Feeds:
Posts
Comments

Archive for the ‘Viruses’ Category

ktic_logo

BY KSRE | April 13, 2017

Kansas State University, Australian Researchers Join Forces to Combat Insect Pest

Photo courtesy of KSRE

MANHATTAN, Kan. – Researchers at Kansas State University and the University of Queensland in Australia have joined forces to attack and control a microscopic pest that can be devastating to the fruit, vegetable and flower industries.

Ralf Dietzgen, an associate professor in agriculture and food innovation at the University of Queensland, is spending three months at K-State as a Fulbright Senior Scholar in a quest to gather data and develop control measures for the small insect known as thrips.

Dietzgen is working directly with plant pathology professors Dorith Rotenberg and Anna Whitfield, who are co-directors of the Center of Excellence for Vector-Borne Plant Virus Disease Control.

Not known to grow larger than 3 millimeters, thrips are voracious eaters, using their asymmetrical mouths to puncture the surface of food crops, flowers and leaves and suck up their contents.

Of equal concern to researchers is that thrips are vectors, or carriers, of more than 20 viruses that cause plant disease, especially the tospoviruses, which also multiply in thrips. Given the right conditions, such as those found in greenhouses, thrips can reproduce exponentially and form large swarms that can transmit viruses to healthy plants.

“They’re very challenging to control, for several reasons,” Whitfield said. “For one, the insect is hard to kill. It is resistant to many insecticides. You can’t just spray crops and hope to control the spread of thrips and tospovirus.

“But secondly, the viruses that thrips can spread are very diverse and can change quickly. I call tospoviruses the influenza of the plant virus world. The predominant virus threat may change because they can switch genome segments and can develop resistance to control measures based on genetic changes. So the viruses have a lot of diversity themselves.”

Whitfield said Dietzgen’s lab in Australia is one of a few in the world that studies viruses that replicate in insects and plants.

“The thrips are a significant pest and have an impact on food security and then on top of that they transmit viruses which cause disease symptoms on the produce, like ring spots, which make them unmarketable,” Dietzgen said.

He noted that when thrips feed on flower buds, the developing fruits often become misshapen. “So you have peppers that are crooked and unmarketable,” Dietzgen said.

“We are studying thrips and the viruses they transmit at the molecular level with the goal of developing applied control strategies,” Whitfield said. “We think that better understanding the molecular mechanisms of the interaction is essential for developing sustainable control strategies for thrips and tospoviruses.”

Dietzgen recently saw first-hand the devastation that thrips-transmitted viruses can cause. One Queensland grower who provides fresh tomatoes for a large supermarket chain lost most of his crop one year due to a tospovirus transmitted by thrips. The lost crop was valued at more than $500,000.

“By the time the grower saw the disease effects, the thrips had moved on and the virus had been left behind,” Dietzgen said.

“The virus that Ralf is studying isn’t in the U.S. just yet, but thrips insects are able to move around easily so that they could appear hidden in a shipment of produce,” Whitfield said. “Any shipment of vegetables or plants that is traveling around the world could have similar pathogens and pests in it. As a control measure, we are trying to develop broad spectrum, durable resistance using different technologies.”

While Dietzgen’s stay at Kansas State University is relatively short, the researchers hope their new partnership will help lead to long-term solutions for agriculture.

“Both of our labs have generated large sets of genomic data that we’re starting to compare during my stay,” Dietzgen said. “By doing that, we hope to come up with potential targets for pest and disease control for longer term crop protection. We are asking, ‘What are the functions of these potential molecular targets and can we interfere with them?’”

Rotenberg and graduate student Derek Schneweis have compiled large sets of data outlining the messenger RNA molecules in thrips. Whitfield said their work may give new insight into how to control thrips in horticultural crops, as well as how to protect those crops from tospoviruses and other plant disease.

The prestigious U.S. Fulbright program is the largest educational scholarship of its kind, and was created after World War II by U.S. Sen. J. William Fulbright. It operates between the U.S. and 155 countries.

More than 20 Fulbright Scholarships are awarded each year to Australian students, postdoctoral researchers, academics and professionals to pursue studies or conduct research in the United States.

