Isolates Of Sclerotium Rolfsii Research Articles

Characterizing genetic diversity of Sclerotium rolfsii isolates by biomapping of mycelial compatibility groupings and multilocus sequence analysis.

Genetic diversity in Sclerotium rolfsii is useful for understanding its population structure, identifying different mycelial compatibility groups (MCGs), and developing targeted strategies for disease management in affected crops. In our study, a comprehensive genetic analysis was conducted on 50 isolates of S. rolfsii, collected from various geographic regions and host plants. Two specific genes, TEF1α and RPB2, were utilized to assess the genetic diversity and relationships among these isolates. Notably, out of 1225 pairings examined, only 154 exhibited a compatible reaction, while the majority displayed antagonistic reactions, resulting in the formation of a barrier zone. The isolates were grouped into 10 distinct MCGs. These MCGs were further characterized using genetic sequencing. TEF1α sequences distinguished the isolates into 17 distinct clusters, and RPB2 sequences classified them into 20 clusters. Some MCGs shared identical gene sequences within each gene, while others exhibited unique sequences. Intriguingly, when both TEF1α and RPB2 sequences were combined, all 10 MCGs were effectively differentiated, even those that appeared identical with single-gene analysis. This combined approach provided a comprehensive understanding of the genetic diversity and relationships among the S. rolfsii isolates, allowing for precise discrimination between different MCGs. The results shed light on the population structure and genetic variability within this plant pathogenic fungus, providing valuable insights for disease management and control strategies. This study highlights the significance of comprehending the varied virulence characteristics within S. rolfsii isolates, categorizing them into specific virulence groups based on disease severity index (DSI) values. The association with MCGs provides additional insights into the genetic underpinnings of virulence in this pathogen. Furthermore, the identification of geographical patterns in virulence implies the influence of region-specific factors, with potential implications for disease control and crop protection strategies.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [G. M. Sandeep] Last name [Kumar]. Author 2 Given name: [Praveen Kumar] Last name [Singh]. Also, kindly confirm the details in the metadata are correct.I confirm that the given names are accurate and presented in the correct sequence.

Effect of fungicides on different isolates of Sclerotium rolfsii from Khandesh region

Effect of fungicides on different isolates of Sclerotium rolfsii from Khandesh region

Pathogenicity test of Sclerotium rolfsii isolates causing foot and root rot disease of betelvine (Piper betle L.)

The experiment was conducted under in-vivo condition in a betelvine baroj at Sher-e-Bangla Agricultural University (SAU), Dhaka-1207, Bangladesh. Nineteen isolates of Sclerotium rolfsii collected from different regions of Bangladesh designated as isolate-1 to isolate-19. Soil inoculated with S. rolfsii exhibited mycelial growth on the soil surface and around the base of the betelvine plant within 2-4 days after inoculation. Only 2 days after inoculation were required to manifest cottony colony on soil surface near root zone of inoculated betelvine plants by the isolate-3, 5, 7, 9 and 12. The first disease symptoms were observed within 6 to 16 days after inoculation where minimum days were required by the isolate-9 and maximum by the isolate-2 and 14. The highest lesion length (6.50 cm) was produced by the isolate-9 and isolate-13. All the isolates were found to be pathogenic in some cases, disease delayed due to their degree of pathogenicity. The isolate-9 showed highest disease incidence of 100% which was superior as compared to all other isolates at 15 days after inoculation. The isolate-19 showed least disease incidence of 66.66% even at 30 days after inoculation. Among the isolates, the most pathogenic one was isolate-9 collected from Kaligonj upazilla of Jhenaidah.

Baseline sensitivity and bioactivity of tetramycin against Sclerotium rolfsii isolates in Huanghuai peanut-growing region of China

