A ProMED-mail post <https://url.emailprotection.link/?bczGkw5NaxKViInVN3o8WI7SkfPjCplYcnrvkSnR7vDdzBseB4Z4JgOzMtf4NyhKwZ-87t_ekCqY4X1TR9IACFg~~>
ProMED-mail is a program of the International Society for Infectious Diseases <https://url.emailprotection.link/?bJcYJd1UM9bbZyueyHGqCfuWBsCz6JLr6QpMnBNG04Pz2V8akThtcwE1bjLVZbAR2-PZoubzhx-ALOhYt6Kir6w~~>
Date: Sat 17 Oct 2020 3:00 pm AEDT
Source: Farmonline [edited]
<https://url.emailprotection.link/?bXIHOqZfMegMc4cEF_XUb99LayByTlwvKvQbPK7gEblpNITepTs1CHIMT1o9rodCihPnoPRP-NsIkPMfZwzE9bmLcUImb6coW4kVl_laIvRV4FlnjuiSeMSzKXwo8uB7b>
Agriculture Victoria [AgVic] announced there had been a spike in yellow dwarf virus (YDV) in cereal crops, while officials in other states are also closely monitoring the situation. These widespread viruses can cause yield losses of up to 80 per cent when plants are infected early in the growing season.
AgVic's Narelle Nancarrow said symptoms can take around 3 weeks to appear after infection, however many infected grasses are symptomless, meaning the disease can be wider spread than farmers realise. Another difficulty in identifying the disease is [that] the damage can present very similarly to nutrient deficiency.
YDV is spread by aphids. Last summer and autumn [2019], with good rain allowing a green bridge, was perfect for YDV carryover. Ms Nancarrow said controlling the green bridge was one of the best ways of lowering the YDV risk. Further into the season, she said, farmers could consider an insecticide if aphid loads were particularly high, but that had to be weighed up against potential insecticide resistance and the effects on beneficial insects.
[Byline: Gregor Heard]
--
Communicated by: ProMED-mail <promed@promedmail.org>
[Barley yellow dwarf (BYD) disease occurs worldwide and affects a wide range of grass species (Gramineae) including cereal crops like barley, wheat, oats, rice, maize, triticale (wheat-rye hybrids), and rye. It is the most destructive of the virus diseases for wheat, but oats are particularly susceptible. Grain yields may be reduced severely.
Symptoms include leaf discolouration from yellow to purple (depending on the host species), stunting, reduced tillering, and empty seed heads. Yield reduction is most severe if infection occurs at the seedling stage. Plants infected in autumn may not survive the winter or show severe symptoms when growth resumes. Diseased plants often occur in circular patches within a field, which are associated with colonisation by the aphid vectors.
BYD viruses have now been split into several species in the family Luteoviridae (mostly in the genus _Luteovirus_). They are differentiated by their ability to be transmitted by various aphid species (family Aphididae) and their virulence on a selected variety of oats. Some of the viruses are transmitted equally well by several aphids, whereas others can be transmitted by only one or 2 species.
The bird cherry(-oat) aphid (_Rhopalosiphum padi_) and (English) grain (wheat) aphid (_Sitobion avenae_) are vectors of the severe _Barley yellow dwarf virus-PAV_ (type member of genus _Luteovirus_).
Coinfections of several BYD viruses may occur in one plant, which can result in either more severe (synergistic) or milder (due to cross protection) symptoms, depending on the virus partners.
The viruses cannot be transmitted by seed, pollen, or mechanical means and cannot survive in stubble or in the soil. Volunteer cereal plants or grassy weeds may serve as pathogen reservoirs ("green bridge").
Disease management includes use of crop cultivars with reduced sensitivity to the viruses and control of the aphid vectors. To protect beneficial insects such as bees or other pollinators, some neonicotinoid insecticides have now been banned in a number of countries which, unfortunately, is leading to increased use of other agrochemicals also under debate for potential environmental implications.
