# United States

**Department of Ag**  **riculture**

**Risk Management Document** 

# Importation of **Live Greenhouse -**  **Grown Tomato Plantlets**  **( Solanum**  **lycopersicum )**  **in APHIS -**  **Approved Growing Media**  **from Mexico**  **into the Continental** 

**United States**

**October 28**  **, 20 14**  **Ver. 1. 1**  **7**

**USDA , A**  **nimal and Plant Health Inspection Serv ice**  **Plant Protection and Quarant ine**  **Plant Health Programs Regulations, Permits and Manuals**  **Contact Person: Lydia Col** **ó n** Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 2



## Introduction P lants in growing media imported into the United States must be approved by Umited States Department of Agriculture (USDA), Animal and Plant Health Insp ection Service (APHI S ) and must comply

with all requirements under Title 7 of the Code of Federal Regulations (CFR) , Part 319.37
- 8 ( CFR, 2013 ). Currently , under this regulation, the importation of tomato plantlets in growing media from Mexico into the continental United States is not authorized. Furthermore, as a result of a notice published in the Federal Register on April 18, 2013, tomato plants from all countries other than Canada are not authorized importation pending a pest risk analysis
. APHI S conducted a pest risk assessment (PRA) in response to a request from the Servicio Nacional de Sanidad, Inocuidad y

Calidad Agroalimentaria (SENASI CA), the national plant protection organization (NPPO) of Mexico, for a change in F ederal regulation s to allow the entry of greenhouse
- grown grafted tomato plantlets i n growing media from Mexico for use in commercial greenhouse fruit production (USDA, 2013 )
. The APHI S PRA identified and further analy zed seven pest s that appeared to have a reasonable likelihood of being associated with live plantlets of Solanum lycopersicum : Aleurodicus dispersus (Hemiptera: Aleyrodidae) Bemisia tabaci (including bio types B and Q) (Hemiptera: Aleyrodidae) Trialeurodes vaporarium (Hemiptera: Aleyrodidae) Liriomyza huidobrensis (Diptera: Agromyzidae) Maconellicoccus hirsutus (Hemiptera: Pseudococcidae) Paracoccus marginatus (Hemiptera: Pseudococcidae) Thrips palmi (Thys anoptera: Thripidae). The PRA considered the likelihood and consequences of introducing these pests and indicated that all of the pests selected for further analysis received Negligible risk ratings for likelihood of introduction (i.e., entry

plus establ ishment) into the endangered area via the import pathway
. For pests receiving a N egligible risk rating, p est introduction is considered highly unlikely to occur given the exact combination of events required for successful introduction (USDA, 2012 )
. In reaching this finding, the PRA considered the effects of all greenhouse specifications described in supporting documents provided by the NPPO of Mexic o (SAGARPA 2010, 2013)
. Those production/greenhouse specifications include:

 T omato plantlet production follows s trict sanitation protocols ( SAGARPA, 2010 )
 Plantlets used as rootstock and scion are started from certified seed germinated inside the greenhouses ( SAGARPA, 2010 ).
 Water used in the greenhouse is either spring or well water and is disinfected with chlorine and ultraviolet light ( SAGARPA, 2010 ).
 Workers enter the greenhouse through sanitation stations ( SAGARPA, 2010 ).
 Greenhouse perimet er and all clean areas have double insect screening , including ventilation ports ( SAGARPA, 2010 ).
 Screen openings are small enough to exclude the entrance of thrips into the area, therefore also excluding aphids, whiteflies and larger Hemiptera ( SAGARPA, 2013 ).
 Greenhouses have a

utomated sprinkling s ys tems ( SAGARPA, 2010 ).Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 3



###  In sect traps near entrances and throughout the greenhouse are used to monitor the presence of insects

– ye llow to attract aphids and whiteflies and blue to attract thrips ( SAGARPA, 2010 , 2013 ).
 Biological control agents are released inside the greenhouses on a bi
- weekly basis ( SAGARPA, 2013 ).
 In secticides are available for pest control in the event of pest presence

– these include py rethroids, neem extracts, insecticidal soaps, spinosad, sulphur and bacterial pesticides ( SAGARPA, 2013 ). As described in this Risk Management Document (RMD) , APHI S has evaluated the pests described in the PRA (USDA, 2013) and determined that the requirements in 7 CFR 319.37
- 5(r)(3) and 319.37
- 8 ( CFR, 2013 ) will be effective in managing the risk associated with these pests. APHI S propose s to add Solanum lycopersicon from Mexico to the approved plants in 7 CFR 319 .37
- 8(e). 

