Effect of organic amendments on sclerotial germination, mycelial growth, and Sclerotium rolfsii-induced diseases

The addition of organic residues to soil is an option to control some soil-borne diseases. Benzaldehyde and powders of kudzu (Pueraria lobata), velvetbean (Mucuna deeringiana), and pine-bark (Pinus elliottii and P. taeda) added to soil could reduce certain soil-borne diseases. This study evaluated the effects of benzaldehyde and the dried powders of kudzu, velvetbean, and pine-bark as soil amendments on germination and formation of sclerotia, on mycelial growth of Sclerotium rolfsii, on plant survival, and disease incidence. The data showed that high amounts of benzaldehyde (0.4 ml kg-1 of soil) and velvetbean (100 g kg-1) inhibited S. rolfsii mycelial growth and sclerotium germination. However, low amounts of benzaldehyde (0.1 ml kg-1), kudzu (25 g kg-1), and pine-bark (25 g kg-1) stimulated mycelial growth and sclerotium germination. Kudzu (25-100 g kg-1) and velvetbean (25-100 g kg-1) inhibited the formation of sclerotia. Nevertheless, benzaldehyde at 0.2 and 0.4 ml kg-1 stimulated the formation of sclerotia. Kudzu (50 and 100 g kg-1) and pine-bark (50 g kg-1) favored the colonization of sclerotia by Trichoderma sp. The numbers of soybean (Glycine max) plants were higher and diseased plants were lower than the non-amend soil in the following treatments: kudzu (50 and 100 g kg-1), velvetbean (50 and 100 g kg-1), and pine-bark (50 g kg-1). Disease severity on tomato (Lycopersicon esculentum) plants was low in soil treated with kudzu or velvetbean (30 and 35 g kg-1) and pine-bark (35 g kg-1). Dried powders of kudzu, velvetbean, or pine-bark added to soil can reduce disease by reducing pathogen inoculum.

Download Full-text

Effects of pH and Aeration on Sclerotium rolfsii sacc. Mycelial Growth, Sclerotial Production and Germination

International Journal of Phytopathology ◽

10.33687/phytopath.007.03.2688 ◽

2018 ◽

Vol 7 (3) ◽

pp. 123-129 ◽

Cited By ~ 1

Author(s):

Fakher Ayed ◽

Hayfa Jabnoun-Khiareddine ◽

Rania Aydi-Ben-Abdallah ◽

Mejda Daami-Remadi

Keyword(s):

Mycelial Growth ◽

Sclerotium Rolfsii ◽

Dry Weight ◽

Ph Values ◽

Effects Of Ph ◽

Ph Range ◽

Sclerotial Development ◽

Sclerotial Germination

Sclerotium rolfsii is one of the devastating soilborne fungus responsible for significant plant losses. The effects of pH and aeration on pathogen mycelial growth, sclerotial production and germination were investigated for three Tunisian isolates. Optimal mycelial growth occurred at pH 6 for Sr2 and Sr3 isolates and at pH 6-7 for Sr1. Dry mycelial growth was optimum at pH values ranging between 4 and 7. Sclerotial initiation started on the 3rd day of incubation at all pH values tested and mature sclerotia were formed after 6 to 12 days. Optimal sclerotial production was noted at pH 5. The dry weight of 100 sclerotia varied depending on isolates and pH and occurred at pH range 4-7. At pH 9, mycelial growth, sclerotial production and dry weight of 100 sclerotia were restricted. The optimum sclerotial germination, noted after 24 h of incubation, varied depending on isolates and pH and occurred at pH 4-9. Mycelial growth was optimum in aerated plates with a significant isolates x aeration treatments interaction. Sclerotial initiation occurred at the 3rd day of incubation and mature sclerotia were observed after 6-9 days. Sclerotial development was very slow in completely sealed plates and dark sclerotia were produced only after 15 days of incubation. The highest sclerotial yields were noted in aerated plates. The highest dry weight of 100 sclerotia for Sr1 isolate was recorded in ½ sealed, no sealed and completely sealed plates, while for Sr2, it was noted in ½ and ⅔ sealed plates. For Sr3, the maximum dry weight of 100 sclerotia was recorded in ½, ⅔ and completely sealed plates. Germination of S. rolfsii sclerotia, after 24 h of incubation, did not vary significantly depending on aeration treatments and ranged from 90 to 100% for all isolates.

Download Full-text

Indian Mustard and Allyl Isothiocyanate Inhibit Sclerotium rolfsii

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.127.1.27 ◽

2002 ◽

Vol 127 (1) ◽

pp. 27-31 ◽

Cited By ~ 25

Author(s):

Stephanie G. Harvey ◽

Heather N. Hannahan ◽

Carl E. Sams

Keyword(s):

Treatment Effect ◽

Radial Growth ◽

Mycelial Growth ◽

Sclerotium Rolfsii ◽

Indian Mustard ◽

Allyl Isothiocyanate ◽

Potato Dextrose Agar ◽

Soilborne Pathogen ◽

Low Concentrations ◽

Sclerotial Germination

Allyl isothiocyanate (AITC) is the predominant isothiocyanate produced by damaged tissues of Indian mustard (Brassica juncea (L) Czerniak). This study investigated Indian mustard and AITC mediated suppression of mycelial growth and sclerotial germination of Sclerotium rolfsii Saccardo, a common soilborne pathogen. Indian mustard (IM) treatments of 0, 0.1, 0.2, 0.6, 1.0, 2.0, 4.1, 5.1, 10.2, 20.4, 40.8, 81.6, and 163.3 g·L-1 (weight of reconstituted mustard per liter of air) were evaluated for suppression of mycelial growth. Treatment effect was evaluated by measuring the radial growth of mycelia. Sclerotia were placed in culture tubes containing 18 g autoclaved soil and covered with an additional 5 g soil. AITC at concentrations of 0, 4.0, 16.0, 64.0, 256.0, 1024.0, or 4096.0 μmol·L-1 was injected into the tubes. Treated sclerotia were removed from tubes and plated on potato dextrose agar to determine viability. Mycelial growth was inhibited with IM treatments (P < 0.01). Inhibiting concentrations (IC) of IM for mycelial growth inhibition of 50% and 90% were 0.7 and 1.0 g·L-1, respectively, with death resulting with >2 g·L-1. Inhibition attributable to AITC alone was lower than that achieved by IM producing equivalent amounts of AITC. Germination of sclerotia was negatively correlated with AITC concentration (r = 0.96; P < 0.01). The IC50 and IC90, of AITC were 249.0 and 528.8 μmol·L-1, respectively, at 42 hours. The lethal concentration for sclerotia was not reached; only suppression occurred at the highest treatment concentrations. Sclerotium rolfsii mycelia were sensitive to the IM volatiles and were suppressed at low concentrations. Sclerotia were more resistant than the mycelia and required higher concentrations of AITC to suppress germination.

Download Full-text

CULTURAL, MORPHOLOGICAL AND PATHOGENICITY CHARACTERS OF SCLEROTIUM ROLFSII CAUSING STEM ROT IN GROUNDNUT

PLANT ARCHIVES ◽

10.51470/plantarchives.2021.v21.no1.053 ◽

2021 ◽

Vol 21 (no 1) ◽

Author(s):

Sutha Raja Kumar ◽

R. Arulselvi A ◽

Rex Immanuel R ◽

John Chrsitopher D. ◽

Jaiganesh V. ◽

...

Keyword(s):

Mycelial Growth ◽

Tamil Nadu ◽

Disease Incidence ◽

Sclerotium Rolfsii ◽

Stem Rot ◽

Cent Disease

The present studies were undertaken to investigate the cultural, morphological and pathogenicity characters of Sclerotium rolfsii. Maximum per cent disease incidence was recorded in Nadiyappattu followed by Sivapuri, Kammapuram, Killai, Kurinjipadi, Parangipettai, Chathiram and Puthuchathiram in the decreasing order of merit of Cuddalore district, Tamil Nadu. The native isolates of S. rolfsii were isolated from the respective locations and designated as (SR1 to SR9). All the isolated showed variations with respect to colony character, mycelial growth, no of sclerotia, colour of sclerotia, shape and arrangement of sclerotia. Among the nine isolates of S. rolfsii collected from different groundnut growing areas of Cuddalore district, the isolate (SR5) collected from Nadiyappattu was found to be more virulent and recorded the maximum incidence followed by SR8 collected from Sivapuri. Maximum susceptibility was recorded when the plants are about 45 days showing disease incidence of upto 79.86 per cent.

Download Full-text

Effect of Different Carbon and Nitrogen Sources on Sclerotium rolfsii sacc. Mycelial Growth and Sclerotial Development

International Journal of Phytopathology ◽

10.33687/phytopath.009.01.3066 ◽

2020 ◽

Vol 9 (1) ◽

pp. 17-27

Author(s):

Fakher Ayed ◽

Hayfa Jabnoun-Khiareddine ◽

Rania Aydi-Ben Abdallah ◽

Mejda Daami-Remadi

Keyword(s):

