{"id":1228,"date":"2015-10-19T15:40:44","date_gmt":"2015-10-19T22:40:44","guid":{"rendered":"http:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=1228"},"modified":"2024-04-26T11:17:57","modified_gmt":"2024-04-26T18:17:57","slug":"didymella-bryoniae-auersw-rehm-teleomorph-auersw-rehm","status":"publish","type":"post","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=1228","title":{"rendered":"Didymella bryoniae (Auersw.) Rehm [teleomorph] (Auersw.) Rehm"},"content":{"rendered":"
California Pest Rating for<\/strong><\/h5>\n
Didymella bryoniae <\/em><\/strong>(Auersw.) Rehm [teleomorph] (Auersw.) Rehm<\/strong><\/h5>\n
Pest Rating: \u00a0B<\/h5>\n
\n
PEST RATING PROFILE<\/strong><\/h5>\n
Initiating Event: <\/strong><\/h5>\n

None.\u00a0 The risk of infestation of Didymella bryoniae<\/em> in California is evaluated and a permanent rating is herein proposed.\u00a0 <\/strong><\/p>\n

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

Background<\/u><\/strong>:\u00a0 Didymella bryoniae<\/em> is the fungal pathogen that causes gummy stem blight of cucurbits disease affecting members of the family Cucurbitaceae.\u00a0 Gummy stem blight was first reported in 1891 in France, Italy and the United States and affects the leaves, stems, fruits and seeds of all cucurbits. \u00a0\u00a0The disease is most common in subtropical and tropical regions globally but also found in temperate regions, especially on winter squash and pumpkin and greenhouse grown cucumber (Sitterly & Keinath, 1996).\u00a0 The disease is most common in the southern United States, and in California, gummy stem blight was first reported in greenhouse-produced transplants of watermelon in the Salinas Valley (Koike, 1997).\u00a0 Since 1997, there have not been any further reports of the pathogen in California.<\/p>\n

Didymella bryoniae<\/em> is the sexual (teleomorph) stage of the fungus that produces ascospores, while Phoma cucurbitacearum<\/em> represents the asexual stage (anamorph) that produces conidia.\u00a0 Didymella bryoniae<\/em> was originally described as Sphaeria bryoniae<\/em>, but since then has undergone several classifications that resulted in synonymizations of many different species.<\/p>\n

Hosts: Members of the family Cucurbitaceae including wax gourd (Benincasa hispida<\/em>), watermelon (Citrullus lanatus<\/em>), melon (Cucumis melo<\/em>), cucumber (C. sativus<\/em>), pumpkin (Cucurbita<\/em> sp.), giant pumpkin (C. maxima<\/em>), ornamental gourd (C. pepo<\/em>), buffalo gourd (C. foetidissima<\/em>), bottle gourd (Lagenaria siceraria<\/em>), bitter gourd (Momordica charantia<\/em>), loofah (Luffa cylindrica<\/em>), white bryony (Bryonia alba<\/em>), red bryony (B. dioica<\/em>), chayote (Sechium edule<\/em>), and burcucumber (Sicyos angulatus<\/em>) Occasionally, the pathogen has been found in members of Solanaceae, Caricaceae, and Primulaceae (CABI, 2015; Farr & Rossman, 2015).<\/p>\n

Symptoms:\u00a0 Didymella bryoniae<\/em> invades the leaves and stems of watermelon, cucumber, and muskmelon (cantaloupe) and gummy stem blight diseased plants may exhibit a variety of symptoms which are referred to as leaf spot, stem canker, vine wilt and black fruit rot (Ferreira & Boley, 1992).\u00a0 Initial spots on leaves, petioles and stems usually become pale brown or gray. On stems, spots usually start at the joints, frequently elongate into streaks and exude an amber-colored gummy liquid. \u00a0Lesions on leaves and fruit initiate as spreading water-soaked areas which in leaves may have a chorotic halo, become light brown and irregular in outline, and necrotic.\u00a0 Leaves wilt and collapse; affected plants wilt and eventually die. On fruit, faded and irregular spots first form on the surface and eventually turn dark and may have a hardened droplet of exudates in the center; cracked sunken lesions form with internal rotting \u2013 especially in storage fruit. \u00a0In certain kinds of squash, lesions are superficial and spread almost over the entire fruit surface.\u00a0 When seed-transmitted, the pathogen causes damping-off thereby, killing seedlings.\u00a0 In the field, initial symptoms include plant collapse with sunken girdling cankers that result in total loss of plants.\u00a0 Vine cankers are common near the crown of the plant. \u00a0(Agrios, 2005; CABI, 2015; Ferreira & Boley, 1992; Koike, 1997; Sitterly & Keinath, 1996.)<\/p>\n