In Australia, cereal yellow dwarf viruses are increasingly prevalent in southeastern areas. Recently, another BYD-associated virus, initially identified in South Korea in 2016 and tentatively named Barley virus G (with suggested genus _Polerovirus_), was reported for the first time in the country from Victoria (ProMED-mail post https://url.emailprotection.link/?bK5TvKObqu_97emh29UXtVK6PLd-MV2FHPGUH2kg67aObYpv6-hVtpQ6d1xF_52wSlcsF1VHDOa6MaU13oKU6coQ_yMDBaz6MEdtQBdwTqgdx2LaUPx8n69yyLIG96nhH). So far, little is known about its epidemiology, potential aphid vectors, and impact on crop yields.
Maps
Australia (with states):
<https://url.emailprotection.link/?b_2B7_OinQIBp8d9nd-Dog1auE8QZaiq3HWIUtqyhGxswWBRtKytojUm1o-mVZaIzW4NDp1spMvCJhHW4mZMEk8O0dqZBeZBg6IcQQgVpST24r2rg2hjNyvDcuDO9Yncm>
and
<https://url.emailprotection.link/?b05QFwqPTij9Or0JNntK2Ta028HK0Hy9cXDrxF4Qezb0vv8YS_rXuwnDSeQYI5m6QjOITa0m_pbBb-h0R1OhECw~~>
Pictures
BYD symptoms on cereals
- wheat:
<https://url.emailprotection.link/?b23oInYw7f-UaKqTzvPnrs4b89m8GNIQIPsHICwjDaElcV_WJ008sDP6ptnwfEDxYh3VP2qlroQYzpKzQFqrLrcKf_9nVnbD9zVnzHdInL5gg-9ZuWYyQqXJLIdxt3hrV>,
<https://url.emailprotection.link/?brReBWdOAiNb685wymktQuQZdoymxW_xsLIeA6JiFWgf-bTqb-Sn-VjgiT9rZsGQB8tZhdB5k1dXr-v4s_5Qou5-Bb1_5bE7Msk-1d4mWgr4nsUcLCGe4YKlpXGf_V7Xh>
(compared with healthy),
<https://url.emailprotection.link/?b1T8UgNgJy5Gmd6OqB0bry8-LMMdhasd2Hltb5ixitbdoGA3WMDRMT64OF_ufeQi1k4GeREURR8z7bi1rzkMdMLYYzK0kM7sKxL4AFqYDDIpgz58l2lc5zw_3RXxOHrn53jISBe7rghJn7hSYmhFB0SAxPvNUxPSyeNLZfy5dE7k~>,
and
<https://url.emailprotection.link/?bkzcqz-9IUDv9JBg1wc8g_ejtXWgtNEaRgxDtlVismoaqi-jzZtNNHi87TcHj70FTDT6jYg5OulvLSnCv_xJA2gWcNLAboh74y0mon-5GUyeLbU5FuZZb7FFewgN9PDb9>
(affected field)
- barley:
<https://url.emailprotection.link/?bXX6a9qaT5OgPdw2a_LgeJmZ8pxKqjVn0_RHVXaMcWMVsH1VjL_ZmReGUwxRaQ2hUCJz2_BU5VOj7tVv6yxOsVD7RsXqaBawZVWm4u_M9JlvQAZmdte4iV0fNLL92VHQhm_aLZlBlvq201Uc2CQgspK7dHsgkK4EU67-EidYoU0E~>
- oats:
<https://url.emailprotection.link/?bq60zDisaS73lcI5WtNosa69pX0wxGqFbGQiBeKtd101lmpY_oBCPOBLUgkPgFr83SZ5p9wiAP2KHvRYa2rmRvyAdrq_hNY6MzL5JY1hvUYTc_nNXCghDoTXs9ECzfoT0>,