Peanut stem rot caused by Sclerotium rolfsii is a serious soil-borne disease and poses a threat to the peanut production. The antibiotic fungicide tetramycin has a broad antifungal spectrum against multiple pathogens and possess low environmental risks. In current study, a total of 250 isolates collected from Huanghuai peanut-growing region of China (Henan, Shandong and Hebei Province) were used to establish the baseline sensitivity of S. rolfsii to tetramycin. The baseline sensitivity curve was unimodal and distributed from 0.01 to 0.36 mg/L, with a mean EC50 (50% effective concentration) value of 0.11 ± 0.06 mg/L. Tetramycin also had strong inhibitory activity on the formation and germination of sclerotia. There was no significant correlation of S. rolfsii sensitivity to tetramycin and other commonly used SDHI (succinate dehydrogenase inhibitor), QoI (quinone outside respiration inhibitor) and DMI (demethylation inhibitor) fungicides. Moreover, tetramycin significantly increased the cell membrane permeability and reduced the oxalate acid content. Greenhouse experiments showed that tetramycin has both protective and curative efficacy against S. rolfsii, while protective efficacy was higher than curative efficacy. Anyhow, the bioactivity of tetramycin is similar (curative efficacy) or higher (protective efficacy) than the control fungicide validamycin. In terms of application method, root drench may be more suitable for tetramycin than spraying, because root drench of tetramycin obtained a higher efficacy. These results indicated that tetramycin may be a potential alternative fungicide for the efficient control of peanut stem rot.

Isolation and Morphological Characterization of Sclerotium rolfsii-Inciting Stem rot Disease in Groundnut (Arachis hypogaea L .)

Sclerotium rolfsii is a highly threatening pathogen,affecting more than 500 hosts worldwide. In the present study, ten different isolates of Sclerotium rolfsii were isolated from groundnut growing regions of Tamil Nadu, and their morphological characteristics were observed on potato dextrose agar (PDA) medium. The virulent isolate SR-8 produced pure white with thin mycelia growth, very fast growing mycelium, dark brown colored sclerotia, and the highest number of sclerotia /plate (538). The pathogenicity test was conducted on pot-cultured, grown groundnut plants. The virulent isolate SR-8, S. rolfsii, is infected at various stages of its growth and development in groundnut plants. Lipid peroxidation and pathogenicity are crucial to identify the virulent nature of the pathogen. The pathogenicity of the virulent isolate SR-8 that produced the highest disease incidence was 89.29 % and had a high amount of lipid peroxidation of 0.9589 μmol/g. The least virulent isolates produced the minimum amount of lipid peroxidation and disease incidence. All the ten isolates exhibited different cultural and morphological characteristics, lipid peroxidation rates, and various levels of disease incidence on groundnut.

Bio-Control Potentials of Trichoderma spp. Against Sclerotium rolfsii the Causative of Root and Crown Rot in Tomato, Common Bean and Cabbage

In the current study, evaluation the ability of three isolates of Sclerotium rolfsii isolated from tomato, bean and cabbage to infect their host plants and two non-host plants was carried out. Tomato plants were strongly affected with the three isolates of the pathogen followed by cabbage plants, whereas common bean plants were the least in this respect. Six species of Trichoderma were examined for their bio-control potentials against S. rolfsii the causative of root rot in tomato, common bean and cabbage. In vitro antagonistic test showed that T. koningii exhibited high inhibitory effect as the percentage of inhibition value was higher in case of S. rolfsii (tomato isolate) followed by T. harzianum with S. rolfsii (bean isolate) and S. rolfsii (cabbage isolate). Under greenhouse conditions; T. koningii, T. viride and T. harzianum showed the highest antagonistic effect against the three isolates of S. rolfsii in pots experiment. Microscopic examinations showed that most of Trichoderma spp. grew over mycelia of the tested pathogen with surrounded, coiling, lysis of hyphae and collapse of mycelium. T. koningii and T. viride exhibited the best performance regarding to the defense enzyme secretion; chitinase and β-glucanase followed by T. harzianum. Also, all the tested Trichoderma spp. produced Indole acetic acid (IAA) and Gibberellic acid (GA) as a plant growth promoting substances in variable values.

First Report of Sclerotium rolfsii Causing Southern Blight of Bletilla Orchid in China