In 2014, Kansas State University became the first U.S. educational partner of the Australian-American Fulbright Commission. Each year since, the university has hosted Fulbright Scholars from Australia to study and collaborate with Kansas State University researchers.

Kansas State also helped form the Oz to Oz program to encourage exchanges with faculty at Australian universities, often as seminar speakers.

© 2017 Nebraska Rural Radio Association. All rights reserved. Republishing, rebroadcasting, rewriting, redistributing prohibited. Copyright Information

Read Full Post »

From PestNet

LETHAL NECROSIS, MAIZE – MALAWI: ALERT
**************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>

Date: Wed 22 Mar 2017
Source: MBC Malawi [edited]
<https://www.mbc.mw/index.php/component/k2/item/3982-farmers-warned-about-maize-lethal-necrosis-disease>

Malawians have been warned to look out for maize lethal necrosis [MLN]
disease that has been attacking maize in other neighboring countries.

Johnny Masangwa, Department of Agricultural Research, said, “We are
conducting MLN survey in every district and found that the disease was
not yet in. We are carrying awareness messages as a preventative
measure to contain its spread this year [2017].” In case of an
incursion of MLN, there will be a quarantine of that area and lessons
to farmers on how to limit its spread.

[Byline: Litness Chaima]


Communicated by:
ProMED-mail
<promed@promedmail.org>

[Maize lethal necrosis (MLN) is caused by co-infection of _Maize
chlorotic mottle virus_ (MCMV, genus _Machlomovirus_, transmitted by
chrysomelid beetles) with one of several species in the family
_Potyviridae_. As synergistic partners of MCMV in MLN, _Wheat streak
mosaic virus_ (WSMV, genus _Tritimovirus_) or _Maize dwarf mosaic
virus_ (MDMV, genus _Potyvirus_) have been reported previously from
the Americas and Europe. MLN as well as MCMV were reported for the 1st
time in Africa from Kenya in 2012 (ProMED-mail post
http://promedmail.org/post/20130123.1510727). The disease is spreading
in the region where millets have also been identified as an additional
crop host being affected by MLN (ProMED-mail post
http://promedmail.org/post/20150820.3590521). _Sugarcane mosaic virus_
(SCMV) has been reported as the co-infecting virus in Sub-Saharan
Africa, but MDMV and SCMV belong to a complex of closely related
potyviruses infecting tropical grasses. Based on serology, some
strains (for example, MDMV-B) varying in host range and ability to be
seed transmitted have been reassigned between the species which has
resulted in some confusion in taxonomy.

Symptoms of the individual viruses are synergistically enhanced in MLN
and may include leaf mottling and necrosis, distortion of ears,
absence of kernels, failure to produce tassels, as well as stunting,
premature aging, and death of plants. Symptoms may disappear during
the growing season leaving plants with latent infections but reduced
yield and as virus reservoirs, making disease monitoring difficult.
While MCMV is not seed transmitted, the synergistic partner viruses
WSMV and MDMV (including some reassigned strains previously included
in SCMV) are. Thus, losses from MLN are both due to yield reductions
and trade implications resulting from the risk of virus infected seed.
Infectious vector insects may be carried by wind over long distances.
Disease management may include crop rotation, certified clean seeds,
control of vector species and weedy reservoir hosts, as well as use of
crop cultivars or hybrids with reduced sensitivity to the viruses.

The perceived high risk of a MLN incursion in Malawi, as reported
above, is entirely justified since the disease has been reported from
immediate neighbours Mozambique (ProMED-mail post
http://promedmail.org/post/20131004.1983210) and Tanzania (ProMED-mail
post http://promedmail.org/post/20130403.1620327). While it is being
reported that surveys have not detected the disease in the country as
yet, it is not stated which survey methods were used. If surveys were
only conducted from symptoms and/or without molecular diagnosis on
samples, MLN may well be present already in Malawi but has remained
undetected.