The main diagnostic symptoms are the gummy exudates on stem and fruit lesions, and the presence of abundant closely spaced groups of pale-colored pycnidia (asexual fruiting body) and dark brown to black-colored perithecia (sexual fruiting body) on fruit, stem or leaves.\u00a0 During rainy seasons lesions can become water-soaked and spread resulting in severe defoliation.\u00a0 Gummy substances may exude from cracks, and severe infections can result in death of plants (CABI, 2015).<\/p>\n

Damage Potential: Didymella bryoniae<\/em> has the potential of damaging plant growth causing reductions in plant growth, death of infected plants, fruit rot, and seedling death resulting in significant crop losses.<\/p>\n

Disease Cycle: \u00a0\u00a0The pathogen usually overwinters in diseased plant debris as chlamydospores and possibly in or on seeds.\u00a0 Subsequently, spores or infected seed result in primary infection of plants. Cucurbit plants are predisposed to infection by wounds and bruises although uninjured plants have also been shown to become infected when exogenous nutrients are present (Ferreira & Boley, 1992).\u00a0 The disease thrives in cool moist climates with an optimum temperature of 20-28 C for development.\u00a0 Moisture, especially extended periods of wetness, is necessary for infection (at least 1 hour) and disease development.\u00a0 Leaves are penetrated directly through the cuticle or through intercellular spaces around the bases of trichomes. Stems are penetrated through wounds and fruit are penetrated through wounds or flower scars at the time of pollination.\u00a0 Fruit rot initiates approximately 3 days following infection.\u00a0 Following penetration and development, the fungus produces numerous pycnidia and perithecia.\u00a0 Pycnidia are filled with conidia (spores) that protrude from the fruiting body in a gelatinous substance appearing as long cream to pink tendrils.\u00a0 Water dissolves this gelatinous substance and the conidia are dispersed usually by wind and rain.\u00a0 Perithecia are also produced along with pycnidia and filled with ascospores. Both types of spores serve as inoculum for infection.\u00a0 Neither type survives long after dispersal (Agrios, 2005; Ferreira & Boley, 1992; Sitterly & Keinath, 1996).<\/p>\n

Transmission:\u00a0 Infected planting material (transplants), infected fruit, plant debris, weeds, and soil.\u00a0 In addition, conidia can be transmitted by air transport and water splashing (Ferreira & Boley, 1992).\u00a0 Seed transmission has only been demonstrated experimentally (Brown et al<\/em>., 1970; CABI, 2015; Lee et al<\/em>., 1984).\u00a0 Reports of seed transmission are conflicting and there is no evidence that seed transmission occurs naturally although fruiting bodies (pycnidia and perithecia) of the pathogen have been found on naturally infected cucumber and pumpkin seeds (CABI, 2015).\u00a0 The striped cucumber beetles (Diabrotica undecimpunctata howardii<\/em> and Acalymma vittatum<\/em>) are believed to transmit D. bryoniae<\/em> in a nonpersistent manner by providing wounds in plants as avenues for fungal infections. It has also been shown experimentally that cucumber plants infested with melon aphids were susceptible to D. bryoniae<\/em> and powdery mildew (Ferreira & Boley, 1992).<\/p>\n

