scholarly journals Pathogenicity of Fusarium species associated with crown and root rot of wheat (Triticum aestivum) under different condition

2019 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Bareen Sidqi Shareef Al-Tovi ◽  
Raed Abduljabbar Haleem
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Field Experiments ◽  
Fusarium Species ◽  
Test Tube ◽  
Spore Suspension ◽  
Wheat Crop ◽  
Pathogenicity Test ◽  
Crown And Root Rot

This study was conducted to test the pathogenicity of Fusarium species, the causes of crown and root rot disease of wheat crop, under three different conditions (Laboratory, Greenhouse and Field) and to show the best method for pathogenicity among different conditions. Pathogenicity test of six isolates of Fusarium species (F. graminearum, F. oxysporum, F. avenaceum, F. nivale, F. solani and F. udum) was tested on durum (Simeto) cultivar of wheat by test tube method in the laboratory, the tested fungi had substantial effect on seed germination. F. oxysporum showed the highest germination failure (44.44%) which significantly differed with other species. In the greenhouse, seedlings were inoculated by spore suspension at the base of each plant stem. The most virulent fungus after 35 days of inoculation was F. oxysporum (0.78) followed by F. solani (0.70) and F. graminearum (0.66), while the lowest disease severity was recorded by F. udum (0.16). Also in the field pathogenicity experiments of three Fusarium species (F. graminearum, F. oxysporum and F. solani) were performed on a durum (Simeto) and soft (Cham6) cultivars. Spore suspension was applied at the 2- to 3-leaf Zadoks’s growth stage. Disease severity was calculated at two stages of wheat growth (Booting and Ripening).The most virulent fungus was F. graminearum (0.42) that was significantly different from  other fungi. This work indicated that F. graminearum, F. oxysporum and F. solani showed higher infection than remaining tested species under threeconditions. Pathogenicity test in laboratory by test tube method (In-vitro) appeared more effective than greenhouse and field experiments

Influence of Glyphosate on Rhizoctonia Crown and Root Rot (Rhizoctonia solani) in Glyphosate-Resistant Sugarbeet

Weed Science ◽  
2012 ◽  
Vol 60 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Kelly A. Barnett ◽  
Christy L. Sprague ◽  
William W. Kirk ◽  
Linda E. Hanson
Keyword(s):  
Rhizoctonia Solani ◽  
Ammonium Sulfate ◽  
Disease Severity ◽  
Root Rot ◽  
Radial Growth ◽  
Field Experiments ◽  
Herbicide Treatments ◽  
Tolerant Variety ◽  
Crown And Root Rot

Previous greenhouse studies with a noncommercial glyphosate-resistant sugarbeet variety indicated that susceptibility to Rhizoctonia crown and root rot could increase after glyphosate was applied. Greenhouse and field experiments were conducted in 2008 and 2009 to determine if glyphosate influenced disease severity in potential commercially available varieties of glyphosate-resistant sugarbeet. In the first greenhouse experiment in 2008, Hilleshög 9027RR, the most tolerant variety to Rhizoctonia crown and root rot, exhibited an increase in disease severity when glyphosate was applied. There were no significant differences between herbicide treatments in Hilleshög 9028RR, and glyphosate decreased disease severity in Hilleshög 9032RR when compared with the no-herbicide treatment. Experiments conducted to determine if glyphosate influenced Rhizoctonia solani growth in vitro indicated that glyphosate did not increase the radial growth of R. solani, except at 10× (190 µg ae ml−1) the normal rate of glyphosate plus ammonium sulfate (AMS). Field and additional greenhouse experiments were conducted using four commercial varieties. Differences in disease severity were observed when comparing varieties, but glyphosate did not significantly influence the severity of Rhizoctonia crown and root rot when compared with the no-herbicide control. Choosing a glyphosate-resistant sugarbeet variety with the best demonstrated tolerance to Rhizoctonia crown and root rot is an important factor in reducing disease severity and maintaining sugarbeet yield.

scholarly journals Fungi associated with root and crown rot of wheat in the Kerman province of Iran

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Maryam Rouzbeh ◽  
Gholam Reza Baradaran
Keyword(s):  
Root Rot ◽  
Fusarium Species ◽  
Wheat Root ◽  
Fungal Species ◽  
Control Measures ◽  
Crown Rot ◽  
Pathogenicity Test ◽  
Potato Dextrose Agar Medium ◽  
Root And Crown Rot ◽  
Crown And Root Rot