## Risk Management **Measures** S. lycopersicum plants in growing media imported into the United States from Mexico must , at a minimum , comply

with the requirements in 7 CFR 319.37
- 8, and all other requirements in 7 CFR 319.37 including the requirem ents of 7 CFR 319.37
- 5(r)(3) ( CFR, 2013 ) for restrict ed articles of Pelargonium spp. or Solanum spp. The requirements in 7 CFR 319.37
- 8 and 7 CFR 319.37
- 5(r)(3) comprise “systems approaches” with a combination of integrated measures aimed at reducing pest risk. The International Plant Protection Convention (IPPC) defines a “systems approach” as, “ The integration of different risk management measures, at least two of which act independently , and which cumulatively achieve the appropriate level of protection against regulated pests ” ( IP PC, 2010 ). Similarly , the Plant Protection Act of 2000 ( PPA, 2000 ) defines a “systems approach” as “...a defined set of phy tosanitary procedures, at least two of which have an independent effect in mitigating pest risk associated with th e movement of commodities.” The USDA Minimum Sanitation Protocols for Offshore Geranium Cutting Production (USDA, 2007) provides the operational details for the systems approach described in 7 CFR 319.37
- 5(r) (3)
. As noted above, the PRA (USDA, 2013 ) considered procedures described in supporting documents provided by

the NPPO of Mexic o , and listed above (SAGARPA 2010, 2013) , as mandatory
. Inaddition to those procedures , APHI S has determined the pest risk management measures necessary

for the importation of tomato plantlets in growing media from Mexico into the United States must inclu de the following integrated pest risk management measures listed in 7 CFR 319.37
- 8 and 7 CFR 319.37
- 5(r)(3) : 1. The NPPO of Mexico must enter into a bilateral workplan with APHI S setting out the conditions for producing and monitoring plant production and enforcement of the requirements of the regulations and ; 2. The grower must enter into a written agreement with the NPPO of Mexico and agree to comply with the provisions of the regulations and to allow the NPPO access forMexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 4



### monitoring inspections. The producti on site must be registered with and approved by both APHI S and the NPPO of Mexic o . Shipments of exported tomato plantlets must be traceable bac k to the the production site where they originated ; 3. After the initial approval, the production site must be ins pected annually by APHI S and /or the NPPO of Mexico ; 4. Plants must be grown in APHI S
- approved growing medium which has not been used previously

and is treated as described in USDA ( 2007 ) to ensure free dom from Ralstonia solanacearum race 3 biovar 2 ; 5. Growing media and the containers in which the plants are grown must be safeguarded from contact with potentially infested soil or media and must not come in direct contact with any water source such as a hose end or irrigation emitter; 6. Plants must be grown solely in pest ex clusionary

greenhouses that meet the following requirements:
 Sanitary

procedures to exclude quarantine pests must always be employed, including the cleaning and disinfection of b enches, floors and tools ;  Pest management measures , including monitoring for pests with ye llow or blue sticky traps , must be applied to protect against quarantine pests . While in the greenhouse, plants must be treated with appropriate pesticides as needed to maintain a pest
- free condition ; 7. The greenhouse must be free from sand and soil ; 8. Dicotyledonous weeds must be controlled inside the greenhouse;
 All vents and openings except entry ways must be covered with screens having openings small enough to exclude arthropod pests including thrips 1 

### ;  Entry ways must be equipped with automatic closing double doors ; 9. Plants must be grown in a greenhouse unit that is used solely for articles grown in compliance with these regulations; 10. Greenhouses must be constructed in such a manner to prevent runoff water from surrounding areas to enter the gre enhouse; 11. Greenhouses must be surrounded by a one meter buffer free of dicotyledonous weeds and sloped so that water drains away from the greenhouse ;

