Document ID: EPA-HQ-OAR-2006-1016-0086
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-08-27T04:00Z

Methyl Bromide Critical Use Nomination for Preplant Soil Use for
SweetPotato Propagative Hot Beds Grown in Open Fields and Protected with
Row Covers – Related to the Use Recommended by MBTOC for 2005

For Administrative Purposes Only:

Date received by Ozone Secretariat:

YEAR:                              CUN:

Nominating Party:	The United States of America

Brief Descriptive Title of Nomination:	Methyl Bromide Critical Use
Nomination for Preplant Soil Use for Sweet Potato Propagative Hot Beds
Grown in Open Fields and Protected with Row Covers – Related to the
Use Recommended by MBTOC for 2005 (Prepared in 2006 for 2008)

Nominating Party Contact Details

Contact Person:	John E. Thompson, Ph. D.

Title:

	Address:	Office of Environmental Policy

	U.S. Department of State

	2201 C Street N.W. Room 4325

	Washington, DC 20520

	U.S.A.

Telephone:	(202) 647-9799

Fax:	(202) 647-5947

E-mail:	  HYPERLINK "mailto:ThompsonJE2@state.gov" 
ThompsonJE2@state.gov 

	

Following the requirements of Decision IX/6 paragraph (a)(1), the United
States of America has determined that the specific use detailed in this
Critical Use Nomination is critical because the lack of availability of
methyl bromide for this use would result in a significant market
disruption.

                

( Yes                                  ( No

Signature

Name

Date

Title:

Contact or Expert(s) for Further Technical Details

Contact/Expert Person:	Richard Keigwin

Title:	Acting Director

Address:	Biological and Economic Analysis Division

	Office of Pesticide Programs

	U. S. Environmental Protection Agency

	Mail Code 7503C

	Washington, DC 20460

	U. S. A.

Telephone:	(703) 308-8200

Fax:	(703) 308-8090

E-mail:	Keigwin.Richard@epa.gov

	

List of Documents Sent to the Ozone Secretariat in Official Nomination
Package

List all paper and electronic documents submitted by the Nominating
Party to the Ozone Secretariat

Paper Documents:

Title of Paper Documents and Appendices	Number of Pages	Date Sent to
Ozone Secretariat

electronic copies of all paper documents: 

Title of Electronic Files	Size of File (kb)	Date Sent to Ozone
Secretariat

CUN2006 Sweet Potato Propagative Photos	2,205

	

Table of Contents

  TOC \f \h \z    HYPERLINK \l "_Toc125819833"  Part A: Summary	 
PAGEREF _Toc125819833 \h  6  

  HYPERLINK \l "_Toc125819834"  1. Nominating Party	  PAGEREF
_Toc125819834 \h  6  

  HYPERLINK \l "_Toc125819835"  2. Descriptive Title of Nomination	 
PAGEREF _Toc125819835 \h  6  

  HYPERLINK \l "_Toc125819836"  3. Crop and Summary of Crop System	 
PAGEREF _Toc125819836 \h  6  

  HYPERLINK \l "_Toc125819837"  4. Methyl Bromide Nominated	  PAGEREF
_Toc125819837 \h  6  

  HYPERLINK \l "_Toc125819838"  Table 4.1: Methyl Bromide Nominated	 
PAGEREF _Toc125819838 \h  6  

  HYPERLINK \l "_Toc125819839"  5. Brief Summary of the Need for Methyl
Bromide as a Critical Use	  PAGEREF _Toc125819839 \h  6  

  HYPERLINK \l "_Toc125819840"  Table A.1: Executive Summary	  PAGEREF
_Toc125819840 \h  6  

  HYPERLINK \l "_Toc125819841"  6. Summarize Why Key Alternatives Are
Not Feasible	  PAGEREF _Toc125819841 \h  7  

  HYPERLINK \l "_Toc125819842"  7. Proportion of Crops Grown Using
Methyl Bromide	  PAGEREF _Toc125819842 \h  7  

  HYPERLINK \l "_Toc125819843"  8. Amount of Methyl Bromide Requested
for Critical Use	  PAGEREF _Toc125819843 \h  8  

  HYPERLINK \l "_Toc125819844"  9. Summarize Assumptions Used to
Calculate Methyl Bromide Quantity Nominated for Each Region	  PAGEREF
_Toc125819844 \h  8  

  HYPERLINK \l "_Toc125819845"  Region A - Part B: Crop Characteristics
and Methyl Bromide Use	  PAGEREF _Toc125819845 \h  9  

  HYPERLINK \l "_Toc125819846"  Region A - 10. Key Diseases and Weeds
for which Methyl Bromide Is Requested and Specific Reasons for this
Request	  PAGEREF _Toc125819846 \h  9  

  HYPERLINK \l "_Toc125819847"  Region A - 11. Characteristics of
Cropping System and Climate	  PAGEREF _Toc125819847 \h  9  

  HYPERLINK \l "_Toc125819848"  Region A - 12. Historic Pattern of Use
of Methyl Bromide, and/or Mixtures Containing Methyl Bromide, for which
an Exemption Is Requested	  PAGEREF _Toc125819848 \h  10  

  HYPERLINK \l "_Toc125819849"  Region A - Part C: Technical Validation	
 PAGEREF _Toc125819849 \h  11  

  HYPERLINK \l "_Toc125819850"  Region A - 13. Reason for Alternatives
Not Being Feasible	  PAGEREF _Toc125819850 \h  11  

  HYPERLINK \l "_Toc125819851"  Region A - 14. List and Discuss Why
Registered (and Potential) Pesticides and Herbicides Are Considered Not
Effective as Technical Alternatives to Methyl Bromide:	  PAGEREF
_Toc125819851 \h  12  

  HYPERLINK \l "_Toc125819852"  Region A - 15. List Present (and
Possible Future) Registration Status of Any Current and Potential
Alternatives	  PAGEREF _Toc125819852 \h  13  

  HYPERLINK \l "_Toc125819853"  Region A - 16. State Relative
Effectiveness of Relevant Alternatives Compared to Methyl Bromide for
the Specific Key Target Pests and Weeds for which It Is Being Requested	
 PAGEREF _Toc125819853 \h  13  

  HYPERLINK \l "_Toc125819854"  Region A - 17. Are There Any Other
Potential Alternatives Under Development which Are Being Considered to
Replace Methyl Bromide?	  PAGEREF _Toc125819854 \h  14  

