From brian at gweep.ca Wed Feb 4 17:07:50 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:01 2005 Subject: PRO/PL> Tomato yellow leaf curl, tomato - Reunion (French OD) Message-ID: <37ad3ytmlm.fsf@lios.aq2.gweep.ca> TOMATO YELLOW LEAF CURL, TOMATO - REUNION (FRENCH OVERSEAS DEPARTMENT) ********************************************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 31 Jan 2004 From: ProMED-mail Source: EPPO Reporting Service 2003, No. 11 [edited] 2003/172 Details on the situation of Tomato yellow leaf curl begomovirus in Reunion In Reunion, Tomato yellow leaf curl begomovirus (EPPO A2 list) was first reported in September 1997 near St. Pierre. The virus was found both in protected and field-grown tomatoes, causing serious epidemics. In 1998, it was considered that eradication was not feasible, but control programmes were initiated. Molecular studies of isolates from Reunion suggested that they correspond to a single recent introduction from a single origin. Studies on the insect vector, _Bemisia tabaci_ [Bt] (_Homoptera_: _Aleyrodidae_ - EPPO A2 list), showed that the Bt predominates on the island, but some specimens belonged to another biotype (also present in Madagascar, Mauritius, Seychelles and designated biotype Mascareignes). In 1998/1999, surveys showed that TYLCV was present from La Possession (north) to St. Joseph (south), and to Makes towards the centre of the island (900 m altitude). The eastern part of the island was not affected by TYLCV, but it is not a tomato-producing area. No specific studies were done on crop losses, but losses up to 85 percent were observed on the most susceptible tomato cultivars (e.g. Farmer, Boa). Control measures are being taken to contain both TYLCV and its vector. In nurseries, insect-proof screenhouses and yellow sticky traps are used, and planting material is tested. Growers are recommended not to establish new tomato crops in the vicinity of old plots, to apply weed control, chemical or biological control against Bt, and to use more tolerant tomato cultivars. Import checks have been also strengthened to avoid further introductions of infested tomato fruits or plants, and of Bt. Source: Reynaud, B.; Wuster, G.; Delatte, H.; Soustrade, I.; Lett, J.M.; Gambin, O.; Peterschmitt, M. (2003) Les maladies a begomovirus chez la tomate dans les departements francais d'Outre-Mer. Le Tomato yellow leaf curl virus (TYLCV) a la Reunion. Phytoma - La Defense des Vegetaux no. 562, 13-17. ------------------------------ ProMED-mail [Tomato yellow leaf curl disease is well-established in the country after 7 years of cropping. Genetic resistance to TYLCV in tomato cultivars appears to controlled by at least 5 genes, and crossing experiments yielded only tolerant hybrids. Production of genetically engineered tomato is a possible management strategy. Useful references: - Mod.DH] [see also: 2003 ---- Tomato yellow leaf curl virus, tomato - Guadeloupe 20031231.3174 Tomato yellow leaf curl, new strain, tomato - Spain 20030722.1788 Tomato yellow leaf curl, tomato - Italy 20030615.1478 2002 ---- Tomato yellow leaf curl, new species - Madagascar 20021122.5870 Tomato yellow leaf curl, tomato - France 20021114.5793 Tomato yellow leaf curl virus, bean - Cuba 20020707.4682] .......................................dh/pg/lm *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Wed Feb 4 17:07:45 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Bacterial spot, tomato, pepper - Turkey (Antalya) Message-ID: <37ektatmlq.fsf@lios.aq2.gweep.ca> BACTERIAL SPOT, TOMATO, PEPPER - TURKEY (ANTALYA) ************************************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 27 Jan 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] Bacterial Spot of Tomato and Pepper Caused by _Xanthomonas axonopodis_ pv. _vesicatoria_ in the Western Mediterranean Region of Turkey. H. Basim, University of Akdeniz, Faculty of Agriculture, Department of Plant Protection, 07050, Antalya, Turkey; E. Basim, University of Suleyman Demirel, Faculty of Agriculture, Department of Plant Protection, 32260, Isparta, Turkey; and J. B. Jones, G. V. Minsavage, and E. R. Dickstein, University of Florida, Department of Plant Pathology, Gainesville 32611. Plant Dis. 88:85, 2004; published on-line as D-2003-1112-01N, 2004. Accepted for publication 22 Oct 2003. _Xanthomonas axonopodis_ pv. _vesicatoria_, causal agent of bacterial spot of tomato (_Lycopersicon esculentum_ L.) and sweet pepper (_Capsicum annuum_ L.), was isolated from tomato and pepper plants in greenhouse production in the Province of Antalya, in southwestern Turkey. Disease incidence was less than 4 percent of plants observed in 2001 and ranged from 1 to 20 percent in 2002. 11 seedling-producing companies and 26 greenhouses that produce tomato and pepper were surveyed during the rainy seasons of 2001 and 2002. The increase in disease incidence in 2002 is an indication that this disease is becoming more prevalent on tomato and pepper plants grown in greenhouses in southwestern Turkey. A gram-negative bacterium producing yellow-pigmented colonies on nutrient agar was consistently isolated from brown, circular spots on leaflets of tomato and sweet pepper seedlings. 