{"id":3681,"date":"2017-05-17T16:10:41","date_gmt":"2017-05-17T23:10:41","guid":{"rendered":"http:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=3681"},"modified":"2024-04-26T10:56:59","modified_gmt":"2024-04-26T17:56:59","slug":"cercospora-ruscicola-v-g-rao-a-s-patil-1972","status":"publish","type":"post","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=3681","title":{"rendered":"Cercospora ruscicola"},"content":{"rendered":"
California Pest Rating for<\/strong><\/h5>\n
Cercospora ruscicola<\/em><\/strong> V. G. Rao & A. S. Patil 1972<\/strong><\/h5>\n
Pest Rating: B<\/strong><\/h5>\n
\n
PEST RATING PROFILE<\/strong><\/h5>\n
Initiating Event: <\/strong><\/h5>\n

On April 28, 2017, a shipment of Ruscus<\/em> (Ruscus<\/em> sp.) plants with symptoms of leaf spots and destined to a private resident in Contra Costa County, was intercepted by Contra Costa County officials.\u00a0 The shipment had originated in Florida.\u00a0 A sample of diseased \u201cleaves\u201d was sent to the CDFA Plant Pathology Laboratory for diagnosis.\u00a0 On May 8, 2017, Suzanne Latham, CDFA plant pathologist, identified the fungal pathogen, Cercospora ruscicola<\/em> associated with the diseased leaf tissue. As there have not been any earlier reports of this pathogen in California, it was given a temporary \u2018Q\u2019 rating.\u00a0 Subsequently, the consequences of introduction and establishment of C. ruscicola<\/em> in California is assessed and a permanent rating is proposed herein.<\/p>\n

History & Status:<\/strong><\/h5>\n

Background<\/strong><\/u>: \u00a0\u00a0The fungal pathogen, Cercospora ruscicola<\/em> was originally identified from necrotic lesions on \u201cleaves\u201d (actually, \u2018cladodes\u2019 which are leaf-like modified stems) of several Ruscus<\/em> plants at Poona, India (Rao & Patil, 1972).\u00a0\u00a0 There have not been any further reports of the global spread of this species, however, Cercospora<\/em> spp., including C. ruscicola<\/em> have been detected in federally intercepted samples of Ruscus<\/em> plants, according to USDA\u2019s National Mycologist (personal communications: S. Latham, CDFA plant pathologist).<\/em>\u00a0 Cercospora ruscicola<\/em> is not known to be present in California.\u00a0 The recent detection of this species in intercepted plants from Florida marked a first record.\u00a0 <\/em>\u00a0Cercospora ruscicola<\/em> is also known by its teleomorph (sexual) stage, Mycosphaerella ruscicola <\/em>A. Pande 1980.<\/p>\n

Disease development<\/u><\/strong>: In general, in infected plants, Cercospora<\/em> species produce conidiophores (specialized hypha) that arise from the plant surface in clusters through stomata and form conidia (asexual spores) successively.\u00a0 Conidia are easily detached and blown by wind often over long distances.\u00a0 On landing on surfaces of a plant host, conidia require water or heavy dew to germinate and penetrate the host.\u00a0 Substomatal stroma (compact mycelial structure) may form from which conidiophores develop.\u00a0 Development of the pathogen is favored by high temperatures and the disease is most destructive during summer months and warmer climates.\u00a0 High relative humidity is necessary for conidial germination and plant infection.\u00a0 The pathogen can overwinter in or on seed and as mycelium (stromata) in old infected leaves (Agrios, 2005).<\/p>\n

Dispersal and spread:<\/em> air-currents, infected nursery plants, infected leaves, seeds (Agrios, 2005).<\/p>\n

Hosts:<\/em> \u00a0Ruscus aculeatus<\/em> (butcher\u2019s broom), Ruscus<\/em> sp. (Farr & Rossman, 2017; Rao & Patil, 1972; CDFA Pest and Damage Record, May 8, 2017<\/em>).<\/p>\n

Symptoms<\/em>: \u00a0Similar to most other Cercospora<\/em> diseases, symptoms caused by C. ruscicola<\/em> are leaf spots.\u00a0 Spots may be irregularly circular to angular, with or without a distinct border, and usually coalesce to form extensive blighted regions.\u00a0 Rao and Patil (1972) observed extensive, irregular necrotic regions on leaves of Ruscus<\/em> plants.<\/p>\n