  HYPERLINK \l "_Toc125819855"  Region A - 18. Are There Technologies
Being Used to Produce the Crop which Avoid the Need for Methyl Bromide?	
 PAGEREF _Toc125819855 \h  14  

  HYPERLINK \l "_Toc125819856"  California - Summary of Technical
Feasibility	  PAGEREF _Toc125819856 \h  14  

  HYPERLINK \l "_Toc125819857"  Part D: Emission Control	  PAGEREF
_Toc125819857 \h  15  

  HYPERLINK \l "_Toc125819858"  19. Techniques That Have and Will Be
Used to Minimize Methyl Bromide Use and Emissions in the Particular Use	
 PAGEREF _Toc125819858 \h  15  

  HYPERLINK \l "_Toc125819859"  20. If Methyl Bromide Emission Reduction
Techniques Are Not Being Used, or Are Not Planned for the Circumstances
of the Nomination, State Reasons	  PAGEREF _Toc125819859 \h  15  

  HYPERLINK \l "_Toc125819860"  Part E: Economic Assessment	  PAGEREF
_Toc125819860 \h  15  

  HYPERLINK \l "_Toc125819861"  21. Costs of Alternatives Compared to
Methyl Bromide Over 3-Year Period	  PAGEREF _Toc125819861 \h  15  

  HYPERLINK \l "_Toc125819862"  22. Gross and Net Revenue	  PAGEREF
_Toc125819862 \h  15  

  HYPERLINK \l "_Toc125819863"  Measures of Economic Impacts of Methyl
Bromide Alternatives	  PAGEREF _Toc125819863 \h  16  

  HYPERLINK \l "_Toc125819864"  Summary of Economic Feasibility	 
PAGEREF _Toc125819864 \h  16  

  HYPERLINK \l "_Toc125819865"  Part F. Future Plans	  PAGEREF
_Toc125819865 \h  16  

  HYPERLINK \l "_Toc125819866"  23. What Actions Will Be Taken to
Rapidly Develop and Deploy Alternatives for This Crop?	  PAGEREF
_Toc125819866 \h  16  

  HYPERLINK \l "_Toc125819867"  24. How Do You Plan to Minimize the Use
of Methyl Bromide for the Critical Use in the Future?	  PAGEREF
_Toc125819867 \h  16  

  HYPERLINK \l "_Toc125819868"  25. Additional Comments on the
Nomination	  PAGEREF _Toc125819868 \h  17  

  HYPERLINK \l "_Toc125819869"  26. Citations	  PAGEREF _Toc125819869 \h
 17  

  HYPERLINK \l "_Toc125819870"  APPENDIX A.  2008 Methyl Bromide Usage
Numerical Index (BUNNI).	  PAGEREF _Toc125819870 \h  18  

 



List of Tables

  TOC \f F \h \z \c "Table"    HYPERLINK \l "_Toc125819890"  Part A:
Summary	  PAGEREF _Toc125819890 \h  6  

  HYPERLINK \l "_Toc125819891"  Table 7.1: Proportion of Crops Grown
Using Methyl Bromide	  PAGEREF _Toc125819891 \h  7  

  HYPERLINK \l "_Toc125819892"  Region A - Table 8.1: Amount of Methyl
Bromide Requested for Critical Use	  PAGEREF _Toc125819892 \h  8  

  HYPERLINK \l "_Toc125819893"  Region A - Part B: Crop Characteristics
and Methyl Bromide Use	  PAGEREF _Toc125819893 \h  9  

  HYPERLINK \l "_Toc125819894"  Region A - Table 10.1: Key Diseases and
Weeds and Reason for Methyl Bromide Request	  PAGEREF _Toc125819894 \h 
9  

  HYPERLINK \l "_Toc125819895"  Region A - Table 11.1: Characteristics
of Cropping System	  PAGEREF _Toc125819895 \h  9  

  HYPERLINK \l "_Toc125819896"  Region A - Table 11.2 Characteristics of
Climate and Crop Schedule	  PAGEREF _Toc125819896 \h  10  

  HYPERLINK \l "_Toc125819897"  Region A - Table 12.1 Historic Pattern
of Use of Methyl Bromide	  PAGEREF _Toc125819897 \h  11  

  HYPERLINK \l "_Toc125819898"  Region A - Part C: Technical Validation	
 PAGEREF _Toc125819898 \h  11  

  HYPERLINK \l "_Toc125819899"  Region A – Table 13.1: Reason for
Alternatives Not Being Feasible	  PAGEREF _Toc125819899 \h  12  

  HYPERLINK \l "_Toc125819900"  Region A – Table 14.1: Technically
Infeasible Alternatives Discussion	  PAGEREF _Toc125819900 \h  12  

  HYPERLINK \l "_Toc125819901"  Region A – Table 15.1: Present
Registration Status of Alternatives	  PAGEREF _Toc125819901 \h  13  

  HYPERLINK \l "_Toc125819902"  California – Table 16.1: Effectiveness
of Alternatives – Nematodes	  PAGEREF _Toc125819902 \h  13  

  HYPERLINK \l "_Toc125819903"  Region A – Table C.1: Alternatives
Yield Loss Data Summary	  PAGEREF _Toc125819903 \h  14  

  HYPERLINK \l "_Toc125819904"  Part D: Emission Control	  PAGEREF
_Toc125819904 \h  15  

  HYPERLINK \l "_Toc125819905"  Table 19.1: Techniques to Minimize
Methyl Bromide Use and Emissions	  PAGEREF _Toc125819905 \h  15  

  HYPERLINK \l "_Toc125819906"  Part E: Economic Assessment	  PAGEREF
_Toc125819906 \h  15  

  HYPERLINK \l "_Toc125819907"  Part F. Future Plans	  PAGEREF
_Toc125819907 \h  16  

  HYPERLINK \l "_Toc125819908"  APPENDIX A.  2008 Methyl Bromide Usage
Numerical Index (BUNNI).	  PAGEREF _Toc125819908 \h  18  

 

Part A: Summary  TC "Part A: Summary" \f F \l "1"    TC "Part A:
Summary" \f C \l "1"  

1. Nominating Party  TC "1. Nominating Party" \f C \l "2"  :

The United States of America

2. Descriptive Title of Nomination  TC "2. Descriptive Title of
Nomination" \f C \l "2"  :

Methyl Bromide Critical Use Nomination for Preplant Soil Use for Sweet
Potato Propagative Hot Beds Grown in Open Fields and Protected with Row
Covers – Related to the Use Recommended by MBTOC for 2005.  Prepared
in 2006 for use in 2008.

