Long-lasting changes in the species spectrum of cucurbit powdery mildew in the Czech Republic – influence of air temperature changes or random effect?

Two ectoparasite powdery mildew species Golovinomyces cichoracearum (Gc) and Podosphaera xanthii (Px) occurring on cucurbits differ, besides other characteristics, by specific ecologic requirements. While Px is common in subtropical and tropical areas and greenhouse crops, Gc occurs more frequently in temperate and cooler areas under field conditions. Their presence on cucurbit field crops (Cucurbita pepo, C. maxima, Cucumis sativus) was monitored in the Czechoslovakia (1979–1980) and in the Czech Republic (1995–2007). Their identification was carried out by microscopic observation of the morphological characteristics of the dry conidia on 1527 leaf samples. Data on air temperature in 1979–2007 were provided by the Czech Hydrometeorological Institute. In 1979–1980 Gc was identified in 86.0% of samples, Px in 14.0% samples, there was no mixed infection; prevalence of Px was recorded in South Slovakia and South Moravia, and on crops under cover. Since 1995 species Px was recorded each year on field crops in different locations of Bohemia and Moravia, usually in mixed infection with Gc. The average year temperature of 8.1°C for period 1992–2007 was higher than corresponding value of 7.4°C in 1979–1983. Similarly, average temperature in vegetation season of 16.2°C in 1992–2007 was higher than corresponding value of 15.7°C in 1979–1983. The higher air temperature can positively influence spreading of Px in the Czech Republic. Climate variability and effect of their changes are discussed in relationship to the geographic distribution and geographic patterns of cucurbit powdery mildews.

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Golovinomyces powdery mildews on Asteraceae in the Czech Republic

Plant Protection Science ◽

10.17221/129/2019-pps ◽

2020 ◽

Vol 56 (No. 3) ◽

pp. 163-179

Author(s):

Barbora Mieslerová ◽

Miloslav Kitner ◽

Veronika Petřeková ◽

Jitka Dvořáková ◽

Michaela Sedlářová ◽

...

Keyword(s):

Czech Republic ◽

Powdery Mildew ◽

Host Specificity ◽

Host Species ◽

Morphological Characteristics ◽

Fungal Species ◽

Great Variability ◽

The Czech Republic ◽

Powdery Mildews ◽

Asteraceae Family

Powdery mildews on the Asteraceae family were surveyed during 2007–2015 in the Czech Republic with the aim to increase our knowledge about occurrence, morphological characteristics and host specificity of powdery mildews on this family. In total, 32 host species with symptoms of powdery mildew were collected, and the fungal species were identified based on microscopic observations. These showed great variability in their morphological characteristics. Our study confirmed the high host specificity of powdery mildew species to their original hosts. A deeper knowledge of the taxonomy of the Asteraceae has brought substantial changes in the delimitation of powdery mildew species. In particular, delimitation of the three varieties of Golovinomyces asterum was studied and discussed.

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The impact of the air temperature on measuring the zenith angle during the year in the ground layer of the atmosphere for the needs of engineering surveying

Acta Polytechnica ◽

10.14311/ap.2021.61.0476 ◽

2021 ◽

Vol 61 (3) ◽

pp. 476-488

Author(s):

Tomáš Suk ◽

Martin Štroner

Keyword(s):

Czech Republic ◽

Numerical Model ◽

Central Europe ◽

Air Temperature ◽

Zenith Angle ◽

Geographical Area ◽

Temperature Gradients ◽

The Czech Republic ◽

Different Seasons ◽

The Impact

This paper presents the results of over a year-long experiment dealing with a temperature measurement to calculate the theoretical effect of the atmosphere on the measured zenith angle in engineering surveying. The measurements were performed to determine the accurate and specific temperatures (temperature gradients), which can be recorded in different seasons in the low level of the atmosphere (up to 2 m above the ground, where most Engineering Surveying measurements take place) for the geographical area of Central Europe - specifically the Czech Republic. A numerical model was then applied to the resulting determined temperature gradients to calculate the path of the beam passing through an inhomogeneous atmosphere. From these values, the apparent vertical shifts caused by refraction in a given environment and time were finally determined.

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Evaluation of gooseberry cultivars resistance to the American gooseberry powdery mildew Sphaerotheca mors uvae Schwein and its chemical control

Plant Protection Science ◽

10.17221/10561-pps ◽

2017 ◽

Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽

pp. 583-587

Author(s):

M. Vaverka ◽

S. Vaverka

Keyword(s):

Biological Activity ◽

Czech Republic ◽

Powdery Mildew ◽

Chemical Control ◽

Biological Effect ◽

Field Trials ◽

The Czech Republic ◽

Biological Efficacy ◽

Extensive Field ◽

Susceptibility Evaluation

In the course of 1993–2001 extensive field trials were carried out to evaluate the resistance (susceptibility) level of 34 gooseberry cultivars to the American gooseberry powdery mildew Sphaerotheca mors uvae Schwein. Cultivars originated from the Czech Republic and from other European countries. Each tested cultivar had 7 trees (5–10 years old). Beside the resistance (susceptibility) evaluation, biological efficacy of 9 fungicides using EPPO methods has been checked at the same number of cultivars and at the same number of gooseberry trees. Highly significant differences of resistance or susceptibility were observed among gooseberry varieties. Analogical results (differences in biological activity of fungicides) have been attained in the course of chemical treatment. 18 cultivars has been classified as low resistant, 12 cultivars as moderate resistant and 4 cultivars as high resistant. None of the tested fungicides proved perfect biological efficacy (100% healthy berries). 4 of them proved high biological effect (more than 90% healthy berries), 3 proved low biological activity (less than 75% healthy berries) and 2 proved moderate biological activity (75–90% healthy berries).

