scholarly journals First Report of Cucumber Black Root Rot Caused by Phomopsis sclerotioides in Italy

Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 425-425 ◽  
Author(s):  
C. Cappelli ◽  
V. M. Stravato ◽  
G. Carannante ◽  
R. Parisella
Keyword(s):  
Root Rot ◽  
Management Practices ◽  
Central Italy ◽  
Economic Losses ◽  
Test Plant ◽  
Infested Soil ◽  
Centraalbureau Voor ◽  
Black Root Rot ◽  
First Report ◽  
Phomopsis Sclerotioides

During April 2002 to September 2003 in unheated plastic greenhouses located in Fondi and Sperlonga (Latium Region of central Italy), in which more than 100 ha of cucumber (Cucumis sativus L.) were cultivated, an unusual disease causing decay of roots and plant wilting was observed. Many of the most common cultivars showed susceptibility, and in some farms, severe economic losses occurred. Disease symptoms observed on young plants included stunting, wilting, black root rot, and marked reduction of root development where pseudosclerotial structures were produced. The degree of root symptoms was proportional to the wilting. During periods of high evapotranspiration, wilting was severe in plants at the early stages of disease development, and even lightly infected plants wilted rapidly. Symptoms resembled those caused by vascular wilt fungi and were generally more severe in greenhouses with poorly drained soils. Samples from each of four greenhouses were collected during different periods of the growing season. Each sampling unit consisted of five to eight root pieces that were surface disinfected in 0.1% HgCl2 for 30 s, rinsed in sterile water, placed on petri dishes containing potato dextrose agar (pH 5.5), and incubated for 7 days at 25°C. Phomopsis sclerotioides van Kesteren (1,2) (identification confirmed by R. A. Samson, Centraalbureau voor Schimmelcultures of Utrecht, the Netherlands) was consistently recovered from affected tissues. Subcultures of three isolates were prepared and evaluated for pathogenicity. The experiments were conducted in a greenhouse with a 12-h photoperiod at 25 to 32°C. Seven-week-old seedlings (20 representatives per isolate) of a susceptible hybrid were dipped for 2 min in an agar slurry suspension of the pathogen and then returned to pots. Within 4 to 5 weeks after inoculation, all plants inoculated with each P. sclerotioides isolate showed the same symptoms observed in the field and caused wilting and death of approximately 80% of the inoculated plants. P. sclerotioides was consistently reisolated from the symptomatic test plant, whereas the fungus was never isolated from control plants. Another experiment using naturally infested soil in comparison with sterilized soil confirmed the soilborne nature of the fungus and its pathogenicity. To our knowledge, this is the first report of P. sclerotioides on cucumber in Italy. According to the experience of farmers and agricultural consultants, the disease was first observed in the last 3 to 4 years in unheated plastic greenhouses. However, we cannot exclude the possibility that the disease may have been present in central Italy prior to our observations, since it can be misdiagnosed and the symptoms can be masked by symptoms of other diseases. For these reasons, an accurate monitoring of the pathogen is necessary to determine the magnitude of the problem and its impact on the industry. Management practices that include long-term crop rotation with nonsusceptible hosts, removal and destruction of infected crop debris, and steam soil sterilization are suggested to reduce the economic losses. References: (1) E. Punithalingam et al. No. 461 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, U.K., 1975. (2) H. A. Van Kesteren. Neth. J. Plant Pathol. 73:112, 1967.

scholarly journals First Report of Pythium Cluster B2a Species Causing Root Rot in Welsh Onion

Plant Disease ◽  
2021 ◽  
Author(s):  
Sachiko Shimizu ◽  
Motoaki Tojo
Keyword(s):  
Growth Rates ◽  
Root Rot ◽  
Management Practices ◽  
Tap Water ◽  
Hyphal Growth ◽  
Economic Losses ◽  
Welsh Onion ◽  
Daily Growth ◽  
Causal Organism ◽  
First Report