3. Crop and Summary of Crop System  TC "3. Crop and Summary of Crop
System" \f C \l "2"  : 

Sweet potatoes are transplanted from plant propagules called slips that
are transplanted between late April and late May.  The majority of sweet
potatoes are harvested in early November.  They are a warm-season crop
and are sensitive to even a light frost and must be planted and
harvested during seasons where there is no chance of frost.  Sweet
potato production generally occurs in sandy to loamy sand soils since
heavy soils affect yield and root quality.  Currently, cover crops, such
as rye, or a wheat/barley forage mix, are typically planted in December
after fields are fumigated and plowed, prior to the planting of sweet
potatoes (4-5 month period).  

Sweet potato growers use methyl bromide for two purposes: fumigating
transplants in a greenhouse-like setting and fumigating open fields
planted with sweet potatoes.  California sweet potato growers have
transitioned away from using methyl bromide for open field pre-plant
soil fumigation.  In 2001 and 2002, California sweet potato producers
used no methyl bromide on their open fields.  Due to the recent price
increases on methyl bromide, growers limited methyl bromide use to
fumigating transplants.  For open field use, they relied on 1,3
dichloropropene which has satisfactory efficacy in areas of sweet potato
production where there is no greater than moderate pest pressures. 
However, because 1,3 dichloropropene is a suspected carcinogen, it is
subject to township caps (the cap is the maximum amount that can be used
within the boundary of a township) in California, as established by the
California Department of Pesticide Regulation.  One township is equal to
an area of 93 square kilometers.  In Merced County, there is an
especially high concentration of crops that require fumigation,
particularly almonds, nectarines, peaches, and grapes.  Therefore, an
open-field option other than 1,3 dichloropropene must be available to
sweet potato growers when township caps are exceeded.  The MBTOC list of
alternatives for sweet potatoes is limited to fallow/crop rotation and
flooding/water management.

California growers produce their transplants (slips) for propagation in
open fields and initially cover plants with clear plastic row covers
supported by hoops.  Typically individual fields to be planted were
either fallowed or planted to rye or sweet potatoes the previous season.
 The transplants (slips) must be watered during establishment and the
low rainfall amounts and public water restrictions that exist in the
production areas make it imperative that fields are situated near
private irrigation wells, which significantly limits the land available
for growing transplants.  

4. Methyl Bromide Nominated:   TC "4. Methyl Bromide Nominated" \f C \l
"2"  :

Table 4.1: Methyl Bromide Nominated  TC "Table 4.1: Methyl Bromide
Nominated" \f \l "1"  

Year	Nomination Amount (kg)	Nomination Area (ha)

2008

5. Brief Summary of the Need for Methyl Bromide as a Critical Use  TC
"5. Brief Summary of the Need for Methyl Bromide as a Critical Use" \f C
\l "2"  ::

The US nomination is for growers who may be denied the use of Telone
plus chloropicrin as a result of Telone township caps being met. 
Additionally, growers and crop specialists are uncertain of the pest
control suitability of a Telone plus chloropicrin product for pests
other than nematodes, especially weeds and diseases.  

Table A.1: Executive Summary  TC "Table A.1: Executive Summary" \f \l
"1"  

Region	Sweet Potato Council of California

Amount of Applicant Request

2008	Kilograms	18,144

Amount of Nomination *

2008	Kilograms

	*See Appendix A for complete description of how the nominated amount
was calculated.

6. Summarize Why Key Alternatives Are Not Feasible  TC "6. Summarize Why
Key Alternatives Are Not Feasible" \f C \l "2"  : 

The key alternative is thought to be a Telone plus chloropicrin
combination product.  This combination of active ingredients is highly
rated for control of nematodes and certain diseases, respectively.  This
is based upon years of grower experiences on other crops using the
respective ingredients alone and in combinations..  This combination
does not control weeds and may not control diseases that are not listed
on chloropicrin labels.  This request, however, is for those growers who
cannot use Telone due to regulatory constraints (township caps).  Unless
and until the township caps are increased growers cannot be assured of
having available the main alternative to methyl bromide fumigation. 
Even were the caps to be increased, telone fumigation is not legal in
California during the month of January when significant fumication for
sweet potato slips need to take place.

7. (i) Proportion of Crops Grown Using Methyl Bromide  TC "7. Proportion
of Crops Grown Using Methyl Bromide" \f C \l "2"    (if particular
agricultural or political regions only use methyl bromide, provide local
data as well as national figures):

Table 7.1: Proportion of Crops Grown Using Methyl Bromide  TC "Table
7.1: Proportion of Crops Grown Using Methyl Bromide" \f F \l "1"  

Region where Methyl Bromide use is requested	Total crop area in 2002
(ha)	Proportion of total crop area treated with methyl bromide in 2002
(%)

Sweet Potato Council of California	81	80-90 %

National Total:	81	80-90

7. (ii) If only part of the crop area is treated with methyl bromide,
indicate the reason why methyl bromide is not used in the other area,
and identify what alternative strategies are used to control the target
pathogens and weeds without methyl bromide there.

Organic sweet potato growers do not use methyl bromide, or any other
fumigants, in their transplant beds.  It has been observed that fewer
and less vigorous transplants result.  Since data are not available to
address these options, the extent of these differences cannot be
quantified.  In addition, in order to produce their crops, organic
producers of sweet potatoes must use significant amounts of hand
weeding.  Current costs are not available, however, the State of
California has recently acted to significantly restrict hand weeding and
to mandate that hoes must be at least 4 feet (1.2 meters) in length. 
The new regulations allow only a few hours of hand weeding per day. 
This regulatory action effectively eliminated hand weeding for
commercial scale operations; it is only feasible in situations such as
organic production, where the scale of operation is small and where
growers can command a premium price..  

7. (iii) Would it be feasible to expand the use of these methods to
cover at least part of the crop that has requested use of methyl
bromide?  What changes would be necessary to enable this?