1 7CFR§319.37
- 8 requires all vents and openings must be covered with screens having openings no greater than 0.6 mm (30 mesh). However, SAGARPA (2013) states, “The tomato plantlets are grown in the dedicated nursery area that is fitted with screens on all openings. These screens are small enough to exclude the entrance of Thrips into the growing area, therefore also excluding the larger Hemiptera insects, aphids and whiteflies.” Because of thrips small size, a mesh size of 80 (0.177 mm opening) or smaller is required to restrict their entry into the greenhouse ( Bethke, 1994 ; Ghidiu and Roberts ; Sood, 2010 )
.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 5



### 12. Plants must be grown solely from certified seeds germinated in the aforementioned pest exclusionary

greenhouse; 13. Water must be derived from an APHI S
- approved source and/or be treated by an APHI S
approved method (USDA, 2007 ); water must be tested at least annually and found free from Ralstonia solanacearum race 3 biovar 2 ; 14. Ebb and flow irrigation is not permitted and drip irrigati on systems must be equipped with back flow preventers; 15. All equipment that comes in contact with S. lycopersicum plants must be sanitized so that R

. solanacearum race 3 biovar 2 is not transmitted between plants or enter from outside the production site v ia the equipment ; 16. Production site personnel must receive training to recognize and prevent the introduction of R

. solanacearum race 3 biovar 2 ; 17. Production personnel must adequately sanitize clothing and shoes and wash their hands before entering the greenhouse; 18. Plants must be grown on benches supported by legs at least 46 cm above the floor ; 19. Plants must be s tored and packaged in areas free from s oil, sand and quarantine pests; 20. Plants must be handled and packed to prevent the introduction of R

. solanace arum race 3 biovar 2 and labeled to identify the production site; 21. Plants must be i nspected in the greenhouse and found free from evidence of quarantine pests by APHI S or the NPPO of Mexico no more than 30 days prior to export ; 22. The production site must co nduct ongoing testing for R

. solanacearum race 3 biovar 2 using an APHI S
- approved testing protocol (USDA, 2007 ) . R ecords must be kept and made available to APHI S and the NPPO of Mexico for two growing seasons; 23. Detection of R

. solanacearum race 3 biovar 2 at the production site or in consignments from the production site will result in removal from export eligibility until reinspection determines the site is free from R

. solanacearum race 3 biovar 2 and APHI S is satisfied all problems have been addressed; 24. Consignments must be accompanied by a Phy tosanitary Certificate with an Additional Declaration indicating the requirements of 7 CFR 319.37
- 5(a) [potato cyst nematode], 7 CFR 319.37
- 5(r)(3) [Ralstonia ] and 7 CFR 319.37
- 8 (e) [growing media] have been met
. 25. Inaddition to the integrated pest risk management measures of 7 CFR 319.37
- 8 and 7 CFR 319.37
- 5(r)(3), APHI S will require a signed Compliance Agreement betweenMexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 6



### APHI S and the importing greenhouse. Stipulations within the Compliance Agreement will require periodic APHI S inspe ctions of the facility and plant material while actively growing in the importing greenhouse. Conditions of the compliance agreement include the following, as well as additional measures as deemed necessary by APHI S Officials in order to maintain phy

tosan itary protection of U
. S
. agriculture and the environment: **Import ation**  **/Notification/Transport ation** 

 An importing greenhouse representative shall inform the APHI S Plant Protection and Quarantine ( PPQ ) State Plant Health Director (SPHD) (or their authorized designee) and the Plant In spec tion Station (PI S) at least 24 hours prior to the arrival of the tomato plantlets
.  The tomato plantlets must be imported in sealed packaging
.  The tomato plantlets must enter through a PI S . An APHI S inspector at the PI S will c onfirm that the shipment is accompanied by an official foreign phy

tosanitary certificate.
 The tomato plantlets must arrive with specified lot numbers or other distinguishable marks which will allow for any necessary

