scholarly journals Effect of Sugar Beet Variety and Nonhost Plant on Rhizoctonia solani AG2-2IIIB Soil Inoculum Potential Measured in Soil DNA Extracts

2016 ◽  
Vol 106 (9) ◽  
pp. 1047-1054 ◽  
Author(s):  
Sascha Schulze ◽  
Heinz-Josef Koch ◽  
Bernward Märländer ◽  
Mark Varrelmann
Keyword(s):  
Sugar Beet ◽  
Rhizoctonia Solani ◽  
Soil Samples ◽  
Resistant Variety ◽  
Winter Rye ◽  
Inoculum Potential ◽  
Soil Dna ◽  
Soil Inoculum ◽  
Sugar Beet Variety ◽  
Soil Inoculum Potential

A direct soil DNA extraction method from soil samples (250 g) was applied for detection of the soilborne sugar-beet-infecting pathogen Rhizoctonia solani anastomosis group (AG) 2-2IIIB using a newly developed real-time polymerase chain reaction assay that showed specificity to AG2-2IIIB when tested against various R. solani AG. The assay showed a good relation between cycle threshold and amount of AG2-2IIIB sclerotia detected in three spiked field soils and was also able to detect the pathogen in naturally infested field soil samples. A field trial was conducted to quantify R. solani AG2-2IIIB soil inoculum potential (IP) before and after growing a susceptible and a resistant sugar beet variety as well as after subsequent growth of an expected nonhost winter rye. Plants of the susceptible sugar beet variety displayed a higher disease severity. A more than sixfold increase of the R. solani AG2-2IIIB soil IP was observed in contrast to the resistant variety that resulted in a constant IP. Growing winter rye significantly reduced soil IP to the initial level at sowing. Further research is required to better understand the interaction between disease occurrence and soil IP as well as the environmental influence on IP development.

scholarly journals Control of Rhizoctonia solani in Sugar Beet and Effect of Fungicide Application and Plant Cultivar on Inoculum Potential in the Soil

Plant Disease ◽  
2017 ◽  
Vol 101 (6) ◽  
pp. 941-947 ◽  
Author(s):  
Anika Bartholomäus ◽  
Stefan Mittler ◽  
Bernward Märländer ◽  
Mark Varrelmann
Keyword(s):  
Sugar Beet ◽  
Rhizoctonia Solani ◽  
Natural Infection ◽  
Resistance Management ◽  
The United States ◽  
Similar Efficacy ◽  
Field Trials ◽  
Crown Rot ◽  
Inoculum Potential ◽  
Fungicide Application

Rhizoctonia solani (AG 2-2 IIIB) is the causal agent of Rhizoctonia root and crown rot, a disease that causes severe economic problems in sugar beet growing areas worldwide. In the United States, azoxystrobin is the most important active ingredient for fungicidal control of R. solani in sugar beet, showing efficacy superior to other substances. First reports on resistance development in R. solani, however, underline the importance of a careful fungicide resistance management. For this reason, the efficacy of a new fungicide mixture of azoxystrobin and difenoconazole was compared with a fungicide containing only azoxystrobin. Field trials were carried out under natural infection conditions as well as with inoculation in the years 2012, 2013, and 2014. Evaluation of the disease severity and the obtained white sugar yield of different sugar beet cultivars demonstrated that both fungicide treatments possess a similar efficacy, reducing the diseased beet surface by up to 78% and preventing yield losses. Additionally, a real-time PCR assay, based on DNA extracts from representative soil samples (250 g), was used to directly determine the effect of chemical treatment and plant cultivar on the soil-borne inoculum. Fungicide application significantly reduced the concentration of soil-borne inoculum by up to 97%. Furthermore, the results demonstrated that the cultivation of a susceptible cultivar significantly increases the concentration of R. solani in the soil by a factor of 200. In conclusion, the study implies that only a combination of resistant cultivar and fungicide application can prevent an accumulation of R. solani inoculum under conducive conditions in infested fields.

scholarly journals Aphanomyces euteiches Inoculum Potential: A Rolled-Towel Bioassay Suitable for Fine-Textured Soils

Plant Disease ◽  
1998 ◽  
Vol 82 (4) ◽  
pp. 386-390 ◽  
Author(s):  
J. L. Williams-Woodward ◽  
F. L. Pfleger ◽  
R. R. Allmaras ◽  
V. A. Fritz
Keyword(s):  
Random Error ◽  
Superior Performance ◽  
Steam Treatment ◽  
Multiple Infection ◽  
Root Tip ◽  
Inoculum Potential ◽  
Aphanomyces Euteiches ◽  
Soil Inoculum ◽  
Soil Volume ◽  
Soil Inoculum Potential

