From brian at gweep.ca Wed Oct 1 14:46:27 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Wheat stripe rust, new strains - Australia (SA) Message-ID: <37y8w4elek.fsf@lios.aq2.gweep.ca> WHEAT STRIPE RUST, NEW STRAINS - AUSTRALIA (SOUTH AUSTRALIA) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 29 Sep 2003 From: ProMED-mail Source: Australian Broadcasting Corp., ABC News 26 Sep 2003 [edited] New strains of wheat disease found in SA ---------------------- It is feared an early outbreak of a highly infectious wheat disease could dramatically reduce South Australia's wheat yields. Stripe rust disease has been detected in crops at Loxton and parts of the Yorke Peninsula. Richard Saunders of the South Australian Research and Development Institute says the earlier-than-usual outbreak is a concern because crops have not yet reached a stage of resistance. He suggests it may be a new strain of the fungus that is causing the disease. Saunders said that there are 2 new strains of stripe rust in Australia, one in western Australia and another in eastern Australia. The western strain was very prolific in 2002 and is expected to eventually occur in South Australia. ------------------------------------------------------------------------ ProMED-mail [Wheat stripe rust is caused by the fungus _Puccinia striiformis_ f.sp. _tritici_ (Ps). The fungus, also known as yellow rust or glume rust, is a problem for grain farmers in cooler climates and at higher elevations in Australia. The first outbreak of Ps in Western Australia in 2002 caused crop losses ranging from 30-50 percent with greater losses (65 percent) in some areas. Disease control measures (chemical control) applied at early stages of growth reduced crop damage considerably. A major concern is that the western pathotype/strain could spread to eastern Australia where the disease has been present since 1979. Partial and major resistance genes are present in the eastern wheat cultivars, which should provide some degree of disease protection. A popular cultivar, H45, which is susceptible to Ps and blotch caused by _Septoria tritici_, is likely to be withdrawn in favor of more resistant cultivars such as Bowerbird and Drysdale. - Mod.DH] [see also: Wheat stripe rust - Australia (WA) 20030624.1553 2002 ---- Wheat stripe rust - Australia (Western): alert 20020831.5198] .......................................mpp/dh/pg/mpp *##########################################################* 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-majordomo@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Wed Oct 1 14:46:55 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Charcoal rot, soybean - USA (Illinois) Message-ID: <37u16selds.fsf@lios.aq2.gweep.ca> CHARCOAL ROT, SOYBEAN - USA (ILLINOIS) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 30 Sep 2003 From: ProMED-mail Source: The Corn & Soybean Digest, 26 Sept 2003 [edited] New Illinois Survey Uncovers More Disease Problems in Soybean Fields -------------------------------------------------- Soybean growers in Illinois are facing a major outbreak of charcoal rot of soybean according to a recent survey conducted by researchers from the University of Illinois [UI] and Southern Illinois University [SIU], Carbondale. The annual survey is conducted in late August and early September of each year to determine the levels of various diseases as the soybean crop heads toward harvest. Primary funding is provided by the Illinois Soybean Checkoff Board. According to Glen Hartman, USDA plant pathologist at UI, and Jason Bond at SIU, large numbers of fields in northern, central, and southern parts of the state are affected. Charcoal rot is caused by a soil-inhabiting fungus that can be found in virtually every field in the state. Symptoms of the disease normally show up only during periods of hot, dry weather. "Every time we have any drought conditions, we can get charcoal rot," Hartman said. "A long dry period with high temperatures in August 2003 was enough for the fungus to take hold and cause the problems we are seeing right now." Infected soybean plants turn brown and mature early but are not often killed outright before podding occurs, especially when the disease occurs late in the growing season, as it did this year. "Under the current conditions, yield losses could run from very little up to 30 percent," Hartman said. "The problem will most often vary greatly within different parts of a field. Hartman points out that there are currently no practical options for managing this disease. "We do not have any resistant varieties available to recommend to growers," he said. The only way to control this problem is to irrigate or not plant soybeans in a field for 10 or 15 years, which is impractical. Hartman advocates a 2-pronged research approach for dealing with the problem in the long term. "We need to look at both bio-tech and traditional approaches to finding genetic resistance," he said. "Our screening for resistance so far has looked at only a small portion of the 16 000 soybean accessions in the USDA Soybean Germplasm Collection housed at the UI. We may also have to extend the search to the wild progenitor of the modern soybean and the perennial relatives of the soybean." Hartman said that if "we had a 2-3 year period of dry weather, charcoal rot would suddenly become the most important disease