ASSESSMENT OF STROBILURIN RESISTANCE IN CERCOSPORA BETICOLA ON SUGAR BEET IN MICHIGAN AND NEBRASKA, USA

2013 ◽  
Author(s):  
William W Kirk ◽  
L. E. Hanson ◽  
N. Rosenzweig ◽  
G. D. Franc ◽  
W. L. Stump ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Cercospora Beticola

scholarly journals Sensitivity of Cercospora beticola Isolates to Azoxystrobin

2020 ◽  
Vol 69 (1-2) ◽  
pp. 1-4
Author(s):  
Milijanka Balandžić ◽  
Vera Stojšin ◽  
Mila Grahovac ◽  
Ferenc Bagi ◽  
Mladen Petreš ◽  
...  
Keyword(s):  
Biological Activity ◽  
High Risk ◽  
Sugar Beet ◽  
Mycelial Growth ◽  
Cercospora Beticola ◽  
Experimental Site ◽  
Sugar Beets ◽  
Qoi Fungicides ◽  
Moderately Resistant ◽  
Very High

SummarySugar beet leaf spot, caused by the air-borne fungus Cercospora beticola Sacc., leads to a decrease in sugar beet leaf mass and the consequent regrowth of leaves based on exploiting the sugar reserves stored in the plant’s roots, thus ultimately resulting in lower yields and sugar contents of sugar beets. Azoxystrobin belongs to the group of QoI fungicides, which inhibit mitochondrial respiration by blocking cytochrome c reductase. The QoI fungicides are characterized by a very high risk of resistance interfering with their biological activity. For the purpose of testing the azoxystrobin sensitivity of the Cercospora beticola population found at the site of Rimski Šančevi, a collection of 84 isolates was assembled and tested for sensitivity to azoxystrobin by measuring the mycelial growth on fungicide-amended media with the addition of SHAM. The results obtained indicate that none of the isolates tested exhibited complete sensitivity to azoxystrobin, 4% were found to have reduced sensitivity, 26% were moderately resistant and 70% were highly resistant. A higher proportion of resistant isolates recorded is associated with the loss of azoxystrobin biological efficacy at the experimental site.

scholarly journals Tolerance of certain sugar beet varieties to diseases

2008 ◽  
Vol 53 (3) ◽  
pp. 173-181
Author(s):  
S. Radivojevic ◽  
Irena Dosenovic ◽  
V. Filipovic ◽  
R. Rozic
Keyword(s):  
Statistical Analysis ◽  
Sugar Beet ◽  
Sugar Industry ◽  
Sugar Yield ◽  
Cercospora Beticola ◽  
Infestation Level ◽  
Chemical Analyses ◽  
Standard Methods ◽  
Trial Network ◽  
Second Year

Sugar beet varieties' micro trials were conducted at Kikinda site in 2005 and at five localities from the provincial trial network in 2006. The micro trials were set according to standard methods with 5 replications each year. Sugar beet was harvested at two periods in both years. Chemical analyses were conducted at the laboratories of the Faculty of Technology. The obtained data were processed according to the standard methods used in the Serbian sugar industry. Statistical analysis was performed using two-way ANOVA procedures. The results showed that varieties with triple tolerance to diseases (Solea and Gazeta) had marked performance in the trial at Kikinda site as compared to other varieties. Variety Solea was the highest in granulated sugar yield (10.941 t/ha) while control had 6.565 t/ha in the second harvest term at Kikinda site. The lowest infestation level with Cercospora beticola was recorded for the above mentioned varieties with triple tolerance and which were scored with 1.8 and 1.3 points, respectively, in the ranking scale that ranged from 0 to 5 points. Similar results were obtained in the second year of experiment. Variety Prestige, also triple tolerant to diseases, showed the best performance in the granulated sugar yield, yielding 13.969 t/ha. This variety showed the best tolerance to Cercospora beticola, being scored with only 0.4 points on the ranking scale for infestation level. Accordingly, the triple tolerant varieties of sugar beet were among the highest in the root and granulated sugar yields with equal number of treatments against Cercospora beticola.

scholarly journals Efficacy of Variable Tetraconazole Rates Against Cercospora beticola Isolates with Differing In Vitro Sensitivities to DMI Fungicides

Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1749-1756 ◽  
Author(s):  
Melvin D. Bolton ◽  
Viviana Rivera-Varas ◽  
Luis E. del Río Mendoza ◽  
Mohamed F. R. Khan ◽  
Gary A. Secor
Keyword(s):  
Sugar Beet ◽  
Disease Severity ◽  
Cercospora Beticola ◽  
In Planta ◽  
Sensitivity Testing ◽  
In Vitro Sensitivity ◽  
Wide Range ◽  
Fungicide Efficacy ◽  
Dmi Fungicides

