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Examining reaction of sunflower genotypes on planting time on chernozem soil
93-99Views:122We 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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The effect of the sowing time on the yield and oil content of sunflower (Helianthus annus L.) in different crop protection models
57-61Views:149The field research was carried out at the experimental farm of the University of Debrecen at Látókép on calcareous chernozem soil in Hungary. We examined the effects of the sowing time and the fungicide treatment on the yield, oil yield and oil content of two different genotypes of sunflower hybrids (NK Ferti, PR64H42) in 2012 and 2013. We applied three different sowing times (early, average, late) and two different treatment levels of fungicides (control =no fungicides applied, double fungicide protection).
During our research, we received better results in 2013 than in 2012. The application of different planting times affected the yield and oil yield production and the oil content as well. The optimal circumstances for yield and oil yield production were provided by late planting in 2012, while by average planting time in 2013. The highest oil yield results were reached by late plating in both years (except for hybrid PR64H42 in the double treated parcels where average plating time turned out to be more effective). The correlation between the plating time, the yield and oil yield production and the oil content was strong in 2012 (r=0.600**, r=0.639**, r=0.590**). On the other side, in 2013, the correlation was medium between the planting time, the yield production and the oil content.
We applied Pearson’s correlation to analyze the effect of the double fungicide treatment on the yield and oil yield production (2012: r=0.498**, r=0.407**). These results were better in 2013 (r=0.603**, r=0.623**), besides, the double fungicide treatment also increased the oil content (r=0.315**).
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The effect of crop protection and agrotechnical factors on sunflower in the Hajdúság region
39-46Views:97Extreme weather conditions are becoming more and more frequent in the crop years, thus increase the risk of sunflower production.
The objective of researches into plant production is to minimize these effects as much as possible. In this sense, the optimization of
agrotechnological factors is of high importance. Within these factors, the appropriate crop technology (sowing time, crop density)
and optimized, rational crop protection technologies are important, especially in the highly sensitive sunflower cultures. The effect of
sowing time, crop density, and fungicide treatments on the yield of sunflower hybrids was analysed in different crop years in 2008
and 2009. In each case, the infection was highest with the early sowing time and at the highest crop density level (65000 ha-1). When
one fungicide treatment was applied, the rate of infection decreased compared to the control treatment. The further decrease of the
infection rate was less after the second fungicide treatment.
In the humid year of 2008 the crop yield was the highest at 45000 ha-1 crop density level in the control treatment and at 55000 crop
ha-1 crop density level when fungicides were applied. In the draughty year of 2009 the maximum yield was gained at 55000 ha-1 crop
density level in the control treatment and at 65000 crop ha-1 when fungicides were applied. In 2008 and 2009 as regards the crop
yield, the difference between the optimal and minimal crop density levels was higher in the fungicide treatments than in the control
treatment (in 2008: control: 517 kg ha-1; one application of fungicides: 865 kg ha-1; two applications of fungicides: 842 kg ha-1), (in
2009: control: 577 kg ha-1; one application of fungicides: 761 kg ha-1; two applications of fungicides: 905 kg ha-1).
In each and every case, the first treatment with fungicides was more effective than the second. In 2008, the highest yield was
obtained with the third, late sowing time in each fungicide treatment. The differences between the crop yields with different sowing
times was less than in 2009, when the results of the second treatment exceeded those of the first and third treatment in each case. -
Preliminary studies on in vitro sensitivity of Venturia inaequalis populations to some fungicide active ingredients
165-168Views:127Aim of this study was to investigate the sensitivity of conidia of Spilocaea pomi to main fungicide active ingredients (cyprodinil, pirimethanil, fluquinconazole, tebuconazole, difenoconazole, dodine és trifloxistrobin) at dosages of 0.5, 1 and 2 times incubated in vitro at 24 and 48 hours collected from three integrated apple orchards. Results showed that degree of conidial germinations at the fungicide treatnemts decreased in the order of dosages of untreated, 0.5, 1 and 2 times. Considerable conidial germination was observed at higher dosages of some fungicides (e.g. groups of strobilurines and EBI) which confirmed the possibilities of sensitivity reduction of Spilocaea pomi to some funigicides in the sampled Hungarian apple orchards.