Ammonium Chloride ◽

Radial Growth ◽

Mycelial Growth ◽

Sodium Citrate ◽

Ammonium Acetate ◽

Sclerotium Rolfsii ◽

N Source ◽

Sclerotial Formation ◽

Sclerotial Development ◽

Sclerotial Germination

In vitro studies were conducted on Potato Dextrose Agar using different carbon (C) and nitrogen (N) sources to evaluate their effects on the mycelial growth, and the sclerotial development of three Tunisian Sclerotium rolfsii Sacc. isolates. Radial growth was optimum on basal medium supplemented with ammonium chloride (0.48 gram of nitrogen per liter (g of N.L-1)) as N source but was restricted on L-Arginine and completely inhibited on ammonium acetate amended media (0.48 g N.L-1). Sclerotial initiation occurred from the 3rd to the 12th day of incubation for all tested isolates. Potassium nitrate was the most suitable N source for sclerotial formation whereas sclerotial development was completely inhibited on ammonium acetate amended medium. Optimal sclerotial germination was recorded using L-Arginine (78-80%) followed by L-Asparagine (46-94%) and ammonium chloride (46-88%) as N sources. Nevertheless, the lowest sclerotial germination rate was noted on sodium nitrate and ammonium acetate amended media. As for C sources (16 gram of carbon per liter (g of C.L-1)), optimal radial growth occurred using D-mannitol for Sr1 and Sr2 isolates and maltose for Sr3, but no mycelial growth was recorded using sodium citrate for all isolates. All C sources tested, except sodium citrate, were suitable for sclerotial formation, production, and germination. Mature sclerotia became brownish after 6 to 12 days of incubation and sclerotial production was highest using D-mannitol, maltose, and D-glucose, depending on isolates used, as C sources. Optimal germination of sclerotia was noted using D-glucose, D-mannitol and maltose for Sr1 isolate, maltose for Sr2 and D-glucose and maltose for Sr3. It was concluded that N and C sources are both important factors for the growth of S. rolfsii and its survival.

Download Full-text

Powders of kudzu, velvetbean, and pine bark added to soil increase microbial population and reduce Southern blight of soybean

Fitopatologia Brasileira ◽

10.1590/s0100-41582006000600003 ◽

2006 ◽

Vol 31 (6) ◽

pp. 551-556 ◽

Cited By ~ 3

Author(s):

Luiz E. B. Blum ◽

Rodrigo Rodríguez-Kábana

Keyword(s):

Microbial Population ◽

Disease Incidence ◽

Soil Amendments ◽

Sclerotium Rolfsii ◽

Enterobacter Aerogenes ◽

Soil Microbial Activity ◽

Pine Bark ◽

Southern Blight ◽

Soil Microbial ◽

Soil Microbial Population

Southern blight (Sclerotium rolfsii) of soybean (Glycine max) is an important disease throughout the world. Some soil amendments can reduce disease levels by improving soil microbial activity. The main goals of this study were to investigate the effects of soil amendments such as dried powders of kudzu (Pueraria lobata), velvetbean (Mucuna deeringiana), and pine bark (Pinus taeda), on soil microbial population and disease caused by S. rolfsii on soybean. Pine bark, velvetbean (mucuna) and kudzu (25 g kg-1) added to soil were effective in reducing disease incidence [non-amended (NA) ~ 39%; amended (A) ~ 2 to 11%)]. Bacillus megaterium was the bacteria most frequently isolated in soils with velvetbean or kudzu (NA ~ log 5.7 CFU g-1 of dried soil; A ~ log 6.2). Soils with velvetbean and kudzu stimulated increase in population of Enterobacter aerogenes (NA ~ log 3; A ~ log 5.1-5.8). Pseudomonas putida population was higher in A than in NA (NA ~ log 4; A ~ log 5.5), and was negatively correlated (r = -0.83, P = 1%) to disease incidence. Soil amended with kudzu and pine bark stimulated increases in populations of Trichoderma koningii (NA ~ log 1.6; A ~ log 2.9) and Penicillium citreonigrum (NA ~ log 1.3; A ~ log 2.6), respectively. Penicillium herquei soil population increased with addition of kudzu (NA ~ log 1.2; A, ~ log 2.5). These microorganisms are antagonists of soil-borne pathogens. Powders of velvetbean, kudzu, and pine bark can increase antagonistic population in soil and reduce disease.