Cercospora leaf spot (CLS) of sugar beet is caused by the fungus Cercospora beticola. CLS management practices include the application of the sterol demethylation inhibitor (DMI) fungicides tetraconazole, difenoconazole, and prothioconazole. Evaluating resistance to DMIs is a major focus for CLS fungicide resistance management. Isolates were collected in 1997 and 1998 (baseline sensitivity to tetraconazole, prothioconazole, or difenoconazole) and 2007 through 2010 from the major sugar-beet-growing regions of Minnesota and North Dakota and assessed for in vitro sensitivity to two or three DMI fungicides. Most (47%) isolates collected in 1997–98 exhibited 50% effective concentration (EC50) values for tetraconazole of <0.01 μg ml–1, whereas no isolates could be found in this EC50 range in 2010. Since 2007, annual median and mean tetraconazole EC50 values have generally been increasing, and the frequency of isolates with EC50 values >0.11 μg ml–1 increased from 2008 to 2010. In contrast, the frequency of isolates with EC50 values for prothioconazole of >1.0 μg ml–1 has been decreasing since 2007. Annual median difenoconazole EC50 values appears to be stable, although annual mean EC50 values generally have been increasing for this fungicide. Although EC50 values are important for gauging fungicide sensitivity trends, a rigorous comparison of the relationship between in vitro EC50 values and loss of fungicide efficacy in planta has not been conducted for C. beticola. To explore this, 12 isolates exhibiting a wide range of tetraconazole EC50 values were inoculated to sugar beet but no tetraconazole was applied. No relationship was found between isolate EC50 value and disease severity. To assess whether EC50 values are related to fungicide efficacy in planta, sugar beet plants were sprayed with various dilutions of Eminent, the commercial formulation of tetraconazole, and subsequently inoculated with isolates that exhibited very low, medium, or high tetraconazole EC50 values. The high EC50 isolate caused significantly more disease than isolates with medium or very low EC50 values at the field application rate and most reduced rates. Because in vitro sensitivity testing is typically carried out with the active ingredient of the commercial fungicide, we investigated whether loss of disease control was the same for tetraconazole as for the commercial product Eminent. The high EC50 isolate caused more disease on plants treated with tetraconazole than Eminent but disease severity was not different between plants inoculated with the very low EC50 isolate.

Comparative Structural Study of Leaf Spot Disease of Safflower and Sugar Beet by Cercospora beticola

2007 ◽  
Vol 6 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Robert T. Lartey ◽  
Andrew W. Lenssen ◽  
Robert G. Evans ◽  
Soumitra Ghoshroy
Keyword(s):  
Sugar Beet ◽  
Structural Study ◽  
Leaf Spot ◽  
Cercospora Beticola ◽  
Leaf Spot Disease ◽  
Spot Disease

scholarly journals Direct Polymerase Chain Reaction-Based Detection of Cercospora beticola in Field Soils

Plant Disease ◽  
2010 ◽  
Vol 94 (9) ◽  
pp. 1100-1104 ◽  
Author(s):  
R. T. Lartey ◽  
T. C. Caesar-TonThat ◽  
A. W. Lenssen ◽  
J. Eckhoff ◽  
S. L. Hanson ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Sugar Beet ◽  
Fragment Size ◽  
Rapid Screening ◽  
Cercospora Beticola ◽  
Field Soil ◽  
Chain Reaction ◽  
Field Soils ◽  
Total Dna ◽  
Polymerase Chain

Cercospora beticola, the causal agent of Cercospora leaf spot of sugar beet, survives as pseudostromata in infected sugar beet residues in the soil. Under optimal conditions, overwintering propagules germinate and produce conidia that are dispersed as primary inoculum to initiate infection in sugar beet. We developed a polymerase chain reaction (PCR) technique for rapid detection of C. beticola in field soils. Total DNA was first isolated from soil amended with C. beticola culture using the PowerSoil DNA Kit. The purified DNA was subjected to PCR in Extract-N-Amp PCR mix with CBACTIN primers over 35 cycles. The amplified products were resolved and compared by electrophoresis in 1% agarose gels. The PCR fragment size of C. beticola from the amended field soil correlated in size with the amplicon from control C. beticola culture DNA extract. Additionally, sample soils were collected from sugar beet fields near Sidney, MT and Foxholm, ND. Total DNA was extracted from the samples and subjected to PCR and resolved as previously described. The amplicons were purified from the gels and subjected to BigDye Terminator Cycle sequencing. All sequences from field soils samples, C. beticola-amended field soil, and pure culture were compared by alignment with a C. beticola actin gene sequence from GenBank. The result of the alignment confirmed the amplicons as products from C. beticola. Rapid screening for the presence of C. beticola in the soil by PCR will improve research capabilities in biological control, disease forecasting, and management of this very important sugar beet pathogen.

scholarly journals Non-invasive Presymptomatic Detection of Cercospora beticola Infection and Identification of Early Metabolic Responses in Sugar Beet

2016 ◽  
Vol 07 ◽  
Author(s):  
Nadja Arens ◽  
Andreas Backhaus ◽  
Stefanie Döll ◽  
Sandra Fischer ◽  
Udo Seiffert ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Metabolic Responses ◽  
Cercospora Beticola ◽  
Non Invasive
Sign in / Sign up

Export Citation Format

Share Document