California Pest Rating for
Convolvulus arvensis L.: Field bindweed
Pest Rating: C | Proposed Seed Rating: R
PEST RATING PROFILE
Convolvulus arvensis is currently C-rated. A pest rating proposal is required to support an official pest rating based on current information.
History & Status:
Background: Convolvulus arvensis is a deep-rooted perennial herb with prostrate stems. The leaves are hairless and obovate with a notched base, and they reach up to 7.5 cm long and 3 cm wide. The flowers are trumpet shaped, white to pink in color, and 2.5 cm to 3.8 cm inches wide. Reports indicate that seeds of this species can persist in soil for up to 60 years and the roots are reported to grow up to 30 feet deep (Appleby, 1999). It is a highly invasive garden and agricultural weed that difficult to eradicate. It is also found in other habitats, including wooded areas.
Worldwide Distribution: Convolvulus arvensis is native to Eurasia and has been introduced widely to temperate and tropical regions throughout the world. It may be found between 60°N and 45°S latitude (Discover Life, 2016).
Official Control: Convolvulus arvensis is listed as a harmful organism in Australia, Ecuador, Honduras, Nauru, Nicaragua, and Taiwan. It is listed as a noxious weed in Alaska, Arizona, Arkansas, Hawaii, Idaho, Iowa, Kansas, Michigan, Minnesota, Missouri, Montana, North Dakota, South Dakota, Texas, Utah, Wisconsin, Wyoming, California, Colorado, New Mexico, and Oregon.
California Distribution: Convolvulus arvensis was first reported in California in 1850 in San Diego (CalFlora 2018, CCH 2018). It has since spread, and it is documented from all counties in California except Del Norte.
California Interceptions: Convolvulus arvensis has been intercepted 123 times from 2003 through September 2018 by CDFA. These interceptions were mostly through seed certification program and general botany surveys (PHPPS- PDR Database).
The risk Convolvulus arvensis (field bindweed) would pose to California is evaluated below.
Consequences of Introduction:
1) Climate/Host Interaction: Convolvulus arvensis has become widely established throughout California, so it has demonstrated that the climates and habitats found in the state are conducive to its establishment. This plant can grow in nurseries, crops, vineyards, and range land. Therefore, it receives a High (3) in this category.
Evaluate if the pest would have suitable hosts and climate to establish in California:
– Low (1) Not likely to establish in California; or likely to establish in very limited areas.
– Medium (2) may be able to establish in a larger but limited part of California.
– High (3) likely to establish a widespread distribution in California.
2) Known Pest Host Range: Convolvulus arvensis does not require any one host, but grows wherever ecological conditions are favorable. It receives a High (3) in this category.
Evaluate the host range of the pest.
– Low (1) has a very limited host range.
– Medium (2) has a moderate host range.
– High (3) has a wide host range.
3) Pest Dispersal Potential: Convolvulus arvensis spreads by seed and sprouted rhizomes and roots. Each plant produces up to 500 seeds that can be viable in the soil for up to 20 or more years. These seeds can be dispersed by birds, water, and contaminated farm vehicles. The most common dispersal method of this weed is the use of contaminated seed stocks in Commerce. It receives a High (3) in this category
Evaluate the natural and artificial dispersal potential of the pest.
– Low (1) does not have high reproductive or dispersal potential.
– Medium (2) has either high reproductive or dispersal potential.
– High (3) has both high reproduction and dispersal potential.
- Economic Impact: Convolvulus arvensis grows rapidly and competes with native vegetation and agricultural crops. Yield reductions of 20-80% have been reported in annual crops, including cereals and grain legumes (Phillips and Timmons, 1954; Black et al., 1994). Convolvulus arvensis can impede harvesting of annual crops because the crop becomes entangled with the twining stems of this plant. The heavy infested foliage contains alkaloids that can cause intestinal problems in horses (Todd et al., 1995). It receives a High (3) in this category.
Evaluate the economic impact of the pest to California using the criteria below.
Economic Impact: A, B, C, D, F
A. The pest could lower crop yield.
B. The pest could lower crop value (includes increasing crop production costs).
C. The pest could trigger the loss of markets (includes quarantines).
D. The pest could negatively change normal cultural practices.
E. The pest can vector, or is vectored, by another pestiferous organism.
F. The organism is injurious or poisonous to agriculturally important animals.
G. The organism can interfere with the delivery or supply of water for agricultural uses.
Economic Impact Score: 3
– Low (1) causes 0 or 1 of these impacts.
– Medium (2) causes 2 of these impacts.
– High (3) causes 3 or more of these impacts.
5) Environmental Impact: Convolvulus arvensis can compete with native vegetation for nutrients, moisture, space, and light, which could decrease the biodiversity of infested areas in California. Infestations of this plant could trigger additional private treatment programs in infested areas. It receives a High (3) in this category.
Evaluate the environmental impact of the pest on California using the criteria below.
Environmental Impact: A, D
A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.
B. The pest could directly affect threatened or endangered species.
C. The pest could impact threatened or endangered species by disrupting critical habitats.
D. The pest could trigger additional official or private treatment programs.
E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.
Environmental Impact: Score: 3
– Low (1) causes none of the above to occur.
– Medium (2) causes one of the above to occur.
– High (3) causes two or more of the above to occur.
Consequences of Introduction to California for Convolvulus arvensis (Field bindweed): High (15)
–Low = 5-8 points
-Medium = 9-12 points
-High = 13-15 points
6) Post Entry Distribution and Survey Information: Convolvulus arvensis is fully established and widespread in California. It receives a High (-3) in this category.
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:
-Not established (0) Pest never detected in California or known only from incursions.
-Low (-1) Pest has a localized distribution in California or is established in one suitable climate/host area (region).
-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.
-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.
The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)
Convolvulus arvensis has been in California for over 120 years and it has become established in every county except Del Norte, although in limited areas. Therefore, it is little uncertainty associated with this assessment.
Conclusion and Rating Justification:
Based on the score listed above, Convulvulus arvensis is medium risk. It will continue to spread, but it is already widespread through the state. Because it is so widespread in California, a “C” rating is recommended.
Appleby, A. 1999. Field bindweed (Convolvulus arvensis). Accessed September 19, 2018.
CABI Crop Protection Compendium online data sheet. Convolvulus arvensis (bindweed). CABI Publishing 2011. Accessed September 18, 2018
CalFlora: Information on California plants for education, research and conservation. Accessed September 18, 2018.
Consortium of California Herbaria [CCH], 2018. Data provided by the participants of the Consortium of California Herbaria. Regents of the University of California. Accessed September 2018. http://ucjeps.berkeley.edu/consortium/.
Phillips, W. and Timmons, F. 1954. Bindweed – how to control it. Bulletin 366, Fort Hays Branch, Kansas Agricultural Experimental Station, Manhattan, Kansas, USA.
Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. Accessed September 18, 2018. http://phpps.cdfa.ca.gov/user/frmLogon2.asp
University of California Agriculture and Natural Resources. Accessed September 18, 2018.
USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed September 19, 2018.
Javaid Iqbal; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695
Dean Kelch, Primary State Botanist, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6650; plant.health[@]cdfa.ca.gov.
11/29/2018 – 1/13/2019
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Pest Rating: C | Proposed Seed Rating: R
Posted by ls