Extreme 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
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.
We 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 infecti...ons 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.
The 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 a...pplied 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**).
In 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 microsc...lerotia, 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.
Application 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 m...icrobiota 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.
The 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 betwee...n 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.
The 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 (fre...quency 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.
...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">Our 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.
In 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
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.