scholarly journals Occurrence of Sclerotinia Stem Rot of Osteospermum sp., Felicia amelloides, and Ranunculus asiaticus in Argentina

Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 1014-1014
Author(s):  
E. R. Wright ◽  
M. C. Rivera ◽  
G. Chiesa ◽  
D. Morisigue
Keyword(s):  
Pathogenic Fungi ◽  
Soft Rot ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Transparent Plastic ◽  
Plastic Bags ◽  
Leaf Yellowing ◽  
Ranunculus Asiaticus ◽  
Stem Lesions ◽  
And Control

Three ornamental species, Osteospermum sp. (L.), Felicia amelloides (L.) Voss, and Ranunculus asiaticus L., cultivated in greenhouses on the outskirts of Buenos Aires, showed sudden wilt and death during October 2002. These species are new ornamentals in Argentina. The diseased plants were cultivated in plastic containers filled with commercial potting mix. Soft rot was observed at the base of the plants. Stem lesions became covered with whitish mycelium that produced large, black sclerotia (5 to 7 mm in diameter) characteristic of Sclerotinia sclerotiorum (Lib.) de Bary (1). The fungus was consistently recovered from infected stem pieces that were disinfested for 1 min in 0.2% NaOCl and plated on potato dextrose agar (PDA), pH 7. Pathogenicity of the three isolates obtained from infected plants was confirmed by inoculating 10 3-month-old healthy plants of each species in 14-cm-diameter plastic pots. Each isolate was inoculated on the host from which it had been isolated. Inoculum consisted of three mycelial plugs from 7-day-old PDA cultures that were placed on the substrate at the base of the plants. Control plants were treated with sterile agar plugs. Inoculated and noninoculated plants were covered with transparent plastic bags for 2 days and incubated in a growth chamber at 20 to 24°C with a 12-h photoperiod. All inoculated plants developed symptoms of leaf yellowing and wilt. Soft and watery tissues were observed at the base of the plants, soon followed by the appearance of white mycelium. Disease symptoms were similar to those observed on the original infected plants and appeared 6, 5, and 3 days after inoculation on Osteospermum sp., F. amelloides, and R. asiaticus, respectively. All inoculated plants died within 3 weeks, and control plants remained healthy. S. sclerotiorum was reisolated from inoculated plants of each species, fulfilling Koch's postulates. To our knowledge, this is the first report of the occurrence of Sclerotinia stem rot on these three plant species in Argentina. Reference: (1) J. E. M. Mordue and P. Holliday. No. 513 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK. 1976.

scholarly journals First Report of Sclerotinia sclerotiorum on Coneflower

Plant Disease ◽  
1997 ◽  
Vol 81 (9) ◽  
pp. 1093-1093 ◽  
Author(s):  
K. F. Chang ◽  
R. J. Howard ◽  
R. G. Gaudiel ◽  
S. F. Hwang
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Echinacea Purpurea ◽  
Stem Rot ◽  
Perennial Herb ◽  
Sclerotinia Stem Rot ◽  
Transparent Plastic ◽  
Potato Dextrose Agar Medium ◽  
First Report ◽  
Plastic Bags ◽  
Stem Lesions

Purple coneflower (Echinacea purpurea (L.) Moench; Asteraceae), a perennial herb originating from North America, is used as a garden ornamental and is grown commercially for use in medicinal preparations as an immunostimulant. In October 1996, a previously undescribed stem rot disease was observed in a research plot of 6-month-old echinacea plants at Brooks. Seedlings had been raised in small rockwool cubes (2 × 2 × 5 cm3) in a greenhouse, then transplanted into the field in early June. By late August, dead and dying plants were observed throughout the stand. They had dark brown to black stem lesions above and at the soil level and dead leaves with bleached petiole lesions that extended ca. 15 cm above the axil. Diseased stems and petioles often disintegrated, leaving only fibrous tissues intact. Roots were rotted and black. Superficial white mycelium developed over the basal part of affected stems. Black, oblong to irregular-shaped sclerotia, 5.1 to 17.6 mm in size, formed externally on the crown areas after plant death. Sclerotinia sclerotiorum (Lib.) de Bary (1) was isolated from the diseased plants. Five isolates were selected to fulfill Koch's postulates with 3-month-old echinacea seedlings grown in 12-cm pots of soilless mix. Sclerotia from wilted, field-grown echinacea plants were transferred onto potato dextrose agar medium for 2 days at 20°C. Agar disks were cut with a 1-cm cork borer and two plugs containing sclerotial and mycelial tissues were inserted into the soilless mix 0.5 cm deep and 0.5 cm from the opposite sides of stems of test plants. Inoculated plants were enclosed in transparent plastic bags for 5 days and incubated in a growth chamber at 15/18°C (night/day) with a 12-h photoperiod. One to four lower leaves per plant wilted within 1 week after inoculation and aerial mycelia appeared on the petioles. Infected leaves quickly withered, dried, and dropped off the plant after the bags were removed. Plants often died 3 weeks after inoculation and S. sclerotiorum was reisolated from infected crown tissues. This disease was also found on 3-year-old plants of E. pallida (Nutt.) Nutt. var. angustifolia (DC.) Cronq. in Vernon, British Columbia, Canada, in May 1997. This is the first report of sclerotinia stem rot on Echinacea spp., a disease that could have a significant impact on the longevity and productivity of this crop in the field and greenhouse. Reference: (1) L. H. Purdy. Phytopathology 69:875, 1979.