Damage Potential:\u00a0 <\/em>Quantitative losses due to Cercospora ruscicola<\/em> have not been reported.\u00a0 Photosynthetic area can be reduced due to leaf spotting.\u00a0 In severe infections, leaf wilt and drop may be expected.\u00a0 Rao and Patil (1972) stated that the \u201csevere\u2019 disease ultimately resulted in defoliation and blight of Ruscus<\/em> plants in India.\u00a0 Generally, the damage potential due to this pathogen is likely to be similar to other Cercospora<\/em> diseases which is usually low (Agrios, 2005).<\/p>\n

Ruscus<\/em> spp. are evergreen, perennial plants that are uncommon and not grown commercially in California, even though they are able to tolerate a wide range of temperatures, except freezing, and grow in shade under wet and dry conditions (Stamp, 2001).\u00a0 In California, they may be found in ornamental nurseries, and residential and public gardens where they may be at risk of infection and damage by Cercospora ruscicola<\/em>. \u00a0Furthermore, Ruscus<\/em> stems and berries are used in dried or fresh floral arrangements.\u00a0 Damage caused by C. ruscicola<\/em> may significantly impact commercial and private florist businesses.<\/p>\n

Worldwide Distribution<\/u>:<\/strong> \u00a0Asia<\/em>: India (Farr & Rossman, 2017; Rao & Patil, 1972).<\/p>\n

Official Control<\/u>:<\/strong> \u00a0Presently, Cercospora ruscicola<\/em> is on the \u2018Harmful Organism\u2019 list for Paraguay (USDA-PCIT, 2017).<\/p>\n

California Distribution<\/u>: \u00a0<\/strong>Cercospora ruscicola<\/em> is not known to be established in California.<\/p>\n

California Interceptions<\/u>: \u00a0<\/strong>Cercospora ruscicola<\/em> was detected in a single shipment of Ruscus <\/em>sp.<\/em> intercepted by Contra Costa County officials in April 2017 (see<\/em>: \u2018Initiating Event\u2019).<\/p>\n

The risk Cercospora ruscicola<\/em> would pose to California is evaluated below.<\/p>\n

Consequences of Introduction:\u00a0 <\/strong>\u00a0<\/strong><\/h5>\n

1) Climate\/Host Interaction: <\/strong>Ruscus<\/em> are not commonly grown in California. However, they are able to grow in shade under wet and dry conditions and can tolerate a wide range of temperature (except freezing). These conditions enable the plants to grow in several areas in California and, if introduced, Cercospora ruscicola<\/em> would be able to establish wherever its host plant is grown under high relative humidity\/moisture and warm climate.\u00a0 However, as the plants are not commercially cultivated and are uncommonly grown in residential and public gardens and ornamental nurseries, the pathogen is given a low score in this category.<\/p>\n

Evaluate if the pest would have suitable hosts and climate to establish in California.<\/p>\n

Score: 1<\/span><\/strong><\/p>\n

– Low (1)<\/strong> Not likely to establish in California; or likely to establish in very limited areas.<\/span><\/p>\n

– Medium (2) may be able to establish in a larger but limited part of California.<\/p>\n

– High (3) likely to establish a widespread distribution in California.<\/p>\n

2) Known Pest Host Range:<\/strong> Presently, the host range is only limited to Ruscus<\/em> and R. aculeatus<\/em> in the family Ruscaceae.<\/p>\n

Evaluate the host range of the pest.<\/p>\n

Score: 1<\/span><\/strong><\/p>\n

– Low (1)<\/strong> has a very limited host range.<\/span><\/p>\n

– Medium (2) has a moderate host range.<\/p>\n

– High (3) has a wide host range.<\/p>\n

3) Pest Dispersal Potential: <\/strong>Cercospora ruscicola<\/em> has high reproductive potential resulting in the successive production of conidia which are dependent on air currents, infected plants, and seed for dispersal and spread.<\/p>\n

Evaluate the natural and artificial dispersal potential of the pest.<\/p>\n

Score: 3<\/span><\/strong><\/p>\n

– Low (1) does not have high reproductive or dispersal potential.<\/p>\n

– Medium (2) has either high reproductive or dispersal potential.<\/p>\n

– High (3)<\/strong> has both high reproduction and dispersal potential.<\/span><\/p>\n

4) Economic Impact: <\/strong>Diseased Ruscus<\/em> plants exhibiting leaf spot symptoms could result in lowered value of plants and loss of markets to nurseries and florist businesses. Increased costs of production can be expected with the necessary use of appropriate fungicides and other disease management strategies.<\/p>\n

Evaluate the economic impact of the pest to California using the criteria below.<\/p>\n