Hiroshima Prefecture has the highest production area of hydroponically grown Welsh onions (Allium fistulosum L.) in Japan. Since the cultivation began in 1988, root rot (Fig. 1A) followed by leaf browning (Fig. 1B) has caused significant economic losses. Approximately 80% (loss of 45 million JPY) of plant loss occurred from May to Sep 2009 (Shimizu, unpublished), and the disease was observed again in 2020. Diseased Welsh onions (five to six leaf stage) were collected in 2009. Abundant nonseptate hyphae of Pythium-like organisms were observed in the rotted roots (Fig. 1C). Disinfected symptomatic tissue samples were placed on NARF medium (Morita and Tojo 2007) and incubated at 25°C for 3 to 7 days. Six Pythium-like organisms were isolated, and their morphological features on a grass blade culture, potato carrot agar (PCA) (van der Plaats-Niterink 1981), cornmeal agar (CMA) and V8 juice agar (Miller 1955) were examined. Hyphal growth rates from 1–46°C were measured by culturing on PCA. The ribosomal internal transcribed spacer (ITS) regions and mitochondrial COI of the isolates were amplified and sequenced according to Ueta and Tojo (2016). All six isolates obtained showed similar morphology, hyphal growth rates, and sequences of ITS and COI. Detailed descriptions are provided here for the representative isolate 72 (MAFF246451). The isolate produced asexual structures but did not form sexual structures, including oogonia, antheridia, and oospores on all the media used. Hyphae were up to 6.8 μm wide. Appressoria were knob-like terminations (Fig. 1D). Sporangia were filamentous and indistinguishable from the hyphae. Zoospores (Fig. 1E) were formed at 5–25°C. The diameter of encysted zoospores ranged 7.4–10.1 (av. 8.9) μm (Fig. 1F). Cardinal temperatures for hyphal growth on PCA were 5°C min, 28–31°C opt, and 35°C max. The daily growth rate at 25°C was 15.0 mm per day. The sequence analysis of all isolates, including isolate 72 (GenBank ac nos AB700596 for ITS, LC630955 for COI) showed the present isolates belonged to Pythium Cluster B2a (Robideau et al. 2011) (Fig. 2). Based on these features, the six isolates were identified as Pythium Cluster B2a sp. In the inoculation test, isolate 72 was cultured on CMA at 25°C for 5 days. Mycelium disks (5 mm diam) obtained from the culture were placed on the primary roots of 8-day-old Welsh onion seedlings (cv Koutou), which were grown at a density of six plants on rock wool cubes moistened with tap water in a 50 mL plastic pot. The inoculated and non-inoculated plants were grown at 28°C for 7 days in a growth chamber. The experiment was repeated twice using three pots per replication. The plants inoculated with isolate 72 wilted, and their roots rotted 7 days after inoculation. No disease was found observed on the non-inoculated plants. The isolate of Pythium Cluster B2a sp. was consistently re-isolated from the diseased plants, thus, fulfilling Koch’s postulates. Pythium Cluster B2a sp. causing stem rot on lettuce has been recorded in Italy (Garibaldi et al. 2017). To our knowledge, this is the first report of Pythium Cluster B2a sp. on Welsh onions. Since significant losses to root rot of Welsh onion have occurred in Japan, identification of the causal organism will enable the development of management practices to reduces losses.

scholarly journals First Report of Fusarium oxysporum f. sp. lentis of Lentil in Italy

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 562-562 ◽  
Author(s):  
L. Tosi ◽  
C. Cappelli
Keyword(s):  
Root System ◽  
Management Practices ◽  
Sandy Loam ◽  
Central Italy ◽  
Agar Plate ◽  
Deionized Water ◽  
Centraalbureau Voor ◽  
First Report ◽  
Soil Mix ◽  
Lower Stem