Maps
Malawi:
<http://nthambazale.com/wp-content/uploads/2009/05/malawi_map.gif>
and
<http://healthmap.org/promed/p/176>
Africa, overview:
<http://www.worldatlas.com/webimage/countrys/africa/maps/africa.jpg>

Pictures
Maize lethal necrosis:
<http://cabiplantwise.files.wordpress.com/2013/04/maize-lethal-necrosis.jpg>
and
<https://iapps2010.files.wordpress.com/2017/01/9f498-maize.jpg>
Symptoms of MCMV, SCMV and MDMV single infections in maize via:
<http://maizedoctor.org/image-galleries/viral-diseases>

Links
Information on maize lethal necrosis:
<http://www.fao.org/fileadmin/user_upload/emergencies/docs/MLND%20Snapshot_FINAL.pdf>,
<http://mfarm.co.ke/blog/post/Maize-Lethal-Necrosis-MLN-Signs-and-Precautions>,
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=119663>,
and
<http://apsjournals.apsnet.org/doi/full/10.1094/PHYTO-12-14-0367-FI>
Information on MCMV:
<http://www.dpvweb.net/dpv/showdpv.php?dpvno=284> and
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=32129>
Information on MDMV:
<http://www.dpvweb.net/dpv/showdpv.php?dpvno=341>,
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=8157>,
and
<http://maizedoctor.org/pests-diseases/list/12-english/pests-and-diseases/395-maize-dwarf-mosaic-virus>
Information on SCMV:
<http://www.dpvweb.net/dpv/showdpv.php?dpvno=342>,
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=49801>,
and
<http://maizedoctor.org/pests-diseases/list/12-english/pests-and-diseases/416-sugarcane-mosaic-virus>
Virus taxonomy via:
<http://ictvonline.org/virusTaxonomy.asp?version=2016>
– Mod.DHA]

Read Full Post »

FRESH

PLAZA

A number of citrus trees in Malta have been infected with a deadly virus, a surveillance programme has found. The infected trees, originating from Sicily, were discovered in various garden centres following sampling and testing. The monitoring was carried out by the Plant Health Directorate within the Parliamentary Secretariat for Agriculture with the objective of monitoring the status of pest occurrence.The directorate activated the contingency plan and carried out the destruction of the infected consignments. To ensure the eradication of this pest, the public is being asked to notify the directorate of any purchase of citrus trees in the last six months.

The Citrus Tristeza Virus is the most destructive citrus disease worldwide. The most recent outbreak dates back to 2012 when an area in San Blas and Daħlet Qorrot Valleys in Gozo was demarcated.

The virus cannot be controlled by pesticides, and the only control mechanism for this disease is that of uprooting and burning infected trees and applying pesticides for the vectors.

For more information:
The Plant Health Directorate
Tel: +356 2292 6535
plant.health@gov.mt

Read Full Post »

PHYS ORG

March 23, 2017

Novel virus breaks barriers between incompatible fungi
SsMYRV4-mediated enhancement of horizontal transmission between different VCGs effectively prevents and controls Sclerotinia diseases. Credit: Wu S, et al. (2017)

Scientists have identified a virus that can weaken the ability of a fungus to avoid pairing with other incompatible fungi, according to new research published in PLOS Pathogens. By promoting fungal pairing, the virus could aid transmission of additional unrelated viruses between fungi.

Fungi, like all other organisms, can recognize foreign substances; such non-self recognition can help protect against pathogens. Some also use non-self recognition to avoid pairing and sharing genetic material with incompatible strains. The fungus Sclerotinia sclerotiorum, which infects hundreds of plant species worldwide, employs this strategy, which is known as vegetative incompatibility.

While studying S. sclerotiorum, Jiatao Xie of Huazhong Agricultural University, China, and colleagues discovered a they named Sclerotinia sclerotiorum mycoreovirus 4 (SsMYRV4). To better understand this novel virus, they grew infected S. sclerotiorum alongside other vegetatively incompatible strains and investigated the molecular effects.

The researchers found that SsMYRV4 decreased expression of S. sclerotiorum genes that promote vegetative incompatibility. Vegetative incompatibility is a molecular process that normally causes when two incompatible strains touch each other; in this study, Xie’s team found a reduction in the amount of cell death that normally occurs in intermingled colonies of incompatible strains.

S. sclerotiorum infected with SsMYRV4 successfully made connections with incompatible by fusing filamentous structures known as hyphae. To investigate the consequences, the scientists grew SsMYRV4-infected fungi alongside fungi infected with other unrelated viruses. They found that the unrelated viruses were able to pass through the fused hyphae, crossing between fungal pairs.