<https://url.emailprotection.link/?bqDN0JOwEPrZf5q6BOSimV7qf9d9vXwBVqBzGZSljR_Ifg3aCwuwwgQJ85ipZ9eNkzHWJJ_OrT1s-JBXjubzTPxDJoKRY8yAOmZK25iyKRjb-mLmk8O0m_iceRvyqOntf>,
<https://url.emailprotection.link/?bknNSxYXhNHkXmGOW6bjmpEDcv2RFoQnh7Pu-SEzzeIq34x9ipqz2-rAkHNabuBxlygozqbEojdEkh19HsYXyIpHYBKOeZbCansvNFxqLcZjBJIeafuPDoewEtirLLgZN>,
and
<https://url.emailprotection.link/?bty37oQYNR8KK8FXdpl-UV0Lw_wBWBdoqULh7d-OTheoQmoQOJBDPh2RnJEKujOlz4fBM6FN_vj48H9YTLqWkGIVM3Y1pMs1TQiNUj5CkD3wU22m6HTkY7tZQ13P_q6XYteKOR61c8zzYdZvcgdnWY6iXUjnMhqnjYz3godU9eSA~>
Aphids:
<https://url.emailprotection.link/?bjFvmqMj9nn5U_cTwgQQn3ISDqul-Kie1NwyJsJHRNJ345R9OwYgh3rpA1MACXIFBzBjvkYHjJko7f-k35bAdPqkz87DO6LlVXiao-vKcrM8oekXicdyXqdERY5B1cYF7VJsFtmlX7jCROajo-XQFL7YcwSZMgc9jnehZKwwdXxw~>
and
<https://url.emailprotection.link/?bZ2_D7HtfldhH0e056M3lmdE34Kyay9FSzaubLS-ItkqnA5RpmjBehQN1lK8zHc7p7zpABckjGdjDzGselvIoH0nvWR7dVoJc6KX99de9H2s7eYN2NxnaJQ3_CVeZn0qi2qjdtOhsOTwD5SR6Jnm_d6PDndXd30mV9goTcB2FcN0~>
Links
BYD disease and virus information:
<https://url.emailprotection.link/?bCbtKEhR91SCUynJpgEokju4zkJx6TN8uAWMF0lKeGdQZeCb_dMdGDq8fOKGoxKxCQY-Xp0U7uVMMKvKB16m5zA~~>,
<https://url.emailprotection.link/?bG3RTAjz_PzSi-R5YEwmRUMBbKJgWbWI3PNGBcrQb0FTeakeeWaQx-3sqSptJC4eQA72QpOJ3N7uWUpO7jAh-71DqMd44r4hNxGwa3X_hD1Ogp7Kpz5AOuU5aeobbbXI6>,
<https://url.emailprotection.link/?bnyeGU85JeFi4mpbOaU2tcsz7zAr5vgPgdtpUKWyLzzacN1LePv2ew73PZfDs_gLM_bHoH9YSLes1ZUNZTy0LjhzqnhaUTbuT3blmlyE9xfxnxzGtyu44JcGGzHtf9CbUxzk-dGVX3gQyvsL5jDgGx0XRSTR_433BZHfddrs5Mpw~>,
<https://url.emailprotection.link/?bT9EQiBRglNEnFQraPqADHYarclpDNXE0lcErGgMZ1xup8HbD8QOBKIDTkuvGqutItxaxnPFy-4h2hLVwXke5bcg0HkVwqCbplVFSHzYVWZ_Bf_gisq8h880YBk32EP65>,
<https://url.emailprotection.link/?bWJ1UDWSxsMs8az6jOLNT3vFTy9RlBdijCGTb7gZSGVBOH-1tOYa6oMQQw_7B6TFUYUzHuDXBm1NMpsWxPgydmrxKSSnQjZXDsHi_hKGChLTIkrXNHV2GDNFEXNPe-mfa>,
<https://url.emailprotection.link/?bQstJNOUlFCZmizYM8TsDxwcBXbD758qto0_UnxWR-I24p8hrShe3jyhpIuPVD24ZJzJ6TX8gpzyHxFqYueu25mwsh8HBhXTTUsHp2gHZjj2LgdwVYwipMDQN-E0g0YOx>,
and
