{"id":3779,"date":"2017-06-29T13:24:10","date_gmt":"2017-06-29T20:24:10","guid":{"rendered":"http:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=3779"},"modified":"2024-04-26T10:56:39","modified_gmt":"2024-04-26T17:56:39","slug":"phytophthora-cambivora-petri-buisman-1927","status":"publish","type":"post","link":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=3779","title":{"rendered":"Phytophthora cambivora (Petri) Buisman 1927"},"content":{"rendered":"
California Pest Rating for<\/strong><\/h5>\n
Phytophthora cambivora<\/em><\/strong> (Petri) Buisman 1927<\/strong><\/h5>\n
Pest Rating: B<\/strong><\/h5>\n
\n
PEST RATING PROFILE<\/strong><\/h5>\n
Initiating Event: <\/strong><\/h5>\n

None.\u00a0 The current risk and status of Phytophthora cambivora <\/em>in California are reassessed and a permanent rating is proposed.<\/p>\n

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

Background:<\/u><\/strong>\u00a0 Phytophthora cambiv ora<\/em> is an oomycete pathogen that can cause crown and root rot disease, usually in conjunction with other Phytophthora<\/em> spp., in its hosts.\u00a0 Phytophthora<\/em> root and crown rot disease are among the most important soilborne diseases of stone fruits (Browne & Mircetich, 1995).\u00a0 The pathogen is known to cause ink disease in chestnut.\u00a0 It is widespread in temperate regions of all continents and occurs in soils of natural forests, agricultural fields, and orchards.\u00a0 It can persist and spread in different environments and is capable of surviving in the soil as a saprophyte and by producing resting spores.<\/p>\n

In California, P. cambivora<\/em> has been found in several fruit and nut, forest, and native host plants, including: apple, avocado, American plum, apricot, chamise, hoary manzanita, palm, birchleaf mountain mahogany, apple avocado, American plum, apricot, sweet cherry, cherry plum, sour cherry, European plum, sweet almond, holly leaf cherry, Mahaleb cherry, peach, nectarine, Japanese plum, European\/common pear, oak, canyon oak, California live oak, Japanese maple, toyon, madrone, bristlecone fir (French, 1989, CDFA Pest Damage Records<\/em>).\u00a0 \u00a0\u00a0Phytophthora<\/em> diagnostic scientists have also found P. cambivora<\/em> in other symptomatic (damaged) native plant species in natural stands in California.\u00a0 These unpublished records of P. cambivora<\/em>-infected native plants include, Ione manzanita (Arctostaphylos myrtifolia<\/em>), sticky white leaf manzanita (A. viscida<\/em>), pallid manzanita (A. pallida<\/em>), Raiche\u2019s manzanita (A. stanfordiana<\/em> ssp. raichei<\/em>), coyote ceanothus (Ceanothus ferriseae<\/em>), valley oak (Quercus lobata<\/em>), and California coffeeberry (Frangula californica<\/em>) (comments from S. Frankel, plant pathologist, USDA Forest Service, and \u2018Phytophthoras in Native Habitats Work Group\u2019.\u00a0 July, 2017)<\/em>.\u00a0 The pathogen has also been recovered from various habitats including flowing water, stream and ditch banks, edges of roadsides and highways, forests, residential gardens, parks, cemeteries, recreational areas, and nurseries.<\/p>\n

Saavedra et al<\/em>., (2007) reported decline and mortality of golden chinquapin trees (Chrysolepis chrysophylla<\/em>) in parts of northern and north-western California, similar to the damage caused by P. cambivora<\/em> on the same host in Oregon.\u00a0 The native range for this host species extends through the Coast Range Mountains from San Luis Obispo County, California, to Benton County, Oregon.<\/p>\n

Recently, Jung et al<\/em>., (2016) demonstrated by phylogenetic analysis that Phytophthora cambivora<\/em> is a natural interspecific hybrid (a cross between two different Phytophthora<\/em> species) in ITS Clade 7a, and, therefore, suggested that its name be changed to P. xcambivora<\/em>. \u00a0Hybrid Phytophthora<\/em> are often more aggressive than their parental species and fare better in nurseries and out-planted settings. Furthermore, P. xcambivora <\/em>(= P cambivora<\/em>) is the most thermo-tolerant of all species in Clade 7a, with the ability to grow at temperatures greater that 35\u00b0C.\u00a0 This ability to grow at high temperatures enables the pathogen to grow in warm climates in California.<\/p>\n

