Document ID: EPA-HQ-OPP-2005-0123-0339
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-05-02T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE  OF 

PREVENTION, PESTICIDES AND 

TOXIC SUBSTANCES

  SEQ CHAPTER \h \r 1 

MEMORANDUM

SUBJECT:	Summary of Assessments of the Benefits of Soil Fumigation with
Methyl Bromide in Crop Production  (DP# 337501)

FROM:	Colwell Cook, Ph.D., Entomologist

	Biological Analysis Branch

	T J Wyatt, Ph.D., Agricultural Economist

	Biological and Economic Analysis Division (7503P)

THRU:	Arnet Jones, Chief 	

	Biological Analysis Branch

	Timothy Kiely, Chief

	Economic Analysis Branch

	Biological and Economic Analysis Division (7503P)

TO:	John Leahy, Senior Policy Analyst

	Steven Weiss, Chemical Review Manager

	Special Review and Reregistration Division (7508P)

Product Review Panel:  April 18, 2007

SUMMARY

Methyl bromide, in combination with chloropicrin, is used to treat a
variety of pests, including soil pathogens, nematodes, and weeds.  The
benefits of fumigation with methyl bromide include increases in yield
and reductions in production costs.  In some cases, methyl bromide makes
production viable where pest pressure would otherwise be too great. 
BEAD assessed those crops that have been granted a critical use
exemption from the phase-out of methyl bromide under the Montreal
Protocol or those crops that qualify for methyl bromide use under
quarantine-preshipment criteria.  The benefits are generally divided
between producers, who benefit from higher net operating revenue, and
consumers, who benefit from increased supply and lower prices.

This document provides only a summary of the main conclusions of the
crop-specific analyses.  Readers are encouraged to consult the
individual analyses for more detail, especially concerning the
analytical methods and assumptions used, and the limitations of the
analysis.

Background

As part of the Reregistration Eligibility Decision (RED) process, EPA is
assessing the risks and benefits of the use of several soil fumigants: 
chloropicrin, dazoment, metam potassium, metam sodium, and methyl
bromide.  This document summarizes the results of assessments of the
benefits provided by methyl bromide, in the production of the crops
listed in Table 1.

Table 1.  Assessments of Benefits of Methyl Bromide by Crop.

Crop	Title	Authors

Cucurbits	Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, and Metam-Sodium in Cucurbit Production
Bill Chism and David Donaldson

Eggplant	Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Metam-Sodium, and Methyl Bromide in Eggplant Production
Angel Chiri and David Donaldson

Forest Seedlings	Assessment of the Benefits Soil Fumigants with (Methyl
Bromide, Chloropicrin, Metam-Sodium, Dazomet) Used by Forest Tree
Seedling Nurseries Production	John Faulkner and Leonard Yourman

Nursery, Fruit, Nut, & Rose	Assessment of the Benefits of Soil
Fumigation with Chloropicrin, Dazomet, Metam Potassium and Metam Sodium
Use for Fruit and Nut Deciduous Tree Nurseries and Rose Bush Nurseries
in California	Leonard Yourman and Steve Smearman

Orchard Replant – Grapes	Assessment of the Benefits of Soil Fumigation
with Methyl Bromide, Chloropicrin, and Metam-sodium in Grape Production
Leonard Yourman and TJ Wyatt

Orchard Replant – Tree Nuts	Assessment of the Benefits of Soil
Fumigation with Methyl Bromide and Chloropicrin in Tree Nut Production
Leonard Yourman and TJ Wyatt

Orchard Replant – Stone Fruit	Assessment of the Benefits of Soil
Fumigation with Methyl Bromide, Chloropicrin, and Metam Sodium in Stone
Fruit Production	Leonard Yourman and TJ Wyatt

Ornamentals	Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, Metam Sodium and Dazomet in Ornamental
Production	Nicole Zinn and Steve Smearman

Pepper , Bell	Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, and Metam-Sodium in Bell Pepper Production
Bill Chism and David Donaldson