The Telone township cap limitation effectively limits the amount of
telone that can be used on a sliding scale.  This scale is a function of
amount, method of fumigation, and time of year.  To the extent that
telone or a telone chloropicrin mixture can be used, it is being used. 
California growers prefer to use telone when possible (where the key
pests are controlled and where the township caps are not binding) as it
is less costly than mixtures using methyl bromide  The US nomination is
for growers who may be denied the use of Telone alone or in combination
with chloropicrin as a result of Telone township caps.  SOlarization is
undergoing evaluation, however, it is not likely that solarization can
completely replace fumigation.  Land for sweet potato operation si often
leased.  Solarization can only take place during the same time period as
cropping (the non-cropping season is not warm enough to allow soils to
reach the temperatures necessary to kill key pests to the required soil
depths.

8. Amount of Methyl Bromide Requested for Critical Use  TC "8. Amount of
Methyl Bromide Requested for Critical Use" \f C \l "2"  :

California - Table 8.1: Amount of Methyl Bromide Requested for Critical
Use  TC "Region A - Table 8.1: Amount of Methyl Bromide Requested for
Critical Use" \f F \l "1"  

Region:  Sweet Potato Council of California

Year of Exemption Request	2008

Kilograms of Methyl Bromide	18,144

Use: Broadacre or Strip/Bed Treatment	Broadcast

Formulation (ratio of methyl bromide/chloropicrin mixture) to be used
for the CUE	57:43

Total Area to be treated with the methyl bromide or methyl
bromide/Chloropicrin formulation (m2 or ha)	81ha

Application rate* (kg/ha) for the formulation [ACTIVE INGREDIENT]	392

Application rate (kg/ha) for METHYL BROMIDE	224

Dosage rate* (g/m2) of formulation [ACTIVE INGREDIENT] used to calculate
requested kilograms of methyl bromide	39.2

Dosage rate (g/m2) of METHYL BROMIDE	22.4

* For broadacre treatment application rate and dosage rate may be the
same.

9. Summarize Assumptions Used to Calculate Methyl Bromide Quantity
Nominated for Each Region  TC "9. Summarize Assumptions Used to
Calculate Methyl Bromide Quantity Nominated for Each Region" \f C \l "2"
 :

The amount of methyl bromide nominated by the U.S. was calculated as
follows:

The percent of regional hectares in the applicant’s request was
divided by the total area planted in that crop in the region covered by
the request.   

Hectares counted in more than one application or rotated within one year
of an application to a crop that also uses MeBr were subtracted.  There
was no double counting in this sector. 

 Growth or increasing production (the amount of area requested by the
applicant that is greater than that historically treated) was
subtracted.  There was no growth in this sector.  

There was a small adjustment for use rate in one of the applications.

Quarantine and pre-shipment (QPS) hectares are not relevant to this
request because the plants are grown for planting on the same facility,
thus not triggering quarantine regulations.

 California - Part B: Crop Characteristics and Methyl Bromide Use  TC
"Region A - Part B: Crop Characteristics and Methyl Bromide Use" \f F \l
"1"    TC "Region A - Part B: Crop Characteristics and Methyl Bromide
Use" \f C \l "1"  

California - 10. Key Diseases and Weeds for which Methyl Bromide Is
Requested and Specific Reasons for this Request  TC " Region A - 10. Key
Diseases and Weeds for which Methyl Bromide Is Requested and Specific
Reasons for this Request" \f C \l "2"   (List only those target weeds
and pests for which methyl bromide is the only feasible alternative and
for which CUE is being requested):

California - Table 10.1: Key Diseases and Weeds and Reason for Methyl
Bromide Request  TC "Region A - Table 10.1: Key Diseases and Weeds and
Reason for Methyl Bromide Request" \f F \l "1"  

Region where methyl bromide use is requested	Key disease(s) and weed(s)
to genus and, if known, to species level	Specific reasons why methyl
bromide is needed 

(e.g. Effective herbicide available, but not registered for this crop;
mandatory requirement to meet certification for disease tolerance)

Sweet Potato Council of California	Root-knot nematodes (Meloidogyne
incognita)	Township caps likely to be reached and prevent use of the
best available alternative Telone C-35

	Fungal Diseases: Pox (Streptomyces ipomea); Scurf (Monilochaetes
infuscans); Fusarium wilt (Fusarium oxysporum); Black rot (Ceratocystis
fimbriata)

Weeds: pigweed (Chenopodium spp.); crabgrass (Digitaria spp.)

Grubs (Scarabid beetles)

Wireworms (Limonius spp.)

	

California - 11. (i) Characteristics of Cropping System and Climate  TC
" Region A - 11. Characteristics of Cropping System and Climate" \f C \l
"2"  

California - Table 11.1: Characteristics of Cropping System  TC " Region
A - Table 11.1: Characteristics of Cropping System" \f F \l "1"  

Characteristics	California

Crop Type: (e.g. transplants, bulbs, trees or cuttings)	Development of
transplants (slips) from tubers

Annual or Perennial Crop: (# of years between replanting) 	Propagative
beds are used annually

Typical Crop Rotation (if any) and use of methyl bromide for other crops
in the rotation: (if any)	Land used the previous year could have been
fallow, rye, or sweetpotatoes;  many consecutive sweetpotato hotbed
plantings are possible

Soil Types:  (Sand, loam, clay, etc.)	Light soil with 0-2% organic
matter

Frequency of methyl bromide Fumigation: 

(e.g. every two years)	Annually

Other relevant factors:	No other relevant factors were identified.

California - Table 11.2 Characteristics of Climate and Crop Schedule  TC
" Region A - Table 11.2 Characteristics of Climate and Crop Schedule" \f
F \l "1"  

Mar	Apr	May	Jun	Jul	Aug	Sept	Oct	Nov	Dec	Jan

Climatic Zone	USDA climate zone 10b

Soil Temp. ((C)

Rainfall (mm)	300mm per year; private wells must be available to
supplement the low rainfall rate

Outside Temp. ((C) Madera 	15/

3.1	19.1/ 4.6	21.3/6.1	26.8/

10.1	30.4/

12.6	33.2/

15.1

16.1/

3.3	12/

2.2	11.4/

1.8

Fumigation Schedule

X	X	X

Plant Hot Beds	X	X

Harvest Slips & Plant Field Beds

	X	X	X	X

Outside temperature data ((C) for Madera County, CA (High/Low) for 2000
– 2005. 