Hosts:<\/em> Reported hosts of Phytophthora cambivora<\/em> are present in 30 genera in 19 families: Abies bracteata<\/em> (bristlecone fir), A. fraseri <\/em>(fraser fir), A. procera<\/em> (noble fir), Abies <\/em>sp., Acer palmatum<\/em> (Japanese maple), A. pennsylvanicum <\/em>(striped maple), A. platanoides <\/em>(Norway maple), A. rubrum<\/em> (red maple), A. saccharum <\/em>(sugar maple) , Acer <\/em>sp.,<\/em> Adenostoma fasciculatum<\/em> (chamise), Aesculus hippocastanum <\/em>(horse chestnut), Alnus cordata <\/em>(alder), A. rubra <\/em>(red alder),<\/em> Arbutus<\/em> menziesii<\/em> (madrone), Arctostaphylos canescens <\/em>subsp. canescens<\/em> (hoary manzanita), Areca<\/em> sp. (palm),\u00a0 \u00a0Castanea <\/em>sp. <\/em>(chestnut), C. crenata <\/em>(Japanese chestnut), C. dentata <\/em>(American chestnut), C. mollissima<\/em> (Chinese chestnut), C. pumila <\/em>(allegheny chinquapin), C. sativa <\/em>(chestnut), Castanea x coudercii<\/em> (Couderc chestnut), Casuarina equisetifolia <\/em>(casuarina), Cercocarpus betuloides<\/em> (island mountain mahogany), C. montanus <\/em>var. glaber<\/em> (birchleaf mountain mahogany), \u00a0Chamaecyparis lawsoniana<\/em> (Port Orford cedar), Chamaecyparis <\/em>sp.<\/em> (cypress\/false cypress), Chrysanthemum cinerariifolium<\/em> (pyrethrum), Chrysolepis chrysophylla<\/em> (giant chinquapin), Cineraria <\/em>sp., Dahlia campanulata <\/em>(weeping tree dahlia), Erica <\/em>sp., Eucalyptus <\/em>sp. <\/em>(eucalyptus), Fagus <\/em>sp.<\/em> (beech), F. sylvatica<\/em> (common beech), Ficus carica <\/em>(common fig), Heteromeles arbutifolia<\/em> (toyon), Impatiens hawker <\/em>(New Guinea impatiens), Juglans regia<\/em> (English walnut), Juglans <\/em>sp. <\/em>(walnuts), Lithocarpus densiflorus <\/em>(tanoak), Lobelia erinus<\/em> (lobelia), Lupinus <\/em>sp. <\/em>(lupine), L. albus <\/em>(white lupine), Malus <\/em>sp. <\/em>(ornamental species apple), M. domestica <\/em>(apple), M. pumila <\/em>var. domestica<\/em> (apple), M. pumila var. dulcissima, M. sylvestris<\/em> (European crab apple), Nothofagus <\/em>sp.<\/em> (southern beeches), Persea americana <\/em>(avocado), Petunia parviflora<\/em> (seaside petunia), Pieris <\/em>sp., P. japonica<\/em> (lily-of-the-valley shrub), Pisum <\/em>sp., P. sativum <\/em>(pea), Pistacia vera (<\/em>pistachio), Poncirus trifoliata <\/em>(hardy orange), Prunus <\/em>sp., P. americana<\/em> (American plum), P. amygdalus<\/em> (almond), P. armeniaca<\/em> (apricot), P. avium <\/em>(sweet cherry), P. campanulata <\/em>(Taiwan cherry), P. cerasifera<\/em> (cherry plum), P. cerasus <\/em>(sour cherry), P. domestica <\/em>(European plum), P. dulcis <\/em>(sweet almond), P. ilicifolia<\/em> (hollyleaf cherry), P. mahaleb<\/em> (Mahaleb cherry), P. persica <\/em>(peach), P. persica <\/em>var nectarina<\/em> (nectarine), P. salicina <\/em>(Japanese plum), Pyrus communis <\/em>(European pear), P. serotina<\/em> (black cherry), Quercus <\/em>sp. <\/em>(oak), Q. cerris <\/em>(European Turkey oak) Q. agrifolia<\/em> (California live oak), Q. alba<\/em> (white oak), Q. chrysolepis <\/em>(canyon oak), Q. macrocarpa<\/em> (bur oak), Q. petraea <\/em>(durmast oak), Q. ilex <\/em>(holm oak), Q. robur<\/em> (common oak), Q. rubra <\/em>(northern red oak), Q. pubescens <\/em>(downy oak), Rhododendron <\/em>sp. <\/em>(azalea), R. ponticum<\/em> (common rhododendron), Rubus idaeus<\/em> (American red raspberry), Senecio <\/em>sp. <\/em>(groundsel), S. cruentus, <\/em>soil, Solanum tuberosum<\/em> (potato), Tanacetum cinerariifolium (<\/em>Pyrethrum), Taxus baccata<\/em> (English yew), Ulmus <\/em>sp. <\/em>(elms), Vaccinium macrocarpon <\/em>(cranberry), Vitis vinifera <\/em>(grapevine) \u00a0(CABI, 2017; Farr & Rossman, 2017; French, 1989).<\/p>\n