threat to our soybean crop." He advises that a vigorous screening program be implemented, even when there is no disease threat. Eventually there would be resistant soybean cultivars as insurance against this potentially troublesome disease. ------------------------------------------------------------------------ ProMED-mail [Charcoal rot, caused by the soil-inhabiting fungus _Macrophomina phaseolina_, occurs worldwide. It is a weak pathogen, but under drought conditions (27- 35 deg C) Mp can induce severe stress on soybean. It also infects corn. Disease management involves reduction of plant stress (providing adequate moisture, optimum fertility, and proper spacing between plants), utilization of resistant cultivars, and crop rotation away from soybean for 2 years. - Mod.DH] [see also: Charcoal rot, soybean - USA (North Dakota) 20030606.1394] .......................................dh/pg/mpp *##########################################################* 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-majordomo@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Wed Oct 1 15:48:10 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Tomato leaf curl virus, potato - India: first report Message-ID: <374qyseijq.fsf@lios.aq2.gweep.ca> TOMATO LEAF CURL VIRUS, POTATO - INDIA: FIRST REPORT ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 26 Sep 2003 From: ProMED-mail Source: British Society Plant Pathology, New Disease Reports, Vol 8: Aug 2003 - Jan 2004 [edited] Potato leaf curl - a new disease of potato in northern India caused by a strain of Tomato leaf curl New Delhi virus K. S. Usharania, Plant Virology Unit, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi 110012, India; B. Surendranatha (as for Usharania); S.M. Paul-Khurana, Central Potato Research Institute, Shimla, 171001, India; I.D. Garg, (as for Paul-Khurana); and V.G. Malathia ) Accepted for publication 1 Sep 2003. A severe leaf curl disease has been observed since 1999 in potato (_Solanum tuberosum_) crops in northern India. Affected plants were severely stunted with apical leaf curl, crinkled leaves, and expressed conspicuous mosaic. Garg et al. (2001), using polyclonal antiserum to Indian cassava mosaic virus in IEM, detected a begomovirus associated with this disease. Inoculum from a severely affected potato plant was sap-transmitted to _Nicotiana benthamiana_ [Nb] seedlings, in which it induced severe leaf distortion and stunting 15 days post inoculation. Meristem-derived plantlets of potato cv. Kufri Anand inoculated with sap from infected Nb leaves developed yellow mottling, mosaic, and leaf curl symptoms. Double-stranded viral replicative DNAs were purified from infected potato and Nb plants and cloned at HindIII, BamHI, XbaI, and PstI sites in the vector pUC18. The clones at the XbaI and PstI sites had a unit genome length insert (approx. 2.7 kb) which hybridized with the viral replicative forms from the infected plants. The nucleotide sequence of the XbaI and PstI clones corresponded to the DNA A (Accession No. AY286316) and B (Accession No. AY158080) components of the causal begomovirus. Comparison of the complete nucleotide sequence of DNA A revealed that it has 93-95 percent identity with that of ToLCV-NDe isolates and <75 percent identity with other Tomato leaf curl virus isolates and Potato yellow mosaic virus. A whitefly-transmitted potato begomovirus has not been reported previously in India, probably as potato crops on the North Indian plains have been cultivated during winter months, when whitefly populations are low. However, in recent years, potato crops have been planted earlier, resulting in a sufficient buildup of whitefly populations that might have led to the emergence of a new potato disease. The nucleotide sequence data indicate that the cause is a virus closely related to ToLCV-NDe which, unlike the strain infecting potato, is not sap-transmissible and is not known to infect potato naturally. Therefore it is likely that a new strain of ToLCV-NDe has emerged that infects potato, a new host. This is the first observation of a begomovirus causing a severe disease of potato in India. We conclude that potato leaf curl disease is caused by a strain of Tomato leaf curl New Delhi virus (ToLCV-NDe). Reference: Garg ID, Paul-Khurana SM, Kumar S, Lakra BS, 2001. Association of a geminivirus with potato apical leaf curl in India and its immuno-electron microscopic detection. Journal of Indian Potato Association 28, 227-232. ------------------------------------------------------------------------ ProMED-mail [This piece is a good example of virus evolution at work. A whitefly-transmitted begomovirus originating in potato fields in Northern India is shown to be closely related to ToLCV-NDe. What is interesting is that the new virus is a relatively rare example of a sap-transmissible begomovirus. Based on genome sequence analysis, it is closely related to ToLCV-NDe but less closely related to other ToLCV isolates/strains. At least 3 other begomovirus strains/isolates have been reported from Asia. The one associated with cucumber yellow leaf curl disease in Thailand shares 95.6 percent nucleotide sequence similarity with the DNA-A of ToLCV-NDe, and pumpkin yellow vein mosaic virus is most closely related to the same virus. Recently a begomovirus in sponge gourd (_Luffa cylindrica_) from India is now