5 isolates were pathogenic on commercial cultivars of tomato and pepper when bacterial suspensions (100 million CFU/ml) were infiltrated into the intercellular spaces of leaves to determine race by using procedures described by Bouzar et al. (1). All the isolates produced hypersensitive reaction responses on tomato genotype cv. Hawaii 7998 and pepper genotype cvs. 20 R and 30 R and were designated tomato race 1 pepper race 1 (T1P1) (1). Fatty acid analysis of the strains identified them as _X. axonopodis vesicatoria_ with similarity index values of 0.872 to 0.933. In addition, the strains were tested with _X. axonopodis vesicatoria_-specific polymerase chain reaction primers (RST 2/3 and RST 9/10) (2). The isolates were determined to be _X. axonopodis vesicatoria_. Although bacterial spot of tomato has been suspected in Turkey for a number of years, to our knowledge, this is the first report of the bacterium on tomato. References: (1) H. Bouzar et al. Phytopathology 84:663, 1994. (2) R. P. Leite, Jr. et al. Appl. Env. Microbiol. 60:1068, 1994. ------------------------------ ProMED-mail [_Xanthomonas axonopodis_ pv. _vesicatoria_ [Xav] has been in Turkey for some time. Long-distance spread of the pathogen in the country is likely, mainly by movement of infected or infested tomato seed. The fact that Xav has infected tomato may be the consequence of environmental conditions. Xav is comprised of strains (races) that infect only pepper or tomato, or both crops. - Mod.DH] [see also: 2003 ---- Bacterial spot, pepper - Turkey 20030315.0644 2001 ---- Bacterial spot disease, tomato, pepper - Tanzania 20010908.2155 Bacterial spot disease, pepper - Turkey 20010907.2152 Bacterial speck disease, tomato - Turkey 20010813.1912] ................................dh/pg/lm *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Thu Feb 12 17:25:06 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Soybean rust - Zimbabwe Message-ID: <377jyr7rml.fsf@lios.aq2.gweep.ca> SOYBEAN RUST - ZIMBABWE *********************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 9 Feb 2004 From: Dr Clive Levy [edited] Soybean rust - Zimbabwe: first report in 2004 [edited] ------------------------------------------------------ This is just to inform everyone that soybean rust [caused by _Phakopsora pachyrhizi_] has been confirmed today (23 Jan 2004) within the Lions' Den area of Zimbabwe in several commercial plantings. This is the first confirmation of the disease for this season. There is also an unconfirmed report in the Kwekwe area (I am awaiting samples). Although the level of severity at Lions' Den is very low, initial infection is likely to have taken place at least 15 days ago under very dry, hot conditions. The disease, however, will most likely spread very rapidly on any unsprayed crops under the very wet, humid conditions that are now prevailing. Farmers who have not already started spraying are urged to follow fungicide control recommendations as soon as possible to avoid yield loss. Disclaimer ---------- Unless specifically stated that this message is a Commercial Farmers' Union communique, or that it is being issued or forwarded to you by the sender in an official CFU capacity, the opinions contained therein are private. Private messages also include those sent on behalf of any organisation not directly affiliated to the Union. The CFU does not accept any legal responsibility for private messages and opinions held by the sender and transmitted over its local area network to other CFU network users and/or to external addressees. ------------------------------ Dr Clive Levy Plant Pathologist, CFU Commodities Technical Team, Commercial Farmers Union of Zimbabwe [I thank Clive Levy for sending this note. The piece was delayed because of computer problems, for which I apologize. - Mod.DH] [see also: 2003 --- Soybean rust - Brazil 20030426.1022 Soybean rust - Brazil (Mato Grosso & Bahia) 20030415.0917 Soybean rust - Zimbabwe (Arcturus) 20030222.0456 Soybean rust - Brazil (Sao Paulo State) 20030124.0214 2002 --- Phakopsora sp., soybean rust - S. Africa, Argentina 20021231.6167 Phakopsora sp., soybean rust - South Africa 20020206.3495 2001 --- Phakopsora sp., soybean rust - South Africa (03) 20011213.3014 Phakopsora sp., soybean rust - South Africa (02) 20010405.0679 Phakopsora sp., soybean rust - S. Africa (confirmed) 20010322.0569 Phakopsora sp., soybean rust - South Africa 20010312.0505 Phakopsora sp., soybean rust - Africa (02) 20010310.0491 Phakopsora sp., soybean rust - Africa 20010309.0487 Phakopsora sp., soybean rust - Nigeria 20010309.0486] ......................dh/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Sun Feb 15 22:31:57 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Pepper golden mosaic virus, tomato - Mexico Message-ID: <37brnzwpwy.fsf@lios.aq2.gweep.ca> PEPPER GOLDEN MOSAIC VIRUS, TOMATO - MEXICO ******************************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 13 Feb 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] Pepper golden mosaic virus Affecting tomato crops in the Baja California Peninsula, Mexico -------------------------------------------------- RJ Holguin-Pena, R Vazquez Juarez, Centro de Investigaciones Biologicas del Noroeste, PO Box 128, La Paz, Baja California Sur 23000, Mexico; RF Rivera-Bustamante, Departamento de Ingenieria Genetica, Centro de Investigacion y de Estudios Avanzados, U Irapuato, PO Box 629, Irapuato, Gto 36500, Mexico. Plant Dis 2004; 88: 221; published on-line as D-2003-1127-01N, 2004. Accepted for publication 27 Oct 2003. In the state of Baja California Sur, tomatoes (_Lycopersicon esculentum_ Mill.) are cultivated on about 1000 ha. Occurrence of viral diseases is currently causing low yields and severe losses. Virus-like symptoms (severe leaf curling, stunting, reduced leaf size, and mosaic patterns) were observed on 99 per cent of tomato plants in 2002 in La Paz, Baja California Sur. Whiteflies (_Bemisia tabaci_ Gennadius) were present in affected fields and appeared to be associated with the disease. The virus was experimentally transmitted from infected plants to tomato and peppers seedlings by whiteflies and as infectious DNA (replicative form) by mechanical and biolistic inoculation. Symptoms similar to those found in the field were observed in experimental transmission assays. DNA from inoculated plants was extracted and analyzed by DNA hybridization and polymerase chain reaction (PCR) using degenerate (1) and specific (2) primers. The PCR products (1.1 kb) obtained from the common region (GenBank Accession No. AY368336) suggested the presence of a bipartite geminivirus. The nucleotide sequence of the PCR products showed a 98 per cent identity to Pepper golden mosaic virus-Tamaulipas strain (PepGMV-Tam) in the intergenic region (IR). Similar identities (97 per cent) were obtained by using the predicted amino acid sequences of the amino termini of the coat proteins. Identities in the replication proteins (92 per cent) and IR iterative sequence analyses show that the PepGMV-La Paz isolate is a closely related strain of PepGMV-Tam. To our knowledge, this is the first report of PepGMV affecting tomato crops in Baja California Sur, Mexico. References: (1) MR Rojas, et al. Plant Dis 1993; 77: 340. (2) I Torres-Pacheco, et al. Phytopathology 1996; 86: 1186. ------------------------------ ProMED-mail [Pepper golden mosaic begomovirus, formerly designated as Serrano golden mosaic virus (SGMV) and Texas pepper virus (TPV), is present in Costa Rica, Guatemala, Honduras, Mexico (7 states), and USA (Texas), and causes significant crop losses. Scientists in Mexico are attempting to select tomato plants that appear to be asymptomatic following inoculation with PepGMV, suggesting that they may be useful in developing resistant cultivars. Part of the resistance mechanism appears to be the lack of virus movement in infected plants. At least 2 closely related strains of PepGMV (Tamaulipas and La Paz) are present in Mexico. A useful reference: - Mod.DH] .........................dh/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Sun Feb 15 22:32:06 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Iris yellow spot virus, onion - USA (WA) Message-ID: <377jynwpwp.fsf@lios.aq2.gweep.ca> IRIS YELLOW SPOT VIRUS, ONION - USA (WASHINGTON) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 12 Feb 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] Iris yellow spot virus in onion bulb and seed crops in Washington ----------------------------------------------------------------- LJ du Toit, Washington State University-Mount Vernon Research and Extension Unit, Mount Vernon 98273; HR Pappu, KL Druffel, Department of Plant Pathology, Washington State University, Pullman 99164; GQ Pelter, Grant/Adams Counties, Washington State University Cooperative Extension, Ephrata 98823. Plant Dis 2004; 88: 222, published online as D-2003-1201-03N, 2004. Accepted for publication 30 Oct 2003. The geographic distribution of Iris yellow spot virus (IYSV, genus Tospovirus, family Bunyaviridae) in onion (_Allium cepa_ L.) crops in the western United States has increased with the most recent report in Colorado (1,2). Furthermore, the incidence of IYSV has increased significantly in onion crops in the Treasure Valley of southern Idaho and eastern Oregon, where the disease was first detected in the United States (1,3). Surveys of onion seed crops in Washington during the past 2 years showed the presence of plants with symptoms characteristic of IYSV infection, including distinct diamond-shaped chlorotic or necrotic lesions, as well as indistinct circular to irregular, chlorotic or necrotic lesions of various sizes on the scapes of flowering plants. To date, symptomatic plants have been observed in 5 seed crops in Washington, at incidences ranging from 1 per cent to about 20 per cent in individual seed crops. Enzyme-linked immunosorbent assays carried out directly on symptomatic onion samples collected in July 2002, and on _Nicotiana benthamiana_ plants mechanically inoculated with sap from these symptomatic plants, did not detect the presence of IYSV. In late July 2003, symptomatic plants were collected from an onion seed crop in Grant County and tested for IYSV infection by reverse transcription-polymerase chain reaction (RT-PCR). Total nucleic acid was