In the growing season of 2016-17, the fungal agents associated with crown and root rot of wheat in the Kerman province of Iran were identified. For this purpose, different fields were randomly selected for sampling and percentages of disease were estimated. Infected parts of root and crown were surface sterilized and cultured on Potato Dextrose Agar medium. A total of 260 isolates were obtained and identified on the basis of macroscopic and microscopic characters and valid keys. Of the total isolates, 212 belonged to Fusarium, 28 to Bipolaris and 20 isolates belonged to Drechslera species. Fungal species included F. oxysporum (96 isolates), F. nivale (20 isolates), F. poae (18 isolates), F. anthophilum (9 isolates), F. subglutinans (22 isolates), F. solani (32 isolates), F. culmorum (11 isolate), F. proliferatum (2 isolate), F. chlamydosporum (2 isolates), B. kusanoi (11 isolates), B. australiensis (17 isolates) and D. tetrarrhene (20 isolates). The pathogenicity test was conducted using greenhouse root dip technique. The pathogenicity confirmed five Fusarium species, two Bipolaris and one Drechslera species associated with wheat root and crown rot in Kerman province of Iran. It is concluded that wheat root and crown rot is fairly distributed in the Kerman province and showed virulence of varying degrees demanding strict control measures to minimize losses.

EVALUATION OF ALFALFA CULTIVARS FOR REACTION TO CROWN AND ROOT ROT

1985 ◽  
Vol 65 (1) ◽  
pp. 95-98 ◽  
Author(s):  
R. MICHAUD ◽  
C. RICHARD
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Dry Matter ◽  
Forage Yield ◽  
Dry Matter Yield ◽  
Crown And Root Rot ◽  
Disease Free

Fourteen alfalfa cultivars were grown for 2 yr at three locations and evaluated for forage dry matter yield and crown and root rot. Significant differences were found among cultivars for dry matter yield. All cultivars were affected by crown and root rot, most cultivars showing between 20 and 30% of infected tissues. Differences were observed among as well as within the cultivars for disease severity. The frequency of disease-free plants was less than 1.3% of the plants evaluated. Correlation between root rot index and forage yield was −0.87 [Formula: see text] when data were pooled over years and locations.Key words: Lucerne, root rot, cultivar, yield

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.

scholarly journals Cultural Characteristics, Virulence and In-vitro Chemical Control of Fusarium oxysporum f. sp. phaseoli of Bush bean (Phaseolus vulgaris L.)

2014 ◽  
Vol 12 (1) ◽  
pp. 103-110 ◽  
Author(s):  
SS Siddique ◽  
MKA Bhuiyan ◽  
R Momotaz ◽  
GMM Bari ◽  
MH Rahman
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Growth Stages ◽  
Pathogenicity Test ◽  
Flowering Stage ◽  
Pathology Laboratory ◽  
Leaf Yellowing ◽  
Bush Bean ◽  
Different Growth Stages

An experiment was conducted at Microbiology Laboratory of Plant Pathology Department, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU) during 2007 to determine the virulence and variation in symptom development by Fusarium oxysporum f. sp. phaseoli isolates at different growth stages such as emergence and early vegetative stage, branching and rapid vegetative growth stage and early flowering stage of Bush bean, and in-vitro control of the pathogen with the selected fungicides. Eight isolates of this pathogen were collected from different pathology laboratory of BARI, BAU and BSMRAU. IS3 isolate collected from Bushbean seeds were found most virulent in pathogenicity test such as pre-emergence mortality, root rot, root lesion, leaf yellowing and wilting when this isolate was inoculated at different growth stages of bush bean. Four fungicides such as Vitavax, Rovral, Cupravit and Aimcozim were evaluated invitro to test the efficacy against isolate IS3. Aimcozim at different concentration (50-400 ppm) was found most effective in in-vitro evaluation. DOI: http://dx.doi.org/10.3329/agric.v12i1.19865 The Agriculturists 2014; 12(1) 103-110

Composts containing fluorescent pseudomonads suppress fusarium root and stem rot development on greenhouse cucumber

2010 ◽  
Vol 56 (11) ◽  
pp. 896-905 ◽  
Author(s):  
Geoffrey G. Bradley ◽  
Zamir K. Punja
Keyword(s):  
Disease Severity ◽  
Total Population ◽  
Fusarium Species ◽  
Severity Index ◽  
Stem Rot ◽  
Bacterial Strains ◽  
Growth Room ◽  
Greenhouse Cucumber ◽  
Layer Chromatography