considered to be a putative strain of ToLCV-NDe. Clearly new viral species continue to emerge in Asia. - Mod.DH] [see also: Tomato leaf curl, tomato - Australia 20030608.1413 2001 ---- Tomato viruses - Tunisia 20010926.2349 Tomato leaf curl begomovirus, tomato - Greece 20010707.1307 Tomato leaf curl begomovirus, tomato disease - India (02) 20010402.0663 Tomato leaf curl begomovirus, tomato disease - India 20010331.0649] .......................................dh/pg/mpp *##########################################################* 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-majordomo@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Fri Oct 3 11:06:18 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Colletotrichum acutatum, citrus, fruit drop - Brazil Message-ID: <374qyq6yk6.fsf@lios.aq2.gweep.ca> COLLETOTRICHUM ACUTATUM, CITRUS, FRUIT DROP - BRAZIL ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 1 Oct 2003 From: ProMED-mail Source: British Society for Plant Pathology, NEW DISEASE REPORTS, Vol.8: Aug 2003 - Jan 2004 [edited] Outbreak of postbloom fruit drop of citrus, caused by _Colletotrichum acutatum_, in Santa Catarina State, southern Brazil --------------------------------------------------- G.F. Theodoro , Centro de Pesquisa para Agricultura Familiar (Cepaf), Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina (Epagri), CP 791, CEP 89801-970, Chapeco, Santa Catarina, Brazil; N.A.R. Peres, Instituto Biologico, Univ of Florida - UNIEMP Project, Avenida Conselheiro Rodrigues Alves, 1252, CEP 04014-002, Sao Paulo, Brazil; and L.A.F. Verona (as for Theodoro). Accepted for publication 1 Sep 2003 Postbloom fruit drop (PFD), caused by _Colletotrichum acutatum_, [Ca] is an important disease of citrus, especially in orchards planted in humid areas of the Americas (Timmer et al., 1994). In Brazil, PFD was first reported in 1979 and causes variable yield losses depending on the weather conditions (Feichtenberger, 1994). Until recently, the disease was not considered serious in the southern state of Santa Catarina, in which about 100 sq. km is planted with citrus. In 2002, PFD symptoms were reported in numerous orchards in western Santa Catarina. These were reddish brown spots on petal tissues followed by abscission of fruitlets at the base of the ovary, with the basal disk, calyx and peduncle remaining firmly attached to the tree. These persistent calyces (buttons) are diagnostic for the disease and may persist for many months after flowering (Timmer et al., 1994). In September, during the main flowering period, weather conditions were particularly suitable for disease development, as the mean temperature during the month was low (11.1C) and associated with long periods of leaf wetness. Severity of infection was estimated by the number of infected flowers and persistent calyces observed on 20 trees randomly distributed in a 7-year-old "Rubi" sweet orange orchard. On each tree, the number of buttons in a 1 sq. m quadrant was counted. An average of 58.6 persistent calyces per sq. m was calculated and 100 percent yield losses were observed. 5 isolates of a slow-growing fungus were recovered from calyces plated on PDA. After 7 days of incubation at 25C in the dark, there was abundant production of orange conidial masses. Conidia were mostly fusiform, without setae and were 11.5 ? 1.1 micrometers long by 4.0 ? 0.5 micrometers wide. The morphological characteristics of these isolates fit the description of Ca (Agostini et al., 1992, Brown et al., 1996). Flowers of 3- to 4-year-old potted sweet orange trees in a screenhouse were inoculated with a conidial suspension (100 000 conidia per ml). A control treatment was sprayed with distilled water only. The characteristic reddish brown lesions on the petals were observed on the inoculated flowers and Ca was reisolated from the infected tissues, fulfilling Koch's postulates. This is the first report of a significant outbreak of PFD in Santa Catarina State, Brazil. References Agostini JP, Timmer LW, Mitchell DJ, 1992. Morphological and pathological characteristics of strains of Colletotrichum gloeosporioides from citrus. Phytopathology 82, 1377-1382. Brown AE, Sreenivasaprasad S, Timmer LW, 1996. Molecular characterization of slow-growing orange and key lime anthracnose strains of Colletotrichum from citrus as C. acutatum. Phytopathology 86, 523-527. Feichtenberger E, 1994. Podridao floral dos citros: historico, sintomatologia, etiologia e epidemiologia. Laranja 15, 109-128. Timmer LW, Agostini JP, Zitko SE, Zulfiqar M, 1994. Postbloom fruit drop, an increasingly prevalent disease of citrus in the Americas. Plant Disease 78, 329-334. ------------------------------------------------------------------------ ProMED-mail [Postbloom fruit drop (PFD) of citrus was first reported in Belize in 1979 and has since spread to Florida, the Carribean, and South America. Sweet orange and lime are susceptible, and substantial yield reduction has been reported in Florida. In Australia, Ca has been widely recorded as causing a ripe fruit rot of many fruits including pawpaw (_Asimina triloba_) and strawberry. Though our resources -- which are not up-to-date -- state that PBFD has not been recorded to date in Australia, I hope that our readers in Australia will provide more relevant data. Disease management basically involves applications of systemic