extracted from symptomatic areas of the scapes with the procedure described by Presting and colleagues (4). Primers specific to the nucleocapsid (NP) gene of IYSV were designed based on sequences in GenBank: 5'-TCA GAA ATC GAG AAA CTT-3' and 5'-TAA TTA TAT CTA TCT TTC TTG G-3' (sense and antisense polarity, respectively). The RT-PCR assay produced an amplicon of the expected size (about 700 bp) that was cloned and sequenced. Comparison with the GenBank IYSV gene sequences showed 98 per cent sequence identity of the NP gene. In August 2003, symptoms of IYSV infection were observed in 2 onion bulb crops, each located within 2 miles of the symptomatic onion seed crop in Grant County. The presence of IYSV in these crops was confirmed by RT-PCR with cloning and sequencing of the amplicon, as described for the seed crop samples. To our knowledge, this is the first confirmation of IYSV in onion bulb and seed crops in Washington, where 16 000 to 18 000 acres of onion bulb crops and 700 to 900 acres of onion seed crops are grown annually (USDA National Agricultural Statistics Service). The increase in prevalence of IYSV in the Pacific north west highlights the need for additional research to clarify the epidemiology of this potentially significant pathogen and to develop a regional management program for iris yellow spot. References: (1) JM Hall, et al. Plant Dis 1993; 77: 952. (2) HF Schwartz, et al. Plant Dis 2002; 86: 560. (3) JW Moyer, et al. (abstr.) Phytopathology 2003; 93(suppl): S115. (4) GG Presting, et al. Phytopathology 1995; 85: 436. ------------------------------ ProMED-mail [In addition to infected onion crops in Washington and Colorado, IYSV is present in Brazil, Iran, Israel, the Netherlands, and Slovenia. IYSV has been endemic in south western Idaho and eastern Oregon onion, leek, and chive seed production fields for over 10 years. It has also been detected in onion seed plants from California and Arizona. The virus is vectored by onion thrips (_Thrips tabaci_) but not by western flower thrips (_Frankliniella occidentalis_), which are an efficient vector of the virus. Although there is no cure, diseased plants can still produce reasonable yields through irrigation and good soil fertility. Not much is known about resistance to IYSV in onion. Additional references: - Mod.DH] [see also: 2002 --- Iris yellow spot virus, onion - USA (Colorado) 20020614.4495 Iris yellow spot virus, onion - USA (Colorado) 20020613.4489] .........................dh/sp/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Sun Feb 15 22:32:13 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Fusarium graminearum, soybean - Argentina Message-ID: <373c9bwpwj.fsf@lios.aq2.gweep.ca> FUSARIUM GRAMINEARUM, SOYBEAN - ARGENTINA ***************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 13 Feb 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] First report of pathogenic association between _Fusarium graminearum_ and soybean -------------------------------------- RN Pioli, L Mozzoni, EN Morandi, Facultad de Ciencias Agrarias, University Nacional Rosario, PO 14, 2123 Zavalla, Santa Fe, Argentina. Plant Dis 2004; 88: 220, published online as D-2003-1119-01N, 2004. Accepted for publication 27 Oct 2003. _Fusarium graminearum_, a pathogen of wheat and corn, was reported recently as a saprophytic fungus colonizing soybean (_Glycine max_ L. _Merr._) fruits and seeds at R7 in Argentina (1). To evaluate the capacity of _F. graminearum_ obtained from stem and seeds of symptomatic soybean plants that cause disease on soybean seedlings, isolates were obtained during the 2001 to 2002 growing season from: (i) the basal 1/3 of stems from field-grown soybean plants, collected at R5, with light brown external and internal discoloration and leaves with interveinal chlorosis; and (ii) soybean seeds with pink tegument. The pathogen was isolated on potato glucose agar acidified with 0.2 per cent lactic acid (PGAA). Isolates were identified as _F. graminearum_ on the basis of growth rate and pigmentation of colonies on PGAA, lack of microconidia (2), and morphology and size of typical macroconidia in sporodochia developed on Spezieller Nahrstoffarmer Agar (3). Isolates of _F. graminearum_, CE135 and CE136 (from wheat) and CE137 (from corn) deposited in the Centro de Referencia en Micologia (CEREMIC), Fac. Farmacia y Bioquimica, UNR, Argentina, were used as references in identifying the soybean isolates. Plants (14 day old) were inoculated separately with stem and seed isolates in the greenhouse at 26 ? 2 and 20 ? 2 deg C day/night temperature by inserting a piece of mycelium into a wound made with a scalpel in the hypocotyl. A completely randomized block design (RCB) was utilized with 4 replicate pots with 4 plants per pot. Plants wounded but without mycelium served as controls. This test was conducted twice (experiments 1 and 2). Another test was completed by burying a thin layer of wheat caryopsis colonized by fungal mycelium of the stem isolate CE170 in the soil of pots. Plants in pots with soil without inoculum served as controls (4). The experiment was conducted twice (experiments 3 and 4) in an RCB with 5 replications, 4 plants per replication. The progress of symptoms in experiments 1 and 2 were stem with light brown discoloration around the inoculation point that extended progressively along the stem, interveinal chlorosis or loss of turgence of unifoliate leaves, and interveinal chlorosis of trifoliate leaves followed by plant wilting and death. 