Vegetative is considered a significant obstacle to using viruses to effectively control fungal diseases. These new findings could point to a new strategy that uses SsMYRV4 to weaken barriers between fungi. They could also improve understanding of virus ecology and evolution.

Explore further: Potential biological control agents found for fungal diseases of soybean

More information: Wu S, Cheng J, Fu Y, Chen T, Jiang D, Ghabrial SA, et al. (2017) Virus-mediated suppression of host non-self recognition facilitates horizontal transmission of heterologous viruses. PLoS Pathog 13(3): e1006234. DOI: 10.1371/journal.ppat.1006234

Read more at: https://phys.org/news/2017-03-virus-barriers-incompatible-fungi.html#jCp

https://cm.g.doubleclick.net/push?client=ca-pub-0536483524803400&srn=gdn

Read Full Post »

R&D Magazine

Tue, 01/10/2017 – 2:42pm2 Comments

by Kenny Walter – Digital Reporter – 

@RandDMagazine

Researchers have begun to learn more about how viruses are transmitted by mosquitoes and other arthropods.

Scientists have tapped into a new resource in the ongoing fight against viruses transmitted by mosquitoes and other arthropods.

In a new study, researchers have uncovered for the first time that a plant hormone is the major host factor to mediate the attractions between insect vectors and infected plants.

This discovery may lead to a new strategy to control viral diseases by targeting either the viral effector protein or the host hormone required for attracting disease vectors to the infected host for virus transmission.

The study was led by a team of scientists from the University of California, Riverside and Tsinghua University in China, who uncovered molecular mechanisms that the cucumber mosaic virus uses to manipulate plants to make them release odors that attract aphids, which transmit the virus.

“Recent studies have shown that pathogen-induced vector attraction can be odor-dependent, suggesting, presumably, the presence of a specific mechanism by which pathogens manipulate the host’s ability to emit odors that could attract disease vector,” the researchers write in the study.

Diseases like the cucumber mosaic virus are often caused by pathogens that are transmitted by disease carrying arthropods.

The emergence and success of these pathogens are shaped by molecular interactions between both the host and the arthropods.

Plants utilize RNA interference (RNAi) to protect themselves against diseases like the cucumber mosaic virus.

Shou-Wei Ding, Ph.D., a professor of plant pathology and microbiology at UC Riverside, previously discovered that the 2b protein in the cucumber mosaic virus blocks the plant from launching antiviral RNA interference.

Ding was able to build on the previous research by finding some pathogens that can manipulate plants and animals to cause them to release odors that are attractive to the mosquitoes and aphids that transmit the pathogen.

Until Ding’s study, the molecular mechanism underlying the host manipulation was unknown.

The science team found that the aphid-borne cucumber mosaic virus employs the 2b protein to suppress a specific hormone pathway in plants, making the aphid vectors more attracted to the diseased plant.

The cucumber mosaic virus, which is found worldwide, spreads rapidly and can cause irreversible damage to plants, including many used in landscaping and vegetable crops like tomatoes, peppers, lettuce and cucumbers.

However, the researchers said they can harness the virus to produce more disease resistant vegetables and larger crop yields for farmers.

This represents the first time a viral effector protein has been seen as attracting insect vectors to feed on plants through odor.

According to the study, the cucumber mosaic virus is one of the most successful plant pathogens as it can infect more than 1,200 different types of plant species.

The study was published in Cell Research.

 

Grahame Jackson
24 Alt street
Queens Park
NSW 2022
Australia

Phone: +612 9387 8030
Mobile: +61 412 994 206
Skype: gvhjackson

www.pestnet.org
www.ediblearoids.org
www.terracircle.org.au

Read Full Post »

A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>

Date: November 2016
Source: Plant Disease [edited]
<http://apsjournals.apsnet.org/doi/full/10.1094/PDIS-09-16-1261-PDN>