Strawberry Fruit	Assessment of the Benefits of Soil Fumigation with
Chloropicrin, Methyl Bromide, and Metam-sodium In Strawberry Fruit
Production	Leonard Yourman and Stephen Smearman

Strawberry Nursery	Chloropicrin, Methyl Bromide, Metam-sodium and
Dazomet Use In Strawberry Nursery Runner Production	Leonard Yourman and
Steve Smearman

Tomato	Assessment of the Benefits of Soil Fumigation with Chloropicrin,
Methyl Bromide, and Metam-sodium in Tomato Production	Nikhil Mallampalli
and Elisa Rim

Conceptually, the benefits of a pesticide like a soil fumigant are the
improvements in production and/or reductions in cost resulting from the
pesticide’s use.  The social benefits of a pesticide are divided
between the users of the pesticide, e.g., growers, and consumers. 
Consumers benefit because higher production and/or lower costs translate
into a cheaper and more abundant supply of products.

The documents summarized are assessments of the benefits of methyl
bromide.  As such, they compare the current situation in which methyl
bromide is available for use, subject to existing label restrictions, to
the situation that is estimated to occur were methyl bromide not
available.  This is somewhat different from an assessment of the impacts
of regulation, as no specific regulatory scheme is considered.

Methyl bromide is currently applied in mixtures with chloropicrin.

Agricultural Production

Methyl bromide is currently used on a large number of crops.  BEAD only
assessed the benefits in a subset of these crops, largely determined
based on whether they have been granted a critical use exemption from
the phase-out of methyl bromide under the Montreal Protocol or those
crops that qualify for methyl bromide use under quarantine-preshipment
criteria.  Table 2 provides information on the acreage, production and
value of the crops assessed.

Table 2.  Annual acreage, production, and value, selected crops and
regions.

Crop	Region	Acres	Production (1,000 tons)	% of U.S. Production	Value

($1,000)

Cucurbits 1	Midwest 2	47,080	576.6	12.3	114,610

	Southeast 3	197,770	1,959.9	42.0	522,320

Eggplant	Florida and Georgia	2,480	40.9	54.2	20,800

Forest Seedling 4	Southeast 5	3,250	not applicable	80.0	160,000

Nursery Crops 6	National	not available	not applicable	3,970,000

Grape – Vineyard replant	California	809,400	6,057.8	89.7	2,623,960

Stone Fruit 7 – Orchard replant	California	254,940	1,639.1	43.2
691,780

Tree Nut 8 – Orchard replant	California	766,200	647.3	100.0	2,025,160

Ornamentals 9	National	90,570	not applicable	5,036,000

Pepper	Michigan	1,800	22.2	2.8	10,420

	Southeast 10	27,400	326.9	41.5	230,130

Strawberry, Fruit	California	31,400	942.0	87.9	1,066,980

	Florida	7,100	84.3	7.9	164,360

Strawberry, Nursery	California	4,600	Not applicable	Not available	Not
available

	North Carolina	200	Not applicable	Not available	Not available

Tomato, Fresh	Midwest 11	10,120	124.9	7.0	102,150

	Southeast 12	67,250	1,082.0	58.0	801,360

Source:  BEAD assessments referenced in Table 1.

1	Cucumber, cantaloupe, honeydew, pumpkin, squash, and watermelon.

2	Illinois, Indiana, Michigan, and Ohio.

3	Alabama, Arkansas, Florida, Georgia, Louisiana, Maryland, Missouri,
Mississippi, North Carolina, South Carolina, Tennessee, Texas, and
Virginia.

4	Large variety of species cultivated, but data cover pine for
reforestation only.

5	Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina,
Oklahoma, South Carolina, Tennessee, Texas, Virginia

6	Diverse set of species and production practices, including plants for
commercial and non-commercial uses.  Fruit tree seedlings and rose
bushes included in assessment.  California is the major source of data,
but production occurs throughout the U.S.