traceback investigations by the NPPO of Mexic o .  An APHI S inspector will conduct an inspection of the tomato plantlets. I f found free of obvious pests, the packaging will be resealed and conditionally forwarded to the importing greenhouse under APHI S seal.
 At the importing greenhouse, all shipping boxes and crates may only be opened by trained facility

staff within the confines of the approved importing greenhouse. All subsequent actions or handling of the tomato plantlets, (repotting, etc.) may only be performed inside the importing greenhou se by trained facility

staff.
 Plants or plant parts (e.g., prunings) may only be removed from the approved importing greenhouse for destruction on the premises with specific authorization and safeguarding instructions from a PPQ officer. Shipping boxes an d crates may be removed or discarded only with specific authorization and approved instructions from a PPQ officer.
 **Pest Management**

 Prior to importation, the facility manager of the importing greenhouse will provide a pest management plan to APHI S for review and approval.
 Any pest detections by

facility personnel within the greenhouse will require immediate notification of the APHI S PPQ SPHD.  Any pest detections or sy

mptoms of infestation found on plant material by the facility personnel must be preser ved and submitted for review by a PPQ o ffic er who will obtain an official identification of the pest or assess the need for further action.
 The approved importing facility shall take steps to contain the pests as soon as detected.
 Upon the detection of any quarantine significant pests by the facility personnel ,Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 7 

### the greenhouse should be sealed and no entry permitted until authorized by APHI S and the State Plant Regulatory Official (SPRO)
. **Production**

 The imported tomato plantlets will be used only for fruit production. No increase of these plants by

cuttings, grafting, suckers, flowers, seeds or air layers is authorized; distribution of the imported tomato plantlets beyond the confines of the importing facility

is prohibited. **Facility Inspections and Audit**  **s**

 PPQ will inspect the greenhouse, the imported tomato plantlets, and the surrounding area for any

evidence of pests of quarantine significance to the United States. PPQ will also perform paper and operational audits to verify compliance with the stipulations outlined in the signed Compliance Agreement for this program.  PPQ will inspect the importing greenhouse within one week of the arrival of the tomato plantlets and prior to the first fruit harvest
.  PPQ may

conduct additional periodic inspections during the production cycle for each lot of tomato plantlets.
 If pests are found, APHI S shall consult with the authorized facility manager to determine the appropriate action to take based on the circumstances and the ty pe of pest detected.
 If actionable pest s are discovered, the level of contamination will be assessed by PPQ , taking into consideration the segregation and safeguarding of various sections with the facility . This may result in the need to destroy part or all of the importing greenhouse plant material.
 Plants infested with actionable pests shall be incinerated , heated to 170° F for 30 minutes or otherwise destroyed by methods approved by

APHI S . However, any finding of pests or pest damage would be preserved until the PPQ officer can obtain an o fficial identification of the pest or assess the need for further action
. A discussion of the applicability and efficacy

of the various measures that are required by 7CFR§319.37
- 8, 7CFR§319.37
- 5(r) , measures indicated by the NPPO of Mexic o ( SAGARPA, 2010 , SAGARPA, 2013 ) and identified in the PRA (USDA, 2013 ) as mandatory and additional measures required by

APHI S for this request is found below
.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 8



## Selected Ev **idence for the Efficacy**  **of Risk Management Measures**  The efficacy

of m easures required for risk m anagement on S. lycopersicum plantlets in growing media from Mexico is summarized in Table 1
. **Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** Wr itten compliance a greements (1, 2) All pests The NPPO of the producing country must enter into a bilateral workplan with APHIS setting out the conditions for producing and monitoring plant p roduction and enforcement of the requirements of the regulation

. Likewise, the production facility must enter into a compliance agreement with the producing country NPPO. Improper production and handling practices are often the primary means by

which pest s are introduced and spread in the place of production. The phy tosanitary

written agreements and admini strative measures included in 7 CFR § 319.37 - 8 and 7CFR§ 319.37 - 5 (r) (3) provide additional phy tosanitary

quality control and rigor over other measures, and reduce the possibilities of improper practices being employed. These measures are standard for many export programs and assist in maintaining quality of the program. Registered p laces of production (2) All pests Places of production are registered to ef fectively maintain quality

control and traceback. Traceability (2) All pests Labelling of consignments to allow traceback is required. Traceback is effective at removing problem places of production from the systems approach. 7CFR§ 319.37 - 5 (r)(3) requir es removal of export eligibility of a facility in the event of the d etection of Ralstonia at the in consignments

