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Date: Fri 11 Jul 2014
Source: Daily Guide Ghana [edited]
<http://www.dailyguideghana.com/tomato-disease-attacks-farms-in-agotime-ziope/
Over 600 farmers in the Agotime-Ziope District of the Volta Region have lost virtually everything [due to] the infestation of over 1000 hectares of tomato [crops] by leaf-curling known as _Tomato yellow leaf curl virus_ (TYLCV). [Tomatoes] serve as a source of livelihood to many households in the communities.
In early June this year [2014], the farmers reported that almost all their tomato crops were being attacked by the leaf curl virus. They said that was the 1st time such a situation had occurred. The application of insecticides could remedy the situation.
The District Agricultural Officer explained that [they] would intensify outreach programmes to educate farmers on the need to cover their crops at the nursery stage to prevent a recurrence of the infection. The situation is likely to result in a shortage of tomatoes in various markets of the country.
[Byline: Fred Duodu]
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[_Tomato yellow leaf curl virus_ (TYLCV; genus _Begomovirus_) originates from the Middle East and is one of the most damaging viruses of tomato worldwide. It can also affect a number of other solanaceous and leguminous hosts. Symptoms on tomato include small chlorotic, puckered leaves and stunting of plants. Yield losses of up to 80 percent have been reported.
The virus is transmitted in a persistent manner by the silverleaf whitefly (_Bemisia tabaci_ biotype B), which in itself is a serious pest of tomatoes and other vegetable crops. TYLCV can also be transmitted by mechanical inoculation (poorly), plant material (such as infected tomato transplants, as referred to in the story above) and by grafting, but is not transmitted by seed or contact between plants.
Disease management may include use of certified vector- and virus-free planting material, cultural practices, as well as removal of infected crop residues and possible pathogen and/or vector reservoirs to reduce inoculum. Control of the vector is most important, but this may cause problems of chemical residues on the fruit and is extremely difficult in open field situations due to the widespread presence and wide host range of the vector.
Field cropping of tomatoes has been abandoned in some areas due to TYLCV. Tomato cultivars with increased levels of resistance or tolerance are available. Transgenic tomato plants incorporating TYLCV capsid protein genes have been found to be resistant to the virus.
TYLCV belongs to the tomato leaf curl and yellow leaf curl clades of the genus _Begomovirus_. Known species in these clades cause similar diseases on solanaceous and other crops and can lead to considerable yield losses.
Whiteflies in themselves are serious pests of many vegetable crops. If virus sources are available locally, high vector numbers are often reflected in high levels of the viral diseases they transmit.
_Begomovirus_ control is particularly difficult in open field crops due to the widespread presence and wide host range of whiteflies.
Disease management may include pathogen exclusion, vector control, and elimination of possible pathogen and/or vector reservoir plants. In some cases, crop cultivars with increased virus resistance are available.
Maps
Ghana:
Ghana regions:
Pictures
TYLCV symptoms on tomato plants:
Leaf curl disease on tomato:
and
Whiteflies (_B. tabaci_), picture gallery:
Links
Information on TYLCV:
TYLCV description:
Information on tomato leaf curl viral diseases:
TYLCV taxonomy & current species list of the clade via:
Information on whiteflies:
- Mod.DHA
A HealthMap/ProMED-mail map can be accessed at:
[See Also:
Tomato leaf curl New Delhi virus - Spain: (AN) alert 20140321.2345942
2013
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Tomato leaf curl New Delhi virus, zucchini - Spain: (MU) 1st report
20131223.2131729
Yellow leaf curl & blights, tomato - Pakistan: (SD) 20130206.1531086
2011
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Vegetable viruses - Australia: (WA, QL) 20110314.0817 Tomato yellow leaf curl, cowpea - China: new host, (SH) 20110121.0244
2010
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Tomato yellow leaf curl virus - Spain: (AL) 20100923.3444
2009
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Tomato yellow leaf curl virus - Australia (QL) 20090605.2079 Tomato viruses - India, USA: new pathogens 20090508.1718 New begomovirus, tomato & capsicum - Indonesia: (SW) 20090317.1080 Begomoviruses, multicrop - Cuba: new pathogens 20090303.0866
2008
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Spearmint disease - India: new begomovirus 20081005.3140 Tomato golden mottle virus - Mexico: 1st rep, (SLP) 20080310.0977 Squash leaf curl China virus, pumpkin - Thailand: 1st rep.
20080306.0921
and older items in the archives]
Topics
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