[ref: MA Achon, et al (2016). First report of _Maize chlorotic mottle
virus_ on a perennial host, _Sorghum halepense_, and maize in Spain.
Plant Disease 100, posted online; DOI: 10.1094/PDIS-09-16-1261-PDN]
———————————————————————
Maize lethal necrosis disease (MLND) is caused by the synergistic
interaction between _Maize chlorotic mottle virus_ (MCMV) and _Maize
dwarf mosaic virus_ (MDMV), _Sugarcane mosaic virus_ (SCMV) and _Wheat
streak mosaic virus_ (WSMV). MLND is an economically devastating
disease in the New World and an emerging disease in Africa and Asia.
The rapid spread of MLND in these continents generated increasing
concern in Spain. MLND has not been formally observed in Spain because
_Maize rough dwarf virus_ in single or mixed infections with MDMV and
SCMV is the major threat, and these viruses cause diseases that are
able to mask the symptoms of MLND.

To assess the presence of MCMV in Spain, 198 samples of weed grasses
including 102 of _Sorghum halepense_, 34 of _Setaria_ sp., 22 of
_Cynodon dactylon_, 14 of _Phragmites australis_, 8 of _Brachypodium
phoenicoides_, 6 of _Echinochloa crus-galli_ and 12 of other
_Gramineae_ species were collected in northeastern Spain during 2014
and 2015. _S. halepense_ was the unique grass showing symptoms
consisting of mosaic, yellowing, and in some plants, necrotic lesions.
Moreover, 10 maize (_Zea mays_) samples with mosaic symptoms and
yellowing longitudinal bands along leaves were collected in the same
area.

All these samples were analyzed by DAS-ELISA using commercial antisera
against MCMV, MDMV and SCMV. 48 samples of _S. halepense_ tested
positive to both MDMV and MCMV, 13 to MDMV, and 3 to MCMV. Out of 10
maize samples, 9 were positive to MDMV and MCMV, the remaining one to
MCMV only. None of the other grass species tested positive to any of
the viruses.

To confirm results, 12 _S. halepense_ and 6 maize leaves including
mixed MCMV-MDMV and single MCMV infected samples [were] analyzed for
MCMV by reverse transcription (RT)-PCR. The 18 samples gave the
expected PCR product. One product from _S. halepense_ was sequenced.
Comparisons of the 519 bp segment showed 96 to 99 per cent identity
with MCMV sequences in GenBank. 6 _S. halepense_ and 4 maize samples
were also analyzed with primers designed to amplify a 950 bp [segment]
of MCMV. The sequence from _S. halepense_ shared identities from 96 to
100 per cent with MCMV sequences in GenBank.

To our knowledge, this is the 1st report of the occurrence of MCMV in
Spain and in Europe. Furthermore, this is the 1st report of MCMV in a
perennial host such as _S. halepense_. The role that this grass could
play in the epidemiology of this virus needs further investigation.


communicated by:
ProMED-mail
<promed@promedmail.org>

[Maize lethal necrosis (MLN) is caused by co-infection of _Maize
chlorotic mottle virus_ (MCMV, genus _Machlomovirus_, transmitted by
chrysomelid beetles) with one of several species in the family
_Potyviridae_. As synergistic partners of MCMV in MLN, _Wheat streak
mosaic virus_ (WSMV, genus _Tritimovirus_) or _Maize dwarf mosaic
virus_ (MDMV, genus _Potyvirus_) have been reported previously from
the Americas and Europe. MLN as well as MCMV were reported for the 1st
time in Africa from Kenya in 2012 (ProMED-mail post
http://promedmail.org/post/20130123.1510727). The disease is spreading
in the region where millets have recently also been identified as an
additional crop host being affected by MLN (ProMED-mail post
http://promedmail.org/post/20150820.3590521). _Sugarcane mosaic virus_
(SCMV) has been reported as the co-infecting virus in Sub-Saharan
Africa, but MDMV and SCMV belong to a complex of closely related
potyviruses infecting tropical grasses. Based on serology, some
strains (for example, MDMV-B) varying in host range and ability to be
seed transmitted have been reassigned between the species which has
resulted in some confusion in taxonomy.