7	Apricot, cherry, nectarine, peach, plum and prune.

8	Almond and walnut.

9	Diverse set of plants grown for indoor and outdoor purposes.  Data
primarily cover floriculture only and based on information from
California, Florida, Hawai’i, Michigan, New Jersey, New York, Texas,
and Washington.

10	Florida, Georgia, and North Carolina.

11	Indiana, Michigan, and Ohio.

12	Alabama, Arkansas, Florida, Georgia, Maryland, North Carolina, South
Carolina, Tennessee, Texas, and Virginia.

Use of Methyl Bromide

Data on the use of fumigants are limited.  Several publicly available
data sources as well as EPA proprietary data were consulted.  Table 3
presents the best estimates of fumigant use available to BEAD.  More
detail is available in the individual crop assessments.

Methyl bromide is currently only available in combination with
chloropicrin.

Table 3.  Annual average methyl bromide usage, selected crops and
regions.

Crop	Region	Planted Acres	Acres Treated (%)	Acres Treated	lb Applied
Rate 1

(lb/acre/year)

Cucurbits 2	Michigan	19,740	5	500	100,000	200

	Southeast 3	145,640	12	17,000	2,025,000	120

Eggplant	Florida and Georgia	2,480	83	2,050	135,000	65

Forest Seedlings 4	Southeast 5	3,250	50	1,620	not available	235 - 350

Nursery, Fruit, Nut, & Rose 6	National	not available

Grape – vineyard replant	California	17,780	3	490	147,000	300

Stone Fruit 7 – orchard replant	California	10,120	29	2,950	109,400	40

Tree Nut 7 – orchard replant	California	27,000	51	13,800	275,000	20

Ornamentals 9	National	90,570	not available

Pepper, Bell	Michigan	1,800	15	250	328,000	200

	Southeast 10	27,400	78	21,300	3,105,000	145

Strawberry Fruit	California	31,400	not available

	Florida	7,100	not available

Strawberry Nursery	California	4,600	not available

	North Carolina	200	not available

Tomato,

Fresh	Michigan	2,100	65	1,370	290,000	210

	Southeast 10	50,840	85	43,410	6,730,000	155

Source:  BEAD Assessments, Table 1.  

1	“Broadcast equivalent” rate, not per area treated, i.e., lb
applied to field divided by total field area.

2	Cucumber, cantaloupe, honeydew, pumpkin, squash, and watermelon.

3	Florida, Georgia, North Carolina, and Texas.

4	Large variety of species cultivated, but data cover pine for
reforestation only.

5	Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina,
Oklahoma, South Carolina, Tennessee, Texas, Virginia.

6	Diverse set of species and production practices, including plants for
commercial and non-commercial uses.  Fruit tree seedlings and rose
bushes included in assessment.  California is the major source of data,
but production occurs throughout the U.S.

7	Apricot, cherry, nectarine, peach, plum and prune.

8	Almond and walnut.

9	Diverse set of plants grown for indoor and outdoor purposes.  Data
primarily cover floriculture only and based on information from
California, Florida, Hawai’i, Michigan, New Jersey, New York, Texas,
and Washington.

10	Florida, Georgia, and North Carolina.

Fumigation is characterized by a number of factors.  Table 4 presents
the time of fumigation, methods of application, methods of sealing the
surface, and estimated area treated per day.

Table 4.  Characteristics of Methyl Bromide Fumigations.

Crop	Region	Period	Application Method	Surface Sealing	Area Treated/Day 1

(acres)

Cucurbits 2	Michigan	Mar - Apr	Shank	Strip	tarp	10 to 40

	Southeast 3	Jan - Apr or June - Sept.

