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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

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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
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are  posted,  but  the  accuracy  and  completeness  of  the
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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.
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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

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

Growers say the fungal disease is piling on their miseries brought about by distribution of substandard fertiliser that affected germination of the crop

Wednesday August 17 2016

Mr Jeremiah Kipyego inspects maize on his farm in Uasin Gishu County in May.

Mr Jeremiah Kipyego inspects maize on his farm in Uasin Gishu County in May. Maize farmers in the region expressed fears of yield decline this season due to attack by head smut disease. FILE PHOTO | NATION MEDIA GROUP 

In Summary

  • Growers expressed fears of serious yield decline this season due to the disease referred to as head smut.
  • Maize farmers asked to practice crop rotation to break the cycle of the fungal disease.
  • The fungal attack follows repeated outbreak of Maize Lethal Necrosis (MLN) disease that ravaged parts of the country last season, forcing some farmers to uproot the crop.
  • Maize production in Rift Valley dropped from 21 million bags to 16 million bags last season due to erratic rainfall pattern and repeated outbreak of MLN disease.

By BARNABAS BII
More by this Author

An outbreak of a maize disease has left many farmers in the North Rift uncertain of their harvests putting the country’s food security at risk.

Growers yesterday expressed fears of serious yield decline this season due to the disease referred to as head smut, which is adding to the miseries bought about by distribution of sub-standard fertiliser that affected germination patterns of maize.

“We are worried that fungal disease will add to the miseries of high cost of production, rendering agriculture a non-profit investment,” said Mr Patrick Kemboi from Chepkumia, Nandi County.

The disease has been reported in parts of Uasin Gishu, Nandi  and Elgeyo Marakwet County.

Maize producers are now accusing the Kenya Seed Company of supplying them with poor seeds that has led to the outbreak of the fungal disease.

“I wonder why our crop has been attacked yet I planted certified seed from the company sourcing from the Kenya Seed Company,” said Mr Wilson Sang from Chembulet, Uasin Gishu County.

Growers have taken issue with the Kenya Seed management due to alleged failure in cracking down on traders dealing in sub-standard planting materials.

“Poor quality seed and a failure to crack down on fake seed being supplied by Kenya Seed’s accredited stockists,” said Mr Andrew Rotich, a maize farmer from Cherang’any.

Kenya Seed managing director Azariah Soi has, however denied responsibility for the outbreak of the fungal disease saying that studies conducted in conjunction with the Kenya Plant and Health Inspectorate Services (Kephis) have shown that the head smut disease has nothing to do with seed.

PRODUCTION OF DISEASE RESISTANT SEEDS

“The head smut disease that has affected maize in Rift Valley is not as a result of seed distributed by our company,” said Mr Soi noting that the disease was in the soil.

He asked maize farmers to practice crop rotation to break the cycle of the fungal disease. “Our researchers are working closely with those from Kephis to come up with further remedies that can be employed by farmers in future including a possible production of seeds, which are disease-resistant,” Mr Soi said.

The fungal attack follows repeated outbreak of Maize Lethal Necrosis (MLN) disease that ravaged parts of the country last season, forcing some farmers to uproot the crop.

“The recurrence of MLN disease and attack of the crop by head smut is a serious challenge to maize cultivation,” said Mr Isaac Kibogy from Sergoit, Uasin Gishu County.

Farmers have been asked to implement crop rotation to break the cycle of the disease that damaged over 260,000 hectares of maize valued at Sh2 billion in Rift Valley last season.

“Feeding the plants to cattle is not appropriate because the fungus which cannot be digested is passed out through dung and later reproduces posing threat to crops again,” said Mr Soi.

Maize production in Rift Valley dropped from 21 million bags to 16 million bags last season due to erratic rainfall pattern and repeated outbreak of MLN disease.

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Posted Mon at 10:02pm

A potentially devastating plant virus able to infect a number of horticultural crops has been detected for the first time in Western Australia.

The Cucumber Green Mottle Mosaic Virus has been found in a continental cucumber crop near Geraldton, about 400 kilometres north of Perth.

In 2014 the virus was first found in Australia in watermelon crops near Katherine in the Northern Territory. Crops were destroyed and the region was placed under quarantine restrictions for nearly two years.

Geraldton is a significant production region for Australia’s continental cucumber crop.

CGMMV affects a range of cucurbit crops such as cucumbers, melons, pumpkins, squash and can cause substantial crop losses.

Department of Agriculture and Food Western Australia Chief plant biosecurity officer John van Schagen said DAFWA would investigate the disease source, however the obvious pathway was from infected seed.

“One of our staff is going up to Geraldton. It’s definitely on the one property, possibly a second one and maybe even more, we don’t know at this stage,” he said.

“We diagnosed it from cucumber leaf samples that were submitted by an agronomist.