Worldwide Distribution<\/u>:<\/strong>\u00a0 Didymella bryoniae<\/em> is distributed worldwide in several countries in Asia, Africa, North America, Central America and Caribbean, South America, Europe, and Oceania (CABI, 2015).<\/p>\n

In the USA, it has been reported from Florida, Georgia, New York, North Carolina, and South Carolina.<\/p>\n

Official Control<\/u><\/strong>:\u00a0 Didymella bryoniae<\/em> is included on the \u2018Harmful Organism Lists\u2019 for nine countries namely: Bangladesh, Ecuador, Egypt, Indonesia, Iran, Israel, Panama, Syrian Arab Republic and Timor-Leste (PCIT, 20115).\u00a0 It is a quarantine pest in Jordan (EPPO, 2015). \u00a0\u00a0Currently, it is an actionable, temporary \u2018Q\u2019-rated pathogen in California.<\/p>\n

California Distribution<\/u><\/strong>: Didymella bryoniae<\/em> has only been reported once in 1997 in Salinas in greenhouse watermelon transplants.\u00a0 The diseased plants would have been destroyed following detection.\u00a0 The pathogen has not been reported since then and is not known to be established in California.<\/p>\n

California Interceptions<\/u><\/strong>: \u00a0None reported.<\/p>\n

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

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

1) Climate\/Host Interactio<\/span>n:<\/strong> Evaluate if the pest would have suitable hosts and climate to establish in California. Score:<\/p>\n

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

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

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

Risk is Medium (2)<\/span> <\/em><\/strong>\u2013 <\/em>Didymella bryoniae requires cool and moist conditions to infect cucurbit hosts and cause gummy stem blight disease.\u00a0 At least 1 hour of wetness is required for infection and extended periods for disease development.\u00a0 This may limit the establishment of the disease in cucurbit productions in California and may also be why this disease has not been observed outside greenhouse production in California since the early 1990s.\u00a0 Therefore, a \u2018medium\u2019 rating is given to this category.<\/em><\/p>\n

2) Known Pest Host Range<\/span>:<\/strong> Evaluate the host range of the pest. Score:<\/p>\n

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

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

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

Risk is Medium (2) <\/span><\/em><\/strong>\u2013 The host range is mainly limited to various species of the Cucurbitaceae family.\u00a0 Nevertheless, Cucurbitaceous hosts, including watermelon, melon, squash and cucumber, are widely grown commercially within California.<\/em><\/p>\n

3)\u00a0Pest Dispersal Potential<\/span>:<\/strong> Evaluate the natural and artificial dispersal potential of the pest. Score:<\/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

Risk is High (3)<\/span> <\/em><\/strong>\u2013 Under favorable environmental conditions <\/em>Didymella bryoniae has a high reproductive rate and depends on wind and moisture or rain for its short distance dispersal.\u00a0 Infected planting material, infected fruit, plant residues, weeds, soil, and possibly seed provide the means for long distance dispersal, also in fields and greenhouses. In addition, the striped cucumber beetles are believed to transmit <\/em>D. bryoniae in a nonpersistent manner by providing wounds in plants as avenues for fungal infections. <\/em>\u00a0<\/strong><\/p>\n

4) Economic Impact<\/span>:<\/strong> Evaluate the economic impact of the pest to California using the criteria below. Score:<\/p>\n

A. \u00a0The pest could lower crop yield.<\/p>\n

B. \u00a0The pest could lower crop value (includes increasing crop production costs).<\/p>\n

C. \u00a0The pest could trigger the loss of markets (includes quarantines).<\/p>\n

D. \u00a0The pest could negatively change normal cultural practices.<\/p>\n

E. \u00a0The pest can vector, or is vectored, by another pestiferous organism.<\/p>\n

F. \u00a0The organism is injurious or poisonous to agriculturally important animals.<\/p>\n

G. \u00a0The organism can interfere with the delivery or supply of water for agricultural uses.<\/p>\n

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

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

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

Risk is High (3)<\/span><\/em><\/strong> \u2013\u00a0 The cucurbit gummy stem blight pathogen could lower crop value and yield, cause increases in production costs for disease management, and negatively change normal cultural practices to mitigate potential damages.\u00a0 There is also the possibility for the pathogen to be vectored by pestiferous striped cucumber beetles.\u00a0 Therefore, a \u2018high\u2019 rating is given to this category. \u00a0\u00a0<\/em><\/p>\n

