scholarly journals Development of Brown Patch and Pythium Blight in Tall Fescue as Affected by Irrigation Frequency, Clipping Removal, and Fungicide Application

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 543-546 ◽  
Author(s):  
D. M. Settle ◽  
J. D. Fry ◽  
N. A. Tisserat
Keyword(s):  
Rhizoctonia Solani ◽  
Tall Fescue ◽  
Pythium Aphanidermatum ◽  
Irrigation Frequency ◽  
Brown Patch ◽  
Fungicide Application

We studied the effects of irrigation frequency, clipping removal, and fungicide application on the development of Rhizoctonia brown patch (Rhizoctonia solani) and Pythium blight (Pythium aphanidermatum) in tall fescue. Brown patch severity was not significantly different between plots irrigated daily and those irrigated on alternate days. Similarly, no differences in brown patch were observed in plots where grass clippings were returned to the sward with a mulching mower compared with plots where clippings were removed. Preventive applications of azox-ystrobin at 35-day intervals or postinfection applications of chlorothalonil reduced brown patch severity, but only the azoxystrobin treatment provided aesthetically acceptable (<10%) levels of brown patch control. However, azoxystrobin applications also increased Pythium blight compared with untreated or chlorothalonil-treated tall fescue, especially in plots that received daily irrigation.

scholarly journals Impact of Bispyribac-sodium Application on Annual Bluegrass Control and Brown Patch Severity in Tall Fescue

2012 ◽  
Vol 30 (4) ◽  
pp. 195-200
Author(s):  
Matthew Cutulle ◽  
Jeffrey Derr ◽  
Adam Nichols ◽  
David McCall ◽  
Brandon Horvath
Keyword(s):  
Rhizoctonia Solani ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Iron Supplementation ◽  
Field Research ◽  
Field Trials ◽  
Control Field ◽  
Brown Patch ◽  
Annual Bluegrass ◽  
Application Rates

Annual bluegrass (Poa annua L.) is a problematic weed in tall fescue [Festuca arundinacea (Schreb.) S.J. Darbyshire], with limited options available for postemergence control. Field research was conducted to evaluate bispyribac-sodium application rates (37 or 74 g ai·ha−1) (0.033 or 0.066 lb ai·A−1) and timings (March, April or May) as well as iron supplementation on brown patch (Rhizoctonia solani) severity, annual bluegrass control, and tall fescue quality. In general, applying bispyribac-sodium to tall fescue did not result in significantly more brown patch than in untreated plots in field trials. Applying bispyribac-sodium in March or April resulted in significantly higher annual bluegrass control than applications in May. In greenhouse experiments, bispyribac-sodium at 37 and 74 g ai·ha−1 (0.033 or 0.066 lb ai·A−1) was applied to brown patch-inoculated tall fescue plants. Under conditions of high inoculum and humidity in those greenhouse studies, applications of bispyribac-sodium increased the number of brown patch lesions relative to untreated plants. Tall fescue plant height was initially reduced after being treated with bispyribac-sodium; however, six weeks after application tall fescue plants in treated with herbicide were taller than the nontreated plants.

Effect of Brown Patch (Caused by Rhizoctonia solani) Control on Preemergence Herbicide Efficacy in Tall Fescue (Festuca arundinacea)1

2003 ◽  
Vol 17 (4) ◽  
pp. 747-750 ◽  
Author(s):  
JASON A. FERRELL ◽  
TIM R. MURPHY ◽  
LEON L. BURPEE ◽  
WILLIAM K. VENCILL
Keyword(s):  
Rhizoctonia Solani ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Brown Patch

scholarly journals Screening Tall Fescue for Resistance to Rhizoctonia solani and Rhizoctonia zeae Using Digital Image Analysis

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 358-362
Author(s):  
Virginia R. Sykes ◽  
Brandon J. Horvath ◽  
David S. McCall ◽  
Antonius B. Baudoin ◽  
Shawn D. Askew ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Disease Severity ◽  
Tall Fescue ◽  
Block Design ◽  
Geographic Variability ◽  
Resistance Response ◽  
Brown Patch ◽  
Plant Introductions ◽  
Randomized Complete Block Design ◽  
Rhizoctonia Zeae