21 days after inoculation, average percentages of dead plants were 42 and 21 per cent for stem and seed isolates, respectively. For experiments 3 and 4, percentage of dead plants was 56, 45 days after emergence. These plants had roots with light brown, necrotic areas. Control plants remained healthy. The pathogen was reisolated from the stem (100 per cent) and root (57 per cent) tissues of symptomatic plants but not from similar tissues of control plants. To our knowledge, this is the first report of a pathogenic relationship between _F. graminearum_ and soybean. References: (1) RN Pioli, et al. Fitopatologia 2000; 35(2): 111. (2) PE Nelson, et al. Fusarium species: an illustrated manual for identification. University Park, PA: Pennsylvania State University Press, 1983. (3) BA Summerell, et al. Plant Dis 2003; 87: 117. (4) CE Windels. Fusarium. In: LL Singleton, JD Mihail, CM Rush, editors. Methods for research on soilborne phytopathogenic fungi. St Paul, MN: American Phytopathological Society, 1992: pp 115-28. ------------------------------ ProMED-mail [Infection of wheat and barley by _Fusarium graminearum_ (Fg) is epidemic in USA and is increasingly becoming a threat to the world's food supply due to recent outbreaks in Asia, Canada, Europe, and South America. Crop quality and yield have been adversely impacted. A major effect of Fg infection in cereals is contamination of seeds with trichothecene and estrogenic mycotoxins, making them unsuitable for food or feed. In Brazil, soybean crop residues in fields under conservation tillage have been found to be heavily infested with Fg. Although the fungus also reportedly grows on living soybean stems and seeds, many consider the fungus non-pathogenic to soybean. Recent surveys of soybean seed grown in Brazil also revealed infection by Fg. Fg strains from Brazilian soybean seed consistently caused pod rot and root rot disease on all soybean varieties, under all conditions tested. These same strains also caused FHB in wheat. Farmers who use a soybean/wheat crop rotation should be aware of a potential build-up of strains that infect both wheat and soybean, reducing the usefulness of the rotation. Brazilian strains, which also produce a novel mycotoxin known as 3-acetylnivalenol, have not yet been found in the U.S. In Argentina, a range of wheat cultivars are known to be infected by Fg. Additional references: - Mod.DH] [see also: 2002 --- Fusarium head blight, oats - Canada (Manitoba) 20021017.5573 2001 --- Fusarium head blight, wheat - USA (Michigan) 20010725.1452 2000 --- Fusarium head blight: biological control 20000824.1416 Fusarium head blight, cereal - Canada (Manitoba) 20000823.1405 Fusarium head blight fungicide approved - Canada 20000624.1038 1999 --- Crop diseases - Canada (Manitoba) 19990816.1417 Scab-resistant wheat, McVey cultivar - USA 19990801.1311 Scab disease, wheat - Canada, USA 19990508.0756] ..........................dh/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Tue Feb 17 22:21:51 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Sour rot, peaches, nectarines - USA (CA) Message-ID: <37isi5dksw.fsf@lios.aq2.gweep.ca> SOUR ROT, PEACHES, NECTARINES - USA (CALIFORNIA) ************************************************ A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 17 Feb 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] 1st Report of Sour Rot of California Peaches and Nectarines Caused by Yeasts ---------------------------------------------------------------------------- T. J. Michailides & D. P. Morgan, Department of Plant Pathology, University of California, Davis/Kearney Agricultural Center, 9240 South Riverbend Ave., Parlier 93648; and K. R. Day, University of California Cooperative Extension, 4437 S. Laspina Str., Tulare 93274. Plant Dis. 88:222, 2004; published on-line as D-2003-1205-01N, 2004. Accepted for publication 18 Nov 2003. In early July 2001, samples of nectarine and peach fruit were brought from orchards in northern Tulare County or from packinghouses to our laboratory for diagnosis of an unusual decay. When the decay lesions originated close to the stylar end, leaking juice streamed from it. When the decay lesion was on the stem end of the fruit and touched the packing box, it developed a decay consisting of a ring of 0.5 to 2.0 cm (inner diameter) and 1.0 to 3.0 cm (outer diameter). The leaking juice dissolved the cuticle, epidermis, and some of the flesh, creating distinct furrows in the tissue. Samples with similar decay lesions were examined in 2001, 2002, and 2003. In each year, isolations from these fruit consistently yielded 2 or 3 different yeasts that were identified as _Geotrichum candidum_ Link, _Issatchenkia scutulata_ (Phaff et al.) Kurtzman et al., and Kloeckera apiculata_ (Reess emend. Klocker) Janke. All 3 yeasts were isolated from most of the samples, although sometimes, different combinations of 2 of the yeasts were recovered. To complete Koch's postulates, each yeast was single spored and cultured on acidified potato dextrose agar at 25 deg C to prepare a dense (100 million) cell suspension. 