. Traceback enables the identification of the problem facility

. Annual facility

inspection (3) All pests Requiring an annual inspection of each registered facility by APHIS and / or the NPPO of Mexico ensures compliance with written workplans and compliance agreements which, in turn, helps ensure that U.S. import requirements are met.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 9

**Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** Grown in sterilized APHIS
approved growing m edia (4, 5) R alstonia solanacearum Liriomyza huidobrensis Thrips palmi 7CFR§319.37
- 5 (r)(3) requires that growing m edia m ust be free of R. solanacearum and must be an APHIS approved growing medium as listed in 7CFR§319.37
- 8 ( e ) (1). SAGARPA, 2010 indicates that tomato plantlets will be grown in peat and rock wool; both are approved media. The USDA Minimum Sanitation Protocols f or Offshore Gera nium Cutting Production ( USDA, 2007 ) further requires that the growing media be sterilized by steam or fumigation. T he use of new, sterilized growing m edia reduces the risk of introducing Liriomyza pupae into the crop ( Bethke, 2010 )

. S oil sterilization, including steam and methy l bromide are effective in controlling soil inhabiting pupae of Liriomyza ( Cheek, 1999 ). S oil sterilization will kill im ma ture thrips that are pupating in the soil ( Shipp et al., 1991 ). In general, using sterile or sterilized growing media reduces the likelihood of crop infestation by

soil - dwelling pest life sta ges ( Cheek, 1999 ).Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 10

**Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** Sanitation (disinfection of surfaces, equipment,etc.; removal of plant debris, sand, soil , weeds ) (5, 6 , 7 ) All pests Sanitation and exclusion are highly effective in controlling most pests ( Dreistadt, 2001 ). “ Strict adherence to good sa nitation practices is essential to the management of bacterial diseases ” ( Dicklow, 2013 )

. SAGARPA ( 2010 ) provides ge neral information indicating that grafting areas will be disinfected regularly and that grafting benches are equipped with disinfectant for tools. The APHIS Minimum Sanitation Protocols f or Offshore Geranium Cutting Production ( USDA, 2007 ) requires that g reenhouse floors be mai ntained free of debris and weeds and f loors must drain properly to prevent puddling. Plant m aterial (cuttings, trimmings, etc) that falls to the floor should not be retrieved by greenhouse workers who are in the process of handling production stock plants ; it should be removed on a periodic basis (minimum weekly ) and disposed of by other workers or by

same workers after harvesting of cuttings is completed. Floors are to be sanitized at least once annually

when greenhouses are cleared of stock production p lants or before they

are set up for the next growing season. Furthemore, the protocol requires s urfaces upon which plants are grown should be disinfested prior to use and constructed so water draining from pots does not make contact with other pots. Gree nhouse equipment used to ma ke grafts or cuttings or used for other functions involving contact with plants is to be surface disinfested prior to and between use on each plant or container. Alternatively , a set of knives can be assigned to a specific bench and rotated and disinfected between each plant. Carts and collection baskets are to be sprayed with a surface disinfectant on all surfaces that are likely

to come into contact with plants or equipment used in processing plants . Equipm ent (knives, etc) u sed to harvest cuttings is to be soaked in surface disinfectant when not in use

. Liriomyza larvae remain inside the leaf onto which they hatched until they pupate. After feeding, mature larvae exit the leaf and drop to the ground to pupate. Pupae can re ma in viable in the soil or substrate for several mo nths at low tem peratures and cause re - infestation in the following crop. Sanitizing floors, benches or areas underneath benches lowers the potential for these areas to harbor pupae. Regular, rapid removal of plant debris prevents the continuing developm ent of foliar stages of pests such as Liriomyza spp. on excised leaves ( Cheek, 1999 )