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Lessons of a stripe rust epidemic in a wheat fungicide trial in Debrecen
35-46Views:161During the 2014 year a fungicide application trial was made as a part of technology development in Debrecen (East-Hungary). Both in this trial and across in Hungary a serious stripe rust epidemic developed and caused great yield losses. The first sympotoms were observed in April on one of trial plots and during some following weeks a serious infection grown up. On the base of 13 fungicide active ingredients and dosages by two spraying applications, their efficacy could be evaluated in stripe rust control. Picoxystrobin 250 g/L acive ingredient applied in 0.6, 0.8 and 1 L/ha dosages (Acanto), picoxystrobin 200 g/L + ciproconazole 80 g/L combined active ingredients in 0.5, 0.75, and 1 L/ha dosages (Acanto Plus), epoxiconazole 83 g/L, moreover protioconazole 125 g/L + tebuconazole 125 g/L combinations gave good efficacy, respectively. The yield of well protected plots were 5 to 8 t/ha, but the losses were 40-70% when fungicides with no sufficient efficacy in stripe rust control were applied. The great infection, which was observed on different grasses late in the Autumn, 2014 might forecast a further stripe rust epidemic for the 2015 year.
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Population genetic results of Hungarian Botrytis cinerea isolates establishing new technologies with decreased chemical usage against grey mould
259-261Views:127Botrytis cinerea causes gray mold on a high number of crop plants. Information about the populations of plant pathogen fungi may help to develop new strategies for the effective and economic crop protection with reduced fungicide usage. Hungarian B. cinerea populations were characterized with using different molecular genetic parameters. B. cinerea group I strains, characterized with high rate of fenhexamid resistance, could be detected only in restricted number. The Hungarian B. cinerea populations were characterized with high genetic diversity, and the regular occurrence of sexual reproduction. These results highlight the importance of rotating different type of fungicide in the plant protection technology against grey mould.
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The efficacy of combining paraffin oil with conventional fungicide treatments against grape powdery mildew in Eger
173-180Views:174We aimed to test the combination of paraffin oil (PFO) with regular fungicide treatment to assess its efficacy against grape powdery mildew (GPM) in a small spraying experiment on two Vitis vinifera L. cultivars (Chardonnay and Kékfrankos) with different susceptibility to Erysiphe necator. The visual symptoms of GPM on leaves and clusters were examined at three phenological states. The harvest yield was characterized by two methods, data were analyzed with one-way ANOVA and Tukey post-hoc test. Regular fungicide treatment (CT) and its combinations with PFO showed better results in both varieties to repress GPM in 2015 relative to sole PFO treatments. Mean values of combined treatments were often lower than CT but did not differ significantly from each other. The same was observed in 2016, despite the higher pressure of GPM, and missed the third survey. No significant differences were detected between treatments in yield. In contrast, the mean cluster weight of CT and combined treatments resulted in (insignificantly) higher values in each variety and year. In summary, the sole PFO showed some disease control capability as reported earlier, but this effect was greatly affected by the given vintage. Combining PFO with CT resulted in increased protection against GPM relative to the solely applied fungicides. However, this effect was not significant in all cases. It also depended on the vintage and cultivar characteristics. The beneficial impact of paraffin oil as an additive to CT may be due to the induction of plant stress responses and/or its ability to support the adherence and absorption of the combined agents.
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Effects of paraffine oil on leaf and berry mycobiota on two grape varieties
61-66Views:213Application of fungicides have advantages and also some direct or indirect disadvantages, such as imbalance and/or fungicide resistance in microbe population. To avoid these problems the development of alternative, eco-friendly methods like mostly spraying with oils are in the focus nowadays. The investigations of the effects of fungicides on microbiota in some cultivations can give a more complex view to this topic and developmental possibilities. In the present study, our aim was testing of the effects of paraffine oil (as alternative fungicide) on microbial properties (CFU and rate of filamentous fungi and yeasts) of Chardonnay and Kékfrankos leaves and berries.