Economic Impact:<\/strong> B, C<\/strong><\/span><\/p>\n

A. The pest could lower crop yield.<\/p>\n

B<\/strong>. The pest could lower crop value (includes increasing crop production costs).<\/span><\/p>\n

C<\/strong>. The pest could trigger the loss of markets (includes quarantines).<\/span><\/p>\n

D. The pest could negatively change normal cultural practices.<\/p>\n

E. The pest can vector, or is vectored, by another pestiferous organism.<\/p>\n

F. The organism is injurious or poisonous to agriculturally important animals.<\/p>\n

G. The organism can interfere with the delivery or supply of water for agricultural uses.<\/p>\n

Economic Impact Score<\/strong>: \u00a02<\/strong><\/span><\/p>\n

– Low (1) causes 0 or 1 of these impacts.<\/p>\n

– Medium (2)<\/strong> causes 2 of these impacts.<\/span><\/p>\n

– High (3) causes 3 or more of these impacts.<\/p>\n

4) Environmental Impact: <\/strong>\u00a0The pathogen could significantly impact ornamental plantings in home\/ urban, public gardens and other recreational environments.<\/p>\n

Evaluate the environmental impact of the pest on California using the criteria below.<\/p>\n

Environmental Impact:<\/strong> E<\/strong><\/span><\/p>\n

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.<\/p>\n

B. The pest could directly affect threatened or endangered species.<\/p>\n

C. The pest could impact threatened or endangered species by disrupting critical habitats.<\/p>\n

D. The pest could trigger additional official or private treatment programs.<\/p>\n

E<\/strong>. The pest significantly impacts cultural practices, home\/urban gardening or ornamental plantings.<\/span><\/p>\n

Environmental Impact Score: 2<\/span><\/strong><\/p>\n

– Low (1) causes none of the above to occur.<\/p>\n

– Medium (2)<\/strong> causes one of the above to occur.<\/span><\/p>\n

– High (3) causes two or more of the above to occur.<\/p>\n

Consequences of Introduction to California for Cercospora ruscicola:<\/em><\/strong> Medium (9)<\/strong><\/span><\/h5>\n

Add up the total score and include it here.<\/p>\n

-Low = 5-8 points<\/p>\n

–Medium<\/strong> = 9-12 points<\/span><\/p>\n

-High = 13-15 points<\/p>\n

6) Post Entry Distribution and Survey Information<\/strong>: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.<\/p>\n

Evaluation is \u2018Not established\u2019<\/span><\/em><\/strong>.<\/span><\/p>\n

Score: 0<\/span><\/strong><\/p>\n

–Not established (0)<\/strong> Pest never detected in California, or known only from incursions.<\/span><\/p>\n

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate\/host area (region).<\/p>\n

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate\/host areas.<\/p>\n

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate\/host areas.<\/p>\n

Final Score:<\/h5>\n

7) The final score is<\/strong> the consequences of introduction score minus the post entry distribution and survey information score: (Score: 9)<\/p>\n

Final Score: <\/em><\/strong>\u00a0Score of Consequences of Introduction \u2013 Score of Post Entry Distribution and Survey Information = <\/strong><\/span><\/em>9<\/strong><\/span><\/p>\n

Uncertainty: <\/strong><\/h5>\n

None.<\/p>\n

Conclusion and Rating Justification:<\/strong><\/h5>\n

Based on the evidence provided above the proposed rating for Cercospora ruscicola<\/em> is B.<\/strong><\/span><\/p>\n

References:<\/strong><\/h5>\n

A<\/strong>grios, G. N.\u00a0 2005.\u00a0 Plant Pathology (Fifth Edition).\u00a0 Elsevier Academic Press, USA.\u00a0 922 p.<\/p>\n

F<\/strong>arr, D. F., and A. Y. Rossman.\u00a0 2017.\u00a0 Fungal Databases, U. S. National Fungus Collections, ARS, USDA. Retrieved May 10, 2017, from http:\/\/nt.ars-grin.gov\/fungaldatabases\/<\/a><\/p>\n

R<\/strong>ao, V. G., and A. S. Patil.\u00a0 1972.\u00a0 Cercospora ruscicola<\/em> sp. nov. from India.\u00a0 Transactions British Mycological Society, 58: 522.<\/p>\n

S<\/strong>tamp, R. H.\u00a0 2001.\u00a0 Florida\/Holland\/Israeli Ruscus<\/em> production and use.\u00a0 University of Florida Extension, IFAS. Circular 1268 (ENH844).<\/p>\n