<https://url.emailprotection.link/?bqB9PcOHkkjSi2LZ01reB3jR4kisUgDZiDovExWIO0RJ2GfhLF9PX2LZhoP03rrsa0Mfo2RlHGXmsnmzJLEz74RnIMODUFussLO83qUWKpKreZ0aEh3mGsQHJLr6425jyM0kIh4P06XKLi2GhTVKx7q7AarfAKYGBRv8p9AgUmlg~>
Information on Barley virus G:
<https://url.emailprotection.link/?bOaySG3WSf1W6RSALik59_9Zf7G6uX5CDizkiiazY2it6quEWx7hsQWY12QPW_vpyk2A4VJgBoJyjoaBCySu45DWWbx9UfhDUvRqi85hxFTpZhmmCYSB3JDWYBFTs-4Wp>,
<https://url.emailprotection.link/?bJCi7WKokZQFVYfW50Bm56DLXvEcs_GdfntKsalcTKuPXpeNpJHZCA_EuPoo5IjPgbCj47cgN9rO-kyUEg_XN_98Na0BMfXi8yFXun-SrO4w82re-MR8jRvsRtm2GlqRz>,
<https://url.emailprotection.link/?boo0gH2NdR8QvUSBp2Igx7ufRlRrT-_rwOxPjjUAdUd3RhhAoZJj8pdwwpjBr-LReDpuwDBBwnKnbiigQBfnW0T9Apdb9AL4TSqJ9y1tQ65SQkdJzxn1Ae8EVYOARQPuS>, and <https://url.emailprotection.link/?bEEvbfhsOS69mSXnkyFZNiw4KY33a3NvXBRJ1KtaZjDfrxJoMgfhp1QI25-0pd-bArSh8TsHG4kC8RhOkpTtFrQx5_ZyZVjPffiDz2sQu3bYjif0F9icJtP6SHrzXUmbV>
BYD disease cycle:
<https://url.emailprotection.link/?bv8Ivl5gLvdY2SAtAz_cb9c8KClahEmlMAaK8vEU5WxxFyQAuaB0REgPXXKntV8DxGN2HibE4J2F2AN8_klIY6HwUzuuEs-1rJao4yOOs_Zv7CQuev5IorukCfSOQsBcZ0bnJXEBvCgO3YCtEiuk2oT4fF_AZGbdfLEv2Au_8Z0w~>
Virus taxonomy via:
<https://url.emailprotection.link/?bhDeZrP8ViC6RnM08F5xq6d0Q_KG7bv5hv-8a_iYfG0CXZ0M8ZPO12ehdzp4e3vxIOOo5QKx_GRhCuivhy5TsmzTRt3DrisNPyzfRsYc5HYiYkejzV6lriYkGvOPsBO-6>
Information on aphid vectors via:
<https://url.emailprotection.link/?b-imaSBqqu8SdF29G8taYBQSs4tLunU4DIrwBZYwvipylHEtyWi17HI1jEdGc_OySEwcxw4y_27rQxYirSdu2Bbm06Afqc99RbMmJgFT1FXkcmyR3PtOxaMQUQVQA3c9Z>
- Mod.DHA]
[See Also:
Barley yellow dwarf, oat - USA: (SD)
https://url.emailprotection.link/?bigQCS7RXneWX2N0GBo3ZuoQYZok5Oi17Y2VGXwLIANcwk0mGw470B1cR0vqTsYtwfGSZTMx5DBzaVjaVKvzFliUP4Vzdl1LRXf7BWRZ2PWPJ_exqQ2ucEETXCif0ukU1
2019
----
Barley yellow dwarf, cereals - UK: control https://url.emailprotection.link/?bI3VhMCnUgWGCN9tqFBBxodCNeO7ruO4iCdLIY6jvENY2C1yQ-g_jJcyIJxIZCmrEDUhaaxEmkFZQJKNi9iezqPXZmyOJu6u0xvsUQ1RNFwu-yQyKpieqEoE06xcI2ctl
2018
---
Barley virus G - Australia: 1st rep (VI) https://url.emailprotection.link/?bK5TvKObqu_97emh29UXtVK6PLd-MV2FHPGUH2kg67aObYpv6-hVtpQ6d1xF_52wSlcsF1VHDOa6MaU13oKU6coQ_yMDBaz6MEdtQBdwTqgdx2LaUPx8n69yyLIG96nhH