Our results from 2014 showed that the application of paraffine oil as sole spray agent can decrease the presence of saprophytic filamentous fungi on the berries of Chardonnay (susceptible for fungal infections). In the case of Kékfrankos berries opposite properties were observed, which may be the result of the absorption of oil by the thick wax layer of this variety. The oil treatment did not affect the yeast population of Chardonnay and Kékfrankos berries contrary to negative effect of the regular pesticide treatment. The selective fungicide effect of paraffine oil against filamentous fungal population caused the accumulation of yeast cells in the mycobiota of grape berries. The careful use of this yeasts in spontaneous fermentation can improve the aroma profile of wines. The year of 2015 did no prefer the growth of fungi, therefore no interesting properties were detected in the mycobiota of grape varieties. The occurence of the harmful saprophytic filamentous fungi predicted to be increased in mild climate agricultures as the result of the climate change.
In summary, the paraffine oils are seem to be promising tools for the eco-friendly control of harmful fungi of grapes.
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Examination of different fungicides against Macrophomina phaseolina in laboratory conditions
65-69Views:176In Hungary, sunflower is the third most important arable crop, which has a lot of pathogenic fungi. One of these fungi is the Macrophomina phaseolina, which is a well-known fungus in all over the world, since this pathogen has more than 700 host plants. In Hungary, several host plants can be found as well. The M. phaseolina produces microsclerotia, which can survive in the soil and residues for almost 10 years. For now, there is no efficient treatment against this pathogen because of this fungus, since it is extremely resistant and cannot be destroyed easily. The only effective treatment against the fungus is genetic defence. In this study, three different fungicides were tested in vitro against the fungus. The Mirage (prochloraz) seemed to be the most effective fungicide as it completely arrested the hyphal growth. In contrast, the Amistar Xtra (azoxystrobin and ciprochonazol) has only a minor effect on the growth of M. phaseolina. Thirdly, the Retengo (pyrachlostrobin) arrested the hyhpal growth of the fungus with 71% at 100 ppm, in other words, the use of this fungicide seems promising.
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Búzaminták fungicid szermaradvány ellenőrzése és gombafertőzöttségének kimutatása
45-51Views:88To protect crops with chemicals against different microorganisms are very important because residues of toxins could pollute infected grains. This could have the meaning of serious danger to the human and animal health. Similarly important is knowledge of details about presence or absence of any practically applied protective compounds. Experimental studies were performed on fungicide treated cereals of the Cereal Research Non-Profit Company, Szeged. Chromatographic methods were used (GC and some GC-MS) to find low level fungicide residues, microwave-assisted isolation of ergosterol was followed by HPLC to detect possible fungal infections and a more detailed microbiological analysis completed the work. Concerning the dry year 2000, no fungicides were found in the samples (by November), the ergosterol level was found to be less than 8 ppm, meaning good quality, coupled with an extremely low level of fungal infections. This was confirmed by direct microbiological testing. In comparison with the microbiological results from 1999, a negative difference can be recognized, most probably due to the rainy weather throughout the year.
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The response of sunflower hybrids to different plant densities on a chernozem soil
123-128Views:197In our experiment the reaction of six sunflower hybrids of different genotypes (NK Oktava, ES Biba, ES Diagora, ES Ballistic, EGH 8925, PR 64 H 42) towards plant density has been investigated by different fungicide treatments in the crop-year of 2011 on a chernozem soil.
In the crop-year of 2011 sunflower populations were infected by a significant Diaporthe helianthi disease. The extent of this infection was significantly enhanced by the increment of plant density. However, regarding the average of the hybrids and plant densities the two times executed fungicide treatment has decreased the infection rate by 22%. The most susceptible hybrid was the ES Biba. Contrarily, the hybrid ECH8925 proved to be the most resistant hybrid towards this
disease according to our results. According to the results of the Pearson’s correlation analysis it has been revealed that stalk breakage and Diaporthe infection stand in a very close (r=0.782**) and middle close (r=0.523**) correlation resp. with plant density. The relationship between fungucude treatments and stalk breakage, just as Diaporthe infection showed to be middle and close respectively. Our results demonstrate the role of stalk and plate diseases (among them Diaporthe) in causing stalk breakage, for we have found a close positive correlation between stalk breakage and Diaporthe infection (r=0.624**) in our analysis.