8 mature 'Elegant Lady' peach fruit were surface-disinfested in 0.1 percent sodium hypochlorite for 3 min, allowed to dry, and wounded once with a sterile nail (3 x 5 mm) on the fruit cheek. A 50-microliter drop of the cell suspension was placed in each wound, and the peaches were incubated in containers with >95 percent relative humidity at 27 deg C. Fruit inoculated similarly with a 50-microliter drop of sterile water served as controls. In 2001, 2 containers containing 8 fruit each were used for each yeast, and lesions started developing within 1 week after inoculation. The diameter of the decay lesion was measured after 10 days of incubation of the fruit. The diameter of decay lesions ranged from 21 to 68 mm for _G. candidum_, 30 to 55 mm for _I. scutulata_, and 9 to 39 mm for _K. apiculata_ inoculations. The inoculation experiment was repeated with 2 containers of 8 'Red Glo' nectarine fruit per treatment yeast, under the same conditions as described above. Organisms recovered from the decay lesions were the same yeasts used for inoculating the peaches or nectarines. All 3 yeasts caused similar decay lesions in peaches, and the leaking effect was reproduced in both types of fruit. Symptoms were similar to those observed on fruit samples brought to our laboratory. Control fruit did not develop the characteristic decay lesions, although brown rot caused by _Monilinia fructicola_ developed on a few of the control fruit. We concluded that each isolated yeast had the capacity to cause sour rot decay on stone fruit. >From samples and reports, the disease has been found on 'Red Glo', 'Ruby Diamond', 'Zee Grand', 'Spring Bright', and 'Honey Blaze' nectarines and 'Elegant Lady' and 'Fire Red' peaches. _G. candidum_ was isolated from peaches and other fruit in California and incited rot of 'Paloro' peach in 1960 (2) and caused postharvest sour rot of peaches originating from Georgia, Pennsylvania, New Jersey, and North Carolina (1). However, to our knowledge, this is the first report of _G. candidum_, _I. scutulata_, or _K. apiculata_ causing sour rot of commercial peaches and nectarines in the field and postharvest situations in California. References: (1) C. L. Burton and W. R. Wright. Plant Dis. Rep. 53:580, 1969. (2) E. E. Butler. Phytopathology 50:665, 1960. ------------------------------ ProMED-mail [None of these pathogens have been reported in ProMED-mail. The only reference that I could find is the following: The yeasts: a taxonomic study. Ed. Cletus P. Kurtzman, Jack W. Fell. Edition 4th ed. Publisher Amsterdam; New York: Elsevier, 1998. I suggest that readers go back to the references cited for more information. Additional references: - Mod.DH] .......................................dh/pg/jw *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Tue Feb 17 11:09:43 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Sphaeropsis sp., postharvest rot, apple - USA (WA) Message-ID: <371xotk26w.fsf@lios.aq2.gweep.ca> SPHAEROPSIS SP., POSTHARVEST ROT, APPLE - USA (WA) ************************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 16 Feb 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] First Report of a New Postharvest Fruit Rot on Apple Caused by _Sphaeropsis pyriputrescens_ ------------------------------------------------- C. L. Xiao, Tree Fruit Research and Extension Center, Washington State University, Wenatchee, WA; J. D. Rogers, Department of Plant Pathology, Washington State University, Pullman; and R. J. Boal, TFREC, Washington State University, Wenatchee. Plant Dis. 88:223, 2004; published on-line as D-2003-1201-04N, 2004. Accepted for publication 5 Nov 2003. During March to July 2003, a postharvest fruit rot was observed on 'Golden Delicious', 'Granny Smith', and 'Red Delicious' apples (_Malus x domestica_ Borkh.) sampled from commercial packinghouses in Washington State. Losses as high as 24 percent in storage bins were observed in July on 'Red Delicious'. The disease started at the stem bowl area or the calyx end of the fruit. Decayed fruit was apparently not wounded. Decayed areas were brown and firm. Internal decayed flesh appeared yellowish brown. On 'Red Delicious' apples, decayed fruit was apparently discolored from red to brown. As the disease advanced, pycnidia of a fungus might form on the stem, sepals, or the surface of decayed fruit. Pycnidia were 0.3 to 0.7 mm in diameter, black, and partially immersed in decayed tissues. To isolate the causal agent, decayed fruit was lightly sprayed with 70 percent ethanol and air dried. Fragments of diseased tissue were removed from the margin of diseased and healthy tissue and plated on acidified potato dextrose agar (PDA). A fungus was consistently isolated from decayed fruit with the symptoms described above. On PDA, the colonies of the fungus first appeared with dense hyaline mycelium and later turned light yellow to yellow. Black pycnidia of the fungus formed on 2- to 3-week-old oatmeal agar cultures at 20 deg C under 12-h alternating cycles of fluorescent light and dark. The fungus was identified as _Sphaeropsis pyriputrescens_ Xiao & J. D. Rogers, based on the description of the fungus (1). Voucher specimens were deposited at the WSU Mycological Herbarium. 