scholarly journals Biology, Yield loss and Control of Sclerotinia Stem Rot of Soybean

2012 ◽  
Vol 3 (2) ◽  
pp. 1-7 ◽  
Author(s):  
Angelique J. Peltier ◽  
Carl A. Bradley ◽  
Martin I. Chilvers ◽  
Dean K. Malvick ◽  
Daren S. Mueller ◽  
...  
Keyword(s):  
Yield Loss ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
And Control

scholarly journals First Report of Stem Blight Caused by Botrytis cinerea on Jasminum officinalis in Italy

Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1708-1708
Author(s):  
D. Aiello ◽  
G. Parlavecchio ◽  
A. Vitale ◽  
G. Polizzi
Keyword(s):  
Botrytis Cinerea ◽  
Far East ◽  
Weather Conditions ◽  
Economic Loss ◽  
Transparent Plastic ◽  
Disease Symptoms ◽  
First Report ◽  
Stem Blight ◽  
Plastic Bags ◽  
Stem Lesions

Common jasmine (Jasminum officinalis L.) is an evergreen shrub that is native to the Middle and Far East. It is widely grown in Europe as an ornamental plant and in southeastern France for fragrance for the perfume industry. In March of 2008, a previously undescribed disease was observed on potted (6-month- to 3-year-old) common jasmine plants growing in open fields in a nursery of eastern Sicily, Italy. More than 20% of the plants showed disease symptoms. Diseased plants had small to large, brown or black lesions on stem. The lesions expanded rapidly, girdled the stem and caused blight of entire branches, and occasionally killed the plant. Abundant conidia and mycelia were detected on the surface of dead and dying stems under cool and humid conditions, which resulted in a moldy gray appearance. Botrytis cinerea Pers.:Fr. (1) was consistently isolated from affected tissues disinfected for 1 min in 1% NaOCl, rinsed in sterile water, and plated on potato dextrose agar (PDA). Colonies were at first white then became gray after 6 to 7 days when spores differentiated. White sclerotia developed after 8 to 9 days and turned black with age. Size of the conidia produced on 1-month-old culture ranged from 5.0 to 9.5 × 6.5 to 12.5 μm on the basis of 50 spore measurements. Sclerotia were spherical or irregular and ranged from 1.0 to 2.5 × 0.9 to 2.9 mm (average 1.7 × 1.8 mm). Stems of eight 6-month-old common jasmine plants were lightly wounded with a sterile razor and inoculated with 3-mm-diameter plugs of PDA from 10-day-old mycelial cultures, eight similar plants were inoculated with mycelium without wounding, and an equal number of noninoculated plants inoculated with only PDA plugs served as control. After inoculation, plants were enclosed in transparent plastic bags at 20 ± 2°C for 5 days. Stem lesions identical to the ones observed in the nursery were detected on all wounded and on two nonwounded fungus-inoculated plants within 5 to 7 days. Control plants remained healthy. B. cinerea was reisolated from typical lesions. The unusually cool and humid weather conditions recorded in Sicily are supposed to be highly conducive of disease outbreak. Although B. cinerea does not usually kill the plants, under these environmental conditions this disease can cause significant economic loss to ornamental nurseries. To our knowledge, this is the first report of B. cinerea causing stem blight on J. officinalis. Reference: (1) M. B. Ellis. Dematiaceous Hyphomycetes. CAB, Kew, Surrey, England, 1971.