fungicides or copper fungicides. - Mod.DH] [see also: Colletotrichum gloeosporioides, citrus - Morocco 20030626.1575 2000 ----- EPPO intercepted consignment reports - Worldwide 20000531.0875] ................................dh/pg/mpp *##########################################################* 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-majordomo@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Mon Oct 6 12:01:43 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Corn stunt disease - USA (California) Message-ID: <3765j2qmkb.fsf@lios.aq2.gweep.ca> CORN STUNT DISEASE - USA (CALIFORNIA) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases http://www.isid.org Date: 2 Oct 2003 From: ProMED-mail Source: Western Farm Press, 17 Sep 2003 Online Exclusive [edited] Disease vectoring corn leafhopper again threatens corn crop As the corn leafhopper continues to spread the corn stunt pathogen to California's Central Valley, several evaluated insecticides have only a short-term effect, suggesting that other measures, including a corn-free period, have more potential for success. Charles G. Summers, University of California entomologist at the Kearney Research and Education Center, Parlier, says a corn-free period, from Oct. 31 to April 1, would help in management of the leafhopper. The most important step for the time being is for growers to destroy volunteer corn plants that provide the insect, capable of overwintering in the valley, a bridge to infest the next crop. Several commonly used insecticides provided control in his trials, but only for relatively brief periods ranging from 10 - 30 days. Developing plant resistance to the corn stunt pathogen is another potential defense but will take time. Taking yet another approach, Summers and others found in preliminary - but as yet inconclusive - studies that corn plants grown over a mulch of wheat straw for a month after planting had reduced populations of corn leafhoppers. Mulch trials also showed one-third the incidence of corn stunt disease and 25 percent more yield compared to plants on bare soil. Summers suggests that the mulch might be used to repel aphids and whiteflies, as well as leafhoppers. Summers and a team of several farm advisors and UC specialists surveyed valley counties with sticky traps and D-vac sweeps in 2002 and confirmed the leafhopper can successfully overwinter in these counties. Observations are continuing this year. According to Summers, while leafhopper damage can impair yield and quality, the disease poses the greater threat. Corn stunt is caused by a bacterial organism, _Spiroplasma kunkelii_ [Sk]. Beyond stunting of plants, it causes production of multiple ears that fail to fill. In the fall, leaves in the upper portion of infected plants take on a reddish color. The corn leafhopper [_Dalbulus maidis_] is common throughout the southeastern and southwestern U.S. Brownish or tan in color and less than one-eighth of an inch long, it is the only vector of corn stunt disease in California. Summers said the leafhopper, or something very like it, was first reported in Fresno and Tulare counties in 1942 and a disease fitting the description of S. kunkelii was recorded a few years later. Corn stunt is now found from Los Angeles County to Yolo County. Outbreaks once lasted only 1 or 2 years and were blamed on leafhoppers migrating from Mexico, but since 1996 they have been annual events with increasing severity in the southern San Joaquin Valley. The disease formerly was seen mostly in corn planted after July but later showed up in fields planted in April or May. "This suggests to me that both the insect and the disease were overwintering in the San Joaquin Valley," Summers said. The leafhopper has no diapause period and during winter cold it is inactive, only to resume flight when temperatures reach about 55 F. Leafhoppers are present from October Into March on riparian areas, alfalfa, weeds and triticale. Summers said a "real key" to managing the leafhopper is destroying volunteer corn that provides the bridge between seasons. After corn has been cut, thousands of volunteer seedlings emerge, serving as hosts for the insect vector over the winter. In August and September, as chopping intensifies, younger fields catch the full impact of the leafhopper movement. Even though some corn was frozen back, significant numbers found shelter enough in remaining intact whorls. They were discovered in Kings County in February on residue ears that had started to sprout. Global imaging system surveys analyzed by University of California scientists in 2001-2002 showed heaviest and earliest infestations around the Lemoore area of Kings County, confirming earlier observations on the ground. However, the same surveys from 2002 through July of 2003 identified a shift of hot spots of leafhopper populations to Tulare County as pressure continued in Kings County. Tulare County farm advisor Carol Frate said corn stunt appears to be scattered throughout the county and she expects that since much of the acreage is late corn, the problem will worsen by the end of the season. "It's been increasing since 1996-97 and some fields had a 50 percent reduction in yield. We can see the insect in corn but we don't know what the loss will be. Unfortunately, we have a lot of late corn this year, and those fields are most at risk," she