2 isolates of the fungus recovered from decayed apples were tested for pathogenicity on apple. Fruit of 'Golden Delicious' and 'Gala' were surface-disinfested for 5 min in 0.5 percent NaOCl, rinsed, and air-dried. Fruit was wounded with a sterile 4-mm-diameter nail head. A 4-mm-diameter plug from the leading edge of a 3-day-old PDA culture or plain PDA (control) was placed in the wound of each of 10 replicate fruit for each isolate or control. Fruit was tray-packed with polyethylene liners and stored in cardboard boxes in air at 3 deg C, and decay was evaluated 2 weeks after inoculation. 5 decayed fruits from each treatment were selected for reisolation of the causal agent. The experiment was conducted twice. In a separate pathogenicity test, 2 isolates (one each from apple and pear) were included in the test. Fruit of 'Red Delicious' apple was prepared and inoculated as the same manner described above, but fruit was stored in air at 0 deg C. The experiment was conducted twice. All fruit that were inoculated with the fungus developed decay symptoms. No decay developed on fruit in the controls. The same fungus was reisolated from decayed fruit. This indicates that isolates from apple and pear were pathogenic to apple. _S. pyriputrescens_ is the causal agent of a newly reported postharvest disease on 'd'Anjou' pears (1). To our knowledge, this is the first report of this fungus causing postharvest fruit rot on apple. We propose 'Sphaeropsis rot' as the name of this new disease on apple and pear. Preliminary evidence suggests that infection of fruit by this fungus occurred in the orchard prior to storage. Reference: (1) C. L. Xiao and J. D. Rogers. Plant Dis. 88:114, 2004. ------------------------------ ProMED-mail [This piece appears to be the first record of _Sphaeropsis pyriputrescens_ in ProMED-Plant. A related fungus, _S. malorum_, the imperfect stage of _Botryosphaeria obtusa_, causes black rot or frogeye leaf spot of apple. Other species of _Sphaeropsis_ infect citrus. Disease management basically requires strict attention to sanitation in orchards and the use of an appropriate fungicidal spray regimen. A useful reference: - Mod.DH] [see also: 2002 ---- Botryosphaeria, apple, first report - Bolivia 20020507.4125] .......................................dh/pg/jw *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Thu Feb 19 12:18:41 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Pythium irregulare, lentil - USA (WA): first report Message-ID: <37oeru7u9a.fsf@lios.aq2.gweep.ca> PYTHIUM IRREGULARE, LENTIL - USA (WASHINGTON): FIRST REPORT ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 18 Feb 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] First Report of _Pythium irregulare_ on Lentils in the United States. ----------------------------------------------------------- T. C. Paulitz, F. Dugan, and W. Chen, USDA-ARS, Washington State University, Pullman 99163-6430; and N. J. Grunwald, USDA- ARS, 24106 N. Bunn Rd., Prosser, WA 99350. Plant Dis. 88:310, 2004; published online as D-2004-0114-01N, 2004. Accepted for publication 15 Dec 2003. In late June and early July 2002, stunted, chlorotic, and partially defoliated lentils (_Lens culinaris_ Medik.) were observed throughout the lentil-growing areas of eastern Washington. These symptoms were investigated in 2 fields near Garfield, WA and one field near Genesee, ID. Cv. Mason was more affected than cv. Brewer. Roots were dry and brittle with black discoloration in some cases. Isolates of _Fusarium oxysporum_ and _F. solani_ were obtained from washed roots plated on water agar, but they were nonpathogenic in greenhouse testing in pasteurized field soil and peat-based growing mixes. On 21 Apr 2003, volunteer lentils growing in the same fields showed symptoms of root rot, and _Pythium_ oospores were observed in the roots. _Pythium_ spp. were isolated by using a selective medium (2). Oospores were aplerotic, intercalary, 12.6 to 21 micrometers long x 11.2 to 18.2 micrometers wide, mostly smooth, and often formed in chains. Isolates resembled _P. paroecandrum_ Drechs. and _P. irregulare_ Buisman on the basis of morphological characteristics (3), but DNA sequences of the internal transcribed spacer region were closer to _P. irregulare_ on the basis of a comparison with a worldwide database of _Pythium_ sequences (C. A. Levesque, personal communication). Isolates were deposited with the USDA- ARS Western Regional Plant Introduction Station, Pullman, WA. Four hyphal-tip isolates were tested in the greenhouse with inoculum grown in autoclaved sandy loam amended with 1 percent ground rolled oats. Experiments were performed twice in Thatuna silt loam, first in pasteurized and then in nonpasteurized soil. Inoculum was added to the soil at 500 CFU/g, and seeds were planted on the same day. Each isolate was tested on cvs. Brewer and Mason, with 5 replicates per treatment. Plants were grown in 4 plastic tubes 