scholarly journals Development of Sclerotinia Stem Rot in Potato Fields in South-Central Washington

Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 419-423 ◽  
Author(s):  
Z. K. Atallah ◽  
D. A. Johnson
Keyword(s):  
Recurrent Disease ◽  
Disease Onset ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Full Bloom ◽  
Stem Infection ◽  
Plant Infection ◽  
South Central ◽  
Stem Lesions

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a recurrent disease on potato in the Columbia Basin of Washington. The role of ascospores in association with disease onset and stem rot incidence in commercial fields and the role of flower blossoms on plant infection were investigated in 10 fields over 2 years. Ascospores of S. sclerotiorum were detected on a semiselective medium over several weeks, with a peak in number of ascospores near initial full bloom. A high proportion of blossoms at initial full bloom were contaminated with S. sclerotiorum prior to blossom fall in most fields. Stem lesions occurred after row closure and blossom drop, and were associated with mycelial mats growing from contaminated blossoms that had dropped on plant stems in the plant canopy or blossoms that dropped on the ground and stems contacting the ground. Incidence of Sclerotinia stem rot was reduced significantly when blossoms were removed from plants before blossom drop. Flower blossoms were shown to be a paramount bridge between airborne ascospores of S. sclerotiorum and stem infection in the potato canopy.

scholarly journals First Report of Stevia as a Host of Sclerotinia sclerotiorum

Plant Disease ◽  
1997 ◽  
Vol 81 (3) ◽  
pp. 311-311 ◽  
Author(s):  
K. F. Chang ◽  
R. J. Howard ◽  
R. G. Gaudiel ◽  
S. F. Hwang
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Higher Plants ◽  
Stevia Rebaudiana ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
First Report ◽  
Stevia Rebaudiana Bertoni ◽  
Dry Conditions ◽  
Rot Disease ◽  
Stem Lesions

Stevia (Stevia rebaudiana Bertoni; Asteraceae), an annual plant originating from Paraguay, contains glucosides of a diterpenoid (2), which is used as a low-caloric sweetener in some South American and southeast Asian countries. The main active ingredient, stevioside, is 100 to 300 times as sweet as sucrose. Stevia has been experimentally grown under field conditions in central and western Canada and has the potential to become a commercially viable alternative crop. In August 1996, a previously undescribed stem rot disease was observed on stevia plants at the Crop Diversification Centre South, Brooks, Alberta. The disease was found in research plots where 4-month-old plants were growing in loam soil. Diseased stems showed dark brown lesions above and at soil level when plant height reached approximately 30 cm. Under dry conditions, mild stem lesions caused plant stunting with lower leaves turning black and curling downward. Wilted leaf symptoms gradually spread upward in affected plants. Partial wilting symptoms appeared when girdling was restricted to branches. The entire plant collapsed when girdling of the crown and roots occurred. Superficial white mycelium developed over the basal part of affected stems under moist conditions, especially after rainy periods. Black, round to oblong sclerotia, 3.5 to 10.1 mm in size, formed externally on the crown areas after plant death. Sclerotinia sclerotiorum (Lib.) de Bary (1) was consistently isolated from the diseased plants. To confirm pathogenicity, 4-week-old stevia seedlings were obtained from shoot cuttings and grown in 12-cm pots of soilless mix. Sclerotia produced on potato dextrose agar were inserted into the mix 0.5 cm deep and 0.5 cm from the stems of test plants. Plants were placed in a growth chamber at 22°C with a 12-h photoperiod and 95% relative humidity. Two weeks after soil infestation, plants wilted and S. sclerotiorum was reisolated from the diseased crown tissues. This is the first report on stevia of sclerotinia stem rot, a disease that could significantly reduce foliar growth and stevioside production in field plantings. References: (1) L. H. Purdy. Phytopathology 69:875, 1979. (2) T. Robinson. 1991. The Organic Constituents of Higher Plants: Their Chemistry and Interrelationships. 6th ed. Cordus Press, North Amherst, MA.

scholarly journals Curvularia Blight on Lolium perenne on Turfgrasses in Argentina

Plant Disease ◽  
2007 ◽  
Vol 91 (3) ◽  
pp. 323-323
Author(s):  
L. Goldring ◽  
M. Lacasa ◽  
E. R. Wright
Keyword(s):  
Lolium Perenne ◽  
Pathogenic Fungi ◽  
Natural Soil ◽  
Curvularia Lunata ◽  
Distilled Water ◽  
Transparent Plastic ◽  
Conidial State ◽  
Plastic Bags ◽  
Initial Symptoms ◽  
Intermediate Cells