.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 11

**Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** Yellow and blue sticky

traps in the greenhouse mo nitored on a regular basis, at least weekly (6) L. huidobrensis T. palmi Sticky traps are an efficient tool for monitoring early infestations of thrips ( Brødsgaard, 1989 ). In addition to m onitoring plants for Liriom yza feeding an d oviposition dam age (stippling) and for the presence of small mines on plants, sticky traps are used for detection of leafminer activity

. Yellow sticky cards are the best detection method for monitoring populations of adult activity ( Bográn, 2005 ; We intraub and Horowitz, 1996 )

. Required pest management plan. Wh ile in the greenhouse, plants must be treated w ith appropriate pesticides as needed to maintain a pest - free condition (6) Arthropods A comprehensive pest management plan must be implemented, and must include monitoring, inspections for signs of infestation, and targeted pest control as appropriate. In formation gathered from scouting is used to select and schedule appropriate control tactics ( Bethke, 2010 )

. The pest ma nagem ent plan m ust be approved by the NPPO, and if treatments are required, these must be approved and prescribed by the NPPO. All vents and openings are covered with screen (8) Arthropods 7CFR§319.37
- 8 requires a ll vents and openings must be covered with screens having openings no greater than 0.6 mm (30 mesh)

. This mesh size is small enough to exclude leafminers ( Bethke, 1994 ). Adult Liriom yza flies are 1
- 3 mm in length with a wingspan of about the same dim ensions ( CABI, 2014 )

. Adults are excluded by greenhouse screens with a n opening of 0.6 mm or smaller ( Bethke, 1994 ; Bethke et al., 1994 ; Bográn, 2005 )

. Wh ile 0.6 m m mesh will not exclude the other smaller arthropod pests (e.g., aphids, whiteflies, thrips) they may provide some lim ited discouragement to their entry

. M esh hole size does not necessarily

correspond with degree of e xclusion ( Bell and Baker, 2000 ). However, SAGARPA ( 2013 ) states, “The tomato plantlets are grown in the dedicated nursery

area that is fitted with screens on all openings. These screens are small enough to exclude the entrance o f Thrips into the growing area, therefore also excluding the larger Hemiptera insects, aphids and whiteflies.” Because of thrips small size, a mesh size of 80 (0.177 mm opening) or smaller is required to restrict their entry into the greenhouse (Bethke, 1 994; Ghidiu and Roberts; Sood, 2010). W e are specify ing me sh screen to be used in conjunction with a pest ma nagem ent program to ensure that no thrips (or other arthropods) will mo ve with tom ato plantlets.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 12

**Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** Entry ways equipped with automatic closing double doors (8) Arthropods Autom atic closing double doors create a plant free area that workers must pass through reducing the likelihood that pests will enter the growing area ( Dreistadt, 2001 ). Plants grown in a greenhouse unit used solely

for articles grown in compliance with the se regulations (9) All pests Avoiding com ingling reduces the likelihood of contamination.

Greenhouse constructed to prevent water entry (10) R. solanacearum race 3 biovar 2 Runoff surface water from fields or waterways with infected weed or crop hosts can carry Ralstonia ( We nneker et al., 1999 ). USDA ( 2007 ) requires that greenhouses are constructed in a manner to prevent contaminated runoff from entering production areas. One meter buffer free of dic o t weeds around greenhouse (11) All pests San itation including t he removal of weeds from inside and outside g reenhouses is an im portant cultural practice for preventing whitefly infestations within greenhouses ( Shipp et al., 1991 )

. L eafminers feed on a large variety

of plant species including weeds , keep ing greenhouses and areas outside the greenhouse free of weeds, which can serve as reservoirs for leafminer population s and exclusion of immigrating adults is valuable as a cultural control ( Bethke, 2010 )