California – 11. (ii) Indicate if any of the above characteristics in
11. (i) prevent the uptake of any relevant alternatives?

Due to the low rainfall and water restrictions preventing the use of
public water for crop irrigation prior to April, it is difficult to
rotate land used for hotbeds because they need to be situated close to
private water sources (e.g., wells).  

California - 12. Historic Pattern of Use of Methyl Bromide, and/or
Mixtures Containing Methyl Bromide, for which an Exemption Is Requested 
TC "Region A - 12. Historic Pattern of Use of Methyl Bromide, and/or
Mixtures Containing Methyl Bromide, for which an Exemption Is Requested"
\f C \l "2"   

California - Table 12.1 Historic Pattern of Use of Methyl Bromide  TC
"Region A - Table 12.1 Historic Pattern of Use of Methyl Bromide" \f F
\l "1"  

Years	1999	2000	2001	2002	2003	2004	2008 Request

Area Treated (hectares)	1,214	934 	71 	81 	121 	Not Available	121 

ratio of broadacre methyl bromide use to strip/bed use if strip
treatment is used	100% Broadcast	100% Broadcast	100% Broadcast	100%
Broadcast	100% Broadcast	100% Broadcast	100% Broadcast

Amount of methyl bromide active ingredient used 

(total kilograms)	  202,180 	 153,523 	 15,876 	 18,144 	 27,216 	Not
Available	Not Available

formulations of methyl bromide 

(e.g. methyl bromide /chloropicrin)	57:43	57:43	57:43	57:43	57:43	57:43
57:43

Method by which methyl bromide applied )	Shanked to 45.7 cm depth &
tarped	Shanked to 45.7 cm depth & tarped	Shanked to 45.7 cm depth &
tarped	Shanked to 45.7 cm depth & tarped	Shanked to 45.7 cm depth &
tarped	Shanked to 45.7 cm depth & tarped	Shanked to 45.7 cm depth &
tarped

Application rate [active ingredient kg/ha]	224	224	224	224	224	224	224

dosage rate of active ingredient (g/m2)*	22.4	22.4	22.4	22.4	22.4	22.4
22.4

* For broadacre treatment application rate and dosage rate may be the
same.

California – Part C: Technical Validation  TC "Region A - Part C:
Technical Validation" \f F \l "1"    TC "Region A - Part C: Technical
Validation" \f C \l "1"  

California - 13. Reason for Alternatives Not Being Feasible  TC "Region
A - 13. Reason for Alternatives Not Being Feasible" \f C \l "2"   

(Give list of all relevant chemical and non chemical alternatives, and
their combinations)

Data from hotbed growing situations is not available, assessments
presented here are based on the overall experiences/data obtained from
other cropping situations

California – Table 13.1: Reason for Alternatives Not Being Feasible 
TC "Region A – Table 13.1: Reason for Alternatives Not Being Feasible"
\f F \l "1"  

Name of Alternative	Technical and regulatory* reasons for the
alternative not being feasible or available  + citations**	Is the
alternative considered cost effective?

Chemical Alternatives

Telone	Recommended by crop specialists principally for control of
nematodes; township caps; not permitted to be used in January; 1.9
application factor applied against use cap when used in December

	Metam-sodium	Recommended by crop specialists for general control of
diseases, weeds and nematodes; chemical frequently cited as providing
inconsistent efficacy; sprinkler and flood applications methods are
generally considered the most consistently effective methods of
application since the chemical is distributed more effectively in the
soil with these methods; sprinkler applications require a 500’ (152
meter) untreated buffer where occupied structures are present  

	Chloropicrin	Recommended by crop specialists principally for control of
fungal diseases on various crops

	Non Chemical Alternatives

Fallowing/Crop rotation	Low rainfall and water restrictions  limit
freedom to rotate the land because hot bed sites must be near private
irrigation sources; since most land is leased fallowing is not
considered a viable option for many growers because it is an expense
only option and does not provide any income

	Solarization	Needs to be evaluated in the future to determine if it has
any utility; since most land is leased solarization is not considered a
viable option for many growers because it is an expense only option and
does not provide any income

	Combinations of Alternatives

Telone plus chloropicrin	Recommended for control of nematodes and
certain diseases; weed control generally found to be unacceptable
therefore an additional option for controlling  weeds may be necessary

	

California - 14. List and Discuss Why Registered (and Potential)
Pesticides and Herbicides Are Considered Not Effective as Technical
Alternatives to Methyl Bromide:  TC "Region A - 14. List and Discuss Why
Registered (and Potential) Pesticides and Herbicides Are Considered Not
Effective as Technical Alternatives to Methyl Bromide:" \f C \l "2"  

California – Table 14.1: Technically Infeasible Alternatives
Discussion  TC "Region A – Table 14.1: Technically Infeasible
Alternatives Discussion" \f F \l "1"  

Name of Alternative	Discussion

Telone plus chloropicrin	Data lacking from hotbed situations; this
combination may/may not be a suitable alternative until several years of
hotbed data are obtained plus follow-up observations on the
productivity/quality of plants grown from these transplants.  In
addition, there are constraints on its use based on Township caps and
timing (January) of fumigation.

California - 15. List Present (and Possible Future) Registration Status
of Any Current and Potential Alternatives  TC "Region A - 15. List
Present (and Possible Future) Registration Status of Any Current and
Potential Alternatives" \f C \l "2"  :

California – Table 15.1: Present Registration Status of Alternatives 
TC "Region A – Table 15.1: Present Registration Status of
Alternatives" \f F \l "1"  

Alternative	Present Registration Status

	Registration being considered? (Y/N)	Date of possible registration:

Sodium azide	No registration package has been received	No	Unknown

Propargyl bromide	No registration package has been received	No	Unknown

Iodomethane	Not registered in U.S.

Proposed uses include tomatoes, peppers, strawberries, and ornamental
crops	Yes, but not for sweet potato transplant slips	Unknown

Furfural	Not registered.  Registration package has been received.	Yes
Unknown

Muscadore albus Strain QST 20799 	Registration package has been
received.	Yes	Registered but not yet for sale in the U.S.

