scholarly journals Spatial distribution of cabbage root maggot (Delia radicum) and clubroot (Plasmodiophora brassicae) in winter oilseed rape crops in the Czech Republic

2017 ◽  
Vol 53 (No. 3) ◽  
pp. 159-168
Author(s):  
Hlavjenka Vojtěch ◽  
Seidenglanz Marek ◽  
Dufek Aleš ◽  
Šefrová Hana
Keyword(s):  
Spatial Distribution ◽  
Czech Republic ◽  
Oilseed Rape ◽  
Plasmodiophora Brassicae ◽  
Surface Damage ◽  
Root Surface ◽  
Delia Radicum ◽  
Winter Oilseed Rape ◽  
Cabbage Root Maggot ◽  
Root Maggot

The amount and spatial distribution of plants afflicted with cabbage root maggot (Delia radicum; CRM) and clubroot (Plasmodiophora brassicae) in winter oilseed rape crops were assessed in the Olomouc region (Northern Moravia, Czech Republic) over the course of 2012–2014. A total of 16 commercial rape fields were included in the assessments. Plants with tumours showed a significantly lower (P < 0.001) level of infestation induced by CRM (24% of plants infested) compared to plants without tumours (37% of plants infested). According to a generalised linear mixed model, plants with thicker hypocotyls are predisposed to significantly higher levels (P < 0.001) of root surface damage induced by CRM. The correlation analysis indicates rather weak or intermediate levels of correlation between the two variables (hypocotyls thickness × root surface damage induced by CRM). Both CRM and clubroot symptomatic plants showed a significant tendency for aggregation in rape crops, but not in all cases. Distributions of CRM and clubroot symptomatic plants were either significantly spatially dissociated or not associated in crops. Ovipositing D. radicum females showed some tendency to avoid zones with higher number of plants infected by P. brassicae. Distributions of CRM and hypocotyl thickness levels were significantly spatially associated in crops in several cases.

Greenhouse and field experiments with winter oilseed rape cultivars resistant to Plasmodiophora brassicae Wor.

2017 ◽  
Vol 92 ◽  
pp. 60-69 ◽  
Author(s):  
Veronika Řičařová ◽  
Jan Kazda ◽  
Petr Baranyk ◽  
Pavel Ryšánek
Keyword(s):  
Oilseed Rape ◽  
Field Experiments ◽  
Plasmodiophora Brassicae ◽  
Winter Oilseed Rape

ROOT MAGGOT DAMAGE TO CANOLA AND THE DISTRIBUTION OF DELIA SPP. (DIPTERA: ANTHOMYIIDAE) IN MANITOBA

1992 ◽  
Vol 124 (1) ◽  
pp. 49-58 ◽  
Author(s):  
W.J. Turnock ◽  
B. Timlick ◽  
B.E. Galka ◽  
P. Palaniswamy
Keyword(s):  
First Generation ◽  
Delia Radicum ◽  
Feeding Damage ◽  
Yield Losses ◽  
Significant Yield ◽  
The Mean ◽  
Cabbage Root Maggot ◽  
Root Maggot ◽  
Agricultural Regions ◽  
Increasing Precipitation

AbstractThe cabbage root maggot, Delia radicum (L.), was the only Delia species capable of attacking undamaged roots of canola [oilseed rape, Brassica napus (L.)] that was found in commercial fields in Manitoba. Adults of the overwintering generation infest canola. Their progeny, adults of the first generation, left the maturing plants after completing a single generation. Root maggot damage occurred in fields in all agricultural regions of the province. The mean percentage of the roots with damage was higher in the more northerly agricultural regions (15.8%) than in the south (8.0%). Most of the damage was light and the damage did not visibly affect the growth or vigour of the plants. Foot rot fungi were not associated with the feeding damage. In cage experiments, the seed yield of canola did not decrease with increasing proportions of plants damaged by D. radicum. The percentage of plants with root maggot damage (DAM) was best described in a polynomial by the mean daily air temperature (TEMP) and the total precipitation (RAIN) for June and July:log(DAM + 1)=–12.3 + 0.66 TEMP + 0.09 RAIN – 0.004(TEMP × RAIN).The level of damage caused by the larvae of D. radicum to canola in commercial fields during the years 1985 through 1988 did not appear to have caused yield losses. However, the level of damage increased with increasing precipitation and temperature during June and July so a series of favourable years could lead to increased damage and possibly to significant yield losses.

scholarly journals Erroneous records of Aleochara bipustulata from North America: an assessment of the evidence

2005 ◽  
Vol 137 (2) ◽  
pp. 182-187 ◽  
Author(s):  
K.S. Hemachandra ◽  
N.J. Holliday ◽  
J. Klimaszewski ◽  
P.G. Mason ◽  
U. Kuhlmann
Keyword(s):  
North America ◽  
Classical Biological Control ◽  
Delia Radicum ◽  
Museum Specimens ◽  
Canadian Prairie ◽  
Aleochara Bilineata ◽  
Palearctic Species ◽  
Cabbage Root Maggot ◽  
Taxonomic Studies ◽  
Root Maggot