Lolium perenne L. is commonly used alone or in association with blue-grass and fescues in sport fields, parks, and gardens. During 2003, symptoms of an unknown disease were observed on L. perenne turfgrass in western Buenos Aires. Initial symptoms were indefinite yellow and green dappled spots that extended downward from the leaf tip, turned brown and finally gray, causing leaf death. Segments of symptomatic leaf tissues were surface sterilized and placed on 2% potato dextrose agar in petri dishes. After 4 days at room temperature, blackish brown colonies developed with dark brown septate conidiophores. Conidia were 21 to 29 × 9 to 13 μm, 3-septa, curved at the third cell from the base that is longer and darker than the others. Cells at each end are subhyaline and intermediate cells are medium brown. These characteristics are consistent with Curvularia lunata (Wakker) Boedijng (1). Pathogenicity tests were performed in five plastic trays with substrate of natural soil and sand (1:1 [v/v]) where the turfgrass (L. perenne cv. El Cencerro) was seeded. Plants were inoculated by spraying a suspension of 2 × 106 conidia per ml of sterile distilled water. Controls were sprayed with sterile distilled water. The trays were covered with transparent plastic bags, sprayed periodically with water, and incubated at 25°C in a greenhouse for 20 days. The first symptoms were observed 3 days later. After 9 days, 24% of the grass surface area showed blight lesions. C. lunata was consistently reisolated from affected tissues. Control plants remained symptomless. To our knowledge, this is the first report of C. lunata affecting L. perenne in Argentina. Reference: (1) M. B. Ellis and I. A. S. Gibson Cochliobolus lunatus (conidial state: Curvularia lunata). Page 474 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1975.

scholarly journals First Report of Ascochyta Leaf Spot Caused by Phoma exigua var. exigua on Common Bean in Greece

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 653-653 ◽  
Author(s):  
G. A. Bardas ◽  
G. T. Tziros ◽  
K. Tzavella-Klonari
Keyword(s):  
Common Bean ◽  
Leaf Spot ◽  
Morphological Characteristics ◽  
Pathogenic Fungi ◽  
Weather Conditions ◽  
Conidial Suspension ◽  
Phoma Exigua ◽  
First Report ◽  
Plastic Bags ◽  
And Control

Common bean (Phaseolus vulgaris L.) is cultivated extensively in Greece for dry and fresh bean production. During 2005 and 2006, a disease with typical blight symptoms was observed occasionally on dark red kidney, brown kidney, and black bean plants in most bean-producing areas of Greece. It rarely was destructive unless the crop had been weakened by some unfavorable environmental conditions. Infected leaves had brown-to-black lesions that developed concentric zones 10 to 30 mm in diameter and also contained small, black pycnidia. Concentric dark gray-to-black lesions also appeared on branches, stems, nodes, and pods. Infected seeds turned brown to black. Plants sometimes showed defoliation and pod drop. The fungus was consistently isolated on potato dextrose agar from diseased leaves and pods and identified as Phoma exigua var. exigua Sutton and Waterstone on the basis of morphological characteristics of conidia and pycnidia (1,2). Spores were massed in pycnidia from which they were forced in long, pink tendrils under moist weather conditions. Conidia were cylindrical to oval, allantoid, hyaline, pale yellow to brown, usually one-celled, and 2 to 3 × 5 to 10 μm. To satisfy Koch's postulates, a conidial suspension (1 × 106 conidia per ml) of the fungus was sprayed onto leaves and stems of bean seedlings (first-leaf stage) (cv. Zargana Hrisoupolis). Both inoculated and control seedlings (inoculated with sterile water) were covered with plastic bags for 72 h in a greenhouse at 23°C. Inoculated plants showed characteristic symptoms of Ascochyta leaf spot 12 to 15 days after inoculation. The fungus was reisolated from lesions that developed on the leaves and stems of all inoculated plants. The pathogen is present worldwide on bean. To our knowledge, this is the first report of P. exigua var. exigua on common bean in Greece. References: (1) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2007. (2) B. C. Sutton and J. M. Waterstone. Ascochyta phaseolorum. No. 81 in: Descriptions of Pathogenic Fungi and Bacteria. CMI/AAB, Kew, Surrey, England, 1966.

scholarly journals First Report of Crown and Stem Rot of Orchid (Orchis palustris) Caused by Sclerotinia minor

