perspectalis) rapid spread in Europe. In Hungary it appeared first near to the western border of the country in 2011. In the eastern part of Hungary the first specimen was caught in 2015 with blacklight trap. Here we summarize its distribution in northern part of the Alföld (Great Hungarian Plain) on the basis of blacklight, pheromone and feeding attractant traps. We publish five new distribution data from northern part (4 from Hungary, 1 from Transcarpathia) and two from southern part of the Alföld. Beyond that the flight of three generations was observed both in the year 2015 and 2016.
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New occurence of woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) in Hajdúság area, East-Hungary
51-54Views:212Because 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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Mass occurrence of a Phoma-like fungus on common ragweed (Ambrosia artemisiifolia) in Hajdúság region, East Hungary
55-60Views:207Common ragweed (Ambrosia artemisiifolia L.) is one of the most important, allergenic weed species in Hungary. A. artemisiifolia invades both a broad range of often disturbed areas (brownfields) and either undisturbed ones like waste lands, roadsides, riverbanks and railway tracks. In field crops it can cause considerable yield losses mainly in sunflower, maize, cereals and soybean. In Hungary many inhabitants suffer from allergy caused by Ambrosia pollen which results a serious human-health risk. The aim of the control is to prevent flowering and seed propagation of A. artemisiifolia. Until now the occurrence of numerous pathogenic fungi which attack common ragweed plants have been identified in Hungary, however there is not yet available biological weed control program because of shortage in acceptable effectiveness, and endangering cultural plant species. During our weed surveys in the region of Hajdúság (East-Hungary) we found numerous common ragweed plants showing heavy necrotic lesions on leaves and stems. The objective of this study was to identify the fungus which was isolated from diseased tissues of common ragweed (A. artemisiifolia). The identification of fungus based on morphological characters of colonies and features of conidia and chlamydospores developed on malt extract agar (MEA) plates. After examination of axenic cultures we revealed that the fungus isolated from the leaves ands stems of common ragweed was a Phoma-like species.