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First record of powdery mildew on Homalocladium platycladum in the Czech Republic

Plant Pathology ◽

10.1111/j.1365-3059.2007.01594.x ◽

2007 ◽

Vol 56 (4) ◽

pp. 722-722 ◽

Cited By ~ 2

Author(s):

A. Lebeda ◽

B. Mieslerová ◽

V. Rybka ◽

M. Sedlářová ◽

I. Petrželová

Keyword(s):

Czech Republic ◽

Powdery Mildew ◽

First Record ◽

The Czech Republic

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An urban bias in air temperature fluctuations at the Klementinum, Prague, The Czech Republic

Atmospheric Environment ◽

10.1016/s1352-2310(99)00163-6 ◽

1999 ◽

Vol 33 (24-25) ◽

pp. 4211-4217 ◽

Cited By ~ 42

Author(s):

Rudolf Brázdil ◽

Marie Budı́ková

Keyword(s):

Czech Republic ◽

Air Temperature ◽

Temperature Fluctuations ◽

Urban Bias ◽

The Czech Republic

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Severity of powdery mildew on winter barley in the Czech Republic in 1976–2005

Plant Protection Science ◽

10.17221/2247-pps ◽

2008 ◽

Vol 43 (No. 3) ◽

pp. 77-85 ◽

Cited By ~ 3

Author(s):

A. Dreiseitl

Keyword(s):

Czech Republic ◽

Powdery Mildew ◽

Disease Severity ◽

Field Trials ◽

Winter Barley ◽

Sources Of Resistance ◽

The Czech Republic ◽

High Infection ◽

High Disease Severity ◽

Important Disease

Results of scoring the reaction to powdery mildew of 240 winter barley varieties that were gradually included in 392 Czech Official Trials conducted at 21 locations were analysed. The reaction of the varieties was determined on the basis of the level of infection by the disease. Therefore, the data can also be used to assess the disease severity in years and at locations. Several characteristics indicative of disease severity were considered, including the disease severity coefficient (= average infection of susceptible varieties in trials with a high disease severity/the proportion of such trials). The value of the coefficient is inversely proportional to disease severity. The highest powdery mildew severity was found in 1976, and the years 1988, 1990 and 2003 were characterised by high infection of the examined varieties. In contrast, the disease was practically absent in 1979 and 1982, and its severity was also low in 1978, 1981, 1985, 1991 and 1998. Very low disease severity was found for the period 1977–1982 when insufficient disease severity was found on average in 78% of the trials and high disease severity in only 6% of the trials. The highest disease severity was found at locations Trutnov, Horažďovice and Chrastava. The analysis of data from a large number of field trials conducted at various locations for a period of 30 years confirmed that powdery mildew is an important disease of winter barley in the Czech Republic. Known genetic sources of resistance and current methods, such as marker assisted selection, enable breeders to solve this problem.

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Fabian two-row winter barley

Czech Journal of Genetics and Plant Breeding ◽

10.17221/11/2013-cjgpb ◽

2013 ◽

Vol 49 (No. 4) ◽

pp. 175-177

Author(s):

Z. Nesvadba ◽

J. Špunar ◽

M. Kadlíková

Keyword(s):

Czech Republic ◽

Powdery Mildew ◽

Plant Height ◽

Cold Hardiness ◽

Medium Density ◽

The Czech Republic ◽

Variety Trials ◽

Growing Conditions ◽

Moderate Resistance ◽

Very High

Fabian is a medium-late two-row feedin barley of winter habit developed at Agrotest Fyto, Ltd., Kroměříž, Czech Republic (breeders’ rights holder) and registered in the Czech Republic in 2011. In the Official Variety Trials it showed high grain yields under intensive growing conditions (104.5%) and medium yields under low input conditions (101.1%). Fabian has the highest cold hardiness of the registered two-row winter barleys and regenerates very well in the spring. Its resistance to powdery mildew is very high (score 8.2 on a 1–9 scale). It has medium plant height, moderate resistance to lodging and large yellow kernel. The spike is long and of medium density.

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Virulence frequencies to powdery mildew resistance genes of winter barley cultivars

Plant Protection Science ◽

10.17221/466-pps ◽

2010 ◽

Vol 40 (No. 4) ◽

pp. 135-140 ◽

Cited By ~ 11

Author(s):

A. Dreiseitl

Keyword(s):

Czech Republic ◽

Powdery Mildew ◽

Resistance Genes ◽

Powdery Mildew Resistance ◽

Spring Barley ◽

Winter Barley ◽

The Czech Republic ◽

Mildew Resistance ◽

Barley Cultivars ◽

Random Samples

The virulence frequencies to powdery mildew resistance genes possessed by winter barley cultivars registered and newly tested in the Czech Republic were studied in 2000, 2002 and 2004. Random samples of the populations originating from winter and spring barley fields were obtained from the air by a mobile version of a jet spore sampler mounted on a car roof. Conidia were sampled by driving across the Czech Republic. Fourteen differentials, carrying 18 out of 20 currently identified resistance genes present in winter barley cultivars, were used. High virulence frequencies (85–100%) to most resistance genes were found. Lower virulence frequencies (14.1–40.1%) were found to only three resistance genes that have not been described yet; their preliminary designations are Ml(Va), Ml(Dt) and Ml(Ca). The importance of resistance of winter barley cultivars is discussed with respect to limiting the speed with which the pathogen adapts to genetic resistances possessed by commercial cultivars of both winter and spring barley, and to the necessity of lowering the costs for powdery mildew control in barley.

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