Symptoms<\/em>: Phytophthora cambivora<\/em>, along with other Phytophthora<\/em> species, cause root and crown rot disease of walnut, cherry, apple, peach, plum, and apricot (CABI, 2017).\u00a0 The expression of symptoms is dependent on the amount of root and crown tissue affected and speed of destruction.\u00a0 Usually, crown rots advance rapidly and trees fall and die soon after the first warm weather of spring, while their leaves wilt, dry, and remain attached to the tree (Adaskaveg et al<\/em>., 2009).\u00a0 During early stages of infection, infected trees are difficult to differentiate from healthy, non-infected ones.\u00a0 However, as the infection progresses, the leaves become small, chlorotic, and droopy, and grow slowly on terminal shoots.\u00a0 A decline of infected trees sets in and sometimes trees without detectable symptoms die in early summer.\u00a0 Collar and root rot may occur in the same tree.\u00a0 Symptoms of P. cambivora<\/em> often resemble those caused by other root rot or collar rot pathogens.\u00a0 Collar rot is exhibited as decayed bark at the base of the trunk and can start at several points simultaneously, progressing until the lower part of the trunk is completely girdled.\u00a0 Infected roots turn brown, brittle, and necrotic.\u00a0 Infected root systems resulting in necrosis of lateral roots and taproots can affect top growth.\u00a0 Vigorous trees with affected roots may not show appreciable crown symptoms (CABI, 2017).\u00a0 Chronic infections, mainly of roots, cause reduction in growth, early senescence, and leaf fall, and may remain unthrifty for several years before succumbing to the disease.\u00a0 Infected young trees are usually killed due to their small root systems and crown areas (Adaskaveg et al<\/em>., 2015).<\/p>\n

Disease development<\/u>:<\/strong> Similar to most other Phytophthora<\/em> spp., P. cambivora<\/em> survives in the soil in the form of mycelium, sporangia, zoospores and oospores, and thrives in poorly-drained, water-saturated soils.\u00a0 It lives as a saprophyte in litter and in soil containing dead organic material and is favored by moist and moderate climates in a wide range of pH: 3.8-7. It is not resistant to drought.\u00a0 Optimum temperature range for growth is 22-24\u00b0C and maximum temperature (cessation of growth) is >32\u00b0C (CABI, 2017).\u00a0 Jung et al.,<\/em> (2016), reported the ability for P. xcambivora<\/em> (= P. cambivora<\/em>) to grow at temperatures greater that 35\u00b0C.<\/p>\n

Sporangia and zoospores of P. cambivora<\/em> in humid soils are the main source of infection.\u00a0 Sporangia are produced abundantly by young mycelia, which become sterile when they are more than 1 month old.\u00a0 P. cambivora<\/em> produces sporangia from 9 to 30\u00b0C.\u00a0 Most sporangia are found on the ground surface in leaves, petals, or earthworm castings; within the upper 6 cm of soil, and near the crowns of trees (Cox, 2014).\u00a0 Sporangia can germinate directly or, more commonly in P. cambivora<\/em>, indirectly by producing zoospores at 9-27\u00b0C.\u00a0 Zoospores allow a population to increase rapidly and disperse widely in films of free water. \u00a0Zoospores are expelled from sporangia under suitable temperature and moisture conditions and swim by means of their flagella towards their host in response to root exudates.\u00a0 Once a zoospore comes in contact with a root, it germinates producing a germ tube, which penetrates the root directly under waterlogged soil conditions.\u00a0 \u00a0More mycelium develops, and eventually, oospores (sexual spores) are produced, and serve as resting structures that can survive for several years.\u00a0 Phytophthora cambivora<\/em> does not produce chlamydospores (thick-walled, asexual spores) (CABI, 2017).<\/p>\n