From the aspect of yield amount the optimal plant density varied between 45 000 and 55 000 plants per hectare. Fungucude treatments enabled not only the use of higher plants densities, but they had a yield increasing effect as well. In the crop-year of 2011 the highest yield (4 559 kg ha-1) on a chernozem soil has been measured in case of the hybrid ECH8925. -
Possibilities for reducing fungicide treatments in sour cherry production
3-6Views:89The aim of this study was to investigate the possibilities for reducing fungicide treatments of sour cherry. The study was conducted in fruit bearing sour cherry orchards of the Institute of Agriculture at Kyustendil during 1991-2005. Cherry leaf spot was controlled by postinfection applications of ergosterol biosynthesis inhibitors and dodine. Bacterial canker, brown rot, shot-hole syndrome were controlled by protective treatments with copper-containing fungicides in late autumn and early spring. Insecticide treatments were applied when it was necessary. Blumeriella jaapii is the main pathogen of sour cherry which can be controlled successfully by postinfection treatments. Their number could be reduced in some years. Sprays against leaf spot were effective against other diseases too. Protective treatments against Pseudomonas syringae with copper-containing fungicides were effective against shot-hole syndrome and Monilinia laxa as well as Monilinia fructigena.
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Laboratory and small plot fungicide trials to control potato late blight (Phytophthora infestans) next to Sepsiszentgyörgy town (Romania)
72-72Views:127Our experiments were carried out during 2009 and 2010 years on Szépmező field, next to the Sepsiszentgyörgy town, Kovászna county, Romania. The experimental area situated at 520 - 580 m altitude, its soil is a humus rich chernozem, the yearly average temperature is between 7 - 8 oC, the precipitation is 500 - 600 mm/year. 7 different fungicides efficacy were studied for control to potato late blight disease caused by Phytophthora infestans on three potato varieties, viz. Ostara, Santé and Desirée.
In the laboratory the fluanizam (500 g/L, ALTIMA 500) fungicide was the best in inhibition of growing fungus while on the field trial plots cymoxanil + famoxadone (22.1 + 16.6%, EQUATION PRO WP*) and metalaxyl** + mancozeb (200 g/L + 1.600 g/L, RIDOMIL MZ 72WP) were the most effective. This facts were confirmed by statistic Duncan-test and data of yields.
The appearance of Phytophthora infestans epidemic was influenced by the climate conditions too during May and June when the minimum temperature was 12 oC, and the maximum 20 oC, the rain quantity more than 120 mm, the air humidity above 75%, these conditions promote the appearance and spread of fungus.
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Azoxystrobin resistance of Botrytis cinerea Pers.:Fr. isolates
56-63Views:108Fungicide resistance is one of the most important problems endangering the effectivity of practical plant protection today. The frequent and subsequent usage of specific fungicides results the emergence of resistant fungal populations. This threatens is especially high in case of Botrytis cinerea Pers.:Fr. being an endemic pathogen with frequent infection. Nowadays the main method of protection as against Botrytis cinerea is the application of chemical fungicides chemicals. Therefore, a better knowledge of local populations is necessary for the planning of the protection procedures.
Based on the results of our examinations we may establish that the growth of the examined samples showed a significant difference under in vitro circumstances, which shows a great deal of variability of the Botrytis cinerea populations in Hungary. Twenty-five Botrytis cinerea samples from different hosts were analyzed in this study. High resistance was found towards azoxistrobin in seven cases, and low resistance in eight cases.