During June and July 1999-2000, a disease causing severe losses of seedlings of a local ecotype of lentil (Lens culinaria Medik, syn. Lens esculenta Moench.) was observed in four commercial fields in central Italy (Umbria and Latium regions). Disease symptoms, observed in both years, included stunting, wilting, marked reduction of root system, and internal vascular discoloration of the lower stem. Twenty-five samples for each field, consisting of lentil roots and stems, were collected. Seven to eight tissue pieces per sample, derived from the lower stem and a variety of root sizes, were sampled, surface-treated in 1 or 0.1% HgCl2 for 30 s, rinsed in sterile deionized water, placed on petri dishes containing potato dextrose agar (PDA, pH 5.5) and then incubated for 7 days at 25°C. F. oxysporum (2) (identification confirmed by R. A. Samson, Centraalbureau Voor Schimmelcultures of Baarn, Netherlands) was consistently recovered from affected tissues. Monoconidial cultures of four isolates were prepared and evaluated for pathogenicity. Seventy 4-week-old lentil seedlings (local ecotype) were inoculated by dipping the root system of each seedling in a spore suspension of each isolate of F. oxysporum (106 conidia/ml) for 30 min and transplanted into a pot containing a sterilized sandy-loam soil mix. In a second experiment, 100 seeds for each isolate were sown in the same soil mix amended with rice kernels colonized with four isolates of F. oxysporum (10% wt/wt). Seedlings dipped in sterile deionized water and seeds sown in soil amended with noncolonized rice kernels served as controls in the first and second experiments, respectively. Three replications of both pathogenicity tests were carried out in a controlled growth chamber at day/night 22/20 ± 2°C, 60/70% RH, 12 h day (180 μE•m2•s-1). Both experiments were repeated. Two to three weeks after inoculation, all plants inoculated with each F. oxysporum isolate showed the same symptoms observed in the field and caused wilting and death of 80 to 100% of the inoculated plants. F. oxysporum was consistently reisolated from the symptomatic test plants, whereas the fungus was never isolated from all control plants which remained symptomless and healthy. F. oxysporum was not observed in seed health tests (blotter and agar plate methods) carried out on 100 seeds per sample harvested from infected crops. Management practices include long-term crop rotation with nonsusceptible hosts and removal and destruction of infected crop debris. Seed treatment with fungicides (benzimidazoles, thiram) (3) can reduce incidence of the disease but host resistance is the best mean of controlling Fusarium wilt. Most resistant lentil accessions come from Chile, Egypt, India, Iran, and Romania (1). This is the first report of F. oxysporum f. sp. lentis on lentil in Italy. Without adequate control, this seedling disease may become a major factor limiting production of high quality lentils in Umbria and Latium. References: (1) B. Baya et al. Euphytica 98:69, 1997. (2) C. Booth. C.M.I. Description of Fungi and Bacteria. No. 271, 1971. (3) J. Kannayan and Y. L. Nene. Indian J. Plant Prot. 2:80, 1974.

scholarly journals First Report of Black Root Rot Caused by Thielaviopsis basicola on Soybean (Glycine max) in Arkansas

Plant Disease ◽  
2010 ◽  
Vol 94 (9) ◽  
pp. 1168-1168 ◽  
Author(s):  
W. S. Monfort ◽  
A. G. Carroll ◽  
M. J. Emerson ◽  
J. Fortner ◽  
C. S. Rothrock
Keyword(s):  
Root Rot ◽  
Pathogenic Fungus ◽  
Growth Stages ◽  
Infested Soil ◽  
Thielaviopsis Basicola ◽  
Black Root Rot ◽  
First Report ◽  
Soil Temperatures ◽  
Plant Pathol ◽  
Soybean Plants

Thielaviopsis basicola (Berk. & Broome) Ferraris (synonym Chalara elegans Nag Raj & Kendrick) is a soilborne plant-pathogenic fungus reported in many parts of the world. In Arkansas, T. basicola is found commonly in cotton fields (4). This fungus colonizes cortical tissue of seedlings under cool wet conditions, causing a dark brown or black discoloration of the roots and hypocotyls, resulting in stunted, slow-developing plants (4). In 2008, large areas of stunted soybean plants with shortened internodes were reported in a field in Phillips County, AR, where cotton had previously been produced. Soybean was planted in this field in early April when cool soil temperatures (~21 to 24°C) prevailed. Soybean plants at the v3 to v5 growth stages were observed to have extensive areas of black cortical root necrosis. Plant samples were collected and roots were excised, washed, and surface disinfested in a 10% NaOCl solution. Root segments were incubated on the carrot-based selective medium TB-CEN (3). T. basicola was isolated from incubated segments after 2 weeks at 21°C in the dark. Chlamydospore chains (44.8 to 56.0 × 8.4 to 11.2 μm) consisting of an average of six spores and endoconidia (8 to 30 × 3 to 5 μm) were observed with a compound microscope. In addition to plant tissue, soil was assayed and confirmed to be positive for T. basicola by the pour plate technique (3) with the medium TB-CEN. Greenhouse trials were conducted to confirm field observations. Soil from the Phillips County field was sterilized and reinfested with 100 CFU of chlaymdospore suspension per gram (dry weight) of soil. Fifty soybean seeds (cv. Schillinger 457) were planted in infested and sterilized soil and grown for 29 days. Results showed that 38% of plants germinated and survived in the T. basicola-infested soil compared with 71% in the sterile soil treatment. Fifteen of the nineteen plants that survived in the infested soil were positive for T. basicola, while all plants in the sterilized soil were negative for the fungus. Soybean has previously been reported to be a host of T. basicola worldwide, but North American reports have been confined to Canada and Michigan, where cool soil temperatures persist for longer periods during the early part of the growing season (1,2). To our knowledge, this is the first report of T. basicola being important in the growth of soybean in warmer latitudes where the pathogen has been observed frequently on cotton and tobacco. In areas where cotton has historically suffered seedling damage from T. basicola, black root rot may become important on soybean as production of the latter crop increases. Since the initial field observation and confirmation in 2008, multiple soybean fields in 10 Arkansas counties have been documented with black root rot, with an estimated 5 to 30% of plants in each field infected. References: (1) T. R. Anderson. Can. J. Plant Pathol. 6:71, 1984. (2) J. L. Lockwood et al. Plant Dis. Rep. 54:849, 1970. (3) L. P. Specht and G. J. Griffin. Can. J. Plant Pathol. 7:438, 1985. (4) N. R. Walker et al. Phytopathology 89:613, 1999.