Transmission:<\/em> Like most Phytophthora<\/em> species, P. cambivora<\/em> is soil-borne and water-borne and may be spread to non-infected sites through infected plants, nursery and planting stock, and seedlings, soil, run-off and splash irrigation and rain water, and contaminated cultivation equipment, tools, and boots.\u00a0 The pathogen is not seed-borne but can be spread by infected seedlings (CABI, 2017).\u00a0 Irrigation water from canals, rivers, and ponds can be contaminated with Phytophthora<\/em> spp. (Browne & Mircetich, 1995).<\/p>\n

Damage Potential: <\/em>Damage caused by Phytophthora cambivora<\/em> alone may be difficult to assess as more than one species of Phytophthora<\/em> may be associated with root and crown rot of host trees (Mircetich & Matherton, 1976).\u00a0 Loss of production of apple, cherry, noble fir Christmas trees have been reported from North America (CABI, 2017).\u00a0 Walnut, peach, plum and apricot are also susceptible to P. cambivora<\/em> and other Phytophthora<\/em> spp. \u00a0Nurseries, nursery stock and ornamental productions may be at risk and need to be monitored.<\/p>\n

California\u2019s native vegetation is also at risk of root and crown rot caused by P. cambivora<\/em> and other Phytophthora<\/em> spp., many of which are endemic (limited) to the State, while some are rare, endangered, or threatened plants, e.g.,<\/em> pallid manzanita, Ione manzanita, sticky white leaf manzanita, valley oak, bristlecone fir, coffeeberry, etc<\/em>. (CNPS, 2017; Calflora, 2017).\u00a0 Introduction of Phytophthora<\/em> species are a threat to plant health in Bay Area restoration sites, where nursery stock is planted for flood control or to mitigate environmental impacts.\u00a0 \u00a0Detections on madrone, toyon, oaks, and manzanitas in native stands indicate that P. cambivora<\/em> is capable of becoming established in a variety of native plant habitats under a range of soil and environmental conditions and can have negative impacts on native vegetation (comments from S. Frankel, plant pathologist, USDA Forest Service, and Phytophthoras in Native Habitats Work Group.\u00a0 July, 2017)<\/em>.<\/p>\n

Worldwide Distribution<\/u>:<\/strong> Asia<\/em>: India, Japan, Republic of Korea, Malaysia, Taiwan, Turkey; Africa<\/em>: Madagascar, Mauritius, Nigeria, South Africa; North America<\/em>: Canada, USA; Europe<\/em>: Austria, Belgium, Croatia, Czech Republic, Denmark, France, Germany, Greece, Hungary, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Romania, Russian Federation, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, United Kingdom, Yugoslavia (former); Oceania: Australia, New Zealand, Papua New Guinea (CABI, 2017).<\/p>\n

In the USA it has been reported from Alabama, Arizona, Arkansas, California, Georgia, Maryland, Michigan, Minnesota, Missouri, Montana, New Jersey, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, Virginia, Washington, West Virginia (CABI, 2017).<\/p>\n

Official Control<\/u>:<\/strong> \u00a0Presently, Phytophthora cambivora<\/em> is on the \u201cHarmful Organism Lists\u201d for Algeria, Canada, Chile, China, Honduras, Nicaragua, and Peru, while, Phytophthora<\/em> spp. is on the \u201cHarmful Organism Lists\u201d for Peru and South Africa (USDA PCIT, 2017).<\/p>\n

California Distribution<\/u>:<\/strong> Phytophthora cambivora<\/em> is widely distributed within California.\u00a0 From 2013-April, 2017, the pathogen was officially detected in Alameda, Contra Costa, Marin, Monterey, Orange, Plumas, San Mateo, San Francisco, Santa Clara, Solano, and Sonoma Counties (CDFA Pest Damage Records<\/em>).<\/p>\n