20.5 cm long (2 plants per tube) for 1 month at 16 to 22 deg C and supplemented with 14 h light per day. _P. irregulare_ was reisolated from infected roots in both experiments. Damping-off, stunting, chlorosis, and root rot were observed in the _Pythium_-inoculated treatments, which corresponded to symptoms observed in the field in 2002. In pasteurized soil, only one isolate reduced the whole, dry, plant weight of Brewer, but the other 3 isolates reduced the dry weight of Mason. All isolates reduced the root dry weight of Mason in natural soil, but only 2 isolates reduced the root dry weight of Brewer. To our knowledge, _Pythium_ spp., but not _P. irregulare_, have been reported previously from lentils (1). _P. irregulare_ also causes root rot on winter wheat, which is rotated with lentils, and this pathogen likely causes yield reduction in both crops. 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) S. M. Mircetich and J. M. Kraft. Mycopathol. Mycol. Appl. 50:151, 1973. (3) A. J. van der Plaats-Niterink. Stud. Mycol. 21:1, 1981. ------------------------------ ProMED-mail [_Pythium irregulare and _P. ultimum_ are common pathogens that affect many crops, causing damping-off diseases. Yield losses can be very high, especially in soils with heavy moisture-holding capacity. Prevention of diseases under field conditions is a priority, but that is easier said than done -- because once infestation occurs, oospores can remain viable for several years. Disease management depends upon planting of high-quality seeds and treatment of seed with approved fungicides. Infection of wheat by _P. irregulare_ in the Pacific Northwest USA may be more common than we know. 2 additional references: - Mod.DH] [see also: 2003 ---- Phytophthora capsici, tomato - South Africa 20031130.2971 2002 ---- Pythium sp., lettuce - South Africa 20021005.5473 2000 ---- Melon root rot - USA (California): EPPO report 20001228.2290 Vine decline, watermelon - USA (Indiana) 20000901.1475 Melon wilt: control 20000527.0850] .......................................dh/pg/jw *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Fri Feb 27 15:07:37 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:02 2005 Subject: PRO/PL> Bacterial ring rot, potato - UK (Wales) Message-ID: <371xogkwgm.fsf@lios.aq2.gweep.ca> BACTERIAL RING ROT, POTATO - UK (WALES) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 26 Feb 2004 From: ProMED-mail Source: Farming Life [edited] Ringrot Outbreak In Wales Contained -------------------------------------- Tracing and testing work associated with potato stocks at the farm in Wales, where an outbreak of potato ring rot was detected, has confirmed that the outbreak has been contained and that no other farms have grown or received infected stocks. More than 165 000 potato tubers were tested during the outbreak. On the outbreak farm, one stock of the Provento variety and one stock of a Provento/Almera admixture were found to be infected. Apart from these 2 stocks, all tests were negative, including for the remaining 20 seed potato stocks on the outbreak farm. The testing included: all potato stocks on the outbreak farm; other stocks of Provento from the United Kingdom 2003 harvest; other stocks of Almera from the UK 2003 harvest; seed potatoes from the UK 2003 harvest grown from 2002 stock from the outbreak farm; seed potatoes from stocks with a clonal link to stocks grown on the outbreak farm in previous years; seed potatoes on farms with a machinery link to the outbreak farm. A substantial testing programme was also carried out in the Netherlands, where the Provento seed potatoes grown on the outbreak farm originated. A Lessons Learned review will be initiated shortly, to assess the handling of this first outbreak, and UK controls against ring rot. This review is being planned in consultation with the National Farmers' Union (NFU) and will provide an opportunity for all those affected, including individuals, trade organisations and Government officials, to contribute their views. Ben Bradshaw, Plant Health Minister, said: "It is extremely good news that this outbreak has been contained. This is thanks to good co-operation with those in the industry and the substantial Government resources committed to the containment exercise." Potato ring rot is a serious disease and its establishment in the UK would have significant consequences for potato growers and others. "It is now time to take a step back to assess the handling of this outbreak and the controls that are in place against ring rot." ------------------------------ ProMED-mail [The attention to detail exercised by the those responsible for testing potato stocks is very impressive. Kudos to those who contained this outbreak of bacterial ring rot (caused by _Clavibacter michiganensis_ ssp. _sepedonicus_). It will be very interesting to see what recommendations ensue from the final report of this incident. - Mod.DH] [see also: 2003 ---- Clavibacter, potato - UK (England) (02) 20031120.2875 Bacterial ring rot, potato - UK (Wales): 1st report 20031116.2843] ......................................mpp/dh/pg/dk *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################