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 913-913
Author(s):  
C. Eken ◽  
S. Ercişli ◽  
A. Eşitken ◽  
E. Demirci ◽  
G. Y. Yuen
Keyword(s):  
Potato Dextrose Agar ◽  
Stem Rot ◽  
Eastern Anatolia ◽  
Forage Production ◽  
Sclerotinia Minor ◽  
Transparent Plastic ◽  
First Report ◽  
Plastic Bags ◽  
White Mycelium ◽  
Plant Pathol

Orchis palustris Jacq. is a wild orchid native to wetlands in eastern Anatolia. During June of 2003, near Erzurum, Turkey, a decline of this orchid was observed in several meadows that had been irrigated for forage production. Stems were chlorotic, wilted, and collapsed. There was a soft, watery rot at the crowns and lower stems. White mycelium and black sclerotia formed on necrotic stem and crown tissues. The fungus was isolated from sclerotia on potato dextrose agar (PDA) and identified as Sclerotinia minor Jagger on the basis of small sclerotia (0.5 to 2.5 mm long) scattered throughout the colonies (2). Pathogenicity was confirmed by inoculating stems of 8-week-old plants with mycelial plugs from 5-day-old PDA cultures and enclosing inoculated plants in transparent plastic bags for 3 days. After 2 weeks, symptoms similar to those in the field were observed, and S. minor was reisolated from inoculated plants. Noninoculated control plants remained asymptomatic. The disease was previously observed on O. laxiflora Lam. in Turkey (1), but to our knowledge, this is the first report of S. minor infecting O. palustris References: (1) C. Eken et al. Plant Pathol. 52:802, 2003. (2) L.M. Kohn. Phytopathology 69:881, 1979.

scholarly journals First Report of Sclerotinia Stem Rot of Ranunculus asiaticus Caused by Sclerotinia sclerotiorum in Korea

Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1653
Author(s):  
K. S. Han ◽  
M. J. Park ◽  
J. H. Park ◽  
S. E. Cho ◽  
H. D. Shin
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
First Report ◽  
Ranunculus Asiaticus

scholarly journals Occurrence of Stem Rot of Chrysanthemum Caused by Sclerotinia sclerotiorum in Argentina

Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 98-98 ◽  
Author(s):  
E. R. Wright ◽  
H. E. Palmucci
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Buenos Aires ◽  
Dianthus Caryophyllus ◽  
Economic Importance ◽  
Stem Rot ◽  
Transparent Plastic ◽  
Disease Symptoms ◽  
Plastic Bags ◽  
Rot Disease ◽  
Photoperiod Control

Chrysanthemum (Dendranthema × grandiflorum (Ramat.) Kitam.) is one of the most popular flowering plants in Argentina. A previously undescribed stem rot disease was observed in cvs. Alba and Palisade in greenhouses near Buenos Aires and La Plata, an area of intensive floriculture production. The stem was killed within 10 to 15 days causing the plant to wilt and die. Necrotic tissues were covered with whitish mycelium that produced black, irregular shaped (3 to 7 mm diameter) sclerotia. The pathogen was isolated from symptomatic stem sections, surface disinfested for 1 min in 2% NaOCl, and plated on potato dextrose agar (PDA) (1, slightly modified). The organism isolated produced white aerial mycelia and large number of sclerotia characteristic of Sclerotinia sclerotiorum (Lib.) de Bary. Symptoms were reproduced in the greenhouse by inoculating stems of 10 3-month-old plants with five mycelial plugs per plant from 7-day-old PDA cultures. Inoculated plants were enclosed in transparent plastic bags for 6 days with near saturation humidity and incubated in a growth chamber at 22 to 24°C with a 12-h photoperiod. Control plants were treated similarly except agar disks did not contain the fungus. After 6 to 9 days, symptoms were similar to those previously observed, and infected plants died 3 weeks after inoculation. No disease symptoms were observed on uninoculated plants. Koch's postulates were satisfied after reisolating the fungus. To our knowledge, this is the first report of the occurrence of white mold caused by S. sclerotiorum on chrysanthemum in Argentina. The disease has been previously observed in Argentina on lisianthus (Eustoma grandiflora (Raf.) Shinn.) in 1988 (2) and on carnation (Dianthus caryophyllus L.) in 1991, among other floriculture crops of economic importance. References: (1) A. Garibaldi et al. Plant Dis. 85:446, 2001. (2) S. Wolcan et al. Plant Dis. 80:223, 1996.

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