AbstractAleochara bipustulata (L., 1761) (Coleoptera: Staphylinidae) is a Palearctic species and a natural enemy of the cabbage root maggot, Delia radicum (L., 1758) (Diptera: Anthomyiidae). It has been identified as a candidate for introduction to Canada for classical biological control of D. radicum. Recent taxonomic studies assert that A. bipustulata is absent from the Nearctic; however, there are numerous publications reporting the presence of the species in North America. We examined voucher material relating to these publications and additional museum specimens labeled as A. bipustulata. In addition, we reared Aleochara spp. from D. radicum puparia collected in the Canadian prairie provinces. Specimens that, based on external anatomy, could be A. bipustulata were definitively identified using characters of the genitalia. All of the 141 museum specimens labeled A. bipustulata were found to be Aleochara verna Say, 1836. A total of 811 individuals of Aleochara spp. were reared from D. radicum puparia; of these, 690 were Aleochara bilineata Gyllenhal, 1810, 121 were A. verna, and none were A. bipustulata. We have found no evidence that A. bipustulata occurs in North America.

scholarly journals Influence of selected fungicides registered in the Czech Republic for winter oilseed rape on in vitro Sclerotinia sclerotiorum mycelial growth

2018 ◽  
Vol 54 (No. 2) ◽  
pp. 101-110 ◽  
Author(s):  
Poslušná Jana ◽  
Plachká Eva ◽  
Mazáková Jana
Keyword(s):  
Czech Republic ◽  
Oilseed Rape ◽  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Winter Oilseed Rape ◽  
Baseline Sensitivity ◽  
The Czech Republic ◽  
Dose Rates ◽  
The Mean

The baseline sensitivity of 55 isolates of Sclerotinia sclerotiorum, collected from oilseed rape in 6 regions of the Czech Republic, to selected fungicides was determined during the period 2013–2015. One single-component fungicide – Horizon (tebuconazole), and four multicomponent fungicides – Pictor (boscalid, dimoxystrobin), Efilor (boscalid, metconazole), Prosaro 250 EC (prothioconazole, tebuconazole), and Propulse (fluopyram, prothioconazole), were chosen as these are commonly used locally. The effect of each fungicide on the in vitro pathogen radial mycelial growth and EC<sub>50 </sub>values for the respective fungicides were determined. The following MIC values were estimated; for the fungicides Horizon 250 EW, Efilor, and Propulse the mean MIC values ranged between 0.125 and 0.250 µl/ml, for Prosaro 250 EC ranged between 0.0625 and 0.125 µl/ml, and for Pictor ranged from 0.00781 to 0.01562 µl/ml. No strains of S. sclerotiorum resistant to the tested fungicides were detected and the growth of all isolates was fully inhibited at concentrations corresponding to their registered dose rates. The highest fungicidal efficacy on the collected S. sclerotiorum isolates was recorded for Pictor, followed by Prosaro 250 with an EC<sub>50</sub> value 0.05856 µl/ml and then the remaining fungicides Propulse, Efilor, and Horizon 250 EW (EC<sub>50</sub> values 0.07277, 0.07221, and 0.08519 µl/ml, respectively).

scholarly journals Pathotypes of Plasmodiophora brassicae causing damage to oilseed rape in the Czech Republic and Poland

2016 ◽  
Vol 145 (3) ◽  
pp. 559-572 ◽  
Author(s):  
Veronika Řičařová ◽  
Joanna Kaczmarek ◽  
Stephen E. Strelkov ◽  
Jan Kazda ◽  
Wolfgang Lueders ◽  
...  
Keyword(s):  
Czech Republic ◽  
Oilseed Rape ◽  
Plasmodiophora Brassicae ◽  
The Czech Republic

INTERPOPULATION DIFFERENCES IN THE COLDHARDINESS OF DELIA RADICUM (DIPTERA: ANTHOMYIIDAE)

1998 ◽  
Vol 130 (2) ◽  
pp. 119-129 ◽  
Author(s):  
W.J. Turnock ◽  
G. Boivin ◽  
R.A. Ring
Keyword(s):  
British Columbia ◽  
North America ◽  
Cold Injury ◽  
Delia Radicum ◽  
Regression Equations ◽  
Founder Populations ◽  
The Mean ◽  
Cabbage Root Maggot ◽  
Lower Temperature ◽  
Root Maggot