Bletilla striata, known as Chinese ground orchid, is economically important because of its medicinal and ornamental properties around the world, especially in China. The wild population of B. striata is decreasing, it was listed in appendix II (species that may be threatened or extinct) of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) (CITES 2013). Therefore, farm-based cultivation of B. striata is emerging to meet the demands of the industry. In June 2016, disease symptoms similar to orchid southern blight (Punja 1985) were observed in a B. striata cultivation field (N30°21′27.37″, E112°19′58.37″) in Jingzhou, Hubei Province, China. In a follow-up survey, the disease was also found in nearby counties and provinces. Disease incidence reached 25% in the most severely affected field. Symptoms first appeared at the junction of the stem base and the soil, as necrotic dark brown stem lesions. Additional symptoms included leaf yellowing and wilting, root rot, and death during warm and humid weather. White mycelium and tan to brown sclerotia were found on the stems and roots of plants in the field and plants incubated in the lab. To isolate the pathogen, tissue from plant samples collected from a nursery (Orchid Biotechnology, Jingzhou, China) was surface sterilized with 2% sodium hypochlorite (NaOCl) for 3 min and then rinsed and incubated on potato dextrose agar medium with 50 μg/ml of ampicillin and rifampin. After 7 days of incubation at 28°C, sclerotial primordia developed followed by sclerotia approximately 2 mm in diameter after 10 days. No spores were observed. Total genomic DNA of isolate BH-2 was extracted with the cetyltrimethylammonium bromide method and then amplified and sequenced with fungal ribosomal primers ITS1/ITS4 (White et al. 1990). The length of the amplicon was 683 bp (GenBank accession no. KY606616), 99% similarity to Athelia rolfsii (teleomorph) isolate ATCC201126 (accession no. AF499018). Phylogenetic analysis of the internal transcribed spacer sequences with the neighbor-joining method in MEGA6 (Pennsylvania State University, University Park, PA) showed BH-2 was clustered with six Sclerotium rolfsii isolates selected from NCBI database (accession nos. AF499018, JN081867, JN241565, GQ3585118, JF966208, and KJ002764). Therefore, isolate BH-2 was identified as S. rolfsii. To produce inoculum for Koch’s postulates, autoclaved oat grain was inoculated with BH-2 then incubated at 30°C for 10 days. Infected oat grains were placed near the roots of 90-day-old healthy seedlings (n = 3), and sterilized oat grain was used as a control (n = 3). All seedlings were placed in sealed plastic bags with air valves and grown in a greenhouse (25 ± 2°C, relative humidity 65%). Water-soaked streaks and white hyphae were observed after 2 to 3 days. Symptoms typical of southern blight, necrotic stems, and leaf lesions were observed after 9 days. Reisolation was performed with surface-sterilized tissue from symptomatic seedlings, and isolates were confirmed as S. rolfsii based on morphological and molecular characters. To the best of our knowledge, this is the first report of S. rolfsii causing southern blight of Bletilla spp. in China.

Differentiation among Sclerotium rolfsii isolates in response to saponins treatment

Differentiation among Sclerotium rolfsii isolates in response to saponins treatment

Effect of pathogenic, cultural variability and chemical management of Sclerotium rolfsii

Among the ten isolates of Sclerotium rolfsii , collected from major chilli growing areas of Uttar Pradesh found that the pathogenic variability of the pre germination disease incidence was highest (21.20%) in isolate of district Fatehpur and was lowest (9.5%) in Raibarelly isolates. The cultural variability on the radial growth of fungus and sclerotial production indicated that the radial growth of fungus was maximum in the case of SR1 (83.0 mm) isolate, followed by SR9 (82.00 mm) isolate which were statistically at par with each other. The colony characters was excellent, fluffy in SR1, SR2, SR3, SR4, SR8, SR9 and SR10 isolates and compact in isolates of SR5, SR6 and SR7. In vitro studies revealed that the fungicides like Taqat, Hexaconazole, Propiconazole, Tricyclazole, Copper-oxychloride and Vitavax were most effective against the pathogen. The effect of fungicides as seed treatment revealed Taqat and Hexaconazole were found most effective in seed germination (92.8 and 87.5%), respectively and minimum in disease incidence (5.3 and 7.1%), respectively.