Symptoms of the individual viruses are synergistically enhanced in MLN
and may include leaf mottling and necrosis, distortion of ears,
absence of kernels, failure to produce tassels, as well as stunting,
premature aging and death of plants. Symptoms may disappear during the
growing season leaving plants with latent infections but reduced yield
and as virus reservoirs, making disease monitoring difficult. While
MCMV is not seed transmitted, the synergistic partner viruses WSMV and
MDMV (including some reassigned strains previously included in SCMV)
are. Thus, losses from MLN are both due to yield reductions and trade
implications resulting from the risk of virus infected seed.
Infectious vector insects may be carried by wind over long distances.
Disease management may include crop rotation, certified clean seeds,
control of vector species and weedy reservoir hosts, as well as use of
crop cultivars or hybrids with reduced sensitivity to the viruses.

The report above confirms the presence of a perennial reservoir host
for MCMV and this needs to be taken into account for MLN disease
management in all affected areas. It also shows the importance of
molecular diagnosis since symptoms may be influenced or masked by
multiple other factors like environment, host and pathogen strains,
and, as this case illustrates, presence of other pathogens.

_Maize rough dwarf virus_ (MRDV; genus _Fijivirus_) may result in
yield losses of up to 30 per cent. Besides maize, it can also affect
oats, rye, barley, wheat, rice and several grassy weeds. It is
spreading in parts of Europe, Africa and South America.

Maps
Spain:
<http://www.map-of-spain.co.uk/large-map-of-spain.htm>
Provinces of Spain:
<http://www.venamicasa.com/wp-content/uploads/2012/03/spain_map3.gif>
Europe, overview:
<http://www.edinphoto.org.uk/0_MAPS/0_map_europe_political_2001_enlarged.jpg>

Pictures
Maize lethal necrosis:
<http://cabiplantwise.files.wordpress.com/2013/04/maize-lethal-necrosis.jpg>
and
<https://iapps2010.files.wordpress.com/2017/01/9f498-maize.jpg>
Symptoms of MCMV, SCMV and MDMV single infections in maize via:
<http://maizedoctor.org/image-galleries/viral-diseases>
MRDV symptoms on maize:
<http://farm5.static.flickr.com/4118/4927016449_1e2fbd5fe5.jpg> and
<http://seed.aweb.com.cn/upfile/1/2/2009630/135747185.jpg>

Links
Information on maize lethal necrosis:
<http://www.fao.org/fileadmin/user_upload/emergencies/docs/MLND%20Snapshot_FINAL.pdf>,
<http://mfarm.co.ke/blog/post/Maize-Lethal-Necrosis-MLN-Signs-and-Precautions>,
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=119663>
and
<http://apsjournals.apsnet.org/doi/full/10.1094/PHYTO-12-14-0367-FI>
Information on MCMV:
<http://www.dpvweb.net/dpv/showdpv.php?dpvno=284> and
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=32129>
Information on MDMV:
<http://www.dpvweb.net/dpv/showdpv.php?dpvno=341>,
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=8157> and
<http://maizedoctor.org/pests-diseases/list/12-english/pests-and-diseases/395-maize-dwarf-mosaic-virus>
Information on SCMV:
<http://www.dpvweb.net/dpv/showdpv.php?dpvno=342>,
<http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=49801>
and
<http://maizedoctor.org/pests-diseases/list/12-english/pests-and-diseases/416-sugarcane-mosaic-virus>
Information on MRDV:
<http://dx.doi.org/10.1016/0042-6822(77)90377-4> and
<http://www.dpvweb.net/dpv/showdpv.php?dpvno=72>
Virus taxonomy via:
<http://ictvonline.org/virusTaxonomy.asp?version=2015>
– Mod.DHA

A HealthMap/ProMED-mail map can be accessed at:
<http://healthmap.org/promed/p/43>.]