Brown patch, caused by Rhizoctonia solani, is a destructive disease on tall fescue. Compared with R. solani, Rhizoctonia zeae causes indistinguishable symptoms in the field but varies in geographic distribution. This may contribute to geographic variability observed in the resistance response of improved brown patch–resistant cultivars. This study examined R. solani and R. zeae susceptibility of four cultivars, selected based on brown patch performance in the National Turfgrass Evaluation Program (NTEP), and nine plant introductions (PIs). Twenty genotypes per PI/cultivar were evaluated by using four clonal replicates in a randomized complete block design. Plants were inoculated under controlled conditions with two repetitions per pathogen. Disease severity was assessed digitally in APS Assess, and analysis of variance and correlations were performed in SAS 9.3. Mean disease severity was higher for R. solani (65%) than for R. zeae (49%) (P = 0.0137). Interaction effects with pathogen were not significant for PI (P = 0.0562) but were for genotype (P < 0.001). Moderately to highly resistant NTEP cultivars compared with remaining PIs exhibited lower susceptibility to R. zeae (P < 0.0001) but did not differ in susceptibility to R. solani (P = 0.7458). Correlations between R. solani and R. zeae disease severity were not significant for either PI (R = 0.06, P = 0.8436) or genotype (R = 0.11, P = 0.09). Breeding for resistance to both pathogens could contribute to a more geographically stable resistance response. Genotypes were identified with improved resistance to R. solani (40), R. zeae (122), and both pathogens (26).

scholarly journals Evaluation of Chitinase Activity in Tall Fescue Cultivars Inoculated with Rhizoctonia solani

2015 ◽  
Vol 33 (4) ◽  
pp. 143-147
Author(s):  
Matthew Cutulle ◽  
Jeffrey Derr ◽  
David McCall ◽  
Adam Nichols ◽  
Brandon Horvath ◽  
...  
Keyword(s):  
United States ◽  
Rhizoctonia Solani ◽  
Tall Fescue ◽  
The United States ◽  
Chitinase Activity ◽  
The Other ◽  
Brown Patch ◽  
Great Utility ◽  
Before And After ◽  
Humidity Chamber

Tall fescue has great utility as a low maintenance turfgrass in the northern and transition zone regions of the United States. A factor limiting tall fescue utility is its susceptibility to the pathogen Rhizoctonia solani Kuhn, the causal agent of foliar brown patch. Chitinase activity has been positively correlated with resistance to R. solani in other plant species. A chitinase assay was developed for tall fescue. Three tall fescue cultivars with differing agronomic qualities and brown patch susceptibility as well as a resistant hybrid bluegrass cultivar were inoculated with R. solani in a greenhouse humidity chamber. Chitinase activity 48 hours after inoculation was negatively correlated with percent brown patch severity 10 days after inoculation. ‘Jaguar’ tall fescue was the most tolerant to R. solani and exhibited the highest chitinase activity before and after inoculation. No significant increase in chitinase activity was observed in the other tall fescue cultivars following R. solani inoculation. Identifying tall fescue cultivars expressing high amounts of chitinase activity could be important for developing brown patch-tolerant tall fescue cultivars.

Effect of Mowing Height and Fertility on Bermudagrass (Cynodon dactylon) Encroachment and Brown Patch Severity in Tall Fescue

2014 ◽  
Vol 28 (1) ◽  
pp. 225-232 ◽  
Author(s):  
Matthew Cutulle ◽  
Jeffrey Derr ◽  
David McCall ◽  
Adam Nichols ◽  
Brandon Horvath
Keyword(s):  
United States ◽  
Rhizoctonia Solani ◽  
Transition Zone ◽  
Tall Fescue ◽  
Nitrogen Fertilization ◽  
Cynodon Dactylon ◽  
The United States ◽  
Field Trials ◽  
Brown Patch ◽  
Fertilization Level

