scholarly journals First Report of Crown Rot of Gazania rigens Caused by Sclerotinia sclerotiorum in Louisiana

Plant Disease ◽  
2006 ◽  
Vol 90 (8) ◽  
pp. 1114-1114
Author(s):  
G. E. Holcomb
Keyword(s):  
United States ◽  
Sclerotinia Sclerotiorum ◽  
Standard Error ◽  
The United States ◽  
Crown Rot ◽  
First Report ◽  
Bedding Plant ◽  
Leaf Yellowing ◽  
Crown Tissue ◽  
Pathogenicity Tests

Gazania rigens (L.) (treasure flower, Asteraceae) is grown as a winter and summer annual bedding plant in Louisiana and the lower southern United States. In March 2006, cv. Kiss Mix was observed in a wholesale nursery with symptoms of leaf yellowing, wilt, crown rot, and death. White mycelia and black sclerotia were present on some infected and dead plants. The plants had been grown outdoors and approximately 2% of 1,120 plants had been lost. Petiole and crown tissue from infected plants were surface disinfected in 70% ethyl alcohol, and sections were placed on acidified potato dextrose agar (PDA). A fungus that produced white mycelia and black sclerotia consistently grew from tissue pieces. Other characteristics included production of numerous sclerotia (32 to 71 per dish from 10 dishes) that were oval to oblong and formed in a ring at the periphery of culture dishes. Sclerotia measured 3 to 7 mm long (mean = 4.4, standard error = 0.15, N = 50) × 2 to 4 mm wide (mean = 3.0, standard error = 0.06, N = 50). Cells of sclerotial rinds were globose and lacked erect tomentum hyphae (1). Growth rate of the fungus at 26°C on PDA ranged from 1.3 to 3.1 cm/day (mean = 2.2, standard error = 0.05, N = 45) and mycelia covered the dishes after 3 days (2). On the basis of these characteristics, the fungus was identified as Sclerotinia sclerotiorum (Lib.) de Bary. Fungal inoculum for pathogenicity tests was grown on twice-sterilized wheat grains and 1 g of 10-day-old inoculum, consisting of fungus mycelia and sclerotia, was placed at the base of six G. rigens cv. Daybreak Mix plants. Inoculated and noninoculated control plants were placed in a dew chamber held at 22°C for 48 h and then moved to a greenhouse where temperatures ranged from 20 to 25°C. Leaf yellowing, wilt, and crown rot developed after 3 to 4 days on all inoculated plants followed by death after 6 days. S. sclerotiorum was reisolated from all inoculated plants. Noninoculated plants remained healthy. Sclerotinia crown rot of G. rigens was first reported in the United States from California (3) and has also been reported from Italy and Argentina (4). To our knowledge, this is the first report of Sclerotinia crown rot on G. rigens in Louisiana. References: (1) L. M. Kohn. Phytopathology 69:881, 1979. (2) G. Li et al. Mycol. Res. 104:232, 2000. (3) V. M. Muir and A. H. McCain. Calif. Plant Pathol. 16:1, 1973. (4) S. M. Wolcan. J. Plant Path. 86:263, 2004.

scholarly journals First Report of Sclerotinia sclerotiorum on Gazania sp. Hybrid in Italy

Plant Disease ◽  
2001 ◽  
Vol 85 (11) ◽  
pp. 1207-1207
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
G. Gilardi ◽  
M. L. Gullino
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Soil Surface ◽  
Soft Rot ◽  
The United States ◽  
Crown Rot ◽  
First Report ◽  
Initial Symptoms ◽  
Leaf Yellowing ◽  
Stem Necrosis ◽  
Wheat Kernels

Gazania sp. hybrid is produced in pots in the Albenga Region of northern Italy for export to central and northern Europe. During fall 2000 to spring 2001, sudden wilt was observed in commercial plantings of this ornamental. Initial symptoms included stem necrosis at the soil level and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt followed by soft rot occurred within a few days on young plants after the first leaf symptoms. Necrotic tissues became covered with white mycelia that produced dark, spherical (2 to 6 mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from infected stem pieces of Gazania disinfested for 1 min in 1% NaOCl, plated on potato dextrose agar amended with streptomycin sulfate at 100 mg/liter. Pathogenicity of three fungal isolates was confirmed by inoculating 45- to 60-day-old plants grown in containers (14 cm diameter). Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were maintained outdoors where temperatures ranged between 8 and 15°C. Inoculated plants developed symptoms of leaf yellowing, followed by wilt, within 7 to 10 days, while control plants remained symptomless. White mycelia and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of wilt of Gazania sp. hybrid caused by S. sclerotiorum in Italy. A crown rot of Gazania caused by S. sclerotiorum has been reported from California in the United States(1). Reference: (1) V. M. Muir and A. H. McCain. Calif. Plant Pathol. 16:1, 1973.