scholarly journals First Report of Pythium Root Rot of Rau Ram (Polygonum odoratum)

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 340-340
Author(s):  
E. N. Rosskopf ◽  
C. B. Yandoc ◽  
B. Stange ◽  
E. M. Lamb ◽  
D. J. Mitchell
Keyword(s):  
Root Rot ◽  
Vascular System ◽  
Pond Water ◽  
Centraalbureau Voor ◽  
First Report ◽  
Pathogenicity Tests ◽  
Symptomatic Tissue ◽  
Pythium Helicoides ◽  
Production House ◽  
Test Plants

Polygonum odoratum (= Persicaria odorata), known as rau ram or sang hum, is native to southeastern Asia and is a common herb in Vietnamese cuisine (1). It has been studied most extensively for its aromatic compound content (2). In Florida, rau ram commonly is grown hydroponically in greenhouses using large, cement beds with recirculated water. The plants form dense mats from which new growth is trimmed for market. During January of 2002, a severe dieback was observed in one production house in Saint Lucie County, FL. Plants with less severe symptoms were yellowed and stunted. Roots of symptomatic plants were largely decayed with root symptoms beginning as a tip necrosis. The cortex of severely affected roots slipped off easily, leaving a stringy vascular system. Plating of symptomatic tissue from 20 randomly selected plant samples was performed with multiple general and selective media including potato dextrose agar, corn meal agar with pimaricin, ampicillin, rifampicin, and pentachloronitrobenzene (PARP) (3). All colonies produced were identified as Pythium helicoides Drechsler on the basis of sporangial, oogonial, and antheridial characteristics (4). Isolates had proliferous, obovoid, papillate sporangia, and were homothallic with smooth-walled oogonia and thick-walled, aplerotic oospores. Multiple antheridial attachments per oogonium were common with the antheridium attached along its entire length. Pathogenicity tests were conducted using P. odoratum plants grown from commercial transplants. Two tests were performed. Each test was conducted using eight inoculated and eight control plants. In the first test, plants were maintained in 10-cm pots immersed in sterilized pond water for the duration of the test. Plants were inoculated with five 7- × 70-mm sections of freshly growing mycelial culture per plant using 10-day-old cultures of Pythium helicoides grown on water agar. Chlorosis was observed at approximately 2 months after inoculation. Root necrosis was observed in inoculated plants approximately 5 months after inoculation. This test was performed in the greenhouse with temperatures ranging from 20 to 30°C. The second test was performed in growth chambers at 35 to 40°C. Plants were maintained in 10-cm pots immersed in Hoagland's solution and were inoculated with four 6-mm plugs per plant. Symptoms were observed on inoculated plants at this temperature within 1 week of inoculation. No chlorosis or root decay was observed in noninoculated, immersed plants. The pathogen was reisolated from inoculated, symptomatic tissue. To our knowledge, this is the first report of root rot of P. odoratum caused by Pythium helicoides. References: (1) R. E. Bond. Herbarist 55:34, 1989. (2) N. X. Dung et al. J. Essent. Oil Res. 7:339, 1995. (3) M. E. Kannwischer and D. J. Mitchell. Phytopathology 68:1760, 1978. (4) A. J. van der Plaats-Niterink. Monograph of the Genus Pythium. Vol. 21, Studies in Mycology. Centraalbureau voor Schimmelcutltures, Baarn, The Netherlands, 1981.