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

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

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

1) Climate\/Host Interaction: <\/strong>Phytophthora cambivora<\/em> has already established a large distribution under moist and cool to warm climates in California.<\/p>\n

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

Score: 2<\/span><\/strong><\/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

2) Known Pest Host Range:<\/strong> The pathogen has a wide host range.<\/p>\n

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

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

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

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

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

3) Pest Dispersal Potential:<\/strong> Phytophthora cambivora<\/em>, like other Phytophthora<\/em>, has high reproductive capability under moist conditions.\u00a0 It is dependent on moisture for spore dissemination and plant infection. \u00a0It is soilborne and may be spread to non-infected sites through infected plants, nursery and planting stock, and seedlings, soil, run-off and splash irrigation and rain water, and contaminated cultivation equipment, tools, boots, rivers, canals, and ponds.\u00a0 Therefore, it is given a high rating in this category.<\/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>Damage caused by Phytophthora cambivora<\/em> alone may be difficult to assess as more than one species of Phytophthora<\/em> may be associated with root and crown rot of host tree.\u00a0 Loss in production has been reported for apple, certain stone fruit, and noble fir Christmas.\u00a0 Nursery productions of agricultural and environmental host planting stock, could be at risk. Controlling the disease include soil water management and use of resistant varieties, thereby requiring changes in cultural practices and increase in crop production costs.<\/p>\n

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

Economic Impact:<\/strong> A, B, D, G<\/strong><\/span><\/p>\n

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

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

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

D<\/strong>. The pest could negatively change normal cultural practices.<\/span><\/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<\/strong>. The organism can interfere with the delivery or supply of water for agricultural uses.<\/span><\/p>\n

Economic Impact Score<\/strong>: 3<\/strong><\/span><\/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

5) Environmental Impact: <\/strong>In conjunction with other Phytophthora<\/em>, P. cambivora<\/em> may be a contributor to root and crown disease of environmental plants. California\u2019s native vegetation is at risk of root and crown rot damage caused by P. cambivora<\/em> and other Phytophthora<\/em> spp., many of which are endemic (limited) to the State, while some are rare, endangered, or threatened plants.\u00a0 The pathogen is capable of becoming established in a variety of native plant habitats under a range of soil and environmental conditions and can have negative impacts on native vegetation.\u00a0 Also, it may significantly impact ornamental planting.<\/p>\n

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

Environmental Impact:<\/strong> A, B, C,<\/strong> E<\/strong><\/span><\/p>\n

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

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

C<\/strong>. The pest could impact threatened or endangered species by disrupting critical habitats.<\/span><\/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: 3<\/span><\/strong><\/p>\n

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

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

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

Consequences of Introduction to California for Phytophthora cambivora<\/em>:<\/strong><\/h5>\n

Add up the total score and include it here. 14<\/strong><\/span><\/p>\n

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

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

–High<\/strong> = 13-15 points<\/span><\/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\u00a0<\/em><\/strong>Score: (-3)<\/strong><\/span><\/p>\n

-Not established (0) Pest never detected in California, or known only from incursions.<\/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)<\/strong> Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate\/host areas.<\/span><\/p>\n

\u00a0Final Score:<\/h5>\n

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

Final Score: <\/em><\/strong><\/span>\u00a0Score of Consequences of Introduction \u2013 Score of Post Entry Distribution and Survey Information = <\/strong><\/span><\/em>11<\/strong><\/span><\/p>\n

Uncertainty: \u00a0<\/strong><\/h5>\n

None.<\/p>\n

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

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

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

A<\/strong>daskaveg, J. E., J. L. Caprile, W. D. Gubler, B. L. Teviotdale.\u00a0 2009.\u00a0 Cherry: Phytophthora root and crown rot, pathogen: Phytophthora<\/em> spp.\u00a0 UCIPM Statewide Integrated Pest Management Program, University of California Agriculture & Natural Resources.\u00a0 http:\/\/ipm.ucanr.edu\/PMG\/r105100711.html<\/a><\/p>\n