said. ------------------------------------------------------------------------ ProMED-mail promed@promedmail.org [Byline: Dan Bryant] [Corn stunt disease [CSD] is of significant economic importance in a number of Latin American countries. It occurs from the southern U.S. states to Brazil and Peru. Sk and the maize bushy stunt phytoplasma [MBSP]together with Maize rayado fino virus constitute the CSD complex. Using a PCR assay for Sk, the pathogen was found in El Salvador, Guatemala and Panama. Significant yield reductions can follow from dual infections of Sk and MBSP. Disease management depends heavily on cultural practices (disking fields containing volunteer corn, herbicide applications to eradicate alfalfa). In California, all current commercial cultivars of field and sweet corn are susceptible. Generally, insecticides are ineffective in controlling CSD. A useful summary: http://ucce.ucdavis.edu/files/filelibrary/1214/5465.pdf -Mod.DH] [see also: 1996 ----- PROMED-PLANT: Maize diseases - Brazil 19960712.1251] .................dh/mpp *##########################################################* 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-majordomo@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Tue Oct 14 16:53:32 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Tomato spotted wilt, tomato - USA (FL & GA) Message-ID: <37zng3tor8.fsf@lios.aq2.gweep.ca> TOMATO SPOTTED WILT, TOMATO - USA (FLORIDA & GEORGIA) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 8 Oct 2003 From: ProMED-mail Source: Southeast Farm Press, Sept 12, 2003 [edited] Tomato spotted wilt virus targeted ---------------------------------- During the past 2 decades, TSWV has spread around the world by thrips [small insects that feed on plants], causing very high losses to a variety of vegetable, ornamental, and agronomic crops. According to Steve Olson, a professor at University of Florida's North Florida Research & Education in Quincy, TSWV epidemics have been troublesome throughout the southern United States, cutting yields by 20-30 percent on tomatoes. Tomato and pepper crops in Florida and Georgia, valued at about $1 billion annually, have been hit hard, as have peanut crops. Leaves of TSWV-infected plants turn brown, purple, or bronze and stem tips are frequently killed. Infected tomato fruits show spots and rings, and are unmarketable. The virus is transmitted from plant to plant almost exclusively by several species of thrips. The western flower thrips (_Frankliniella occidentalis_) and the tobacco thrips (_F. fusca_) are major species in Florida. Until recently, growers sprayed toxic, broad-spectrum insecticides in an attempt to control thrips, but the chemicals do not prevent virus transmission. The solution, according to researchers at the Quincy center, is to use a variety of new, environmentally friendly strategies known as integrated pest management (IPM). IPM includes new cultural practices, natural insecticides, bio- control agents or natural predators, and a new treatment that boosts the plant's resistance system against viral and bacterial pathogens. According to Tim Momol, an assistant professor of plant pathology at the Quincy center, incidence of TSWV infection in tomato has been reduced by as much as 75 percent, using a new plastic bed cover that reflects UV light and repels thrips. He said that many producers have switched to the UV-reflective mulch, boosting tomato yields by as much as 600 (25-pound) boxes/acre and increasing profits by as much as $4000/acre. Although the reflective mulch costs an extra $200/acre, yield increases and higher returns justify its use. According to Joe Funderburk, a professor of entomology at the Quincy center, a recent survey showed that about 30 percent of the growers in north Florida and Georgia are using the UV- reflective mulch, and its use is expanding to other production areas in the Southeast in 2003. He says a natural insecticide called spinosad, which poses little threat to field workers or the environment, also is helping growers control thrips on tomatoes. And, a new resistance-boosting treatment, which is marketed under the Actigard (R)* trademark, is now being used by about 45 percent of all tomato growers in the region. [*Reference to this product does not constitute an endorsement by ProMED-mail. - CopyEd.PG] Olson, Momol, and Funderburk developed and promoted the new IPM control measures, and the researchers are collaborating internationally so that the program is adopted in other countries. [Byline:Chuck Woods] ------------------------------------------------------------------------ ProMED-mail [This piece reports an interesting application of IPM. Spinosad is a mixture of 2 of the most active, naturally occurring metabolites (spinosyns A and D) produced by the soil-inhabiting actinomycete _Saccharopolyspora spinosa_. They have been registered by EPA to control a variety of insects. Upon ingestion of the spinosyns, death follows due to extremely rapid excitation of the insect nervous system. - Mod.DH] [see also: 2002 ---- Tomato spotted wilt, tomato - USA (North Carolina) 20020622.4565 Tomato spotted wilt, tomato - (USA) Virginia 20020620.4545 2001 ---- Tomato spotted wilt tospovirus, soybean - Iran 20011229.3130 Tomato spotted wilt, peanut - Iran 20011220.3069 Tomato spotted wilt disease, tomato - Kenya 20011109.2778 2000 ---- Tomato spotted wilt tospovirus, crops - USA (Georgia) 20000617.0989 Tomato spotted wilt tospovirus - Europe 20000302.0286] .......................................