scholarly journals First Report of White Mold Caused by Sclerotinia sclerotiorum on Persian Buttercup (Ranunculus asiaticus) in Italy

Plant Disease ◽  
2003 ◽  
Vol 87 (9) ◽  
pp. 1151-1151 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Sclerotinia Sclerotiorum ◽  
Soil Surface ◽  
The United States ◽  
First Report ◽  
Inoculation Trial ◽  
Initial Symptoms ◽  
Leaf Yellowing ◽  
Ranunculus Asiaticus ◽  
Stem Necrosis

Persian buttercup (Ranunculus asiaticus L.) is grown in the Albenga Region of northern Italy for cut flower production and exportation to central and northern Europe. During the winter of 2003, sudden wilt was observed in commercial plantings of R. asiaticus. Initial symptoms included stem necrosis at the soil level and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt occurred within a few days on young plants and was characterized by the presence of soft and watery tissues. Necrotic tissues became covered with whitish mycelium that produced dark, spherical sclerotia (1 to 4 mm in diameter). Sclerotinia sclerotiorum (Lib.) de Bary (1) was consistently recovered from infected stem pieces of R. asiaticus that were disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Pathogenicity of three isolates obtained from infected plants of persian buttercup was confirmed by inoculating 30-day-old plants grown in containers. Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface around the base of each of five plants. Noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 8 and 22°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing followed by wilt within 15 days, while control plants remained symptomless. White mycelium and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants. S. sclerotiorum has been previously reported on R. asiaticus in the United States (2) and Japan (3). To our knowledge, this is the first report of wilt of R. asiaticus caused by S. sclerotiorum in Italy and Europe. References: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (3) T. Urushibara et al. Annu. Rep. Kanto-Tosan Plant Prot. Serv. 46:61, 1999.

scholarly journals First Report of Sclerotinia sclerotiorum on Calendula officinalis in Italy

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 446-446
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Sclerotinia Sclerotiorum ◽  
Soil Surface ◽  
The United States ◽  
Calendula Officinalis ◽  
First Report ◽  
Initial Symptoms ◽  
Leaf Yellowing ◽  
Stem Necrosis ◽  
Pot Marigold

Pot marigold (Calendula officinalis) has recently become popular as a potted ornamental plant in Italy. During the spring 1999, a sudden wilt of 120 day-old plants was observed in the Albenga region of Northern Italy, an area of intensive floriculture production. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues resulted, covered with whitish mycelium that produced dark, spherical (2- to 6-mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from symptomatic stem sections surface disinfested 1 min in 1% NaOCl and plated on potato dextrose agar (PDA), amended with 100 ppm streptomycin sulfate. Pathogenicity of three isolates was confirmed by inoculating 90-day-old pot marigold plants grown in containers. Inoculum that consisted of wheat kernels infested with mycelium and sclerotia was placed on the soil surface around the base of previously wounded or non-wounded plants. Non-inoculated plants served as controls. All plants were kept outdoors where temperatures ranged between 8 and 16°C, under 50% shade and were maintained moist. Inoculated plants developed symptoms of leaf yellowing, followed by wilt within 7 days, while control plants remained symptomless. Sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. This is the first report of stem blight of C. officinalis caused by S. sclerotiorum in Europe. The disease was previously observed in the United States (1). Reference: (1) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN.

scholarly journals First Report of Sclerotinia sclerotiorum on Campanula carpatica and Schizanthus × wisetonensis in Italy

Plant Disease ◽  
2002 ◽  
Vol 86 (1) ◽  
pp. 71-71
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Sclerotinia Sclerotiorum ◽  
Ornamental Plants ◽  
Soil Surface ◽  
The United States ◽  
First Report ◽  
Potted Plants ◽  
Initial Symptoms ◽  
Stem Necrosis ◽  
Campanula Carpatica