. Grown from certified seed germinated in the greenhouse (12) R. solanacearum race 3 biovar 2 (and other seed pathogens) 7 CFR 319.37 - 8 requires that plants are grown from seed germinated in the pest exclusionary greenhouse. SAGARPA ( 2012 ) and the PRA ( USDA, 2013 ) indicate that certified seed will be obtained from several mu l tinational sources but does not specify what pathogens the seed will be certified as free from. SAGARPA ( 2010 ) furt her states that the seed will be disinfected to remove seed transmitted bacterial pathogens. Wa ter from an APHIS
- approved source treated by

an APHIS approved treatment (13) R. solanacearum race 3 biovar 2 The 7CFR§ 319.37 - 5 (r)(3) requirement for treatment of irrigation water is dependent upon its source and the water storage and delivery system in use. W ater treatment is not required for irrigation water collected from deep wells which are properly sealed and where the water is used directly or stored in tanks with no opportunity for contamination of the water supply by native soil or plant material/debris, or from municipal water directly from the municipal water system. SAGARPA ( 2010 ) states w ater used in the greenhouse is either spring or well water and is disinfected with chlorine and ultraviolet light

. The treatment method used must be equivalent to the treatments described in USDA ( 2007 ).Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 13

**Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** No ebb and flow irrigation; backfow preventers; no emitters or hose ends contact with soil (14) R. solanacearum race 3 biovar 2 Ralstonia is a soilborne pathogen may be spread in contaminated soil, runoff and irrigation water ( Hay ward, 1991 ; We nneker et al., 1999 ). Prohibition of ebb and flow irrigation and contact between emitters or hose ends and soil as well as the use of backflow prevention v alves reduce the possibility

of introducing Ralstonia and are required by 7CFR§ 319.37 - 5 (r)(3) ( USDA, 2007 ). E quipm ent that comes in contact with S. lycopersicum plants must be sanitized (15) R. solanacearum race 3 biovar 2 See “Sanitation” above
Wo rker training (16) All pest s 7CFR§ 319.37 - 5 (r)(3) requires that p roduction site personnel receive training to recognize and prevent the introduction of Ralstonia . Mandatory training decreases the likelihood that personnel will participate in activities that might introduce pests int o the facility and, in the event of an introduction, will increase the likelihood that they will recognize pest sy mp toms and take appropriate action. SAGARPA, 2010 states that the production facility

in Mexico “ has continuous training of supervisors and workers to assure that they receive continuous education and qualification about sanitation protocols and practices

... supervisi on personnel has

... basic knowledge on pest identification .” Wo rker hygiene (17) R. solanacearum race 3 biovar 2 SAGARPA ( 2010 ) provides a general description of the worker hyg ie ne system in the production greenhouses. The infrastructure is designed to lim it access and to force the flow of the people through a series of stations and processes for disinfection including a grate to elim inate the debris from shoes ; a l aundry t o wash uniforms ; an area to store personal belongings so they

do not enter the greenhouse; dedicated footwear that is disinfected upon entry ; handwashing station; an entry way that can only be opened by placing hands in a disinfectatnt bath to reach the release button; a d ressing area with dedicated coveralls. This generally follows the requirements of 7CFR§ 319.37 - 5 (r)(3) as outlined in USDA, 2007

.

. Grown on benches at least 46 cm high (18) R. solanacearum race 3 biovar 2 G rowing plants on raised benches is another measure to prevent contact of production plants with runoff, soil, debris or other potentially c ontaminated materials.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 14

**Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** Stored and packaged in areas free from soil, sand and quarantine pests (19) All pests See “Sa nitation” above Plants handled to prevent the introduction of R

. solanacearum ; labeled to identify

the production site (20) R. solanacearum race 3 biovar 2 See “Sanitation” and “Registered places of production” above
Inspected in the greenhouse and foun d free from evidence of quarantine pests by

an APHIS inspector or an inspector of the NPPO of Mexico , no more than 30 days prior to the date of export to the United States (21) All pests Phy tosanitary

inspections are widely

recognized as an important part of a pest management program ( Kahn a nd Mathur, 1999 )

. Many insects, mi tes and pathogens have visible stages and sy mp toms that are readily detected upon inspection. Inspection is the foundation of pest exclusion used by APHIS to prevent pests from entering the United States. Adult Liriomyza females feed on leaf tissues resulting in a stippled or speckled appearance when they puncture the leaf surface with their ovipositors. Females also puncture leaf tissue to lay their eggs. Larvae feed on leaf tissue creating a serpentine leaf
- mi ne. The mines gradually increase in size as larvae feed and grow ( Bográn, 2005 )