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. ************************************************************ * * * Please support the 2003 ProMED-mail Internet-a-thon! * * http://www.isid.org/netathon2003.shtml * * * ************************************************************ 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 Oct 14 16:54:04 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Vector repellent mulches Message-ID: <37vfqrtoqb.fsf@lios.aq2.gweep.ca> VECTOR REPELLENT MULCHES *********************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 10 Oct 2003 From: Mark D. Laing Re: Use of UV-reflective mulches to reduce infection by Tomato spotted wilt tospovirus [see ref. below] With virology colleagues (da Graca, Cradock & Budnik), we have shown that UV- reflective mulches also repel aphids, drastically reducing both feeding and probing by them in sweet pepper (capsicum) and baby marrow (zucchini). Given that potyviruses are a big problem for both these crops in South Africa (PVY and Zucchini yellow mosaic virus or Watermelon mosaic virus, respectively), these repellent mulches resulted in increases in yields of about 100 percent in most trials, relative to a susceptible control with no mulch, for both sweet peppers and baby marrow. Interestingly, organophosphate insecticide applications resulted in increased aphid probing and therefore increased virus disease levels, relative to the control. This phenomenon will probably hold true for most non-persistent viruses that are transmitted during plant probing. ------------------------------------------------------------------------ Mark D. Laing Professor and Chair of Plant Pathology Director, ACCI University of Natal, PBag X01, Scottsville, 3209 South Africa Tel/Fax 27-33-260 5524 Cell 082 3724 945 or [I thank Mark Laing and his colleagues for providing this information. Plastic UV-reflective mulches have been demonstrated to reduce the incidence of plant virus diseases transmitted by aphids, thrips, and whiteflies. Clearly, IPM has much to offer for management of vector-borne plant viruses and the diseases they cause. - Mod.DH] [see also: Tomato spotted wilt, tomato - USA (FL & GA) 20031009.2539] .......................................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. ************************************************************ * * * Please support the 2003 ProMED-mail Internet-a-thon! * * http://www.isid.org/netathon2003.shtml * * * ************************************************************ 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 Oct 15 13:38:09 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Sida golden yellow vein virus - Cuba: first report Message-ID: <378ynmqoke.fsf@lios.aq2.gweep.ca> SIDA GOLDEN YELLOW VEIN VIRUS - CUBA: FIRST REPORT ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 14 Oct 2003 From: ProMED-mail Source: British Society for Plant Pathology, New Disease Reports [edited] First report of Sida golden yellow vein virus infecting _Sida_ species in Cuba A.L. Echemendia (Instituto de Investigaciones de Sanidad Vegetal, 110 # 514, Playa. La Habana. CP 11600. Cuba); P.L. Ramos ; L. D?az (as for Ramos); R. Peral (as for Ramos); A. Fuentes (as for Ramos); M. Pujol (as for Ramos); and G. Gonzalez (as for Echemendia). Accepted for publication 29 Sep 2003. Members of the genus _Sida_ are common weeds in the Caribbean and Central America. _Sida_ spp. with leaves showing yellow mottling have been commonly observed in Cuba. To identify the causal agent(s), symptomatic leaves from _Sida_ plants were collected in the provinces of Havana, Santa Clara, and Guantanamo between 1999 and 2001. Healthy _Phaseolus vulgaris_ L. plants were inoculated using a bioballistic method (Finer et al., 1992) with total DNA extracts purified from infected leaves collected in Havana. Yellow mosaic and curling leaf symptoms were observed in 3 of 15 inoculated bean plants. The presence of a begomovirus in both _Phaseolus_ and _Sida_ samples was shown by strong hybridization signals in Southern blots using DNA-A from Bean golden yellow mosaic virus-Cu as a probe, under high stringency conditions. Total DNA from the Havana Sida sample was further analyzed by PCR using 2 degenerate primer sets; PAL1v1978-PAR1c715 and PAL1c1960-PAR1v722 (Rojas et al., 1993). Amplicons of approximately 1.4 kb and 1.2 kb were amplified and cloned into pZeroTM-2.1 plasmid (Invitrogen, CA, USA) using standard procedures. Nucleotide sequences were compared to those from known begomoviruses using Clustal W analysis. For the coat protein (753 nucleotides [nt]) and rep genes (1080 nt), the highest percentages of identity (93.5 and 99 percent respectively) were to Sida golden yellow vein virus (SiGYVV, GenBank Accession No. U77964). In addition, the Cuban isolate (DNA-A 2600 nt) showed 97percent nt sequence identity with SiGYVV-A. Common region (CR) analysis of SiGYVV-Cu A revealed 98 percent identity when compared to SiGYVV-CR. Similar interons were identified in both viruses. These results confirm that the virus isolated from _Sida_ plants in the province of Havana (GenBank Accession No. AJ 577395) is a strain of SiGYVV. This is the first identification of