“Diagnosis was completed late the week before last.

“We notified Vegetables WA and we also notified people up in Kununurra.

Mr van Schagen said it was yet to be seen how the Geraldton cucumber crop would be effected by the virus.

“It’s got potential to be fairly serious,” he said.

“We haven’t quarantined the property because last year a scientific expert panel looked at what is the risk of spreading this disease through movement of produce, they deemed that was a very low risk, so I think this disease can best be managed by good on farm biosecurity practices.

“Measures include not permitting vehicles, equipment and machinery to move between farms without being thoroughly cleaned and disinfected.

“This also applies to farm workers, by making sure they wear clean clothing when they leave or move between properties.”

Local cucumber growers told ABC Rural they were worried about the virus and were paying close attention to farm hygiene, such as foot baths and hand sanitising.

“There is a national management plan being developed for this disease, that was started after the cases in the Northern Territory, so that’s currently sitting with some national industry bodies for finalising, but we hope to push that through fairly quickly, and that’s got all the information on how best to manage this disease for growers,” Mr van Schagen said.

“We are also doing some research ourselves in management of this disease as well.

“My understanding is once you’ve got it, it’s very difficult to treat. Basically if it’s in the crop you can’t really get it out of the crop. It’s through good on farm biosecurity and also crop rotation, you may be able to minimise the impact of the disease.

“I think that’s what they do in the Northern Territory, they have a two year period where they don’t plant any host plants on the property. Thereby they try to eliminate it from the soil.”

Mr van Schagen said the department would meet with growers to discuss possible crop rotations and gain feedback from growers on the impact the virus had caused in their cucumber crops.

DAFWA will host an information meeting at the Geraldton office on Wednesday, July 27 at 4.30pm.

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UF/IFAS Expert: Whitefly Species Likely to Cause Growers’ Problems

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Newswise — GAINESVILLE, Fla. — A University of Florida Institute of Food and Agricultural Sciences expert predicts the Q-biotype whitefly discovered in April in Palm Beach County will likely cause problems for growers.

The Q-biotype whitefly – not to be confused with the B-biotype, which came to Florida in the mid-1980s – is now being seen outside greenhouses and nurseries and poses a threat to ornamental plants and agricultural crops. After the B-biotype was found in Florida in the 1980s, scientists saw big increases in the diversity and frequency of whitefly-transmitted viruses in many Florida crops, said Jane Polston, a UF/IFAS plant pathology professor. Crops like beans, tomato, watermelon and squash were hit hard by these viruses after the appearance of the B biotype.

“This Q-biotype is a pest that damages crops and resists many of the insecticides that are effective on the B-biotype, the whitefly that is common in many ornamental and vegetable crops,” Polston said. “And like other whiteflies, it is capable of transmitting viruses from one plant to another.”

But because the Q-biotype whitefly feeds for longer periods on some plants, it has a greater chance of acquiring a plant virus, Polston said. The more time a whitefly spends feeding on a plant, the more likely it is to acquire a virus from an infected plant. Only a few studies have been conducted on the host plants that Q and B feed on, but those few studies indicate that Q and B do have different preferences, she said.

Because these whitefly species feed differently, vegetable and ornamental crop growers may see different viruses in their crops, as well as how many plants become infected each season, Polston said.

“And because it’s harder to manage with pesticides, we may see higher populations of this new whitefly, and that can mean high numbers of virus-infected plants,” Polston said.

Viruses may show up in plants that were not infected before, Polston said. Scientists and Extension faculty also should be prepared to see changes in the percentage of infected plants on farms, she said.

In other words, the Q-biotype whitefly is not simply an insect management issue; the insect also transmits viruses, she said.

This whitefly can transmit many different plant viruses, such as Tomato yellow leaf curl virus, Squash vein yellowing virus, Tomato infectious chlorosis virus, Cowpea mild mottle virus, and many others, according to a 2013 paper that Polston co-wrote.

Known scientifically as Bemisia tabaci, the Q-biotype or Mediterranean whitefly is a light-colored, flying insect slightly less than 1 millimeter in length.

When the whitefly was reported this spring, it marked the first time the Q-biotype of Bemisia tabaci had been found outside a greenhouse or nursery in the United States since it was found on an ornamental plant in a greenhouse in 2004-2005, said Lance Osborne, a UF/IFAS entomology professor.

Researchers with UF/IFAS are working with the U.S. Department of Agriculture, Agricultural Research Service and the Florida Department of Agriculture and Consumer Services to manage the whitefly.

Here are some helpful hints regarding the Q-biotype whitefly:
The following measures are recommended to control the spread of Q-biotype whitefly:

• Homeowners who suspect they have a whitefly infestation should contact their UF/IFAS Extension county office. Office locations may be found at http://www.bit.ly/1Q8wguw.