B<\/strong>rowne, G. T., and S. M. Mircetich.\u00a0 1995.\u00a0 Phytophthora root and crown rots.\u00a0 In<\/em> Compendium of Stone Fruit Diseases, Eds: J. M. Ogawa, E. I. Zehr, G. W. Bird, D. F. Ritchie, K. Uriu, and J. K. Uyemoto.\u00a0 APS Press, The American Phytopathological Society. Pages 38-40.<\/p>\n

C<\/strong>ABI.\u00a0 2017.\u00a0 Phytophthora cambivora<\/em> (root rot of forest trees) full datasheet.\u00a0 <\/strong>Crop Protection Compendium. http:\/\/www.cabi.org\/cpc\/datasheet\/40956<\/a><\/p>\n

C<\/strong>alflora.\u00a0 2017. \u00a0Information on California plants for education, research and conservation. [Web application]. 2017. Berkeley, California. The Calflora Database [a non-profit organization]. \u00a0http:\/\/www.calflora.org\/<\/a><\/p>\n

C<\/strong>NPS.\u00a0 2017.\u00a0 Inventory of rare and endangered plants of California (online edition, v8-03 0.38).\u00a0 California Native Plant Society, Rare Plant Program. Website http:\/\/www.rareplants.cnps.org<\/a> [accessed 10 August 2017].<\/p>\n

C<\/strong>ox, K.\u00a0 2014.\u00a0 Phytophthora collar, crown, and root rots.\u00a0 In<\/em> Compendium of Apple and Pear Disease and Pests Second Edition Eds: T. B. Sutton, H. S. Aldwinckle, A. M. Agnello, J. F. Walgenbach.\u00a0 Pages 63-65.<\/p>\n

F<\/strong>arr, D. F., and A. Y. Rossman.\u00a0 2017.\u00a0 Fungal Databases, U.S. National Fungus Collections, ARS, USDA. Retrieved June 9, 2017, from https:\/\/nt.ars-grin.gov\/fungaldatabases\/<\/a><\/p>\n

French, A.M.<\/strong> 1989. California Plant Disease Host Index. California Department of Food and Agriculture, Sacramento (Updated online version by T. Tidwell, May 2, 2017).<\/p>\n

J<\/strong>ung, T., M. H. Jung, B. Scanu, D. Seress, G. M. Kov\u00e1cs, C. Maia, A. P\u00e9rez-Aierra, T. \u2013T. Chang, A. Chandelier, K. Heungens, K. van Poucke, P. Abad-Campos, M. Leon, S. O. Caciola, and J. Bakonyi.\u00a0 2016.\u00a0 Six new Phytophthora<\/em> species from ITS Clade 7a including two sexually functional heterothallic hybrid species detected in natural ecosystems in Taiwan.\u00a0 Persoonia 38: 100-135.<\/p>\n

M<\/strong>ircetich, S. M., and M. E. Matherton.\u00a0 1976.\u00a0 Phytophthora root and crown rot of cherry trees.\u00a0\u00a0 Phytopathology 66: 549-558.<\/p>\n

S<\/strong>aavedra, A., E. M. Hansen, and D. J. Goheen.\u00a0 2007.\u00a0 Phytophthora cambivora<\/em> in Oregon and its pathogenicity to Chrysolepis chrysophylla<\/em>.\u00a0 Forest Pathology, 37: 409-419.<\/p>\n

U<\/strong>SDA PCIT.\u00a0 2017.\u00a0 USDA Phytosanitary Certificate Issuance & Tracking System. Retrieved June 6, 2017. 5:59:40 pm CDT.\u00a0 https:\/\/pcit.aphis.usda.gov\/PExD\/faces\/ReportHarmOrgs.jsp<\/a>.<\/p>\n

\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
NOTE:<\/span><\/h5>\n

You must be registered and logged in to post a comment. \u00a0If you have registered and have not received the registration confirmation, please contact us at\u00a0plant.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

