The Plant Disease Clinic and Field Diagnosis of Abiotic Diseases. M. C. Shurtleff and C. W. Averre III. 8.5 x 11 inches, 242 pp. St Paul, MN, USA: APS Press, 1997. US$ 79 (USA); US$ 99 (elsewhere). ISBN 0-89054-217-1 (paperback).

1999 ◽  
Vol 48 (4) ◽  
pp. 564-564
Author(s):  
Teresa Coutinho ◽  
Bernard Slippers
Keyword(s):  
Plant Disease ◽  
Disease Clinic

scholarly journals Phytopathogenic species of fungi and fungal-like organisms identified in plant samples delivered to the Plant Disease Clinic in 2018–2020

2021 ◽  
Vol 61 (3) ◽  
Keyword(s):  
Host Plants ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Ornamental Plants ◽  
Single Species ◽  
Plant Diseases ◽  
Effective Management ◽  
Fusarium Spp ◽  
Molecular Tests ◽  
Disease Clinic

One of the conditions for effective management of farm is an access to quick diagnostics of plant pathogens in order to reduce the occurrence of plant diseases. The Plant Diseases Clinic receives samples of infected plants supplied by growers and gardeners from all over Poland. In the years 2018–2020, a total of 274 samples were tested at the Clinic for the presence of fungi and fungal-like organisms pathogenic for plants. The tests were carried out using the microscopic method, and in case of doubt, the result was confirmed by molecular tests. The most frequently studied plant was tomato (26%), followed by strawberry (9%), cucumber (5%) and tobacco, sugar beet, onion, blueberry, raspberry, lettuce, cauliflower and potato. Conifers were also a large group, such as: thujas, cypresses and pines; a total of 17 host plants. Single species of ornamental plants were very numerous, e.g. gerbera, anthurium, aster, geranium, phlox, chrysanthemum and others. The fungi of the genus Fusarium spp. constituted about 38% of infections. This was followed by Alternaria spp. (26%), Botrytis cinerea (11%) and Cladosporium sp. (10%). The remaining diseases were caused by Pythium sp., Rhizoctonia sp., Colletotrichum sp., Ulocladium sp., Pestalotia sp. and Phytophthora sp. In recent years, the greatest threat to tomatoes and strawberries has been the fungi of the Fusarium genus, and the pathogens of the Pythium genus to cucumbers.

scholarly journals First Report of Cephaleuros virescens in Arkansas and Its Occurrence on Cultivated Blackberry in Arkansas and Louisiana

Plant Disease ◽  
1998 ◽  
Vol 82 (2) ◽  
pp. 263-263 ◽  
Author(s):  
G. E. Holcomb ◽  
S. R. Vann ◽  
J. B. Buckley
Keyword(s):  
Plant Disease ◽  
Gulf Coast ◽  
Research Station ◽  
Disease Symptoms ◽  
First Report ◽  
Disease Clinic ◽  
Commercial Grower ◽  
Pathogenicity Tests ◽  
Water Drops ◽  
The U.S

Blackberry (Rubus sp.) cane samples (cultivar Navaho) showing disease symptoms were collected from a commercial grower in Texarkana, AR, and sent for diagnosis to the plant disease clinic in Lonoke in June, 1997. Cane symptoms consisted of stem cracking, tissue discoloration beneath the bark, and the presence of an orange, velvetlike growth that was identified as sporangiophores and sporangia of the parasitic green alga Cephaleuros virescens Kunze. Zoospores were released when sporangia were placed in water drops. The alga was isolated from infected canes on potato dextrose agar, but pathogenicity tests were not attempted because pathogenicity has never been demonstrated successfully, nor have zoospores been produced in culture. C. virescens also was found infecting cultivated blackberry at the Louisiana Calhoun Research Station, where it occurred more commonly on thornless than on thorned type cultivars. This parasitic alga occurs commonly along the U.S. Gulf Coast and has been recorded on 287 plant species and cultivars, including 80 that are subject to stem infections (1,2). The occurrence of C. virescens in Arkansas extends its known northernmost range from 32.5°N to 33.5°N in the U.S. This is the first report on the occurrence of C. virescens in Arkansas and the first report of its occurrence on cultivated, commercially grown blackberry. References: (1) G. E. Holcomb. Plant Dis. 70:1080, 1986. (2) R. B. Marlatt and S. A. Alfieri, Jr. Plant Dis. 65:520, 1981.