5) Environmental Impact<\/span>:<\/strong> Evaluate the environmental impact of the pest on California using the criteria below.<\/p>\n

A. \u00a0The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.<\/p>\n

B. \u00a0The pest could directly affect threatened or endangered species.<\/p>\n

C. \u00a0The pest could impact threatened or endangered species by disrupting critical habitats.<\/p>\n

D. \u00a0The pest could trigger additional official or private treatment programs.<\/p>\n

E. \u00a0The pest significantly impacts cultural practices, home\/urban gardening or ornamental plantings.<\/p>\n

Score the pest for Environmental Impact. Score:<\/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

\u00a0<\/strong>Risk is <\/em><\/strong>Medium (2)<\/em><\/strong><\/span> \u2013 Cucurbitaceous plants grown in home\/urban gardens could be negatively impacted if infected with <\/em>Didymella bryoniae.<\/p>\n

Consequences of Introduction to California for Didymella bryoniae:<\/em><\/strong><\/h5>\n

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

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

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

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

Total points obtained on evaluation of consequences of introduction of Didymella bryoniae<\/em> to California = Medium<\/strong> <\/span>(12)<\/span>.<\/strong><\/p>\n

6) Post Entry Distribution and Survey Information<\/span>:<\/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. (Score)<\/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

Evaluation is not established in California (0)<\/span>.\u00a0<\/em><\/strong><\/p>\n

Final Score:<\/h5>\n

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

Final Score: <\/em><\/strong>\u00a0Score of Consequences of Introduction \u2013 Score of Post Entry Distribution and Survey Information =12 (Medium)<\/strong><\/span>.<\/strong><\/em><\/p>\n

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

Infested seeds and transplants are a ready source of introduction of the pathogen to CA fields.\u00a0 The future status of <\/em>Didymella bryoniae, gummy stem blight of cucurbits disease, can be known through periodic surveys, diligent monitoring and testing of seed\/plants in greenhouses and will be necessary in order to mitigate risk of field introduction and potential establishment of the pathogen in California soils.<\/em><\/p>\n

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

Based on the evidence provided above the proposed rating for the anthracnose pathogen, Didymella bryoniae<\/em> is B.\u00a0\u00a0 <\/strong><\/p>\n

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

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

B<\/strong>rown, M. E., E. M. Howard, and B. C. Knight. 1970. Seedborne Mycosphaerella melonis <\/em>on cucumber. Plant Pathology, 19:198.<\/p>\n

C<\/strong>ABI.\u00a0 2015.\u00a0 Didymella bryoniae<\/em> (gummy stem blight of cucurbits) datasheet (full) report.\u00a0 Crop Protection Compendium.\u00a0 www.cabi.org\/cpc\/<\/a><\/p>\n

E<\/strong>PPO.\u00a0 2015.\u00a0 Stagonosporopsis cucurbitacearum<\/em> (DIDYBR).\u00a0 European and Mediterranean Plant Protection Organization PQR database.\u00a0 http:\/\/www.eppo.int\/DATABASES\/pqr\/pqr.htm<\/a> .<\/p>\n

F<\/strong>arr, D. F., and A. Y. Rossman.\u00a0 2015.\u00a0 Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved July 14, 2015, from http:\/\/nt.ars-grin.gov\/fungaldatabases\/<\/a><\/p>\n

F<\/strong>erreira, S. A., and R. A. Boley.\u00a0 1992.\u00a0 Didymella bryoniae<\/em> Gummy stem blight, black rot, canker (Plant Disease Pathogen).\u00a0 http:\/\/www.extento.hawaii.edu\/kbase\/crop\/Type\/d_bryon.htm<\/a><\/p>\n