scholarly journals First Report of Stem Blight Caused by Calonectria colhounii (Anamorph Cylindrocladium colhounii) on Greenhouse-Grown Blueberries in the United States

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1187-1187
Author(s):  
J. J. Sadowsky ◽  
T. D. Miles ◽  
A. M. C. Schilder
Keyword(s):  
United States ◽  
North Carolina ◽  
Root Rot ◽  
The United States ◽  
Vaccinium Corymbosum ◽  
Conidial Suspension ◽  
Centraalbureau Voor ◽  
First Report ◽  
Stem Lesions ◽  
Β Tubulin

Necrotic stems and leaves were observed on 2- to 4-month-old, rooted microshoot plants (Vaccinium corymbosum L. ‘Liberty’ and ‘Bluecrop’, V. angustifolium Aiton ‘Putte’, and V. corymbosum × V. angustifolium ‘Polaris’) in a Michigan greenhouse in 2008 and 2009. As the disease progressed, leaves fell off and 80 to 100% of the plants died in some cases. Root rot symptoms were also observed. A fungus was isolated from stem lesions. On potato dextrose agar (PDA), cultures first appeared light tan to orange, then rusty brown and zonate with irregular margins. Chains of orange-brown chlamydospores were abundant in the medium. Macroconidiophores were penicillately branched and had a stipe extension of 220 to 275 × 2.5 μm with a narrowly clavate vesicle, 3 to 4 μm wide at the tip. Conidia were hyaline and cylindrical with rounded ends, (1-)3-septate, 48 to 73 × 5 to 7 (average 60 × 5.5) μm and were held together in parallel clusters. Perithecia were globose to subglobose, yellow, 290 to 320 μm high, and 255 to 295 μm in diameter. Ascospores were hyaline, 2- to 3-septate, guttulate, fusoid with rounded ends, slightly curved, and 30 to 88 × 5 to 7.5 (average 57 × 5.3) μm. On the basis of morphology, the fungus was identified as Calonectria colhounii Peerally (anamorph Cylindrocladium colhounii Peerally) (1,2). The internal transcribed spacer region (ITS1 and ITS2) of the ribosomal DNA and the β-tubulin gene were sequenced (GenBank Accession Nos. HQ909028 and JF826867, respectively) and compared with existing sequences using BLASTn. The ITS sequence shared 99% maximum identity with that of Ca. colhounii CBS 293.79 (GQ280565) from Java, Indonesia, and the β-tubulin sequence shared 97% maximum identity with that of Ca. colhounii CBS 114036 (DQ190560) isolated from leaf spots on Rhododendron sp. in North Carolina. The isolate was submitted to the Centraalbureau voor Schimmelcultures in the Netherlands (CBS 129628). To confirm pathogenicity, 5 ml of a conidial suspension (1 × 105/ml) were applied as a foliar spray or soil drench to four healthy ‘Bluecrop’ plants each in 10-cm plastic pots. Two water-sprayed and two water-drenched plants served as controls. Plants were misted intermittently for 2 days after inoculation. After 7 days at 25 ± 3°C, drench-inoculated plants developed necrotic, sporulating stem lesions at the soil line, while spray-inoculated plants showed reddish brown leaf and stem lesions. At 28 days, three drench-inoculated and one spray-inoculated plant had died, while others showed stem necrosis and wilting. No symptoms were observed on control plants. Fungal colonies reisolated from surface-disinfested symptomatic stem, leaf, and root segments appeared identical to the original isolate. Cy. colhounii was reported to cause a leaf spot on blueberry plants in nurseries in China (3), while Ca. crotalariae (Loos) D.K. Bell & Sobers (= Ca. ilicicola Boedijn & Reitsma) causes stem and root rot of blueberries in North Carolina (4). To our knowledge, this is the first report of Ca. colhounii causing a disease of blueberry in Michigan or the United States. Because of its destructive potential, this pathogen may pose a significant threat in blueberry nurseries. References: (1) P. W. Crous. Taxonomy and Pathology of Cylindrocladium (Calonectria) and Allied Genera. The American Phytopathological Society, St. Paul, MN, 2002. (2) L. Lombard et al. Stud. Mycol. 66:31, 2010. (3) Y. S. Luan et al. Plant Dis. 90:1553, 2006. (4) R. D. Milholland. Phytopathology 64:831, 1974.