The production of potted ornamental plants is very important in the Albenga Region of northern Italy, where plants are grown for export to central and northern Europe. During fall 2000 and spring 2001, sudden wilt of tussock bellflower (Campanula carpatica Jacq.) and butterfly flower (Schizanthus × wisetonensis Hort.) was observed on potted plants in a commercial greenhouse. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of the lower leaves. As stem necrosis progressed, infected plants growing in a peat, bark compost, and clay mixture (70-20-10) wilted and died. Necrotic tissues were covered with whitish mycelia that produced dark, spherical (2 to 6 mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from symptomatic stem pieces of both plants disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with streptomycin sulphate at 100 ppm. Pathogenicity of three isolates obtained from each crop was confirmed by inoculating 45- to 60-day-old C. carpatica and Schizanthus × wisetonensis plants grown in containers (14 cm diameter). Inoculum that consisted of wheat kernels infested with mycelia and sclerotia of each isolate was placed on the soil surface around the base of previously artificially wounded or nonwounded plants. Noninoculated plants served as controls. All plants were maintained outdoors where temperatures ranged between 8 and 15°C. Inoculated plants developed symptoms of leaf yellowing, followed by wilt, within 7 to 10 days, while control plants remained symptomless. White mycelia and sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of stem blight of C. carpatica and Schizanthus × wisetonensis caused by S. sclerotiorum in Italy. The disease was previously observed on C. carpatica in Great Britain (2) and on Schizanthus sp. in the United States (1). References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) J. Rees. Welsh J. Agric. 1:188, 1925.

scholarly journals First Report of Phytophthora citrophthora on Penstemon barbatus in Italy

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1260-1260 ◽  
Author(s):  
A. Garibaldi ◽  
D. Bertetti ◽  
D. Minerdi ◽  
M. L. Gullino
Keyword(s):  
Its Region ◽  
The United States ◽  
Phytophthora Species ◽  
Crown Rot ◽  
Pathogenicity Test ◽  
Phytophthora Citrophthora ◽  
First Report ◽  
Blastn Analysis ◽  
Root And Crown Rot ◽  
Pathogenicity Tests

Penstemon barbatus (Cav.) Roth (synonym Chelone barbata), used in parks and gardens and sometimes grown in pots, is a plant belonging to the Scrophulariaceae family. During the summers of 2004 and 2005, symptoms of a root rot were observed in some private gardens located in Biella Province (northern Italy). The first symptoms resulted in stunting, leaf discoloration followed by wilt, root and crown rot, and eventually, plant death. The diseased tissue was disinfested for 1 min in 1% NaOCl and plated on a semiselective medium for Oomycetes (4). The microorganism consistently isolated from infected tissues, grown on V8 agar at 22°C, produced hyphae with a diameter ranging from 4.7 to 5.2 μm. Sporangia were papillate, hyaline, measuring 43.3 to 54.4 × 26.7 to 27.7 μm (average 47.8 × 27.4 μm). The papilla measured from 8.8 to 10.9 μm. These characteristics were indicative of a Phytophthora species. The ITS region (internal transcribed spacer) of rDNA was amplified using primers ITS4/ITS6 (3) and sequenced. BLASTn analysis (1) of the 800 bp obtained showed a 100% homology with Phytophthora citrophthora (R. & E. Sm.) Leonian. The nucleotide sequence has been assigned GenBank Accession No. DQ384611. For pathogenicity tests, the inoculum of P. citrophthora was prepared by growing the pathogen on autoclaved wheat and hemp kernels (2:1) at 25°C for 20 days. Healthy plants of P. barbatus cv. Nano Rondo, 6 months old, were grown in 3-liter pots (one plant per pot) using a steam disinfested substrate (peat/pomix/pine bark/clay 5:2:2:1) in which 200 g of kernels per liter of substrate were mixed. Noninoculated plants served as control treatments. Three replicates were used. Plants were maintained at 15 to 20°C in a glasshouse. The first symptoms, similar to those observed in the gardens, developed 21 days after inoculation, and P. citrophthora was consistently reisolated from infected plants. Noninoculated plants remained healthy. The pathogenicity test was carried out twice with similar results. A nonspecified root and crown rot of Penstemon spp. has been reported in the United States. (2). To our knowledge, this is the first report of P. citrophthora on P. barbatus in Italy as well as in Europe. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) F. E. Brooks and D. M. Ferrin. Plant Dis. 79:212, 1995. (3) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (4) H. Masago et al. Phytopathology 67:425, 1977.

scholarly journals First Report of Web Blight on Yellow-Sage (Lantana camara) Caused by Rhizoctonia solani in Europe