\u00a0Pest Rating: B<\/strong><\/h3>\n
\n

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

California Pest Rating for Phytophthora cambivora (Petri) Buisman 1927 Pest Rating: B PEST RATING PROFILE Initiating Event: None.\u00a0 The current risk and status of Phytophthora cambivora in California are reassessed and a permanent rating is proposed. History & Status: Background:\u00a0 Phytophthora cambiv ora is an oomycete pathogen that can cause crown and root rot disease, … Continue reading Phytophthora cambivora (Petri) Buisman 1927<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1117,"featured_media":0,"comment_status":"closed","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":[156,571],"class_list":["post-3779","post","type-post","status-publish","format-standard","hentry","category-fungi","category-plant-pathology","tag-fungus","tag-phytophthora-cambivora"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":false,"jetpack_shortlink":"https:\/\/wp.me\/p5l8vQ-YX","jetpack-related-posts":[{"id":4027,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=4027","url_meta":{"origin":3779,"position":0},"title":"Phytophthora cactorum (Lebert & Cohn) J. Schr\u00f6t. 1886","author":"Admin","date":"August 25, 2017","format":false,"excerpt":"California Pest Rating Proposal for Phytophthora cactorum (Lebert & Cohn) J. Schr\u00f6t. 1886 Pest Rating: B PEST RATING PROFILE Initiating Event: None.\u00a0 The current risk and status of Phytophthora cactorum in California are reassessed and a permanent rating is proposed. History & Status: Background:\u00a0 Phytophthora cactorum is an oomycete pathogen\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":1590,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=1590","url_meta":{"origin":3779,"position":1},"title":"Phytophthora tentaculata Kr\u00f6ber & Marwitz 1993","author":"Admin","date":"February 29, 2016","format":false,"excerpt":"California Pest Rating Proposal for Phytophthora tentaculata Kr\u00f6ber & Marwitz 1993 Pest Rating: B PEST RATING PROFILE Initiating Event:\u00a0 During January 2016, samples of two diseased Diplacus hybrids (monkey flower hybrid varieties) and one of diseased Artemisia palmeri (Palmer sagewort) were collected by Kathleen Kosta, CDFA, from a nursery in\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":2148,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=2148","url_meta":{"origin":3779,"position":2},"title":"Phytophthora quercina T. Jung 1999","author":"Admin","date":"June 21, 2016","format":false,"excerpt":"California Pest Rating for Phytophthora quercina T. Jung 1999 Pest Rating: B\u00a0 PEST RATING PROFILE Initiating Event:\u00a0 On April 25, 2016, two soil samples with roots of valley oak (Quercus lobata) trees that showed symptoms of stunting in a restoration site in Santa Clara County, were collected by Santa Clara\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":1006,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=1006","url_meta":{"origin":3779,"position":3},"title":"Phytophthora siskiyouensis Reeser & E. M. Hansen, 2008","author":"Admin","date":"June 1, 2015","format":false,"excerpt":"California Pest Rating for Phytophthora siskiyouensis Reeser & E. M. Hansen, 2008 Pest Rating: B PEST RATING PROFILE Initiating Event: \u00a0 In October 2014, Suzanne Latham, CDFA plant pathologist detected the oomycete, Phytophthora siskiyouensis which was isolated from a diseased alder tree with a bleeding trunk canker in Mill Valley,\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":829,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=829","url_meta":{"origin":3779,"position":4},"title":"Phytophthora hedraiandra de Cock & Man in\u2019t Veld","author":"Admin","date":"April 9, 2015","format":false,"excerpt":"California Pest Rating for Phytophthora hedraiandra de Cock & Man in\u2019t Veld Pest\u00a0Rating: B PEST RATING PROFILE Initiating Event: Recently, Suzanne Latham, CDFA plant pathologist, detected Phytophthora hedraiaindra in Arctostaphylos pumila samples that were collected from a nursery in Monterey County during an inspection related to an earlier detection of\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":1003,"url":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/?p=1003","url_meta":{"origin":3779,"position":5},"title":"Phytophthora niederhauserii Abad & J. Abad, 2014","author":"Admin","date":"June 1, 2015","format":false,"excerpt":"California Pest Rating for Phytophthora niederhauserii Abad & J. Abad, 2014 Pest Rating: B PEST RATING PROFILE Initiating Event: \u00a0 None.\u00a0 A permanent rating for Phytophthora niederhauserii is proposed herein. History & Status: Background: In 2003, Abad and Abad reported the discovery of a Phytophthora species associated with necrotic collars,\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\/3779","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=3779"}],"version-history":[{"count":10,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts\/3779\/revisions"}],"predecessor-version":[{"id":10586,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=\/wp\/v2\/posts\/3779\/revisions\/10586"}],"wp:attachment":[{"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/Section3162\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}