U<\/strong>SDA PCIT.\u00a0 2017.\u00a0 USDA Phytosanitary Certificate Issuance & Tracking System. May 10, 2017, 12:21:55 pm CDT.\u00a0 https:\/\/pcit.aphis.usda.gov\/PExD\/faces\/ReportHarmOrgs.jsp<\/a>.<\/p>\n

Responsible Party:<\/strong><\/h5>\n

John J. Chitambar, Primary Plant Pathologist\/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.<\/p>\n

\n
Comment Format:<\/h5>\n

\u2666 \u00a0Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s)\u00a0being commented on, as shown below.<\/p>\n

Example Comment:
\n<\/strong>Consequences of Introduction: \u00a01. Climate\/Host Interaction:\u00a0[Your comment that relates to \u201cClimate\/Host Interaction\u201d here.<\/em>]<\/p>\n

\u2666 \u00a0Posted comments will not be able to be viewed immediately.<\/p>\n

\u2666 \u00a0Comments may not be posted if they:<\/p>\n

Contain inappropriate language which is not germane to\u00a0the pest rating proposal;<\/p>\n

Contains defamatory, false, inaccurate, abusive, obscene, pornographic,\u00a0sexually oriented, threatening, racially offensive, discriminatory or illegal\u00a0material;<\/p>\n

Violates agency regulations prohibiting sexual harassment or other forms\u00a0of discrimination;<\/p>\n

Violates agency regulations prohibiting workplace violence, including threats.<\/p>\n

\u2666 \u00a0Comments may be edited prior to posting to ensure they are entirely germane.<\/p>\n

\u2666 \u00a0Posted comments shall be those which have been approved in content and posted to the\u00a0website to be viewed, not just submitted.<\/p>\n

\n

Pest Rating: B<\/strong><\/h3>\n
\n

Posted by ls\u00a0<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

California Pest Rating for Cercospora ruscicola V. G. Rao & A. S. Patil 1972 Pest Rating: B PEST RATING PROFILE Initiating Event: On April 28, 2017, a shipment of Ruscus (Ruscus sp.) plants with symptoms of leaf spots and destined to a private resident in Contra Costa County, was intercepted by Contra Costa County officials.\u00a0 … Continue reading Cercospora ruscicola<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1117,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[8,4],"tags":[559,156,41],"class_list":["post-3681","post","type-post","status-publish","format-standard","hentry","category-fungi","category-plant-pathology","tag-cercospora-ruscicola","tag-fungus","tag-plant-pathogens"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5l8vQ-Xn","jetpack-related-posts":[{"id":2677,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=2677","url_meta":{"origin":3681,"position":0},"title":"Cercospora coniogrammes Crous & R. 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Braun, 2014 Pest Rating:\u00a0B PEST RATING PROFILE Initiating Event: On July 21, 2016, a shipment of lance leaf greenbrier (Smilax sp.) plants from Texas, destined to a wholesale plant company in Santa Barbara, was intercepted by the Santa Barbara County officials.\u00a0 Diseased plants\u2026","rel":"","context":"In "Fungi"","block_context":{"text":"Fungi","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=8"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2963,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=2963","url_meta":{"origin":3681,"position":4},"title":"Pseudocercospora purpurea (Cooke) Deighton 1976","author":"Admin","date":"November 30, 2016","format":false,"excerpt":"California Pest Rating for Pseudocercospora purpurea (Cooke) Deighton 1976 Pest Rating: B PEST RATING PROFILE Initiating Event: On November 17, 2016, USDA APHIS PPQ inquired if CDFA had conducted a pest risk assessment of the fungal pathogen, Pseudocercospora purpurea on avocados in California.\u00a0 Subsequently, the risk of infestation of P.\u2026","rel":"","context":"In "Fungi"","block_context":{"text":"Fungi","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=8"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":4159,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=4159","url_meta":{"origin":3681,"position":5},"title":"Plasmopara constantinescui Voglmayr & Thines 2007","author":"Admin","date":"September 20, 2017","format":false,"excerpt":"California Pest Rating for Plasmopara constantinescui Voglmayr & Thines 2007 Pest Rating: B PEST RATING PROFILE Initiating Event: On August 8, 2017, diseased leaves of Impatiens walleriana plants were collected, from a retail nursery in Placer County, by Placer Agricultural County officials and sent to the CDFA Plant Pathology Laboratory\u2026","rel":"","context":"In "Fungi"","block_context":{"text":"Fungi","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=8"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts\/3681","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/users\/1117"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3681"}],"version-history":[{"count":7,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts\/3681\/revisions"}],"predecessor-version":[{"id":10515,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts\/3681\/revisions\/10515"}],"wp:attachment":[{"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3681"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3681"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3681"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}