California - 16. State Relative Effectiveness of Relevant Alternatives
Compared to Methyl Bromide for the Specific Key Target Pests and Weeds
for which It Is Being Requested  TC "Region A - 16. State Relative
Effectiveness of Relevant Alternatives Compared to Methyl Bromide for
the Specific Key Target Pests and Weeds for which It Is Being Requested"
\f C \l "2"  : 

The Sweet Potato Council of California supports university research and
collaborates extensively with the University of California Cooperative
Extension Program in Merced County.  As the sweet potato industry is
small, it is often difficult to obtain funding for alternatives, but the
Council has strong future research plans to further evaluate the use of
cover crops (i.e., radish, vetch, and barley) in conjunction with 1,3
dichloropropene, Vapam (metam-sodium), and Mocap (ethoprop). These
trials began in December 2001 and are ongoing.  

Furthermore, the University of California Cooperative Extension and the
USDA Agricultural Research Service are actively engaged in numerous
research projects evaluating both chemical fumigants and cropping
systems.  Researchers have found that brassica (including both wild and
domestic plants such as mustard, kale, cabbage, rapeseed, turnips, and
radishes) residues, when incorporated into the soil, reduce the
incidence of several disease pathogens, including Pythium, Rhizoctonia,
Verticillium, and root knot nematodes.   Additional research that could
be undertaken, contingent on funding, would be:  (1) research on the
prospect of lowering 1,3 dichloropropene use rates when used in
conjunction with non-host cover crops; and (2) Use of non-host cover
crops/fallowing in conjunction with the other registered alternatives,
such as ethoprop, metam-sodium, and aldicarb.  The new
nematode-resistant potato Bienville will also be available in limited
amounts and will be tested in several fields.  

Government-funded studies pertaining to U.S. sweet potato production
also include the following:			

Resistance to Diseases and Nematodes in Vegetable Crops (April
2001-April 2003)

This study will describe the nature, genetics, and mechanisms of
host-resistance to major pathogens and root-knot nematodes that attack
vegetable crops in particular regions.  Durable, resistant cultivars and
environmentally compatible management practices that reliably reduce
disease losses and pesticide use will be developed.  Resistance to
root-knot nematodes is a critical component of this study.  In addition,
the USDA will cooperate with public plant breeders and seed companies to
facilitate use of identified resistance and markers in development of
resistant cultivars of vegetable crops.   

The California Sweet Potato Council and the Univ. of California
Extension service did not conduct research for the sweet potato hotbeds.
 However, there is one research trial on nematicides conducted by the
Merced County, California Cooperative Extensive Service (Stoddard,
2002).  These data were generated because pest control in sweet potato
may be difficult due to township caps restricting the use of 1,3-D.  The
initial results from one study suggest that ethoprop and 1,3-D had
similar nematode control.  The study author indicated, however, that
this result might have been due to a block effect (i.e., due to the
location in the field) as opposed to the effect of the nematicides. 
Also, the author noted that this result is from only one year of data
and that previous research showed marginal nematode control with
ethoprop (see Table 3 below).  In general, the USG does not regard one
trial with one year of data sufficiently robust as to serve as a basis
for transition projections.

California – Table 16.1: Effectiveness of Alternatives – Nematodes 
TC "California – Table 16.1: Effectiveness of Alternatives –
Nematodes" \f F \l "1"    

Treatment*	Rate

(kg ai/ha)	Root Knot Nematode

(#/250 ml soil)	Yield

(kg/ha)	Yield as % of MeBr

Control	0	925 ns	15142	53%

Metam sodium	356	963	23520	82%

Ethoprop	9.9	1350	14963	52%

MeBr	224	375	28806	100%

Stoddard, 2002

*Yield per plot, MB and metham sodium were significantly better than the
other two.  There were no significant differences between nematode
counts. 

California – Table C.1: Alternatives Yield Loss Data Summary  TC
"Region A – Table C.1: Alternatives Yield Loss Data Summary" \f F \l
"1"    . 

Alternative	List Type of Pest	Range of Yield Loss	Best Estimate of Yield
Loss

Metam sodium	Nematodes	High	18%

Telone/chloropicrin	Nematodes	0%	unknown

Overall Loss Estimate for All Alternatives to Pests	18%

Yield loss estimates for Telone/chloropicrin were not provided due to
the lack of data from hotbeds.  But, Telone/chloropicrin mixtures would
be assumed to provide nematode control comparable to methyl
bromide/chloropicrin mixtures.

California - 17. Are There Any Other Potential Alternatives Under
Development which Are Being Considered to Replace Methyl Bromide?  TC
"Region A - 17. Are There Any Other Potential Alternatives Under
Development which Are Being Considered to Replace Methyl Bromide?" \f C
\l "2"  

Methyl iodide is generally considered to be a suitable alternative for
all soil uses; so far methyl iodide only has a pending registration for
uses on strawberries, peppers, tomatoes and ornamentals. 

California - 18. Are There Technologies Being Used to Produce the Crop
which Avoid the Need for Methyl Bromide?:  TC "Region A - 18. Are There
Technologies Being Used to Produce the Crop which Avoid the Need for
Methyl Bromide?" \f C \l "2"   

A small percentage of growers are able to use new land each year to
qualify as organic growers; limited feedback from one of these growers
indicates that the lack of pesticides has resulted in a decrease in the
number of plants produced per acre, an increase in plant size
variability and a significant weed problem that requires hand weeding.
As discussed (above), California has recently moved to severely restrict
hand weeding and weeding with hoes of less than 4 feet (1,2 meters) in
length.  These restrictions effectively render hand weeding an option
only for small operations where the grower can command a premium price
for the product, such as organic production.  A second difficulty is
that because of water restrictions during certain crucial months, hotbed
growing areas must be located near wells so as not to rely on irrigation
from public water sources

California - Summary of Technical Feasibility  TC "California - Summary
of Technical Feasibility" \f C \l "2"  

Sweet potato growers need pest free transplants (slips) for their
production fields.  Telone plus chloropicrin is an effective alternative
for nematode and disease control but is not available because of
township caps and the regulatory constraint on its use in January.  The
weaknesses associated with that treatment would continue to be weed
control and possibly disease control.  Actual data from the sweet potato
hotbeds for several consecutive years may be needed to determine a
suitable combination (possible Telone plus chloropicrin followed by
metam sodium would be as a methyl bromide alternative.