scholarly journals Effect of Soil Inoculum Density and Temperature on the Incidence of Cucumber Black Root Rot

Plant Disease ◽  
2016 ◽  
Vol 100 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Kuniaki Shishido ◽  
Hiroyuki Murakami ◽  
Daiki Kanda ◽  
Shin-ichi Fuji ◽  
Takeshi Toda ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Soil Temperature ◽  
Root Rot ◽  
Strongly Correlated ◽  
Black Root Rot ◽  
Soil P ◽  
Control Techniques ◽  
Soil Inoculum ◽  
Phomopsis Sclerotioides ◽  
Soil Disinfection

The effects of the density of Phomopsis sclerotioides in soil and other environmental factors on black root rot of cucumber were investigated. Cucumber plants were grown in soil containing P. sclerotioides at 1, 10, 100, and 1000 CFU/g. Wilt incidence from 3 to 7 weeks after transplanting was strongly correlated with P. sclerotioides density in soil (P < 0.05). Root rot of squash rootstock occurred in soil with very low inoculum densities (0.1 CFU/g), and was strongly related to P. sclerotioides density (Y = −0.3x + 1.2, R2 = 0.743, P < 0.05) at 8 weeks after transplanting. Cucumber plants showed wilt symptoms in soil containing 1 CFU/g. Wilt symptoms in cucumber plants occurred 4 to 7 days earlier in soil at 22°C than in soil at 27 or 17°C. Root rot development could be predicted from the density of P. sclerotioides in soil and soil temperature. However, further studies on the effects of other environmental factors are required to test the linear model in commercial fields. This information is essential for determining the threshold pathogen density at which most control techniques, particularly those other than soil disinfection, will be effective.

scholarly journals Take-All Root Rot of St. Augustinegrass: First Report in Mississippi

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 921-921
Author(s):  
M. Tomaso-Peterson ◽  
L. E. Trevathan ◽  
M. S. Gonzalez
Keyword(s):  
Tall Fescue ◽  
Root Rot ◽  
Potato Dextrose Agar ◽  
Gaeumannomyces Graminis ◽  
Peat Moss ◽  
Infested Soil ◽  
First Report ◽  
Plant Parts ◽  
Home Lawns ◽  
Take All

Take-all root rot has been reported as a destructive disease of St. Augustinegrass home lawns in Florida and Alabama (1). In June 1998 and 1999, St. Augustinegrass home lawns in central Mississippi developed chlorotic, thinning patches ranging from 0.5 to 4.5 m in diameter. By August of each summer, plants within affected patches were necrotic and dead. Roots of affected St. Augustinegrass were necrotic and shorter than those of unaffected plants; nodes on stolons were necrotic, and lesions developed on internodes. Ectotrophic runner hyphae and dark brown, lobed hyphopodia were visible on roots and aboveground plant parts, respectively. Symptomatic tissues collected from St. Augustinegrass home lawns were plated onto potato dextrose agar (PDA); the incitant of take-all root rot, Gaeumannomyces graminis(Sacc.) Arx & Olivier var. graminis, was isolated. Verification of G. graminis var. graminis was based on colony morphology and taxonomic identification consistent with the description by Walker (2). G. graminis var. graminis isolated from symptomatic St. Augustinegrass was grown on sterile tall fescue seed and incorporated into sterile sand/peat moss mix. Asymptomatic St. Augustinegrass sprigs were washed, and roots were removed prior to planting in infested and noninfested soil. Plants were cultured in the greenhouse for 60 days. St. Augustinegrass planted into noninfested soil was asymptomatic while plants collected from G. graminis var. graminis-infested soil were symptomatic for take-all root rot. Crowns and roots of affected plants were necrotic; leaves were chlorotic and necrotic. Both runner hyphae and lobed hyphopodia were visible. G. graminis var. graminis was reisolated from symptomatic tissues and confirmed as the incitant of take-all root rot. This is the first report of take-all root rot of St. Augustinegrass in Mississippi. References: (1) M. Elliott. Plant Dis. 77:206, 1993. (2) J. Walker. Trans. Br. Mycol. Soc. 58:427, 1972.

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