RAPD analysis of Sclerotium rolfsii isolates causing collar rot of eggplant and tomato

Eight isolates of Sclerotium rolfsii from four strategically geographical sites of Bangladesh were characterized and their cultural properties like average linear mycelial growth, colony colour, colony consistency, growth pattern and sclerotia formation were studied. Isolates varied in mycelial growth and other growth characteristics and were grouped into three. The highest linear growth was displayed by S8. DNA concentration of eight isolates varied from 1150-7200 ng/?l. DNA fingerprinting by RAPD prompted the grouping of isolates. Selected 3 primers generated 20 bands with size ranging from 100-1500 bp. Out of the 20 bands, 9 bands (45%) were polymorphic and 11 bands (55%) were monomorphic among the eight isolates of Sclerotium rolfsii. The co-efficient of gene differentiation (Gst) was 1.000 reflecting the existence of high level of genetic variations among the 8 isolates. The lowest genetic distance and highest inter isolate similarity was found in S1 and S2 which would be homogeneous. The highest genetic distance and lowest inter isolate similarity found in S3, S7 and S3, S8 pair which would be most divergent isolates. The cluster analysis also revealed that S3, S7 and S8 belong to different clusters. All five varieties of eggplant and tomatoes were graded as susceptible when inoculated with eight isolates. Plant mortality 93.33% was recorded in S4, S6 and in S8. Considering the isolate factor the most virulent isolate would be S8 whereas the less virulent isolate would be S2 and S7. Host plant of S8 was tomato collected from Thakurgaon. S2 and S7 were collected from BAU farm and Dinajpur and host plants were lentil and tomato respectively. It is evident that Sclerotium rolfsii from Thakurgaon on host tomato is more virulent.Int. J. Agril. Res. Innov. & Tech. 6 (1): 47-57, June, 2016

English

Variability among four isolates of Sclerotium delphinii isolated from infected diseased Khirni (Manilkara hexandra); chafa (Plumeria rubra acutifolia) and Jackfruit (Artocapus heterophyllus) plants of Western Maharashtra region of India were studied. This is the first report on presence of S. delphinii species in India. These isolates varied in colony morphology, mycelial growth rate, sclerotia formation period, sclerotia size and color. On the basis of morphological characters, these isolates were identified as S. delphinii and were also confirmed in Indian type culture collection (ITCC), New Delhi. In mycelial compatibility study, isolates of S. delphinii did not intermingle with Sclerotium rolfsii isolates indicating genetic variation among the species. The isolates of S. delphinii also showed distinct differences in their oxalic acid content. The classification and variability was further confirmed using molecular studies. It was observed that only morphological features and MCGs differentiated the Sclerotium species rather than molecular characterization because they shared some common bands of DNA at genetic level, but showed distinctness in morphological and MCGs study. Key words: Variation, cultural; biochemical, Sclerotium delphinii, RAPD-PCR.

Occurrence, Virulence, Inoculum Density and Plant Age of Sclerotium rolfsii Sacc. Causing Collar Rot of Peppermint

Roving survey was conducted during 2011-2012 around Coimbatore, Dindigul, Erode, Hosur, Krishnagiri, Namakkal, Salem and Theni districts to assess the incidence of collar rot of peppermint. The maximum incidence of 32.33% was recorded in Therkupalayam village of Coimbatore District. The pathogen was isolated from infected samples and 8 Sclerotium rolfsii isolates were maintained. The level of pathogenicity of these isolates revealed that S. rolfsii (I1) from Therkupalayam in Coimbatore District was the most virulent and caused higher levels of collar rot incidence (93.66%). An inoculum load of S. rolfsii at 5% to 1 kg of soil registered the maximum incidence of 92.66% collar rot of peppermint. Significantly higher per cent of wilting of 92.66% was recorded in plants at 20 days after emergence and it was found significantly more susceptible compared to rest of the treatments.

Determination of Genetic Diversity inSclerotium rolfsiiandSclerotium delphiniiby using RAPD and ISSR Markers

The classification and variability among Sclerotium species was studied by using ISSR and RAPD markers. Based on the amplification pattern and reproducibility of eleven RAPD premiers and seven ISSR primers, the delineating variability among the 13 different crops isolates of Sclerotium rolfsii and 4 isolates of Sclerotium delphinii was analyzed. The primer OPB-16 was found to be the best primer for determination of variability among Sclerotium spp. This primer generated at least 17 bands of 230 -1554 base pairs size. Similar results were obtained with IS-8 primer in ISSR marker amplification studies. Though all the isolates of Sclerotium spp. were genetically variable, they share some common bands indicating phylogenetic relationship among them. The ability of primers to highlight the genetic polymorphism between the isolates varied greatly and on the basis of pooled RAPD and ISSR marker analysis these isolates were classified into five broad groups. RAPD-PCR and ISSR molecular marker analysis were found to be efficient and informative technique for differentiating the genetic variability among Sclerotium species.