scholarly journals Late Season Occurrence of Soybean Rust Caused by Phakopsora pachyrhizi on Soybean in Illinois

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 466-466 ◽  
Author(s):  
G. L. Hartman ◽  
R. A. Hines ◽  
C. D. Faulkner ◽  
T. N. Lynch ◽  
N. Pataky
Keyword(s):  
Plant Disease ◽  
The Other ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Morphological Examination ◽  
University Of Illinois ◽  
Physiological Maturity ◽  
Disease Clinic ◽  
Leaf Surfaces ◽  
The University

Soybean rust, first reported in the continental United States in Louisiana in 2004 (2), is one of the most important foliar diseases of soybean worldwide. On 10 October 2006, 20 soybean leaflets from 20 plants at physiological maturity were arbitrarily collected in research plots near Glendale, IL at the University of Illinois Dixon Springs Agricultural Center in Pope County and sent by overnight courier. On 11 October, leaflets were examined with a dissecting microscope at the Soybean Disease Laboratory at the National Soybean Research Center, and then at the Plant Disease Clinic, University of Illinois. Tan, angular lesions that were 2 to 4 mm in diameter were observed on the lower leaf surfaces of two of the 20 leaflets. Within these lesions, there was one uredinum on one leaflet and four on the other leaflet exuding hyaline, echinulate urediniospores (20 × 25 μm). On 11 October 2006, these leaflets were sent by overnight courier to the USDA/APHIS/PPQ/NIS Laboratory, Beltsville, MD Plant Disease Clinic for identification by morphological examination and by PCR using primers specific to Phakopsora pachyrhizi (1). Both tests confirmed the presence of P. pachyrhizi. The 18 leaflets that did not have sporulating pustules on 11 October were incubated in the laboratory for 5 days at near 100% relative humidity. Following incubation, nine leaflets were observed to have uredinia exuding urediniospores with a range of 1 to 43 uredinia per leaflet. These results indicate that incubation may be necessary to maximize the potential to observe uredinia exuding urediniospores. To our knowledge, this is the first report of P. pachyrhizi infecting plants in Illinois. References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) R. W. Schneider et al. Plant Dis. 89:774, 2005.

Use of TEM in Plant Disease Diagnosis: A Xylem-Limited Bacterium Associated with Diseased ‘Toronto’ Creeping Bentgrass

1981 ◽  
Vol 39 ◽  
pp. 414-415
Author(s):  
Karen K. Baker ◽  
David L. Roberts
Keyword(s):  
Osmium Tetroxide ◽  
Plant Disease ◽  
Leaf Tissue ◽  
Infectious Agent ◽  
Creeping Bentgrass ◽  
Disease Diagnosis ◽  
Unknown Etiology ◽  
Agrostis Palustris ◽  
Putting Greens ◽  
Plant Disease Diagnosis

Plant disease diagnosis is most often accomplished by examination of symptoms and observation or isolation of causal organisms. Occasionally, diseases of unknown etiology occur and are difficult or impossible to accurately diagnose by the usual means. In 1980, such a disease was observed on Agrostis palustris Huds. c.v. Toronto (creeping bentgrass) putting greens at the Butler National Golf Course in Oak Brook, IL.The wilting symptoms of the disease and the irregular nature of its spread through affected areas suggested that an infectious agent was involved. However, normal isolation procedures did not yield any organism known to infect turf grass. TEM was employed in order to aid in the possible diagnosis of the disease.Crown, root and leaf tissue of both infected and symptomless plants were fixed in cold 5% glutaraldehyde in 0.1 M phosphate buffer, post-fixed in buffered 1% osmium tetroxide, dehydrated in ethanol and embedded in a 1:1 mixture of Spurrs and epon-araldite epoxy resins.

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