. Stippling and leaf m ines are readily detected by

plant inspection. Careful inspection of all plant material before it is broug ht into the greenhouse and destruction of any

infested plants helps to exclude leafminers. The European and Mediterranean Plant Protection Organization (EPPO) has recommended inspection of plants for planting at least every month as a me ans to prevent the spread of Agromy zidae leafm iners in exported plants ( CABI, 2014 )

.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 15

**Table 1 .**  **Efficac y of risk**  **management requirements**  **for S.**  **lycopersicum plantlets in grow**  **ing media fro**  **m Mexico**  **( n**  **umber in parentheses**  **refers to mitigations list above)**

**Measure(s) Pests**  **Efficacy** Regular testing of each lot for Ralstonia (22, 23) R. solanacearum race 3 biovar 2 All plant m aterial must be free of Ralstonia solanacearum

. The sampling protocol and diagnostic methods must be approved by APHIS

. Records of disease testi ng are to be maintained and made available to APHIS upon request. In addition, plants are scouted regularly for signs of wilt, and tested for R. solanacearum as necessary . All plants that are to be discarded must be tested prior to destruction. W here pos itive results are attained, all plants in the greenhouse are to be destroyed, and the greenhouse decontaminated. The infested facility is to be quarantined, until such time that APHIS and the Mexican NPPO are satisfied that the infestation has been elimin ated ( USDA, 2007 )

. Con signments accompanied by a Phy tosanitary

Certificate indicating the requirements of 7 CFR 319.37
- 5(a) [potato cyst nem atode], 7 CFR 319.37
- 5(r)(3) [ Ralstonia ] and 7 CFR 319.37 - 8 (e) [growing media] have been m et (24) All pests Provides assurance that NPPO has verified that plants in any given consignment have been produced in accordance with the cited regulations. “ Phy

tosanitary

certification is used to attest that consignments me et phy

tosanitary

im port requirements and

... contributes to the protection of plan ts, including cultivated and uncultivated/unmanaged plants and wild flora (including aquatic plants), habitats and ecosystems in the im porting countries. ” ( IPPC, 2011 ) Safeguarding of plants during im portation and transportation (25) All pests As noted above, s anitation and exclusion are highly effective in controlling mo st pests ( Dreistadt, 2001 ). “ Strict adherence to good sanitation practices is essential to the management of bacterial diseases ” ( Dicklow, 2013 )

. G rowth and inspection of im ported plants under compliance agreement (25) All pests Phy tosanitary

inspections are widely

recognized as an important part of a pest management program (Kahn and Mathur, 1999). Postentry inspection will provide additional opportunity to detect pests that devel op as the plant matures from the very young age and stage of development at the time of import. Growth under compliance agreement will provide safeguards on the production of plants , and, in the unlikely event of a pest detection, will ensure that the plan ts are disposed of in a manner that does not result in dissemination of pests. Growth under compliance agreement will also ensure that fruit from the plantlets that is moved from the nursery for commercial distribution does not disseminate plant pests.Mexico Tomato PIGM RMD Ver. 1. 1 6 October 9 , 2014 16



## Summary APHI S concludes that commercial shipments of grafted tomato plantlets established in APHI S
approved growing media produced using the integrated pest risk management measures described in the preceding section of this document in Mexico may sa fely be imported into the continental United States for the intended use of commercial fruit production without the risk of introducing Ralstonia solanacearum race 3 biovar 2 or the seven arthropod pests noted above or other pests of quarantine significanc e as listed in the PRA conducted to inform this market access request (USDA, 2013 )
. Most of the measures included in this risk management document are already requ ired by

APHI S for importation of other plants in growing media. Additionally , if the measures listed above are adhered to, there is a negligible risk of tomato fruit from such plantlets introducing pests of quarantine significance into the United States. 

## Au **thor s**  W
. Gould Senior Risk Manager, R egulations, P ermits and M anuals C. Marasas Senior Risk Manager, Regulations, Permits and Manuals E.V. Podleckis Senior Risk Manager, Regulations, Permits and Manuals


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to greenhouses. California Agriculture 48(3):37
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