It was also proved, that the B. cinerea is able to bypass the inhibition site of the azoxistrobin via the alternative oxidase. The presence of this altermative mitocondrial electrotransport route considerably reduces the effectivity of the chemical. -
Effect of the crop-year on plant protection feature of sunflower
71-75Views:171Our study focused on plant density reactions of sunflower hybrids on chernozem soil in years with different levels of available water (2011 and 2012). We studied factors (i.e.infections, yield) that are most affected by the amount of precipitation.
However the amount of precipitation varied in 2011 (average amount of precipitation) and 2012 (drought), Sclerotinia and Diaporthe infections were significant in both years. Diaporthe was stronger in 2011 while in 2012 Sclerotinia infections were greater than average. Higher plant density provided for a favorable microclimate for pathogens meaning that increased stock density enabled enhanced infections. Maximum levels of infections in both the cases of Diaporthe and Sclerotinia were measured at a plant density level of 65 000 plants ha-1.
2012 yields (control: between 2 289 and 3 261 kg ha-1, two-time treated: between 2 699 and 3 659 kg ha-1) were significantly lower compared to the results of 2011 (control: between 2 825 and 3 672 kg ha-1, two-time treated: between 3 059 and 4 059 kg ha-1). Fungicide treatments led to an increased yield in both years: 9.5% in 2011 and a notable, 15.1% growth in 2012. We applied regression analysis to calculate optimum plant density for the examined years and treatments. Based on the calculations we found that in the cases of both treatments optimum plant density was 53 000 plants ha-1, while in 2012 the optimum was higher due to lower level of infections: 56 000 plants ha-1 in the control stock and 64 000 plants ha-1 in the stock treated twice.
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The effect of location on the incidence of brown rot blossom and shoot blight infection on apricot
89-91Views:199The aim of our study was to assess the incidence of brown rot blossom and shoot blight and caused by Monilinia laxa. Assessments of incidence were made on cv. Bergeron (susceptible to brown rot) in a flatland and a hilly growing area (at Cegléd and Gönc, respectively). In 2004, when spring and summer weather conditions were wet and cold, incidence reached 95 % for blossom blight and 33 % for shoot blight in the untreated plots. Blossom blight incidence was 1.5-2 times higher in the flatland area compared to the hilly growing area. During the blooming period of apricot, two (at flower bud stage and at full bloom) and three (at flower bud stage, at full bloom and at petal fall) fungicide applications were necessary for the successful control at Gönc and Cegléd, respectively. The difference between the two orchards was due to the fact that blooming started one week later in the hilly region (at Gönc) than in the flatland region (at Cegléd), therefore, the critical weather period coincided with blooming in the orchard in the hilly region only partially.
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Spectral analysis of stress symptoms caused by apple powdery mildew (Podosphaera leucotricha
83-88Views:216An orchard can be examined on the basis of spectral data, using methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Calculated on the basis of such hyperspectral data from different index numbers the water supply of foliage conditions can be well characterized.
The research site is an intensive apple orchard, which located in University of Debrecen, Agricultural Sciences Centre, Farm and Regional Research Institute at Pallag. During my experiments the preliminary evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by Podosphaera leucotricha.
Based on the results narrow band greenness indices (NDVI705, mNDVI705, mSR705 and REP) can be used for determination of diseased canopy and for the detection of stress symptoms of Podosphaera leucotricha,. These statements can be utilized in precision plant protection systems, since it can be a basis for such integrated active sensors with LED or laser light source, measuring reflectance at the certain spectral range, which can facilitate real time status assessment of orchards and can control precision fungicide utilization.
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Response of sugar beet to different foliar fertilizers
127-136Views:142The yield and quality of the sugar beet are mainly determined by level crop production system; therefore the effects of foliar fertilization were studied. Our field trials were carried out in 2005 and 2006 in Hajdúböszörmény, at two experimental sites. In our trials the effects of Biomit Plussz, Fitohorm and Kelcare Cu (having high Cu content) as foliar fertilizers, as well as a fungicide with high sulphur content, Cosavet DF, were studied and
compared. Effects of treatments were studied in four replicates.