Part D: Emission Control  TC "Part D: Emission Control" \f F \l "1"   
TC "Part D: Emission Control" \f C \l "1"  

19. Techniques That Have and Will Be Used to Minimize Methyl Bromide Use
and Emissions in the Particular Use  TC "19. Techniques That Have and
Will Be Used to Minimize Methyl Bromide Use and Emissions in the
Particular Use" \f C \l "2"  : (State % adoption or describe change)

Table 19.1: Techniques to Minimize Methyl Bromide Use and Emissions  TC
"Table 19.1: Techniques to Minimize Methyl Bromide Use and Emissions" \f
F \l "1"  

Technique or Step Taken	VIF or High Barrier Films	methyl bromide dosage
reduction	Increased % chloropicrin in methyl bromide formulation	Less
frequent application

What use/emission reduction methods are presently adopted?	High barrier
films	No recent change in application rate	No recent change in
formulation	No reported change

What further use/emission reduction steps will be taken for the methyl
bromide used for critical uses?	No future changes reported	No future
changes reported	No future changes reported	No future changes reported

Other measures (please describe)	1] Elimination of field production
areas from CUE	2] Growers will use Telone/chloropicrin in hotbeds, if
available

20. If Methyl Bromide Emission Reduction Techniques Are Not Being Used,
or Are Not Planned for the Circumstances of the Nomination, State
Reasons  TC "20. If Methyl Bromide Emission Reduction Techniques Are Not
Being Used, or Are Not Planned for the Circumstances of the Nomination,
State Reasons" \f C \l "2"  :

Further research is needed to determine the cost-effectiveness of other
options.  In addition, practices such as deep injection and tarps are
used by sweet potato growers to reduce the MeBr rates required for
transplants (slips).  

Part C: Economic Assessment  TC "Part E: Economic Assessment" \f F \l
"1"    TC "Part E: Economic Assessment" \f C \l "1"  

21. Costs of Alternatives Compared to Methyl Bromide Over 3-Year Period 
TC "21. Costs of Alternatives Compared to Methyl Bromide Over 3-Year
Period" \f C \l "2"  :

This table is not included since none of the alternatives are
technically feasible.  See Summary of Economic Feasibility below.

22. Gross and Net Revenue  TC "22. Gross and Net Revenue" \f C \l "2"  :

These tables are not included since none of the alternatives are
technically feasible.  See Summary of Economic Feasibility below.

Measures of Economic Impacts of Methyl Bromide Alternatives  TC
"Measures of Economic Impacts of Methyl Bromide Alternatives" \f C \l
"2"  

This table was not included since none of the alternatives are
technically feasible.  See Summary of Economic Feasibility below.

Summary of Economic Feasibility  TC "Summary of Economic Feasibility" \f
C \l "2"  

An economic analysis was not done for this sector because most of the
losses cannot be quantified.  This CUN only applies to areas where
township do not permit the use of Telone.  In such areas there are no
technically or economically feasible alternatives and losses could be as
high as 18% (Stoddard, 2002).  Sweet potato transplants (slips) that
survive are not likely to be as healthy and could lead to yield losses
in the production fields.  In addition to direct yield losses,
additional (possible) sources of loss include:

Delayed planting due to use of alternatives

Fallow

Additional use of herbicides

Losses due to weeds, insects and diseases resulting in smaller, less
attractive produce (quality loss)

Part F. Future Plans  TC "Part F. Future Plans" \f F \l "1"    TC "Part
F. Future Plans" \f C \l "1"  

23. What Actions Will Be Taken to Rapidly Develop and Deploy
Alternatives for This Crop?  TC "23. What Actions Will Be Taken to
Rapidly Develop and Deploy Alternatives for This Crop?" \f C \l "2"  

Field tests in actual hotbed areas need to be initiated before a
suitable alternative can be identified.  Although Telone with
chloropicrin is thought to be the best available alternative, it may not
adequately control the full range of target pests, especially the weed,
disease and insect pests.  It should be noted that due to township caps
Telone may not always be available for use.  Due to this potential
problem another alternative needs to be identified to serve as a backup
for Telone/chloropicrin.  No additional plans, beyond dropping the field
production situations, were presented.  For further details regarding
the transition plans for this sector please consult the national
management strategy.

24. How Do You Plan to Minimize the Use of Methyl Bromide for the
Critical Use in the Future?  TC "24. How Do You Plan to Minimize the Use
of Methyl Bromide for the Critical Use in the Future?" \f C \l "2"  

As described in Section 23. 

25. Additional Comments on the Nomination?  TC "25. Additional Comments
on the Nomination" \f C \l "2"   

The MB critical use exemption nomination for Sweet potato transplants
(slips) for the 2008 use season has been reviewed by the U. S.
Environmental Protection Agency and the U. S. Department of Agriculture
and meets the guidelines of The Montreal Protocol on Substances That
Deplete the Ozone Layer.  This use is considered critical because there
are conditions where no feasible alternatives or substitutes are
currently available.  The loss of MB, therefore, would result in a
significant market disruption in providing clean transplants to the
industry.  The effort to avoid market disruption provides the basis for
nomination of this sector for critical use exemption of MB.

26. Citations  TC "26. Citations" \f C \l "2"  

(Crop Production - Acreage - Supplement (PCP-BB).( Crop production -
Acreage 6-28-02. National Agricultural Statistics Service (NASS),
Agricultural Statistics Board, USDA. Retrieved January 21, 2003
<http://usda.mannlib.cornell.edu/reports/nassr/field/pcp-bba/acrg0602.pd
f>

Stoddard, C.S.  2002.  Research Progress Report: Fumigation and cover
crop trial on sweet potatoes.  University of California Cooperative
Extension Service, Merced County.

(Sweetpotato Tips.( Sweetpotato Tips Spring 2002.University of
California Cooperative Extension. Retrieved January 21, 2003
<http://ucce.ucdavis.edu/files/filelibrary/1529/2234.pdf>

Weir, Bill L. (Fumigation and Cover Crop Trial.( Sweet Potato 2000
Research Progress Report University of California Cooperative Extension
Merced County. pp. 21~23 2000.