Three composts (Ball, dairy, and greenhouse) were tested for the ability to suppress the development of Fusarium root and stem rot (caused by Fusarium oxysporum f. sp. radicis-cucumerinum) on greenhouse cucumber. Dairy and greenhouse composts significantly reduced disease severity (P = 0.05), while Ball compost had no effect. Assessment of total culturable microbes in the composts showed a positive relationship between disease suppressive ability and total population levels of pseudomonads. In vitro antagonism assays between compost-isolated bacterial strains and the pathogen showed that strains of Pseudomonas aeruginosa exhibited the greatest antagonism. In growth room trials, strains of P. aeruginosa and nonantagonistic Pseudomonas maculicola , plus 2 biocontrol strains of Pseudomonas fluorescens , were tested for their ability to reduce (i) survival of F. oxysporum, (ii) colonization of plants by the pathogen, and (iii) disease severity. Cucumber seedlings grown in compost receiving P. aeruginosa and P. fluorescens had reduced disease severity index scores after 8 weeks compared with control plants without bacteria. Internal stem colonization by F. oxysporum was significantly reduced by P. aeruginosa. The bacteria colonized plant roots at 1.9 × 106 ± 0.73 × 106CFU·(g root tissue)–1and survival was >107 CFU·(g compost)–1after 6 weeks. The locus for 2,4-diacetylphloroglucinol production was detected by Southern blot analysis and confirmed by PCR. The production of the antibiotic 2,4-diacetylphloroglucinol in liquid culture by P. aeruginosa was confirmed by thin layer chromatography. These results demonstrate that composts containing antibiotic-producing P. aeruginosa have the potential to suppress diseases caused by Fusarium species.

Effects of root inoculation and fungicide soil drenches on sclerotinia blight of coneflower

2000 ◽  
Vol 80 (4) ◽  
pp. 909-915 ◽  
Author(s):  
H. Wang ◽  
K. F. Chang ◽  
S. F. Hwang ◽  
G. D. Turnbull ◽  
R. J. Howard
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Dose Response ◽  
Root Rot ◽  
Field Experiments ◽  
Disease Incidence ◽  
Response Model ◽  
Inoculum Sources ◽  
Sclerotinia Blight ◽  
Seedling Roots

Greenhouse studies showed that root inoculation had significant effects on sclerotinia blight (Sclerotinia sclerotiorum) of coneflower (Echinacea sp.). Seedling wilt and root rot symptoms caused by S. sclerotiorum were most severe when inoculum was placed in direct contact with seedling roots, and diminished as the distance of the inoculum from the roots increased. When colonized agar disks, colonized oat grains and sclerotia as inoculum sources were evaluated on E. angustifolia, grain inoculum was the most virulent and sclerotia the least. An in vitro bioassay was conducted, and a logistic dose-response model was developed for the fungicides benomyl, vinclozolin, iprodione and dicloran. The first three fungicides were further evaluated in greenhouse experiments. Benomyl was the most effective in controlling S. sclerotiorum in both bioassay and greenhouse evaluations. The same three fungicides were evaluated in two field experiments in Alberta, where all were effective in reducing disease incidence. Key words: Echinacea sp., Sclerotinia sclerotiorum, dose-response model

scholarly journals Management of Anthracnose Disease of Aloe vera in Bangladesh

2021 ◽  
pp. 7-15
Author(s):  
Abu Noman Faruq Ahmmed ◽  
Md. Al-Amin Islam ◽  
Fatema Begum ◽  
Salma Sarker
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Bordeaux Mixture ◽  
Block Design ◽  
Aloe Vera ◽  
Pathogenicity Test ◽  
Traditional Use ◽  
Causal Organism ◽  
Anthracnose Disease ◽  
Garlic Bulb