K<\/strong>oike, S. T.\u00a0 1997.\u00a0 First report of gummy stem blight, caused by Didymella bryoniae<\/em>, on watermelon transplants in California.\u00a0 Plant Disease, 81:1331. http:\/\/dx.doi.org\/10.1094\/PDIS.1997.81.11.1331B<\/a>.<\/p>\n

L<\/strong>ee, D. H., S. B. Mathur, and P. Neergaard. 1984. Detection and location of seed-borne inoculum of Didymella bryoniae<\/em> and its transmission in seedlings of cucumber and pumpkin. Phytopathologische Zeitschrift, 109(4):301-308<\/a>.<\/p>\n

P<\/strong>CIT.\u00a0 2015.\u00a0 USDA Phytosanitary Certificate Issuance & Tracking System. July 21, 2015.\u00a0 https:\/\/pcit.aphis.usda.gov\/PExD\/faces\/ReportHarmOrgs.jsp<\/a> .<\/p>\n

S<\/strong>itterly, W. R., and A. P. Keinath.\u00a0 Gummy stem blight. \u00a01996.\u00a0 In, Compendium of cucurbit diseases.\u00a0 Compendium of cucurbit diseases<\/em> ed. T. A. Zitter, D. L. Hopkins, and C. E.\u00a0 Thomas, APS Press \u00a0pg 27-28. http:\/\/www.apsnet.org\/publications\/apsnetfeatures\/Pages\/GummyStemBlight.aspx<\/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