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 875-875 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
D. Bertetti ◽  
R. Nicoletti ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Rhizoctonia Solani ◽  
The United States ◽  
The Philippines ◽  
Lantana Camara ◽  
First Report ◽  
Leaf Spots ◽  
Entire Plant ◽  
Pathogenicity Tests ◽  
Web Blight

Lantana camara is increasingly grown in northern Italy as a potted plant and contributes to the diversification of offerings in the ornamental market. During the spring of 2001, selections of L. camara cuttings growing at a commercial farm located at Albenga (Riviera coast) exhibited tan leaf spots of irregular size and shape. Spots were at first isolated, 4 to 8 mm in diameter, and later coalesced and affected the entire plant. Heavily infected leaves, stems, and branches became blighted and were killed. Infected rooted cuttings also eventually died. Diseased cuttings showed a progressive reduction (to less than 20%) in rooting ability. Isolations from infected leaves and stems on potato dextrose agar (PDA), supplemented with 100 mg/liter of streptomycin sulphate, consistently yielded a fungus with mycelial and cultural characteristics resembling Rhizoctonia solani. The fungal isolates were further characterized as R. solani Kühn AG-4 based on hyphal anastomoses with several AG-4 tester isolates. Pathogenicity tests were performed by placing 5-day-old-fungal mycelial plugs, grown on PDA, at the base of five healthy yellow-sage stems and holding plants in a dew chamber at 18 to 22°C. After 2 days, foliage blight appeared on leaves of inoculated plants, and after 3 days, stems also became infected and entire plants wilted. Five noninoculated plants remained healthy. The fungal pathogen was reisolated from all inoculated plants. R. solani has been observed on L. camara in the United States (1) and the Philippines (2). To our knowledge, this is the first report of R. solani on L. camara in Europe. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) F. T. Orillo and R. B. Valdez. Philipp. Agric. A. 42:292, 1958.

scholarly journals First Report of Postharvest Fruit Rot in Persimmon Caused by Phacidiopycnis washingtonensis in Italy

Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 788-788 ◽  
Author(s):  
A. Garibaldi ◽  
D. Bertetti ◽  
M. T. Amatulli ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Its Region ◽  
The United States ◽  
Fruit Rot ◽  
Diospyros Kaki ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
First Report ◽  
Pathogenicity Tests ◽  
Phacidiopycnis Washingtonensis

Persimmon (Diospyros kaki L.) is widely grown in Italy, the leading producer in Europe. In the fall of 2009, a previously unknown rot was observed on 3% of fruit stored at temperatures between 5 and 15°C in Torino Province (northern Italy). The decayed area was elliptical, firm, and appeared light brown to dark olive-green. It was surrounded by a soft margin. The internal decayed area appeared rotten, brown, and surrounded by bleached tissue. On the decayed tissue, black pycnidia that were partially immersed and up to 0.5 mm in diameter were observed. Light gray conidia produced in the pycnidia were unicellular, ovoid or lacriform, and measured 3.9 to 6.7 × 2.3 to 3.5 (average 5.0 × 2.9) μm. Fragments (approximately 2 mm) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at temperatures between 23 and 26°C under alternating light and darkness. Colonies of the fungus initially appeared ash colored and then turned to dark greenish gray. After 14 days of growth, pycnidia and conidia similar to those described on fruit were produced. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced. BLAST analysis (1) of the 502-bp segment showed a 100% similarity with the sequence of Phacidiopycnis washingtonensis Xiao & J.D. Rogers (GenBank Accession No. AY608648). The nucleotide sequence has been assigned the GenBank Accession No. GU949537. Pathogenicity tests were performed by inoculating three persimmon fruits after surface disinfesting in 1% sodium hypochlorite and wounding. Mycelial disks (10 mm in diameter), obtained from PDA cultures of one strain were placed on wounds. Three control fruits were inoculated with plain PDA. Fruits were incubated at 10 ± 1°C. The first symptoms developed 6 days after the artificial inoculation. After 15 days, the rot was very evident and P. washingtonensis was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice. Since P. washingtonensis was first identified in the United States on decayed apples (2), ‘Fuji’, ‘Gala’, ‘Golden Delicious’, ‘Granny Smith’, ‘Red Chief’, and ‘Stark Delicious’, apple fruits also were artificially inoculated with a conidial suspension (1 × 106 CFU/ml) of the pathogen obtained from PDA cultures. For each cultivar, three surface-disinfested fruit were wounded and inoculated, while three others served as mock-inoculated (sterile water) controls. Fruits were stored at temperatures ranging from 10 to 15°C. First symptoms appeared after 7 days on all the inoculated apples. After 14 days, rot was evident on all fruit inoculated with the fungus, and P. washingtonensis was consistently reisolated. Controls remained symptomless. To our knowledge, this is the first report of the presence of P. washingtonensis on persimmon in Italy, as well as worldwide. The occurrence of postharvest fruit rot on apple caused by P. washingtonensis was recently described in the United States (3). In Italy, the economic importance of the disease on persimmon fruit is currently limited, although the pathogen could represent a risk for apple. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) Y. K. Kim and C. L. Xiao. Plant Dis. 90:1376, 2006. (3) C. L. Xiao et al. Mycologia 97:473, 2005.