(FL Aug-Jan)	Shank	Strip	tarp	10 to 40

Eggplant	Florida	Aug - Jan	Shank	Strip	tarp	10 to 40

	Georgia	July

Forest Seedlings 4	Southeast 5	Late summer or spring	Shank	Broadcast
tarp	not available

Nursery, Fruit, Nut, & Rose 6	extremely diverse, see assessment

Grape – vineyard replant	California	Fall	Shank	Broadcast or Strip	tarp
n/a

Stone Fruit 7 – orchard replant	California	Fall	Shank	Strip	tarp	12-20

Tree Nut 7 – orchard replant	California	Late Summer through Fall	Shank
Strip	tarp	8-15

Ornamentals 9	extremely diverse, see assessment

Pepper, Bell	Michigan	Mar - Apr	Shank	Strip	tarp	10 to 40

	Southeast 10	Jan - Apr or June - Sept

(GA  July

FL  Aug-Jan)	Shank	Strip	tarp	10 to 40

Strawberry Fruit	California	Spring or Late Summer	Shank	Broadcast	tarp
10 to 40

	Florida	Aug - Sept	Shank	Strip	tarp	10 to 40

Strawberry Nursery	California	Apr or 

Aug-Sept	Shank	Broadcast	tarp	10 to 40

	North Carolina	Sept - Oct	Shank	Strip or Broadcast	tarp	10 to 40

Tomato, Fresh	Michigan	April	Shank	Strip	tarp	10-40

	Southeast 10	Jan -Apr or June-Sept

(GA - July

FL - Aug –Jan)	Shank	Strip	tarp	10-40

Source:  BEAD Assessments referenced in Table 1.

1	Area treated per tractor for application other than chemigation. 
Multiple tractors could be used on a single field.

2	Cucumber, cantaloupe, honeydew, pumpkin, squash, and watermelon.

3	Florida, Georgia, North Carolina, and Texas.

4	Large variety of species cultivated, but data cover pine for
reforestation only.

5	Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina,
Oklahoma, South Carolina, Tennessee, Texas, Virginia.

6	Diverse set of species and production practices, including plants for
commercial and non-commercial uses.  Fruit tree seedlings and rose
bushes included in assessment.  California is the major source of data,
but production occurs throughout the U.S.

7	Apricot, cherry, nectarine, peach, plum and prune.

8	Almond and walnut.

9	Diverse set of plants grown for indoor and outdoor purposes.  Data
primarily cover floriculture only and based on information from
California, Florida, Hawai’i, Michigan, New Jersey, New York, Texas,
and Washington.

10	Florida, Georgia, and North Carolina.

Target Pests 

Methyl bromide is used in combination with other soil fumigants to
control a wide variety of soil pests, including weeds, insects and
nematodes, and soil pathogens.  As such, there may be a number of
registered alternatives available, depending on the crop, but the
alternatives may not control the full suite of pests.  Details are
presented in individual assessments.

Benefits of Methyl Bromide

The benefits of fumigation to producers may include increased yield,
higher quality, lower production costs and/or improved market position
(e.g., earlier production when prices are more favorable).  Benefits can
also accrue to consumers through a more abundant supply and lower
prices.  Differences in the production system with and without methyl
bromide depend critically on the availability and efficacy of other pest
control methods.  Efficacy of other control practices often depends on
regional or even local conditions.  Please see the individual crop
assessments for an explanation of how the values summarized below were
estimated.

Cucurbits

Cucurbits include cucumbers, melons, squash, and pumpkins.  In the
Midwest, methyl bromide is primarily used to control fungi, resulting in
higher yields.  The increase in production is estimated to be worth
about $4.5 million annually.  In the southeastern U.S., methyl bromide
provides control of a wide range of pests including fungi, nematodes,
and weeds.  Substantial yields improvements result from fumigation with
methyl bromide with increased production valued at $75 million/year. 
These benefits are shared by consumers, as well as cucurbit producers.

Eggplant

Florida and Georgia growers currently rely on methyl bromide plus
chloropicrin to fumigate over 80% of acres cultivated in eggplant.  Use
of an alternative regime, which would include a combination of
1,3-dichloropropene, chloropicrin, and two herbicide applications, would
not be viable.  Use of methyl bromide enables eggplant production valued
at more than $17.3 million annually in Florida, Georgia and North
Carolina.  A portion of these benefits accrue to consumers, who benefit
from a larger supply of produce and lower prices.