\u00a0Pest Rating: \u00a0B<\/h3>\n
\n

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

California Pest Rating for Didymella bryoniae (Auersw.) Rehm [teleomorph] (Auersw.) Rehm Pest Rating: \u00a0B PEST RATING PROFILE Initiating Event: None.\u00a0 The risk of infestation of Didymella bryoniae in California is evaluated and a permanent rating is herein proposed.\u00a0 History & Status: Background:\u00a0 Didymella bryoniae is the fungal pathogen that causes gummy stem blight of cucurbits … Continue reading Didymella bryoniae (Auersw.) Rehm [teleomorph] (Auersw.) Rehm<\/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":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[8,4],"tags":[211,46,45],"class_list":["post-1228","post","type-post","status-publish","format-standard","hentry","category-fungi","category-plant-pathology","tag-didymella-bryoniae","tag-fungi-2","tag-plant-pathogen"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5l8vQ-jO","jetpack-related-posts":[{"id":10994,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=10994","url_meta":{"origin":1228,"position":0},"title":"Didymella fabae G.J. Jellis & Punith. 1991 (teleomorph) Ascochyta fabae Speg. 1899 (anamorph) = Ascochyta pisi var. fabae R. Sprague 1947 Ascochyta blight Leaf and pod spot of fava beans","author":"Heather.Martin","date":"September 20, 2022","format":false,"excerpt":"California Pest Rating for Didymella fabae G.J. Jellis & Punith. 1991 (teleomorph) Ascochyta fabae Speg. 1899 (anamorph) = Ascochyta pisi var. fabae R. Sprague 1947 Ascochyta blight Leaf and pod spot of fava beansPest Rating: B Download pest rating *NOTE You must be registered and logged in to post a\u2026","rel":"","context":"In "B-Rated"","block_context":{"text":"B-Rated","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=670"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":5606,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=5606","url_meta":{"origin":1228,"position":1},"title":"Tomato Leaf Miner | Liriomyza bryoniae (Kaltenbach)","author":"Kyle Beucke","date":"July 23, 2018","format":false,"excerpt":"California Pest Rating for Tomato leaf miner |\u00a0Liriomyza bryoniae (Kaltenbach) Diptera: Agromyzidae Pest Rating: A \u00a0 PEST RATING PROFILE Initiating Event: Liriomyza bryoniae is currently Q-rated.\u00a0 A permanent pest rating proposal is required to support an official pest rating. History & Status: Background: \u00a0Adult Liriomyza bryoniae are small (approximately 2\u2026","rel":"","context":"In "A-Rated"","block_context":{"text":"A-Rated","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=669"},"img":{"alt_text":"Tomato Leaf Miner (Liriomyza bryoniae)","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/Section3162\/wp-content\/uploads\/2018\/07\/TomatoLeafMiner-LiriomyzaBryoniae_0746042-PPT-300x200.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":9410,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=9410","url_meta":{"origin":1228,"position":2},"title":"Blumeriella jaapii (Rehm) Arx 1961 cherry leaf spot","author":"Heather.Martin","date":"January 5, 2022","format":false,"excerpt":"California Pest Rating for Blumeriella jaapii (Rehm) Arx 1961 cherry leaf spotPest Rating: C DOWNLOAD PEST RATING *NOTE You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at permits[@]cdfa.ca.gov. Posted by ta","rel":"","context":"In "C-Rated"","block_context":{"text":"C-Rated","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=671"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1969,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=1969","url_meta":{"origin":1228,"position":3},"title":"Plant Pathogens","author":"Admin","date":"May 13, 2016","format":false,"excerpt":"Plant diseases can be caused by several pathogenic microorganisms including fungi, bacteria, viruses, viroids, phytoplasmas and plant parasitic nematodes. In California, several plant pathogens have evolved with native plants and consequently, caused little damage. However, many other pathogens are either not present or have only been newly discovered within the\u2026","rel":"","context":"In "Ratings"","block_context":{"text":"Ratings","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=333"},"img":{"alt_text":"Plant pathogens montage","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/Section3162\/wp-content\/uploads\/2016\/05\/plant-diseases-featured-image.jpg?fit=1038%2C588&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/Section3162\/wp-content\/uploads\/2016\/05\/plant-diseases-featured-image.jpg?fit=1038%2C588&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/Section3162\/wp-content\/uploads\/2016\/05\/plant-diseases-featured-image.jpg?fit=1038%2C588&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/Section3162\/wp-content\/uploads\/2016\/05\/plant-diseases-featured-image.jpg?fit=1038%2C588&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2468,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=2468","url_meta":{"origin":1228,"position":4},"title":"Podosphaera xanthii (Castagne) U. Braun & Shishkoff 2000","author":"Admin","date":"August 17, 2016","format":false,"excerpt":"California Pest Rating for Podosphaera xanthii (Castagne) U. Braun & Shishkoff 2000 Pest Rating: \u00a0C PEST RATING PROFILE Initiating Event: On July 13, 216, diseased leaves of Calibrachoa sp. plants exhibiting powdery mildew symptoms were collected during a regulatory nursery inspection, from a nursery in San Luis Obispo County, by\u2026","rel":"","context":"In "Fungi"","block_context":{"text":"Fungi","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?cat=8"},"img":{"alt_text":"Watermelon leaf showing an even distribution of powdery mildew (Podosphaera xanthii) over the entire leaf surface. June 1995 Photo by Gerald Holmes, California Polytechnic State University at San Luis Obispo, Bugwood.org","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/Section3162\/wp-content\/uploads\/2016\/08\/1571367-Podosphaera-xanthii-GeraldHolmes-CA-PolytechStateUniv-SanLuisObispo-Bugwood-202x300.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":377,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=377","url_meta":{"origin":1228,"position":5},"title":"Colletotrichum orbiculare (Berk. & Mont.) Arx 1957","author":"Admin","date":"March 16, 2015","format":false,"excerpt":"California Plant Pest Rating for Colletotrichum orbiculare (Berk. & Mont.) Arx 1957 Pest\u00a0Rating:\u00a0B PEST RATING PROFILE Initiating Event: None. A permanent rating for Colletotrichum orbiculare is proposed herein. History & Status: Background: Colletotrichum orbiculare is a fungal pathogen causing anthracnose disease of cucurbit plants particularly watermelon, cantaloupe, and cucumber. The\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\/1228","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=1228"}],"version-history":[{"count":8,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts\/1228\/revisions"}],"predecessor-version":[{"id":10500,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts\/1228\/revisions\/10500"}],"wp:attachment":[{"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1228"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1228"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1228"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}