Tall fescue is a commonly used turfgrass in the temperate and transition zone areas of the United States. During hot, humid summers, tall fescue is under stress and is susceptible toRhizoctonia solani(brown patch) infection, causing turf thinning, leading to encroachment from weeds, such as bermudagrass. Field trials were established to evaluate the effect of mowing height and fertility programs on disease severity and bermudagrass encroachment in tall fescue. Mowing at 10 cm resulted in less bermudagrass encroachment than did a 6-cm mowing height. Increasing the nitrogen fertilization level from 49 to 171 and 220 kg N ha−1generally led to more bermudagrass encroachment at the 6-cm, but not the 10-cm, mowing height. Plots receiving 220 kg N ha−1annually at the 6-cm mowing height had the most brown patch. Turfgrass cover was greatest in plots mowed at 10 cm and receiving 220 kg N ha−1annually.

scholarly journals A Dimorphic and Virulence-Enhancing Endosymbiont Bacterium Discovered in Rhizoctonia solani

2017 ◽  
Vol 1 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Ken Obasa ◽  
Frank F. White ◽  
John Fellers ◽  
Megan Kennelly ◽  
Sanzhen Liu ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Dna Analysis ◽  
Higher Plants ◽  
Intracellular Localization ◽  
Creeping Bentgrass ◽  
Single Species ◽  
Cool Season ◽  
Plant Host ◽  
Brown Patch ◽  
Bacterial Endosymbionts

The ubiquitous soilborne and plant-pathogenic basidiomycete Rhizoctonia solani, although classified as a single species, is a complex of anastomosis groups (AGs) that cause disease in a broad range of higher plants. Here, we investigated the persistent co-isolation of bacteria with R. solani from brown patch-infected, cool-season turfgrasses, and report the presence of endo-hyphal bacteria, related to members in the genus Enterobacter, in an isolate of R. solani AG 2-2IIIB. The intracellular localization of the bacteria was corroborated by fluorescence, confocal and electron microscopy, and DNA analysis. Furthermore, the Enterobacter sp., which is rod-shaped in the free-living form, exists as an L-form (spheroid) within the fungus, a phenomenon not previously reported in endosymbionts. Our findings also indicate that the bacterium is required for full virulence of R. solani on creeping bentgrass and production of wild type levels of the toxin phenylacetic acid in fungal cultures. The possible presence of bacterial endosymbionts in R. solani AG 2-2IIIB may portend the presence of bacteria in additional AGs as well as other Rhizoctonia species, and may help resolve some of the complexities of R. solani pathogenicity. A closely associated bacterium could influence aspects of plant host pathology.

A Fungicide Application Decision (FAD) Support System for Postbloom Fruit Drop of Citrus (PFD)

2002 ◽  
Vol 3 (1) ◽  
pp. 16 ◽  
Author(s):  
Natália A. R. Peres ◽  
Soonho Kim ◽  
Howard W. Beck ◽  
Nilton L. Souza ◽  
Lavern W. Timmer
Keyword(s):  
Rhizoctonia Solani ◽  
Support System ◽  
Thielaviopsis Basicola ◽  
Seedling Disease ◽  
Cotton Seedling ◽  
Fungicide Application ◽  
Disease Complex ◽  
Fruit Drop ◽  
Application Decision ◽  
Seedling Diseases

Surveys were conducted to identify fungi associated with postemergence cotton seedling disease in Missouri. Samples consisted of 10 cotton seedlings, 2 to 3 weeks after emergence, with symptoms of seedling diseases collected from a 0.25 ha area in each of 60 fields in 1997 and 1998. Four genera of fungi were cultured from the roots (Fusarium, Pythium, Rhizoctonia, and Thielaviopsis) and three species were identified: Rhizoctonia solani, Thielaviopsis basicola, and Pythiumultimum. Rhizoctonia solani, T. basicola, and P. ultimum were cultured from seedlings in 70%, 47%, and 15% of fields sampled in 1997, respectively, and 55%, 17%, and 5% of fields sampled in 1998, respectively. Repeated tests of pathogenicity confirmed that R. solani AG-4, T. basicola, and P. ultimum were major causal agents of postemergence cotton seedling disease in Missouri. This study provides the first documentation on the distribution and frequency of fungi associated with postemergence seedling disease complex of cotton based on a survey of randomly selected fields. Accepted for publication 10 July 2002. Published 31 July 2002.

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.

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