2017
----
Barley yellow dwarf, cereals - UK, Canada https://url.emailprotection.link/?bvTbGFmGq0I9iGrJYKiMmo1jFJW2TIYltpdDe19QdKGTniqu2CIHXUVrc_PDMuJW49V5fG-kNNE31gsHFZOH9WyBWM3laEGUD9zUvQ_AZv-KoHCuurFbwtQ4HReLQC3Kc
Barley yellow dwarf - Ireland: (WX)
https://url.emailprotection.link/?bXyFqXi_5wsfAeblyRWatQZaAKG5uhxna7RNBH4G1ouE5BSo375VlcvrVM4JxI7ul-cfUNspUNA4_SCLLSocz_2UrLDoHOANx-XQ_4tqVwv3-9RTyL3LtM3i9OXlVXiJ9
2016
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Barley yellow dwarf, cereals - UK
https://url.emailprotection.link/?brGQbTCOx-yAZY0JOVN-1Uwi9hkYWQpK5MLS359-JYUK7b1qLMKR4iR1F8S5NPp6dUd2Oz1_GmzpzOJQBI4qdVFmVVTWOu_k-Mr51_Ko_uNpG2e8AS2sv7Cw7nEAIqUWt
2015
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Barley yellow dwarf, wheat - Denmark
https://url.emailprotection.link/?baPM2wHJCj2FYEHXWxioR9ZhlQtfWpOtqkgbWM61bpEmHzKDjCDh9DPibFqcKTozqB9WjdlGJXvVSA2sg2xpo0HL29bE5XGQE0BnJxvmU6LwZfzaBCS4L0ww0pDN-zk0u
Barley yellow dwarf, cereals - USA: (ID) alert https://url.emailprotection.link/?bCwEPloDTVbrYG2QWPba0_PkSTlPFMYtEekP2A_ZpsCnJGKWHyNdvfuqbZICUzzu-RafdBRlBP2SgHBCt2RrgWVKhh0AM2RQlrffDtsRmeLwutsh1zfabp-i7f7DNzkAn
2014
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Barley yellow dwarf virus-PAS, wheat - Turkey
https://url.emailprotection.link/?ba0AhnjdWOAloCommkkihbDIE6Y2fuqLYLiVMir6iuHaIv4LySdjlUxz9D5I4dam2V6-OgrVe7meu3lwtrSXvM-QSxyvpzxs-KWciKXlbcPjH13knob6K-sQaWb5LAv3-
2010
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Wheat streak mosaic & barley yellow dwarf, wheat - USA https://url.emailprotection.link/?bkl2qqZkLnrRjNwV_60AGkIJWoZh0LpiTlfNbeQnGQTRG01u0D5sK_C2M6Qa4KOxvUwv08TgXA5tBTgWbqkTzh2us8yUTupWTI6gbLt4EX6pmJ6WB-R9nYFzlO-fl3QCi
2009
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Wheat viruses - New Zealand: 1st reports https://url.emailprotection.link/?bHUoVkLl4lGE_Y_98Yn7MlPDRXRQc2tqsmgsj7HLfQPHRkFGuQSsgNzv8FSEW7ZwnKO35gUDYsogySYLode623Li7HNy_YdNiYhXmjeoXOiPAapTreh7sHdae5rq8c28N
and older items in the archives]
Topics
Species