SiGYVV in Cuba. References Rojas MR, Gilbertson RL, Russell DR, Maxwell DP, 1993. Use of degenerate primer in the polymerase chain reaction to detect whitefly-transmitted geminiviruses. Plant Disease 77, 340-347. Finer JJ, Vain P, Jones MW, McMullen MD, 1992. Development of the particle inflow gun for DNA delivery to plant cells. Plant Cell Reports 11, 323-328. ------------------------------------------------------------------------ ProMED-mail [To my knowledge, SiGYVV has not been previously reported to infect bean. If any of our readers in the Caribbean and Central America know of reports documenting infection of bean or other food crop legumes by SiGYVV, I would appreciate receiving them. Weeds such as _S. rhombifolia_ have been suggested as natural reservoirs from which the whitefly, _Bemisia argentifolii_, spreads SiGYVV to tomato, a preferred host. In addition to SiGYVV, there are at least 4 other geminiviruses that infect _Sida_ spp. (golden mosaic, mottle, yellow vein, and yellow mosaic). - Mod.DH] .......................................dh/pgdk *##########################################################* 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. ************************************************************ * * * Please support the 2003 ProMED-mail Internet-a-thon! * * http://www.isid.org/netathon2003.shtml * * * ************************************************************ 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 Oct 24 13:24:52 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: Press Release - IS-MPMI Installs New Board Message-ID: <37n0bqv3p8.fsf@lios.aq2.gweep.ca> PRESS RELEASE For immediate release Contact: Amy Steigman Phone: +1.651.454.7250 E-mail: mailto:asteigman@scisoc.org Website: http://www.ismpminet.org/ IS-MPMI Installs New Board St. Paul, MN (October 23, 2003) - The International Society for Molecular Plant-Microbe Interactions (IS-MPMI) is pleased to welcome its new board members for the 2003-2005 term. The new leadership assumed their responsibilities at the conclusion of IS-MPMI's International Congress in St. Petersburg, Russia, July 2003. Members of the IS-MPMI board include: Jonathan Walton, Michigan State University, president; Adam Kondorosi, CNRS, president-elect; Egbertus (Ben) Lugtenberg, Leiden University, immediate past president; Andrew Bent, University of Wisconsin, secretary; Gary Stacey, University of Missouri, treasurer; Dieter Haas, University de Lausanne, director; Steve Lindow, University of California, director; Michael Djordjevic, Australian National University, director; and Jens Stougaard, University of Aarhus, MPMI editor-in-chief. The International Society for Molecular Plant-Microbe Interactions (IS-MPMI) is an international scientific organization devoted to molecular studies of microorganisms that interact with plants, plants responding to such organisms, and the consequences of the interactions. - 30 - From brian at gweep.ca Fri Oct 31 16:19:23 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Tomato severe leaf curl disease - Mexico Message-ID: <37wual0zd0.fsf@lios.aq2.gweep.ca> TOMATO SEVERE LEAF CURL DISEASE - MEXICO ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 27 Oct 2003 From: ProMED-mail Source: American Phytopathological Soc., Plant Dis. Notes 87:1397, 2003 [edited] 1st Report of a Geminivirus Associated with Leaf Curl in Baja California Peninsula Tomato Fields. ------------------------------ R. J. Holguin-Pena & R. Vazquez Juarez, Centro de Investigaciones Biologicas del Noroeste, La Paz, B.C.S. 23000, Mexico; and R. F. Rivera-Bustamante, Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Irapuato, Guanajuato 36500, Mexico. Plant Dis. 87:1397, 2003; published on-line as D-2003-0902-01N, 2003. Accepted for publication 9 Aug 2003. Since November 2001, geminivirus-like symptoms (stunting, reduced leaf size, and leaf curling "chino") have been observed in tomato (_Lycopersicon esculentum_ Mill.) plantings in Baja California Sur, Mexico. Samples of symptomatic plants were collected from commercial fields and analyzed by traditional and molecular methods for the presence of geminiviruses. Inocula prepared from infected plants were experimentally transmitted to tomato seedlings and _Datura stramonium_ by mechanical inoculation and whitefly transmission. Leaf curling and interveinal chlorosis symptoms similar to those found in the field were observed in inoculated tomato and _D. stramonium_. DNA from infected plants was extracted and analyzed by polymerase chain reaction (PCR) and electrophoresis using degenerate primers PALIv1978/PARIc494 (1). PCR fragments of the expected size (1.1 kb) for the common region (CR) were obtained from 28 of 64 plants, cloned and sequenced (GenBank Accession No. AY336088). Comparisons of CR sequences with the NCBI database by using BLAST and MegAlign (DNASTAR, London) indicated that the Baja Californian isolates were New World bipartite begomoviruses sharing the highest nucleotide sequence identity (93 percent) with a partially characterized geminivirus (Tomato severe leaf curl virus (ToSLCV); GenBank Accession No. AF130415) from Guatemala. Reference: (1) M. R. Rojas et al. Plant Dis. 77:340, 1993. ------------------------------------------------------------------------ ProMED-mail [ToSLCV strains have also been reported from Guatemala, Honduras, Nicaragua, and