Search
Search Results
-
A dual infection of two microscopic fungi on common milkweed (Asclepias syriaca) in Hajdúság region (East-Hungary)
189-195Views:177Common milkweed (Asclepias syriaca L.) is one of the most noxious and invasive weed species in Hungary. A. syriaca invades arable lands, horticultural and forestry plantations, natural and semi-natural habitats too. In cases of field crops it can cause considerable yield losses mostly in maize (2–10%), soybean (12–32%) and sorghum (4–29%), but only with high rate of coverage. It can also increase these problems that the common milkweed can be serve as reservoir and host for viruses, other pathogens and pests.
Because of the importance of common milkweed and in spite of demand to develop effective biological control, until now has not been developed a proper control program against A. syriaca. The aim of our research was to identify the necrotrophic fungal pathogens, which were involved in notable disease occurrence on this weed in different parts of Hajdúság region of Eastern-Hungary in 2016.
To the isolation of fungi from leaves and their identification were based on morphological colony characters on potato dextrose agar (PDA) and Sabouraud dextrose agar (SDA). To the description of conidia features were used PDA for Alternaria and synthetic low-nutrient agar (SNA) for Fusarium species, respectively. The examination of axenic cultures revealed that the fungi isolated from the leaves of common milkweed were Fusarium sporotrichioides and Alternaria alternata. -
Mass occurrence of a Phoma-like fungus on common ragweed (Ambrosia artemisiifolia) in Hajdúság region, East Hungary
55-60Views:219Common 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.
-
Host plant preference of Metcalfa pruinosa (Say, 1830) (Hemiptera: Flatidae) in the north of Hungary
84-95Views:226Citrus flatid planthopper, a native insect to North America had for a long time a scarce economic importance there. However, being polyphagous made little damage on citrus trees and some ornamentals. In 1979 it was introduced to Italy where it established and spread quickly. It is now an invasive alien species continually spreading in South and Central Europe causing considerable damage in fruit crops and various ornamentals. Present study shows the results of a series of observations carried out from 2011 to 2015 at a number of habitats in north of Hungary. The pest could be found at each habitat but the hedge, the tree row, the gardens and the orchard/vineyard were the most infested. Frequency and population density of Metcalfa pruinosa were considerable on Asteraceae, Cannabaceae, Fabaceae, Juglandaceae, Lamiaceae, Rosaceae and Sapindaceae. Typical vegetation could be functionally classified as ornamental plants, trees/shrubs, fruit plants, weeds and feral plants. Feral plants – some of them also invasive alien species – were found at each habitat. Plant species native to America were among them the most populated. As the hedgerows were neglected, and most gardens, orchards and vineyards abandoned, these are excellent conditions for the quick and long-lasting establishment of the pest as well as they may be reservoirs to infest cultivated fruit crops and ornamentals. The hedgerow was situated along a railway line. The length of similar hedges can be merely in Pest county several hundred km, which means M. pruinosa has plenty of opportunity for spreading along the railway and infest agricultural and ornamental cultures. On the surveyed alfalfa and maize fields, accidentally very few nymphs and adults were observed. Although, the population density of M. pruinosa was considerable on many hostplants, economic damage or yield losses could not be detected. Economic or significant damage was observed only on roses, raspberries and stinging nettle. This later is cultivated in Germany and Finland. The applied horticultural oil was efficient.
-
The Role of Trichoderma in the Rhizosphere of Tomato Plants
67-69Views:65It is well established that microorganisms are closely associated with the roots of plants can directly influence plant growth and development. Species of Trichoderma, on the other hand are primarily studied for their ability to control plant disease. The ability of species of Trichoderma to directly promote or inhibit plant growth has been noted for many years.
Tomatoes were treated with different Trichoderma strains by seed treatment and soil inoculation. The Trichoderma were grown on malt-agar medium and conidia were washed off by sterile water for making suspension which contained 107 CFU/ml (colony forming unit/ml). The suspension was used for seed treatment and for the soil inoculation by watering as well. The artificial soil inoculation was made by Trichodermas growing on grounded maize were mixed in mould and tomato seed were sown in it. Tomato seeds were also sown in bags made of close-meshed material which allowed the soil microorganisms to colonize the roots but it simultaneously protected the roots from soil contamination. Roots were put on Trichoderma selective medium to check the root colonization of the Trichoderma.
The tomato plants were bedded out in a field in four repetition. After harvesting by hand the results supported by statistics shown that there was significant differences between the yield of the untreated and treated tomato plants by Trichoderma strains. -
Evaluation of blue and red corn landraces
239-243Views:92Corn breeding can be successful only on a broad base of genetic material. The expansion of breeding aims includes the research of germplasm materials. In our experiments, we examined 11 blue, purple and red exotic corn varieties on two locations in Hungary. We conducted a complex study to obtain more information. We studied several morphological and phenological features and determined the most important qualitative parameters (protein, fat, ash). We applied the Tassel Area Index (TAI) under Hungarian conditions and compared it with the pollen producing ability of different genotypes. Results show that there are great opportunities in exotic corn varieties. Their quality exceeds that of the yellow ones in many cases. There are significant differences in yield and nutritional parameters. The favorable nutritional composition is not coupled with great productivity. Based on their flowering time and their agronomical features, they can be cultivated under Hungarian conditions as well. They match the new breeding aims, so they can be used as functional food or energy plants. With their high pollen producing ability and TAI, they can be utilized as markers in future pollen research.
-
The role of green manure crops in Hungarian plant production
49-53Views:228According to the data of KSH (Hungarian Central Statistical Office), the sowing area of cereals in the crop year 2016 was over 2.56 million ha, on which winter wheat and maize were produced in a rate of around 50–50%. Regarding these data it is obvious that the domestic cropping structure has been simplified and become unilateral. This unfavourable crop rotation system causes several problems. The number of Hungarian livestock decreased in the past decades. The amount of manure was 24 million tons in 1960, but only hardly 4.5 million tons of organic manure was applied in 2016. Therefore, the importance of other possibilities, alternatives for organic matter recovery have become enhanced. This is especially important from the aspect of sustainable plant production. The fact that the European Union has introduced new directives for subsidiaries in 2015 has to be noted as well.
The objective of the set experiment is to find new technological solutions that are suitable for the execution of sustainable plant production by inadequate crop rotation, organic substance recovery conditions or under more unfavourable climatic conditions.