• For identification purposes, infested leaves and dead insect specimens should be brought to local Extension offices. Wrap in a dry paper towel and place in a seal-able plastic bag and then in an envelope. Freezing the specimen overnight before transport is highly recommended. Live insects should not be transported.

• The collection information should be included with the sample. Date, location, what type of vegetation is affected, number of suspected whiteflies, and any information about whether a pesticide has been used on the plant, is helpful information to managing the pest. For steps on how to submit a sample to FDACS DPI, visit http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Business-Services/Submit-a-Sample-for-Identification.

• Because new populations have built up resistance to chemicals, it is recommended that suspected whitefly infestations be confirmed before chemically treating the insects, as it may be needless to spray pesticides.

• Landscapers and pest control operators should inspect for signs of whitefly pests, communicate with neighboring properties and homeowners associations, employ good management and growing practices, and implement whitefly management guidelines available at http://www.mrec.ifas.ufl.edu/lso/bemisia/bemisia.htm.

• Nurseries that suspect whitefly infestations should contact the FDACS Division of Plant Industry at 1-888-397-1517.
• Here are some helpful links about the issue:
http://www.bit.ly/1WD6CmM, http://www.bit.ly/1Tm5iBm and http://www.bit.ly/1XxxG6D
• The Whitefly management plan for Growers: http://www.mrec.ifas.ufl.edu/lso/bemisia/DOCUMENTS/WhiteflyManagementProgram_1-15-15.pdf
• The list of materials for landscapers:
http://www.mrec.ifas.ufl.edu/lso/bemisia/DOCUMENTS/LANDSCAPE-Active-Ingredients.pdf.

-30-
By: Brad Buck, 352-294-3303, bradbuck@ufl.edu
Source: Jane Polston, 352-273-4627, jep@ufl.edu

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http://www.abc.net.au/news/2015-04-07/ntch-quarantine-sign-on-mitchell-curtis27-farm/6373242

“Nothing has changed” for Katherine melon grower after virus declared impossible to eradicate
NT Country Hour By Daniel Fitzgerald

A Katherine melon grower says “nothing has changed” for his farm after the Northern Territory Government declared a plant virus cannot be eradicated.

The Department of Primary Industry (DPI) recently stepped back from trying to eradicate Cucumber Green Mottle Mosaic Virus (CGMMV), opting instead for a management program.

The virus, which affects cucurbits like melons, pumpkins, zucchini, squash and cucumbers, was found to have spread from quarantine zones and is now confirmed on 21 properties across the Northern Territory.

Mitchell Curtis grew melons near Katherine until his farm was found to be infected with the virus and put under quarantine restrictions last year.

While the DPI is still putting together a formal plan for management, Mr Curtis said as far as he understands, the move to management will not change anything for his farm in the short term.

“Basically for us, nothing has changed,” he said.

“Most of it is structural at this stage and once they work that out, we might be able to plant crops, not cucurbits, but plant crops here in 12 months.

“Going from eradication, to management leaves a lot of questions to be answered, like whether we can send [cucurbits] down south from an area that’s been infected, what we have to do to stay clean if we do grow here; all those sorts of things to put certainty back into our orchard, so that we can actually grow melons again, all have to be answered.

“It may take us around 12 months to do that, to go and liaise with other states and work on the problem [of] whether or not we can grow in areas and stay clean with some protections in our growing process, or whether we can’t.”

The Territory’s Minister for Primary Industry, Willem Westra van Holthe, confirmed last week Northern Territory farmers growing cucurbits on land not infected with CGMMV are still able to sell their produce interstate with a Plant Health Certificate.

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Mr Curtis said the declaration that CGMMV cannot be eradicated ensured the nature of the Northern Territory melon industry has changed irreversibly.

“I think there’s some big questions over Territory melons, I think that’s to do with people not understanding what this virus is,” he said.

“There are a lot of viruses in melons, this is another virus that we have to learn to manage.

“Once we’ve learnt how to do that and the fear has gone out of what this virus does and how it can affect our growing processes and all those things, I think the name of the melon industry in the Territory will be just as strong as it has been.”

Mr Curtis leased a plot of land from the Northern Territory Government to grow melons on this year, but to his “absolute horror” he found the land was already infected with CGMMV.

“It certainly indicated the problem we thought we had under control was not,” he said.

“It put some big question marks as to how it got there and what’s spreading it as [the land is] about 40 kilometres from the infected area on Fox Road and its about 30 kilometres from [the infected area at] Edith Farms.”

However Mr Curtis said he believes the virus can be safely managed and controlled.

“We’ve got to keep the thing in perspective so that we understand that small areas in the Northern Territory are infected, but there’s a lot of other areas that are quite safe to grow melons and deliver them with no virus,” he said.

“We’ve got to make sure we don’t taint the whole Territory.”

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