Variability in Indian isolates of Sclerotium rolfsii by SDS-PAGE

The variability among 14 different Indian isolates of Sclerotium was studied on the basis of protein profile generated by Polyacrylamide Gel–Electrophoresis (SDS-PAGE). Different characteristics taken into account while studying the variability were sclerotia formation, non-formation, basidial stage formation and non-formation and type of disease symptom, viz. spotted leaf rot and collar rot. A comparison was done between mycelium of the different isolates as well as the sclerotia of the same isolate. All the 14 isolates showed a significant variation among themselves with respect to number and intensity of major and minor bands. It was intriguing to note that isolate L-Brl showed quiet different pattern from the rest of the isolates. A strong induction of a protein band of ∼15 kDa, probably responsible for the sclerotial development, was observed on comparing the protein profile of mycelium with the protein profile of sclerotia of all the isolates taken into consideration. A 66 kDa protein was prominently present in the isolate (L-Sph) which invariably forms basidiospores, but this protein was not present in the mycelial protein profile. A protein band with molecular weight greater than 98 kDa was prominently present in the total protein profile of isolates which does not form sclerotia in its life cycle. Furthermore, a protein band of ∼12 kDa was consistently present in the isolate which causes collar rot and this protein was absent in isolates which cause spotted leaf rot. Two closely placed distinct protein bands of 43 kDa and 46 kDa were invariably present in all the isolates causing spotted leaf rot. The dendrogram constructed with the help of protein profile so obtained was found to be divided into two prominent clusters. The representative isolate (L-Sph) was also investigated for pectinase, cellulase and xylanase production. The presence of hydrolytic enzymes is significant for contributing pathogenicity to the fungus.

An Improved Growth Medium to Assess Mycelial Compatibility Groups in Sclerotium rolfsii

AbstractMycelial compatibility is assayed mainly by pairing mycelial plugs of field isolates on Petri dishes with agar media. Although methodologically simple, mycelial compatibility testing requires an artificial growth medium that permits the identification of compatible and incompatible interactions. In this work, several growth media were studied to assess consistently mycelial interactions between Sclerotium rolfsii isolates. A modification of Patterson’s medium with an increment of 25% glucose from the original concentration at a rate of 23.4 g/l and amended with 180 μl/l of red food colouring was the most effective combination for enhancing the size, density and distinctiveness of the aversion zone between incompatible isolates. This medium allowed the unequivocal identification of compatible and incompatible reactions of a set of five S. rolfsii isolates, which could be determined quickly after 5 days of incubation in the dark at 25°C. This new formulation improved significantly and consistently the assessment of the aversion zone reaction that was visible as a red line on the colony reverse as compared to that assessed using previous media formulations, for which the visualization of aversion zones was scarcely discernible. The utility of the improved growth medium was validated by microscopic observations of the contact area of hyphal pairings between isolates of S. rolfsii in microscope slide cultures.

Molecular variability among the isolates of Sclerotium rolfsii causing stem rot of groundnut by RAPD, ITS-PCR and RFLP

Genetic variability among the virulent isolates of Sclerotium rolfsii was studied using molecular techniques like RAPD, ITS-PCR and RFLP. The RAPD banding pattern reflected the genetic diversity among the isolates by formation of two clusters. A total of 221 reproducible and scorable polymorphic bands ranging approximately as low as 100 bp to as high as 2500 bp were generated with five RAPD primers. ITS region of rDNA amplification with specific ITS1 and ITS4 universal primers produced approximately 650 to 700 bp in all the isolates confirmed that all the isolates obtained are Sclerotium rolfsii. Studies by ITS-RFLP indicated that there was no polymorphism in restriction banding pattern among the isolates with the restriction endonucleases used.

