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Usability of vegetable extracts in the protection against Alternaria alternata
113-116Views:132In our country, wormwood ragweed (Ambrosia artemisiifolia) may cause serious problems. Nearly 5 million hectares of agricultural area was infected with ragweed (Ambrosia artemisiifolia), which is believed useless weed. Allergological point of view, most problematic weeds adventive. However, many physiologically very beneficial compound also included, those with the effects have been known also by the Indians. On this basis, herbs can be thought of as ragweed. Our goal was to present that the ragweed contains antifungal active substances as well. In this paper we tested the biological activity of the extracts against Alternaria alternata F.00750 in vitro. We related based on our examination that ragweed contains biologically active agents, by which it is hampered the reproduction of the Alternaria alternata. The minimum effective concentration was 300 mg extract in a Petri dish, which was three days inhibited the growth of fungus. Full fungicidal effect was observed over dose 525 mg.
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A dual infection of two microscopic fungi on common milkweed (Asclepias syriaca) in Hajdúság region (East-Hungary)
189-195Views:166Common 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. -
Preliminary estimation of the efficacy of Fusarium sporotrichioides Sherb. as biological control agent against common milkweed (Asclepias syriaca L.)
201-204Views:248A study of fungi responsible for severe leaf spots of common milkweed (Asclepias syriaca L.) in the Hajdúság region (East Hungary), Fusarium sporotrichioides and Alternaria alternata were isolated from infested leaf tissues. F. sporotrichioides was the most virulent fungus in pathogenicity tests conducted on healthy leaves of common milkweed plants. Inoculation of common milkweed (A. syriaca) in different growth stages with F. sporotrichioides yielded similar symptoms as the original ones. Spray mixtures containing 1.0×106 conidia/ml gave effective control when common milkweed plants were sprayed until runoff occurred. Laboratory (wet chamber) and field experiments showed that asexual spores of the fungal pathogen, F. sporotrichioides, exhibited bioherbicidal activity against common milkweed (A. syriaca).
More efficient control efficacy was observable on elder plants (at flowering stage) than younger ones. These results initiate that this fungus may be a biocontrol agent for controlling this invasive weed but should clarify its hosts because it could infect cultivated plants as well.
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The dynamics of biodiversity structure of soil microorganisms under the impact of biopreparations during potato growing season
67-74Views:141The use of biological preparations such as Phytotsid and Planryz contributes the increase of the general number of soil bacteria population by 13.0–36.1% in the case of potato variety Scarbnytsya and by 4.5–24.6% for potato variety Oberig compared with control. It also increases the number of saprophyte microflora, which compete with plant pathogens, micromycetes, and causes 1.2–1.8 times reduction in the number of soil fungi – Fusarium and Alternaria. During the application of Rovral Akvaflo the Shannon ecological index of species biodiversity is lower than during the biopreparation use. The decrease of species biodiversity was observed as well as strengthening the dominance of some species (dark pigmentation in fungi).
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Examining reaction of sunflower genotypes on planting time on chernozem soil
93-99Views:103We studied the effect of planting time on plant pathological factors, leaf area index and yield production by applying various fungicid treatments on two different sunflower genotypes in 2013.
By delaying planting time, both the extent of Diaporthe, Alternaria and Phoma infections decreased. The differences between the volume of infections were significant in the case of the early and late sowing time results. The application of fungicide treatments induced a notable decrease in the extent of infections for all three pathogens examined. The LAI-values varied between 0.3 and 5.6 m2/m2 in 2013 depending on the hybrid, sowing time and treatment. Stocks planted at distinct times reached maximum leaf coverage at different times. The planting time and the fungicide treatment had a significant effect on the formation of the leaf area. In the case of average and late planting times, fungicide treatments elongated the preservation of the green leaf area.
With respect to the yield amount, average planting time (27 April, 2013) turned out to be optimal in 2013 (control – NK Ferti: 4.621 kg ha-1, PR64H42: 4.196 kg ha-1; double-treated: NK Ferti: 5.282 kg ha-1, PR64H42: 5.090 kg ha-1). Fungicide treatments resulted in significant yield growth in all cases during our research.
We applied Person correlation analysis to evaluate the hybrids’ sensibility to infections and our results varied in the case of Diaporthe and Phoma (r=-0.343*, -0.379**). Infections of the three pathogens were significantly reduced by delaying the planting time and applying fungicides. Late sown stocks preserved the green leaf area for a longer period. Besides, the application of the fungicide treatment and the hybrid itself also led to the preservation of the green leaf area. However, pathogens examined notably decreased the leaf area by the end of the growing year. The fungicide treatment had a remarkable effect on yield growth (r=0.603**). Furthermore, the presence of higher LAI-values in the period prior to August also induced higher yields.
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Comparison of the geranium (Pelargonium) pathological results of 2016-2017
123-125Views:108The research was carried out in a Gyenes Flower gardening between 2016 and 2017 in Kecskemét. The gardening was founded in 1978. Initially, the main plants were gerbera (Gerbera) and yucca (Yucca), later replaced by the geranium (Pelargonium) cultivation as a result of market demand. In horticulture, there are about than 80 variety geranium of the standing, running, semi-trailer types and English gnawing. The Pelargonium had different sizes and colors. The study was set up in 1,000–1,000 pieces of geraniums each year. The following pathogens have damaged the geranium stock: Botrytis cinerea, Pythium debaryanum, with a rare occurrence of Alternaria porri, Phytophthora cryptogea. The greatest destruction was caused by botrytis (Botrytis cinerea). In the first experimental year, 42% of the 1,000 geraniums tested were infected with fungal diseases (30% B. cinerea, 8% P. debaryanum, 4% other fungi). In 2017, fungal infections were detected on 380 geraniums in the 1,000 tested geraniums (290 Botrytis cinerea, 70 Pythium and 20 other fungal diseases). In addition to the use of fungicides, we increased the spatial position of geraniums, early irrigation and frequent ventilation to ensure successful control. By 2017, we were able to reduce the damage caused by pathogens by 4 percent.