Forest Seedling

Soil fumigation with methyl bromide, in combination with chloropicrin,
provides substantial benefits to tree seedling nurseries and to the
public.  While relatively few acres are treated each year, fumigation
contributes to the health of tree seedlings and to the long-term health
of forests.  Soil fumigation with methyl bromide and chloropicrin makes
nursery tree production viable on nearly half the nursery acreage
currently cultivated because of improved yields and decreased production
costs relative to fumigation with 1,3-dichloropropene with chloropicrin
or with metam sodium.  The value of methyl bromide is not quantified,
because of the difficulty in estimating the future value of forests and
forest products that depend on the supply of forest seedlings.

Nursery, Fruit, Nut, Flower

Methyl bromide with chloropicrin is the dominant fumigant used in
nursery stock production in California, Oregon, and Washington. 
According to available data, approximately 65% of nurseries in
California rely on methyl bromide.  Soil fumigation in nursery
production controls diseases, nematodes and weeds and results in higher
yields, higher quality plant production, and lower costs of production. 
Use of methyl bromide enables nurseries to meet certification
requirements for pest-free plant material and, therefore, the benefits
are substantial.  Because of the great diversity of plants and
production conditions and a general lack of data, BEAD has not been able
to quantify the benefits, but they extend beyond producers to include
consumers of nursery products and multiple considerably throughout the
various production chains.

Grape – Vineyard Replant

Methyl bromide, with chloropicrin, is typically used in for replanting
grape vineyards in California where 1,3-dichloropropene is limited by
township caps.  It penetrates soil better than metam sodium, resulting
in improved yields worth about $270/acre annually.  Extrapolating from
the acres treated to the bearing acres affected implies that the value
of methyl bromide and chloropicrin is about $7.2 million/year.  This
figure does not include the benefits associated with improved survival
of young vines, which may influence the decision to invest in a vineyard
that involves large initial costs.

Stone Fruit – Orchard Replant

Soil fumigation prior to replanting an orchard of stone fruit provides
substantial benefits by decreasing mortality of young trees, improving
growth and speeding maturity, and increasing yields throughout the
lifespan of the orchard.  Fumigation targets a suite of soil pests,
including various nematodes and soil fungi.  Methyl bromide and
chloropicrin are critically important for control of soil pathogens,
especially in California and the Pacific Northwest.  Methyl bromide
penetrates heavy or damp soils better than 1,3-dichloropropene and
provides better pest control.  In these orchards, fumigation with methyl
bromide and chloropicrin contributes about $4.5 million annually in
terms of increased production compared to what would be possible using
1,3-dichloropropene with chloropicrin instead.

Soil fumigation, in general, make investments in orchards viable. 
Orchards are costly to establish and maintain for several years prior to
production.  Without the benefits provided by soil fumigation, future
revenue might not justify the costs for about half the stone fruit
acreage.  Thus, substantial benefits accrue to consumers in the form of
increased supply of fresh and processed fruit and lower prices.

Tree Nuts – Orchard Replant

Soil fumigation with methyl bromide and chloropicrin prior to replanting
almond and walnut orchards provides significant benefits to California
producers and to the economy.  Fumigation increases the survival of
young trees, promotes growth and maturity, and results in higher
productivity throughout the life of the orchard.  Methyl bromide and
chloropicrin are crucial for the control of soil pathogens and
nematodes, especially on heavy clay soils or soils with low porosity. 
BEAD estimates that fumigating less than 15,000 acres with methyl
bromide and chloropicrin each year ultimately contributes about $63.3
million annually in increased production on over 400,000 bearing acres
compared to fumigation with 1,3-dichloropropene followed by an
application of metam sodium.