[See Also:
Lethal necrosis, maize – South America: 1st rep (Ecuador)
http://promedmail.org/post/20160803.4390384
Wheat streak mosaic virus – Canada: (AB)
http://promedmail.org/post/20160711.4336979
Wheat streak mosaic virus – USA: (MT)
http://promedmail.org/post/20160114.3937362
2015

Lethal necrosis, millet – Kenya: new host
http://promedmail.org/post/20150820.3590521
Lethal necrosis, maize – Ethiopia: 1st rep
http://promedmail.org/post/20150130.3130105
2014

Lethal necrosis, maize – Tanzania: (MY)
http://promedmail.org/post/20140918.2782853
Lethal necrosis, maize – Rwanda: 1st rep (NO)
http://promedmail.org/post/20140604.2518403
2013

Lethal necrosis, maize – Mozambique: 1st rep
http://promedmail.org/post/20131004.1983210
Lethal necrosis, maize – Uganda, Tanzania: 1st reports
http://promedmail.org/post/20130403.1620327
Lethal necrosis, maize – Africa: 1st rep. (Kenya)
http://promedmail.org/post/20130123.1510727
2011

Maize dwarf mosaic virus – Uganda (KY): susp.
http://promedmail.org/post/20111006.3002
Rough dwarf disease, maize – Kenya: 1st rep.
http://promedmail.org/post/20110204.0407
2010

Rough dwarf, maize – Africa: 1st rep (Uganda)
http://promedmail.org/post/20100730.2552
2008

Maize dwarf mosaic virus – Poland: 1st rep.
http://promedmail.org/post/20080630.2003
and additional items on the viruses in the archives]
………………………………………….sb/dha/msp/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.
************************************************************
Donate to ProMED-mail. Details available at:
<http://www.isid.org/donate/>
************************************************************
Visit ProMED-mail’s web site at <http://www.promedmail.org>.
Send all items for posting to: promed@promedmail.org (NOT to
an individual moderator).  If you do not give your full name
name and affiliation,  it may not be posted.  You may unsub-
scribe at  <http://ww4.isid.org/promedmail/subscribe.php>.
For  assistance  from   a   human   being, send mail to:
<postmaster@promedmail.org>.
############################################################
############################################################

Grahame Jackson
24 Alt street
Queens Park
NSW 2022
Australia

Phone: +612 9387 8030
Mobile: +61 412 994 206
Skype: gvhjackson

www.pestnet.org
www.ediblearoids.org
www.terracircle.org.au

Read Full Post »

Weird year for Sicilian citrus fruit

“Citrus fruit production this year is quite low, especially for oranges. Producers not only had to deal with the CTV-Citrus Tristeza Virus, but also with a whole lot of other factors – mild temperatures during the past winters, lower blossoming, wider yield alternance. In addition, it rained a lot in September,” reports Corrado Vigo, agronomist and President of the Ordine dei Dottori Agronomi e dei Dottori Forestali in Catania.

For what concerns the rain/drought, Vigo explains that “I have noticed these events are cyclical, they occur every 10-11 years. What is weird is that this cycle coincides with the Sun cycle. We are expecting some more rain in December as well.”

In addition to the weather conditions, there is a series of fungi, pathogens and Phytophthora that, with the temperatures registered so far, spread. “For example, the persistent rain in September triggered Phytophthora citrophthora, which led to a loss of fruit. In addition, in October, there was a late attack of Ceratitis capitata“.

There are a lot of drops of yet unripe oranges as well as a lot of mouldy fruit on the trees. The areas of Scordia, Lentini, Palagonia and Mineo were affected by dessicating wind, which damaged both the fruit and the leaves. “We already expected a drop in volumes, but now they will be even lower.”

Varietal innovation
“There are very few innovative varieties. Producers are looking to replace the trees (especially because of the Citrus Tristeza Virus), but costs are high. The last PSR call for bids, for example, ended in 2012 and the new one hasn’t opened yet. If we consider that, last year, oranges sold at 4 cents, we can see how it might be difficult to end the year positively, let alone make investments.”

We must also keep in mind that orchard response times are slow. “We are talking about seven/eight years for a full production cycle. Another problem is the availability of plants. In Sicily, we generate around 1.5/2 million plants. To reconvert the areas affected, 24-25 million plants are needed and it would take 12-13 years.”

Competition
“Just like every year, our citrus fruit is available on the market as well as oranges from Spain and grapefruit from Israel, for example.”
“I keep thinking about the French, who only buy produce made in France before anything else. Only then do they look for something foreign. In Italy, it seems as if we welcome foreign produce.”

Contacts:
Corrado Vigo
Email: corrado@vigo.it
Web: www.vigo.it

 

Publication date: 12/8/2016

Read Full Post »

Older Posts »