A sensitive measure of soil inoculum potential is needed to evaluate field management of common root rot (Aphanomyces euteiches) in peas (Pisum sativum). A modified rolled-towel (RT) bioassay had been proposed to measure soil inoculum potential in fine-textured soils used for pea production in Minnesota. Homogenized soil was used because organic debris containing the inoculum could not be separated by wet sieving. The poor precision prompted an evaluation of procedures to improve this modified RT bioassay. Seed treatment with a 5% solution of sodium hypochlorite before pea seed germination and plant isolation procedures during the RT bioassay preparation/incubation reduced seedborne contamination and seedling loss to less than 5%. Tests conducted with pasteurized soil that was artificially infested with oospores showed the region of the pea taproot 1 to 2 cm below the seed to be more susceptible to infection (33% compared with 15% infected seedlings) than the region 1 to 2 cm above the root tip. A soil volume of 1.0 cm3 increased inoculum potential compared with 0.5 cm3 applied to each seedling but did not influence the random error; the 40-seedling compared with the 20-seedling RT bioassay reduced random error from 18 to 12%. The modified RT bioassay conducted on soil that was artificially infested after steam treatment or without steam treatment showed superior performance when using 40 seedlings compared with 20 seedlings when evaluated for accuracy and precision. Multiple infection theory demonstrated more multiple infections in the RT bioassay with a 0.5 cm3 soil volume applied to each seedling, which shows that soil mass is a factor preventing a higher percentage of infected seedlings. These modifications to the RT bioassay improved the method enough to reduce the random error by one-half compared with using homogenized soil without the proposed modifications.

scholarly journals (115) Soil Inoculum Potential and Mycorrhizal Colonization of Acer rubrum in Forested and Developed Landscapes

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1079D-1079
Author(s):  
P. Eric Wiseman ◽  
Christina Wells
Keyword(s):  
Forest Soils ◽  
Mycorrhizal Fungi ◽  
Acer Rubrum ◽  
Chemical Properties ◽  
Soil Disturbance ◽  
Native Forest ◽  
Inoculum Potential ◽  
Soil Inoculum ◽  
Forest Sites ◽  
Soil Inoculum Potential

Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with numerous landscape tree species and can improve tree growth and environmental stress tolerance. Construction-related soil disturbance is thought to diminish AMF colonization of transplanted trees in newly developed landscapes. We gathered root, soil, and foliar data from red maples (Acer rubrum) growing in newly developed landscape sites and adjacent native forest sites to test the hypotheses that: 1) landscape trees show lower levels of AMF colonization than forest trees; and 2) the AMF inoculum potential of landscape soils is lower than that of forest soils. Fine roots sampled from landscape maples had significantly lower AMF colonization than maples from adjacent forest sites (3% vs. 22%; P= 0.0002). However, soil-sand mixtures made from landscape soils possessed greater AMF inoculum potential than those made from forest soils (10% vs. 4%; P= 0.0081). Forest soils were more acidic and possessed less extractable P than landscape soils, and differences in AMF colonization between forest and landscape maples appeared to reflect differences in soil chemical properties rather than in soil inoculum potential.

EFFECTIVENESS OF DOSING APPLICATION OF BENATAL GROUP HERBICIDES IN SUGAR BEET SOWING

1970 ◽  
pp. 49-51
Author(s):  
V. Z. Venevtsev ◽  
М. N. Zakharova ◽  
L. V. Rozhkova
Keyword(s):  
Sugar Beet ◽  
Agricultural Research ◽  
Humus Content ◽  
Crop Protection ◽  
Experimental Plot ◽  
Agricultural Research Institute ◽  
Row Crops ◽  
Sugar Beet Variety ◽  
Sowing Machine

Ryazan region annually receives stable yields of sugar beet roots 40 t/ha. Further growth of yields depends on balanced nutrition of plants cultivated hybrids, from the quality of the soil and of the phytosanitary State of sowing culture. Weed vegetation in wider spaced row crops of sugar beet in the initial periods of vegetation is high competition culture. The article presents the results of three studies on the effectiveness of the herbicide betanalnoj group, used to reduce contamination of sowing culture annual dicotyledonous weeds and increase the harvest of sugar beet roots. Studies conducted on experimental fields ISSA-branch FGBNU FNAC WIM (former AGRICULTURAL RESEARCH INSTITUTE in Ryazan). Soil: dark grey forest tjazhelosuglinistaja, humus content 4.0%, potassium and phosphorus-high pH is 5.8. Area of cultivated plots 50 m2, repetition, four sugar beet variety-Ocean. The predecessor-winter wheat. Under the autumn ploughing had made NPK120 under presowing cultivation-N60, SEV conducted seeder sowing machine. For crop protection herbicides were tested annually of sugar beet Betanal progress, UF-1.0 l/HA, Forte di Belvedere-1.0 l/HA, Betanal Max Pro-1.5 l/HA, Bajrang engineering works Super-1.5 l/HA, once applied to weeds. The harvest of sugar beet roots, take into account the square 10 m2 in 4-times repeated with each experimental plot by weighing machinery, processed data by ANOVA. The research found that studied herbicides efficiently at 87-92%, reduced infestation annual dicotyledonous weeds and increase the harvest of sugar beet roots to 29.9-44.1%