Cuba. Cucumber (_Cucumis sativus_) and tomato are natural hosts. These strains likely originated in Central America and the Caribbean region. The genomes of these viruses are either monopartite or bipartite, the viruses are transmitted by whiteflies (_Bemisia tabaci_), and they infect a range of dicotyledonous plants. Disease management involves procedures to delay infection, regulated applications of insecticides, use of biopesticides (parasitoids and predators), and planting resistant cultivars if they are available. Additional references relating to ToSLCV and geminivirus disease management: - 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. ************************************************************ * * * Please support the 2003 ProMED-mail Internet-a-thon! * * http://www.isid.org/netathon2003.shtml * * * ************************************************************ 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 Oct 31 16:21:35 2003 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:13:58 2005 Subject: PRO/PL> Zucchini yellow mosaic, cucumber - Poland Message-ID: <37sml90z9d.fsf@lios.aq2.gweep.ca> ZUCCHINI YELLOW MOSAIC, CUCUMBER - POLAND ***************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 30 Oct 2003 From: ProMED-mail Source: American Phytopathological Soc., Plant Dis. Notes 87:1399, 2003 [edited] First Report of Zucchini yellow mosaic virus in Cucumber in Poland. H. Pospieszny and M. Cajza, Institute of Plant Protection, Department of Virology and Bacteriology, Miczurina 20, 60-318 Poznan, Poland; and R. Plewa, Adam Mickiewicz University in Poznan, Department of Experimental Biology, Animal Physiology, Fredry 10, 61-701 Poznan, Poland. Plant Dis. 87:1399, 2003; published on-line as D-2003-0912-01N, 2003. Accepted for publication 27 Aug 2003. In June 2002, mosaic and interveinal chlorosis were observed on 2 cucumber plants (_Cucumis sativus_) grown in one commercial greenhouse in the western region of Poland. Electron microscopic examination of leaf-dip preparations from infected plants showed flexuous filamentous virus particles typical of potyviruses (720 to 750 nm long). _Chenopodium amaranticolor_, _Chenopodium quinoa_, _Citrullus lanatus_, _C. melo_, _C. sativus_, _Cucurbita maxima_, _Cucurbita pepo_, _Cucurbita pepo_ cv. Giromontiina, _Cucurbita pepo_ cv. Patissoniana, _Nicotiana benthamiana_, and _N. tabacum_ were mechanically inoculated with sap from symptomatic cucumber leaves. The virus caused local chlorotic lesions on _Chenopodium amaranticolor_ and _Chenopodium quinoa_ and systemic infection in all tested cucurbits, but it did not infect tobacco plants. Reverse transcription-polymerase chain reaction (RT-PCR) amplification of the 3' end of the genomic RNA was done by using P9502 as a downstream primer and degenerate CPUP as an upstream primer to amplify a highly conserved region of the potyviral coat protein (1). The PCR products were directly sequenced with the CEQ DTCS dye terminator cycle sequencing kit (Beckman Coulter, Inc., Fullerton, CA), and the analysis of dideoxy terminated fragments was conducted by capillary electrophoresis using a CEQ 2000 DNA Analysis System (Beckman Coulter, Inc.). The obtained 684 nt sequence (GenBank Accession No. AY347476) was almost identical with sequences of Zucchini yellow mosaic virus (ZYMV) isolates from Austria (GenBank Accession Nos. AJ420012-AJ420019 and AJ420027) and Hungary (GenBank Accession Nos. AJ459954 and AJ459955). The above suggested that the Polish isolate of ZYMV belonged to the Central European branch of the phylogenetic tree (2). To our knowledge, this is the first report of ZYMV in Poland. References: (1) R. A. A. van der Vlugt et al. Phytopathology 89:148, 1999. (2) I. Tobias and L. Palkovics. Pest Manage. Sci. 59:493, 2003. ------------------------------------------------------------------------ ProMED-mail [ZYMV, a potyvirus, first observed in 1981 in France and Italy, has since spread worldwide, affecting crops in at least 22 countries, especially in Mediterranean countries, Central Europe and USA. _Cucurbita pepo_ (pumpkin), _Cucumis melo_ (melon) and _Citrullus lanatus_ (watermelon) are the predominant susceptible hosts. ZYMV is often associated with papaya ringspot virus (PRSV-watermelon) or with Watermelon mosaic virus (WMV) in tropical countries. The virus is transmitted by several aphids including (_Aphis citricola_, _A. gossypii_, and _Myzus persicae_). Evidence of seed transmission is equivocal. Disease management utilizes reflective mulches, judicious application of insecticides, and resistant cultivars. Some wild cucurbits are sources of ZYMV resistance genes, which may have application for developing resistant cultivars. Additional references: - Mod.DH] [see also: Vector repellent mulches 20031012.2563 2000 ---- Cucurbit virus study - Brazil: EPPO report 20001205.2114] .......................................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. ************************************************************ * * * Please support the 2003 ProMED-mail Internet-a-thon! * * http://www.isid.org/netathon2003.shtml * * * ************************************************************ 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. ############################################################ ############################################################