scholarly journals First Report of Clubroot on Canola Caused by Plasmodiophora brassicae in North Dakota

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1438-1438 ◽  
Author(s):  
K. Chittem ◽  
S. M. Mansouripour ◽  
L. E. del Río Mendoza
Keyword(s):  
United States ◽  
North Dakota ◽  
Plasmodiophora Brassicae ◽  
The United States ◽  
Soil Samples ◽  
Pcr Analysis ◽  
Infested Soil ◽  
First Report ◽  
Resting Spores ◽  
Pathogenicity Tests

North Dakota leads the United States in canola (Brassica napus L.) production (4). A canola field with a distinct patch of dead plants spreading over an area of approximately 0.4 ha was detected in Cavalier County, North Dakota, in early September 2013. Numerous spots within the patch had plant mortalities >80%. Dead plants pulled from the soil had roots with severe galling and clubbing. Clubbed roots were brittle and disintegrated easily when pressed between fingers. Root and soil samples collected at several locations within and outside the affected patch were pooled in separate groups. All plants collected in the patch were symptomatic but those collected outside were not. In the lab, total genomic DNA from three symptomatic and two healthy root samples was extracted using standard procedures and freehand slices were prepared for observation with a compound microscope. Also, DNA from pooled soil samples was extracted using FastDNA Spin Kit for Soil (MP Biomedicals, Solon, OH). Round resting structures ranging from 2.2 to 4.2 μm in diameter were observed by microscopic examination of symptomatic root tissues. These structures resembled those typically produced by Plasmodiophora brassicae Woronin. This initial identification was later confirmed through PCR analysis using the species specific primers TC1F/R and TC2F/R (1). PCR products of 548 bp (TC1F/R) and 519 bp (TC2F/R) were produced in the three symptomatic and two infested soil samples, confirming the presence of P. brassicae. PCR amplicons were not detected in healthy root and soil samples. Pathogenicity tests were conducted in greenhouse to fulfill Koch's postulates. Briefly, five square plastic pots (10 × 10 × 13 cm) were filled with a 10-cm layer of Sunshine Mix #1 potting mix (Fison Horticulture, Vancouver, BC, Canada) and then 1 g of ground root galls (approximately 5 × 105 resting spores) was spread evenly on its surface and covered with 2 cm of soilless mix. A similar number of pots were filled only with soilless mix and used as controls. All pots were planted with two seeds of canola cv. Westar and incubated in greenhouse conditions at 21°C and 16 h light daily. The experiment was conducted twice. Four weeks after planting, all plants in the inoculated pots had developed galls while plants in control pots were symptomless. Presence of P. brassicae resting spores in the newly developed galls was confirmed by microscopic observations and PCR. Based on the symptoms, morphology of resting spores, PCR reactions, and pathogenicity tests, we confirm the presence of P. brassicae on canola. While P. brassicae has been reported as widespread in North America (2), to our knowledge, this is the first report of clubroot on canola in North Dakota and the United States. Clubroot became the most important disease affecting canola production in central Alberta, Canada, within 5 years of its discovery in 2003 (3); since then, the disease has been detected in Saskatchewan and Manitoba (3), Canadian provinces that share borders with North Dakota. Considering the difficulties in management of clubroot, measures should be initiated to limit the spread of the disease before it could pose a threat to United States canola production. References: (1) T. Cao et al. Plant Dis. 91:80, 2007. (2) G. Dixon J. Plant Growth Regul. 28:194, 2009. (3) S. Strelkov and S. Hwang. Can. J. Plant Pathol. 36(S1):27, 2014. (4) USDA-NASS, Ag. Statistics No. 81, 2012.

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