Influence of a BactoFil microbiological preparation on the intensity of infection by Rhizoctonia solani and the effects on sugar beet yield and quality

2012 ◽  
pp. 102-109
Author(s):  
Suzana Kristek ◽  
Andrija Kristek ◽  
Dragana Kocevski ◽  
Antonija K. Jankovi ◽  
Dražen Juriši
Keyword(s):  
Sugar Beet ◽  
Rhizoctonia Solani ◽  
Nitrogen Fertilizer ◽  
Soil Analysis ◽  
Block Design ◽  
Sugar Content ◽  
Pathogenic Fungi ◽  
Fertilizer Application ◽  
Beet Root ◽  
Set Up

The experiment was set up on two types of the soil: Mollic Gleysols (FAO, 1998) and Eutric Cambisols where the presence of pathogenic fungi – sugar beet root decay agent – Rhizoctonia solani has been detected since 2005. In a two year study (2008, 2009), the experiment was set up by completely randomized block design in 4 repetitions and 16 different variants. Two beet varieties, Belinda, sensitive to pathogenic fungi R. solani, and Laetitia, tolerant to pathogenic fungi R. solani), were grown. The microbiological preparation BactoFil was applied in different amounts in autumn and spring. In addition, the nitrogen fertilizer application, based on the results of soil analysis, was varied. The following parameters were tested: amount of infected and decayed plants, root yield, sugar content, sugar in molasses and sugar yield. The best results were obtained by applying the microbiological preparation BactoFil, and by 30% reduced nitrogen fertilizer application. Preparation dosage and time of application depended on soil properties.

Beet necrotic yellow vein virus genome reassortments in a resistant sugar beet variety showing–in a small area in France–strong rhizomania symptoms

2009 ◽  
Vol 116 (1) ◽  
pp. 7-9 ◽  
Author(s):  
R. Koenig ◽  
B. Holtschulte ◽  
G. Deml ◽  
P. Lüddecke ◽  
S. Schuhmann ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Small Area ◽  
Virus Genome ◽  
Yellow Vein ◽  
Sugar Beet Variety

scholarly journals Penicillium pinophilum has the Potential to Reduce Damping-off Caused by Rhizoctonia solani in Sugar Beet

Sugar Tech ◽  
2021 ◽  
Author(s):  
Md Ehsanul Haque ◽  
Dilip K. Lakshman ◽  
Aiming Qi ◽  
Mohamed F. R. Khan
Keyword(s):  
Sugar Beet ◽  
Rhizoctonia Solani ◽  
Damping Off ◽  
Penicillium Pinophilum

Correlation between lipid peroxidation and phenolics content in leaves and roots of sugar beet infected with Rhizoctonia solani

2013 ◽  
Vol 42 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Biljana Kiprovski ◽  
Djordje Malenčić ◽  
Milan Popović ◽  
Vera Stojšin ◽  
Dragana Budakov ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Sugar Beet ◽  
Rhizoctonia Solani ◽  
Phenolics Content ◽  
Leaves And Roots

scholarly journals Sensitivity of Rhizoctonia solani AG-2-2 from Sugar Beet to Fungicides

Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
Sahar Arabiat ◽  
Mohamed F. R. Khan
Keyword(s):  
Sugar Beet ◽  
Rhizoctonia Solani ◽  
Root Rot ◽  
The United States ◽  
Damping Off ◽  
Growth Assay ◽  
The Mean ◽  
Crown And Root Rot ◽  
Mean Concentration

Rhizoctonia damping-off and crown and root rot caused by Rhizoctonia solani are major diseases of sugar beet (Beta vulgaris L.) worldwide, and growers in the United States rely on fungicides for disease management. Sensitivity of R. solani to fungicides was evaluated in vitro using a mycelial radial growth assay and by evaluating disease severity on R. solani AG 2-2 inoculated plants treated with fungicides in the greenhouse. The mean concentration that caused 50% mycelial growth inhibition (EC50) values for baseline isolates (collected before the fungicides were registered for sugar beet) were 49.7, 97.1, 0.3, 0.2, and 0.9 μg ml−1 and for nonbaseline isolates (collected after registration and use of fungicides) were 296.1, 341.7, 0.9, 0.2, and 0.6 μg ml−1 for azoxystrobin, trifloxystrobin, pyraclostrobin, penthiopyrad, and prothioconazole, respectively. The mean EC50 values of azoxystrobin, trifloxystrobin, and pyraclostrobin significantly increased in the nonbaseline isolates compared with baseline isolates, with a resistant factor of 6.0, 3.5, and 3.0, respectively. Frequency of isolates with EC50 values >10 μg ml−1 for azoxystrobin and trifloxystrobin increased from 25% in baseline isolates to 80% in nonbaseline isolates. Although sensitivity of nonbaseline isolates of R. solani to quinone outside inhibitors decreased, these fungicides at labeled rates were still effective at controlling the pathogen under greenhouse conditions.

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