We took root samples at 4 week intervals, starting in August. The quality of root (sucrose, potassium, sodium and alfa-amino N content) was determined from filtrated beet broth, by an automatic beet laboratory system, called VENEMA. Leaf samples were taken three times in the growing season, element composition was measured by ICP-OES.
We found that the crop and the sugar yield were significantly influenced by the foliar treatments both of the two years. -
The effect of copper fungicides on the rate of photosynthesis and the transpiration of hop plants
117-123Views:114The paper evaluates the effect of copper fungicide spraying on the rate of photosynthesis and transpiration of hops, the influence of spraying on the elemental copper content in the leaves and cones hop variety Agnus. Photosynthetic rate was measured by LC pro+ (infrared analyzer) in the Hop Research Institute Saaz in the field in some periods of 2008, 2009 and 2010. Dry cones and leaf samples (taken before and after application of copper fungicides) were analyzed in an accredited laboratory for elemental copper.
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Testing of paraffin oil efficiency against grape powdery mildew in Eger wine region
73-80Views:410The aim of the present study was to examine the efficiency of paraffin oil against powdery mildew in Eger wine region. The experiment has been carried out in 2013 and 2014 with Chardonnay and Kékfrankos grape varieties, which have different resistance against powdery mildew. The effectiveness of the oil was examined on leaves and clusters (frequency and intensity). This oil was effective against Erysiphe necator infection on field trials in Chile and Brazil. The spread of downy mildew (Plasmopara viticola) was also inhibited by this material in some experiments conducted in Spain and France.
The differences between oil treatments represented the sensitivity of the grape varieties in accordance with the applied dosages. The oil was effective against powdery mildew with different extent as a result of the so called ”vintage effect”. In 2013, the treatment of the highest dosage (D3) didn’t differed significantly in frequency and intensity of infection from the regular treatment (clusters of Kékfrankos, leaves of Chardonnay). In 2014, the oil was not so effective against powdery mildew compared to 2013. No remarkable differences were detected between the treatments due to the strong pressure of powdery mildew. Furthermore, no any effect of the lowest dosage (D1) was detected in the case of the sensitive clusters of Chardonnay and leaves of Kékfrankos in both experimental years.
In summary, the oil treatment has an effect against powdery mildew, however this efficiency largely depends on the vintage characteristics and the pressure of powdery mildew. Further investigations are neccessary, for example field trials with combinations of other sprays. The oil can be useable as fungicide with proper care in eco-friendly integrated and bio (ecological) viticulture.
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Comparison of the geranium (Pelargonium) pathological results of 2016-2017
123-125Views:155The 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.
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Q-PCR analysis of the resistance of Hungarian Botrytis cinerea isolates toward azoxystrobin
41-44Views:120The genes being in the mitochondrial DNA primarily encode the enzymes of cellular respiration. Fungicides belonging to the family of quinol oxidase inhibitors (QoIs) play on important role in the protection against several plant diseases caused by fungi. These fungicides bind to the cytochrome bc1 complex so they block electron transport between cytochrome b and cytochrome c1. This way these fungicides inhibit the ATP synthesis consequently they inhibit the mitochondrial respiration. The QoI resistance has two mechanisms. One of them is the point mutation of the cytochrome b gene (CYTB), e.g. the substitution of a single glycine by alanine at position 143 results in high-resistance. The other is the cyanide-resistant alternative respiration sustained by the alternative oxidase.
In a cell there are several mitochondria. The phenomenon when the genomes of all mitochondria in the cell are identical is called homoplazmy. If in the cell there is wild and mutant mitochondrial DNA this is called heteroplasmy. Whether the mutation in the mitochondria causes fenotypical diversity or does not depend on the dose, i.e. it depends on the percentage of the changed mitochondrials. During our work we investigated Botrytis cinerea single spore isolates which have been collected in 2008-2009 on different host plants. Our goal was to decide whether heteroplasmy influences the level of resistance. We managed to detect the change of the level of heteroplasmy, so the change the level of the resistance due to the treatment with fungicide.