Download Full-text

Evaluation of Pine Bark, Pine Bark With Wood, and Pine Tree Chips as Components of a Container Plant Growing Media

Journal of Environmental Horticulture ◽

10.24266/0738-2898-4.1.22 ◽

1986 ◽

Vol 4 (1) ◽

pp. 22-25 ◽

Cited By ~ 1

Author(s):

A.J. Laiche ◽

V.E. Nash

Keyword(s):

Organic Amendments ◽

Pine Bark ◽

Growth Media ◽

Ligustrum Sinense ◽

Pine Tree ◽

Water Holding ◽

Low Solubility ◽

Low Nitrogen ◽

Very High ◽

Container Plant

Three woody landscape species, Rhododendron indica ‘President Clay’, Ligustrum sinense ‘variegata’, and Ilex crenata ‘compacta’, were grown in media prepared from fresh pine bark, pine bark with wood, and pine tree chips. Although media were variable in physical properties, all exhibited very high hydraulic conductivity and low water holding capacity. The capacity of these media materials to hold fertilizer elements was very low. Nitrogen, potassium, and phosphorus were rapidly removed by leaching while calciuum and magnesium were retained longer because of the low solubility of dolomitic limestone. Pine bark was the best growth media tested for all plant species. Pine bark with wood was less satisfactory than pine bark and growth was poorest in pine tree chips. More research is needed on the use of the organic amendments with greater amounts of wood before being widely used as organic components of growth media.

Download Full-text

Management of collar rot disease in chickpea by Trichoderma species

Journal of AgriSearch ◽

10.21921/jas.v7i03.18694 ◽

2020 ◽

Vol 7 (03) ◽

Author(s):

PREM PANDEY ◽

G. C. SAGAR ◽

SUNDARMAN SHRESTHA2 ◽

HIRAKAJI MANANDHAR ◽

RITESH K. YADAV ◽

...

Keyword(s):

Growth Inhibition ◽

Mycelial Growth ◽

Sclerotium Rolfsii ◽

Maximum Growth ◽

Pot Experiment ◽

Trichoderma Spp ◽

Trichoderma Species ◽

Collar Rot ◽

Rot Disease

Nine isolates of Trichoderma spp. were isolated from different agro- ecological regions of Nepal viz; Jumla, Palpa, Chitwan, Tarahara, Banke, Illam and Salyan and screened against Sclerotium rolfsii Sacc. Adreded soil borne phytopathogen causing collar rot of chickpea in chickpea; In-vitro efficacy of nine fungal antagonist (Trichoderma spp.) against Sclerotium rolfsii were screened. Pot experiment was done to find out the effective management of S. rolfsi through Tricoderma using different methods i.e. Seed treatment, soil drenching and soil application. All the tested isolates of Trichoderma spp. were found effective on mycelial growth inhibition and sclerotial parasitization of S. rolfsii. Trichoderma isolated from Palpa district showed maximum growth inhibition (%) of pathogen periodically after 48(93.78%), 72(96.00%), 96(97.96%) and 120(100.00%) hours of inoculation. Parasitized sclerotium showed minimum sclerotial germination on agar plates. Moreover, Trichoderma species isolated from Palpa districts showed second best percent mycelial growth inhibition periodically at 72(25.00%), 120(29.16%), 168(29.16%) and 216(29.16%).In pot experiment at 40 days after sowing, Seedling height was maximum in soil drenching with 30g per 100ml of water (22.27cm) and Mortality percentage of seedlings was least or highest disease control was observed in seed treated with 109cfu/ml (0.000%).

Download Full-text

A Comparison of Disease Assessment Methods for Southern Stem Rot of Peanut

Peanut Science ◽

10.3146/pnut.29.1.0012 ◽

2002 ◽

Vol 29 (1) ◽

pp. 66-71 ◽

Cited By ~ 4

Author(s):

S. L. Rideout ◽

T. B. Brenneman ◽

K. L. Stevenson

Keyword(s):

Alternative Assessment ◽

Disease Incidence ◽

Sclerotium Rolfsii ◽

Correlation Coefficients ◽

Assessment Method ◽

Assessment Methods ◽

Alternative Methods ◽

Stem Rot ◽

Disease Assessment ◽

Time Required

Abstract Southern stem rot (caused by the soilborne fungus Sclerotium rolfsii Sacc.) of peanut (Arachis hypogaea L.) traditionally has been assessed based on the percentage of infected 30.5-cm row segments, commonly referred to as disease incidence. Several alternative disease assessment methods were evaluated in four fungicide trials during the growing season (aboveground ratings) and immediately after peanut inversion (belowground ratings). Pearson's correlation coefficients compared disease assessments and yields for all trials. Across all disease assessment methods, belowground assessments at inversion showed a stronger correlation with yield than in-season aboveground assessments. Several of the alternative assessment methods showed a stronger negative correlation with yield than did the traditional disease incidence rating. However, none of the alternative methods were consistently more precise across all assessment dates and trials. There was a significant positive correlation between many of the alternative methods and the traditional disease incidence method. Furthermore, none of the alternative methods was better than the traditional method for detecting differences among fungicide treatments when subjected to ANOVA and subsequent Waller-Duncan mean separation tests (k-ratio = 100). Based on comparisons of the time required to assess disease intensity, the traditional disease assessment method was found to be the most time efficient method of those tested in this study.

Download Full-text