Aims: To identify the causal organisms of anthracnose disease of Aloe vera in Bangladesh and to manage this disease in field condition. Study Design: The experiment was designed by Randomized Complete Block Design (RCBD) with three replications. Place and Duration of Study: The field experiments were conducted in Natore, Bangladesh and the laboratory experiments were carried out at the Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh from January, 2017 to December, 2018. Methodology: The causal organism Colletotrichum gloeosporioides was isolated by tissue plating method and identified based on morphological and cultural characteristics and that was confirmed by pathogenicity test. Infested farmer’s fields were selected in rainy season under natural epiphytic condition to evaluate the efficacy of eleven treatments. Results: Among the treatments, Bordeaux mixture gave best result against this disease. Moreover, Tilt 250 EC and Folicur 25 EC and Garlic bulb extract showed better effect against the disease than the other treatments. Lime also has moderate effect against anthracnose disease of A. vera. In 2017, after 4th spray, the lowest incidence was recorded in Bordeaux mixture (58.33%) which was statistically identical with Folicur (64.58%), Tilt (64.58%) and Garlic bulb extract (66.67%). Similarly, the lowest disease severity was found in Bordeaux mixture (3.55) followed by Folicur (5.67%), Tilt (6.67%) and Garlic bulb extract (7.67%). Similar result also found in 2018. After 4th spray, the lowest incidence was recorded in Bordeaux mixture (38.58%) which was statistically identical with Lime (41.66%) and Garlic bulb extract (45.83%). Similarly, the lowest disease severity was found in Bordeaux mixture (0.20%) followed by Lime (0.25%) and Garlic bulb extract (0.36%). Conclusion: Garlic bulb extract could be used as eco-friendly approach. Moreover, use of Bordeaux mixture is better than the traditional use of lime. From chemical pesticides, Tilt 250 EC and Folicur 25 EC could be used for controlling the disease as the last option.

scholarly journals Performance and Resistance to Phytophthora Crown and Root Rot in Squash Lines

2020 ◽  
Vol 30 (5) ◽  
pp. 608-618 ◽  
Author(s):  
Kyle E. LaPlant ◽  
Gregory Vogel ◽  
Ella Reeves ◽  
Christine D. Smart ◽  
Michael Mazourek
Keyword(s):  
Root Rot ◽  
Cucurbita Pepo ◽  
Field Experiments ◽  
Phytophthora Capsici ◽  
Severe Disease ◽  
Field Trials ◽  
Disease Symptoms ◽  
Resistant Lines ◽  
Oomycete Pathogen ◽  
Crown And Root Rot

Phytophthora crown and root rot, caused by the oomycete pathogen Phytophthora capsici, is a devastating disease of squash and pumpkin (Cucurbita pepo). No currently available cultivars provide complete resistance to this disease. Three newly developed squash lines and four hybrids were evaluated in greenhouse and field experiments for their resistance to phytophthora crown and root rot as well as for their horticultural performance. The three newly developed lines ranked among the most resistant entries included in 2 years of field trials. In addition, in a separate greenhouse experiment, one of the lines was shown to display the least severe disease symptoms among a group of accessions previously reported to possess partial resistance to phytophthora crown and root. Furthermore, the resistance was observed to be robust to several isolates of P. capsici. However, the phytophthora-resistant lines had reduced yield relative to standard squash cultivars. These lines are useful for continued breeding efforts toward a phytophthora crown and root rot-resistant cultivar.

scholarly journals Macro- and Microelement Fertilizers Influence the Severity of Fusarium Crown and Root Rot of Tomato in a Soilless Production System

HortScience ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 287-291 ◽  
Author(s):  
B.K. Duffy ◽  
G. Défago
Keyword(s):  
Disease Severity ◽  
Nutrient Solution ◽  
Root Rot ◽  
Management Strategy ◽  
Ammonium Nitrogen ◽  
Mineral Fertilizers ◽  
Solution Ph ◽  
Host Nutrition ◽  
Crown And Root Rot ◽  
Plant Pathogen Interactions

Host nutritional variables were evaluated for their effects on the severity of crown and root rot of tomato caused by Fusarium oxysporum f.sp. radicis-lycopersici. Tomato (Lycopersicon esculentum Mill.) seedlings (cv. Bonnie Best) were grown in a pathogen-infested, soilless rockwool system in the greenhouse and were fertilized with a nutrient solution that was amended with macro- and microelements at various rates. Disease was evaluated after 2 weeks using an index of 0 to 4, and plant fresh weight was measured. Regression analysis indicated that disease severity was significantly increased by ammonium-nitrogen [NH4Cl, (NH4)6Mo7O24, and (NH4)2SO4], NaH2PO4·H2O, Fe-EDDHA, MnSO4, MoO3, and ZnSO4·7H2O. Disease severity was reduced by nitrate-nitrogen [Ca(NO3)2·4H2O] and CuSO4·H2O. Low rates of NH4NO3 (39 to 79 mg·L-1 N) reduced disease, but rates above 100 mg·L-1 N increased it. Disease was not affected by MgSO4·7H2O. In all cases, plant growth was inversely related to disease severity. Mineral fertilizers had no effect on nutrient solution pH. This information sheds new light on environmental factors that influence plant-pathogen interactions, and may be applied to develop a management strategy for Fusarium crown and root rot based on host nutrition.

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