AbstractThe cabbage root maggot, Delia radicum (L.), was introduced to North America in the mid-1800s, likely from northwestern Europe, and probably reached Quebec and British Columbia before 1885 and Manitoba by 1922. The mean temperature of crystallization (Tc) for overwintering pupae was −22.8 ± 1.2 °C for the St-Jean-sur-Richelieu, Quebec, population and −23.8 ± 0.7 °C for the Vancouver, British Columbia, population. The mean Tc for these two populations and for Winnipeg, Manitoba (−24.4 °C), Ascot, England (−22.8 °C), Tallinn, Estonia (−25.2 °C), and St. Petersburg, Russia (ca. −20 °C), did not show any relation to mean January temperatures. These locations represent both temperate oceanic and temperate continental climates and a range of mean January temperatures from +4.6 to −17.7 °C. Survival of puparia from St-Jean-sur-Richelieu exposed to nonfreezing temperatures decreased as temperature decreased and exposure time lengthened. The parameters for the regression equations describing this relationship were similar to those describing the Winnipeg population, and both were more coldhardy than the Ascot population. The upper limit of the cold injury zone (ULCIZ) for the St-Jean-sur-Richelieu population was −12.7 °C and the lower limit of this zone (LLCIZ) was −27.6 °C. Coldhardy populations from temperate continental climates (St-Jean-sur-Richelieu, Winnipeg) showed a rate of decrease in survival with increased cold stress (lower temperature, longer exposure) within the cold injury zone which was much slower than in the less coldhardy population (Ascot). Thus, some individuals from the coldhardy populations would be physiologically capable of surviving exposure to temperatures below Tc, whereas in the Ascot population nonfreezing injury would kill all the overwintering puparia at a temperature (−19.6 °C) well above Tc (−22.8 °C). The observed survival of puparia from Vancouver, following various nonfreezing exposures, resembled more closely the calculated survival for these exposures when the equations describing the Ascot population were used than when the equations for Winnipeg or St-Jean-sur-Richelieu were used. The Ascot and Vancouver populations, both from temperate oceanic climates, are less coldhardy than the populations from St-Jean-sur-Richelieu and Winnipeg (temperate continental climates). The founder populations of D. radicum in North America, which probably originated in the temperate oceanic climates of northwestern Europe, have adapted to the colder temperate continental climates by increasing their ability to survive longer exposures to all temperatures within the cold injury zone and not by lowering Tc. Therefore, selection for coldhardiness in D. radicum must have operated on structures, processes, or physiological-biochemical mechanisms that help the organism to avoid or repair nonfreezing cold injury but not on those that determine Tc.

scholarly journals Influence of Soil-Borne Inoculum of Plasmodiophora brassicae Measured by qPCR on Disease Severity of Clubroot-Resistant Cultivars of Winter Oilseed Rape (Brassica napus L.)

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 433
Author(s):  
Ann-Charlotte Wallenhammar ◽  
Zahra Saad Omer ◽  
Eva Edin ◽  
Anders Jonsson
Keyword(s):  
Disease Severity ◽  
Oilseed Rape ◽  
Plasmodiophora Brassicae ◽  
Severity Index ◽  
Field Trials ◽  
Substantial Variation ◽  
Winter Oilseed Rape ◽  
Brassica Napus L ◽  
Resistant Cultivars ◽  
Gene Copies

Use of resistant cultivars is considered the most effective tool in managing clubroot. Three clubroot-resistant commercial winter oilseed rape (OSR) cultivars and a susceptible ‘Cultivar mix’ were evaluated for disease severity index (DSI) and yield performance in field soils, selected for varying abundance of natural inoculum of Plasmodiophora brassicae. Seven field trials were carried out during 2017–2019 in winter OSR crops, and comparative bioassays were performed in a growth chamber. Substantial variation in clubroot infection between years was observed in the field trials. For Cultivar mix, a negative correlation (y = −252.3ln(x) + 58,897.6) was found between inoculum density and seed yield in five trials, whereas no correlation was found for the resistant cultivars. In bioassays, Cultivar mix exhibited a significantly high correlation between DSIb and number of gene copies g−1 soil (R2 = 0.72). For resistant cvs., Mentor and Alister, correlation was R2 = 0.45 and 0.58, respectively, indicating that resistance was under pressure. In field trials, DSIf of the resistant cultivars was lower (<27). The recommendation is thus to use clubroot-resistant cultivars of OSR as part of Integrated Pest Management in situations where abundance of P. brassicae DNA exceeds 1300 gene copies g−1 soil.

scholarly journals Detecting Pathogens of Verticillium Wilt in Winter Oilseed Rape Using ELISA and PCR – Comparison of the Two Methods and With Visual Stand Evaluation

2017 ◽  
Vol 65 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Tomáš Spitzer ◽  
Pavel Matušinsky
Keyword(s):  
Czech Republic ◽  
Oilseed Rape ◽  
Verticillium Wilt ◽  
Evaluation Methods ◽  
Winter Oilseed Rape ◽  
Visual Evaluation ◽  
The Czech Republic ◽  
Verticillium Longisporum ◽  
Main Species ◽  
Match Rate

During 2013–2015, oilseed rape samples from various locations in the Czech Republic were analysed for the presence of Verticillium wilt. Samples were evaluated in the lab using ELISA and PCR as well as by visual evaluation during the samples collection. A comparison of detection match in individual methods also was made. ELISA and PCR matched in detecting Verticillium wilt in 60 % of cases. For practical use, a higher match rate would be necessary in cases where samples were to be analysed in various laboratories using only one of these techniques. The possibility was demonstrated to use kits as well as primers not targeted specifically to just Verticillium longisporum but recording both main species on oilseed rape (V. longisporum and V. dahliae). The match rates of lab analyses with visual evaluation of stand infection were surprisingly high at 62 % for ELISA and 77 % for PCR. All three stand evaluation methods matched in 56 % of cases.

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