Weir, Bill. (Sweetpotato Research Trials: 2001 Research Progress Report(
Sweet Potato Progress Report 2001 Retrieved January 21, 2003

APPENDIX A.  2008 Methyl Bromide Usage Numerical Index (BUNNI).  TC
"APPENDIX A.  2008 Methyl Bromide Usage Numerical Index (BUNNI)." \f C
\l "1"  ).  TC "APPENDIX A.  2008 Methyl Bromide Usage Numerical Index
(BUNNI)." \f F \l "1"  

Footnotes for Appendix A:

		Values may not sum exactly due to rounding.  

Dichotomous Variables – dichotomous variables are those which take one
of two values, for example, 0 or 1, yes or no.  These variables were
used to categorize the uses during the preparation of the nomination.

Strip Bed Treatment – Strip bed treatment is ‘yes’ if the
applicant uses such treatment, no otherwise.

Currently Use Alternatives – Currently use alternatives is ‘yes’
if the applicant uses alternatives for some portion of pesticide use on
the crop for which an application to use methyl bromide is made.

Tarps/ Deep Injection Used – Because all pre-plant methyl bromide use
in the US is either with tarps or by deep injection, this variable takes
on the value ‘tarp’ when tarps are used and ‘deep’ when deep
injection is used.

Pest-free cert. Required - This variable is a ‘yes’ when the product
must be certified as ‘pest-free’ in order to be sold

Other Issues.- Other issues is a short reminder of other elements of an
application that were checked

Frequency of Treatment – This indicates how often methyl bromide is
applied in the sector.  Frequency varies from multiple times per year to
once in several decades.

Quarantine and Pre-Shipment Removed? – This indicates whether the
Quarantine and pre-shipment (QPS) hectares subject to QPS treatments
were removed from the nomination.

Most Likely Combined Impacts (%) – Adjustments to requested amounts
were factors that reduced to total amount of methyl bromide requested by
factoring in the specific situations were the applicant could use
alternatives to methyl bromide.  These are calculated as proportions of
the total request.  We have tried to make the adjustment to the
requested amounts in the most appropriate category when the adjustment
could fall into more than one category. 

(%) Karst geology – Percent karst geology is the proportion of the
land area in a nomination that is characterized by karst formations.  In
these areas, the groundwater can easily become contaminated by
pesticides or their residues.  Regulations are often in place to control
the use of pesticide of concern.  Dade County, Florida, has a ban on the
use of 1,3D due to its karst geology.

(%) 100 ft Buffer Zones – Percentage of the acreage of a field where
certain alternatives to methyl bromide cannot be used due the
requirement that a 100 foot buffer be maintained between the application
site and any inhabited structure.

(%) Key Pest Impacts - Percent (%) of the requested area with moderate
to severe pest problems.  Key pests are those that are not adequately
controlled by MB alternatives.  For example, the key pest in Michigan
peppers, Phytophthora spp. infests approximately 30% of the vegetable
growing area.  In southern states the key pest in peppers is nutsedge.

Regulatory Issues (%) - Regulatory issues (%) is the percent (%) of the
requested area where alternatives cannot be legally used (e.g., township
caps) pursuant to state and local limits on their use.  

Unsuitable Terrain (%) – Unsuitable terrain (%) is the percent (%) of
the requested area where alternatives cannot be used due to soil type
(e.g., heavy clay soils may not show adequate performance) or terrain
configuration, such as hilly terrain. Where the use of alternatives
poses application and coverage problems.

Cold Soil Temperatures – Cold soil temperatures is the proportion of
the requested acreage where soil temperatures remain too low to enable
the use of methyl bromide alternatives and still have sufficient time to
produce the normal (one or two) number of crops per season or to allow
harvest sufficiently early to obtain the high prices prevailing in the
local market at the beginning of the season.

Total Combined Impacts (%) - Total combined impacts are the percent (%)
of the requested area where alternatives cannot be used due to key pest,
regulatory, soil impacts, temperature, etc.  In each case the total area
impacted is the conjoined area that is impacted by any individual
impact.  The effects were assumed to be independently distributed unless
contrary evidence was available (e.g., affects are known to be mutually
exclusive).   For example, if 50% of the requested area had moderate to
severe key pest pressure and 50% of the requested area had karst
geology, then 75% of the area was assumed to require methyl bromide
rather than the alternative.  This was calculated as follows: 50%
affected by key pests and an additional 25% (50% of 50%) affected by
karst geology.

Most Likely Baseline Transition – Most Likely Baseline Transition
amount was determined by the DELPHI process and was calculated by
determining the maximum share of industry that can transition to
existing alternatives.

(%) Able to Transition – Maximum share of industry that can transition

Minimum # of Years Required – The minimum number of years required to
achieve maximum transition.

(%) Able to Transition per Year – The Percent Able to Transition per
Year is the percent able to transition divided by the number of years to
achieve maximum transition.

EPA Adjusted Use Rate - Use rate is the lower of requested use rate for
2008 or the historic average use rate or is determined by MBTOC
recommended use rate reductions.

EPA Adjusted Strip Dosage Rate – The dosage rate is the use rate
within the strips for strip / bed fumigation.

2008 Amount of Request – The 2008 amount of request is the actual
amount requested by applicants given in total pounds active ingredient
of methyl bromide, total acres of methyl bromide use, and application
rate in pounds active ingredient of methyl bromide per acre.  U.S. units
of measure were used to describe the initial request and then were
converted to metric units to calculate the amount of the US nomination. 

EPA Preliminary Value – The EPA Preliminary Value is the lowest of the
requested amount from 2005 through 2008 with MBTOC accepted adjustments
(where necessary) included in the preliminary value.

EPA Baseline Adjusted Value – The EPA Baseline Adjusted Value has been
adjusted for MBTOC adjustments, QPS, Double Counting, Growth, Use Rate/
Strip Treatment, Miscellaneous adjustments, MBTOC recommended Low
Permeability Film Transition adjustment, and Combined Impacts.

EPA Transition Amount – The EPA Transition Amount is calculated by
removing previous transition amounts since transition was introduced in
2007 and removing the amount of the percent (%) Able to Transition per
Year multiplied by the EPA Baseline Adjusted Value. 

Most Likely Impact Value – The qualified amount of the initial request
after all adjustments have been made given in total kilograms of
nomination, total hectares of nomination, and final use rate of
nomination.

Sector Research Amount – The total U.S. amount of methyl bromide
needed for research purposes in each sector.

Total US Sector Nomination - Total U.S. sector nomination is the most
likely estimate of the amount needed in that sector.

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