These figures do not include the value added by fumigation in making
orchard establishment possible.  Establishing an orchard and maintaining
it through several non-bearing years is very costly.  Higher future
returns resulting from fumigation may make the large investment
worthwhile at many sites, which further contributes to overall
production and a thriving export market.  The figures also do not
include the possibility that 1,3-dichloropropene may not be available to
some growers because of township caps, which restrict the total amount
of 1,3-dichloropropene that may be applied to a given area.

Ornamentals

There is ample evidence of that fumigant use increases yield and quality
and lowers production costs.  However, the wide number of species and
locations combined with limited data make it impossible to conduct a
thorough analysis of the differences between one fumigant pest control
alternative for another.  Variations in pests and conditions suggest
that yield and quality differences would be significant and that methyl
bromide plays a critical role.  This is especially significant for the
propagative sector because changes in the supply of seedling stock would
result in exponential changes to future supplies of products.

Pepper, Bell

Methyl bromide, with chloropicrin, is used to control a mix of
nematodes, plant pathogens, and weeds.  Nationally, methyl bromide is
used on about 33% of pepper acreage, with use concentrated in Michigan
and the southeast, including Florida, Georgia, and North Carolina. 
Fumigation makes production possible on about 15% of Michigan acreage
and over 75% of acreage in the southeast.  Production from this area is
valued at about $178.7 million/year.  A large part of this value is
gained by consumers who benefit from an increased supply and lower
prices of pepper.

Strawberry Fruit

Methyl bromide mixed with chloropicrin has been the leading chemical
pre-plant soil treatment for commercial strawberries grown in California
and Florida, which produce over 90% of commercial strawberries grown in
the U.S.  Fumigation controls nematodes and soil pathogens, resulting in
higher yields.  Benefits amount to about $430/acre in California,
including both increased yields and reduced production costs.  Benefits
are about $110/acre in Florida, where methyl bromide is a more costly
option.  In total, the benefits of methyl bromide use are about $60.8
million annually, a portion of which is gained by consumers through an
increased supply of strawberry and lower prices.

Strawberry Nursery

Methyl bromide is the fumigant of choice in strawberry nursery plant
production in California and the southeastern U.S. (primarily North
Carolina) for a wide range of pests.  Pest-free by state regulations for
nursery stock are an important consideration and fumigation with methyl
bromide meets current standards.  Compared to the alternative
(fumigation with 1,3-dichloropropene and chloropicrin for pathogen and
nematode control followed by an application of metam-sodium or dazomet
for weed management), methyl bromide with chloropicrin results in higher
yields and lower production costs.  In many situations, fumigation with
methyl bromide makes production of strawberry runners viable. 
Nationally, the benefits of methyl bromide amount to about $13.2 million
annually.  A portion of these benefits accrue to strawberry fruit
producers, who enjoy a larger supply of runners at affordable prices. 
Ultimately, benefits may multiply throughout the production chain and
provide consumers with a greater supply of strawberry fruit at lower
prices.

Tomato, Fresh

Methyl bromide, with chloropicrin, is used to control a mix of
nematodes, plant pathogens, and weeds.  Nationally, methyl bromide is
used on about 35% of tomato acreage, with use concentrated in Michigan
and the southeast, including Florida, Georgia, and North Carolina. 
Fumigation makes production possible on about 65% of Michigan acreage
and over 85% of acreage in the southeast.  Production from treated area
is valued at about $747.6 million/year.  A large part of this value is
gained by consumers who benefit from an increased supply and lower
prices of tomato.

CONCLUSION

Methyl bromide, in combination with chloropicrin, is used to treat a
variety of pests, including soil pathogens, nematodes, and weeds.  The
benefits of fumigation with methyl bromide include increases in yield
and lower production costs.  In some cases, methyl bromide makes
production viable where pest pressure would otherwise be too great. 
BEAD assessed a selection of crops, representing those with the highest
fumigant usage in terms of share of crop area treated and total pounds
applied.  The benefits are generally divided between producers, who
benefit from higher net operating revenue, and consumers, who benefit
from increased supply and lower prices.

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