Plant growth promotion and management of collar rot of Chickpea (Cicer arietinum) by mycelial protein of Sclerotium rolfsii

Investigations on the total protein content of seven isolates of Sclerotium rolfsii and the effect of the total protein of different isolates on growth promotion and management of collar rot disease of chickpea was carried out. Various concentrations (0.07, 0.14, 0.21 and 0.28 mg/ml in terms of BSA fraction V equivalents) of fungal protein isolated from BHU-3 isolate, which contained maximum total protein, was sprayed on 20-day-old chickpea (Cicer arietinum) plants. After four days, the sprayed potted plants were inoculated with S. rolfsii and observations were taken on the growth, mortality and phenolic acid content of plants. Among different concentrations of fungal protein, 0.21 and 0.28 mg/ml showed maximum efficacy in plant growth promotion. Also, plant mortality was reduced significantly compared to control following treatment of fungal protein. Phenolic acid content of plant leaves after spray of fungal protein increased compared to control. Further, the level of phenolic acids in plants inoculated with S. rolfsii increased, indicating an important role of the fungal protein in inducing resistance in plants. The results suggest a functional role of fungal protein of the isolate BHU-3 in plant growth promotion as well as resistance induction analogous to phytoimmunoproteins responsible for induction of immune response in plants.

Pathogenic diversity of Sclerotium rolfsii isolates, a potential biocontrol agent against Parthenium hysterophorus L.

Parthenium hysterophorus L. is a wide-spread weed creating problems for agriculture and public health. Microbes and their by products is now proved to be a worthy alternative to toxic chemicals used for weed management. We determined the relative pathogenicity of ten Sclerotium rolfsii isolates recovered from diseased parts of Parthenium collected during a survey of various habitats in Central India. There was a considerable diversity amongst various isolates. The isolate designated Par # 02 from Jabalpur showed the maximum disease incidence (80%) whereas isolate Par#10 also from Jabalpur showed the lowest infection rate against targeted hosts (30%). The wide range of pathogenicity among S. rolfsii support the view that strain breeding for biological control of P. hysterophorus L. is warranted. Key words : Parthenium hysterophorus , variability, pathogenicity, Sclerotium rolfsii

Biochemical Investigations of Sclerotial Exudates of Sclerotium rolfsii and their Antifungal Activity

AbstractExudates from sclerotia of two Sclerotium rolfsii isolates (one causing collar rot in Cicer arietinum, isolate VC971, and the other leaf spots in Rauvolfia serpentina, isolate VL016) were assayed for their antifungal activity against 26 fungi consisting of plant parasites as well as saprophytes. Spore germination of all the test fungi was affected by the exudates reaching 100% in some cases. Foliar spray with exudates of isolate VL016 significantly reduced disease incidence of balsam (Impatiens balsamina) powdery mildew caused by Erysiphe cichoracearum and pea (Pisum sativum) powdery mildew caused by Erysiphe pisi, under field conditions. Characterization of exudates from 25 isolates of S. rolfsii revealed pH ranging from 3.8 to 5.3 and colour from light yellow to deep yellow. Among the phenolic acids found in the exudates were tannic, gallic, caffeic, vanillic, ferulic, chlorogenic and cinnamic acids. Oxalic acid was also found in varied amounts. Among the phenolic acids, ferulic acid was found to be present at high concentration in exudates of most isolates (3.9–153.4 μg/ml). The antioxidant properties of phenolics, which generally inhibit fungal morphogenesis including spore germination along with the antifungal nature of some phenolics are chiefly attributed to the inhibitory effect of sclerotial exudates of S. rolfsii. Additionally, both the isolates VC971 and VL016 showed almost similar antifungal activities despite they are of different origin and thereby demonstrate the antifungal nature of sclerotial exudates.

Pathogenic diversity of Sclerotium rolfsii isolates from Mexico, and potential control of southern blight through solarization and organic amendments

Pathogenic diversity and cultural control of Sclerotium rolfsii are two fields of knowledge not well understood. In this work, two onion isolates of S. rolfsii from the States of Morelos and Guanajuato, Mexico were inoculated to 51 plant species and disease severity levels were determined. Subsequently, 12 out of 51 plant species were selected for the determination of pathogenic reaction to 20 isolates of S. rolfsii from different regions of Mexico. Onion isolates from Morelos and Guanajuato produced variable levels of disease severity for half of the plants tested. Five plant species were susceptible or highly susceptible to all isolates. The remaining plants tested showed differential reactions to individual isolates, ranging from highly resistant to highly susceptible. Three organic soil amendments alone or combined with solarization were tested for control of S. rolfsii on microplots containing onion seedlings in naturally infested soil. A combination of solarization and incorporation of Parthenium hysterophorus into soil was effective in reducing damage and sclerotial numbers of S. rolfsii. However, the amendment alone was associated with increased damage and high sclerotial populations.