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> Number range CHAPTER**UNITED STATES ENVIRONMENTAL PROTECTION AGENCY**
>
> ­­­WASHINGTON D.C., 20460
>
> ­­
>
> OFFICE OF
>
> PREVENTION, PESTICIDES AND TOXIC SUBSTANCES

**[MEMORANDUM]{.underline}**

**SUBJECT:** Assessment of the Benefits of Soil Fumigation with
Metam-Sodium in Carrot Production (DP# 337490)

**FROM:** David Donaldson

Economic Analysis Branch

Richard Michell

Biological Analysis Branch

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

Special Review and Reregistration Division (7508P)

**PRODUCT REVIEW PANEL REVIEW:** February 15, 2007

**SUMMARY**

This assessment estimates the value of metam-sodium use in carrot
production in California and Washington. There are approximately 102,000
acres of carrots grown in the U.S. annually. Metam-sodium, the primary
fumigant used in carrot production, is applied to about 30% or 30
thousand of these acres. Metam-sodium is used to control a mix of
nematodes, plant pathogens, and weeds, resulting in higher yields and
reduced production costs compared to alternative control measures
including 1,3-dichloropropene and additional herbicide and fungicide
applications.

BEAD estimates the benefit of metam-sodium in California carrot
production to be about \$3.5 million annually resulting from reduced
production costs compared to fumigation with 1,3-dichloropropene and
applications of other herbicides and fungicides. However,
1,3-dichloropropene is subject to regulatory restrictions in California
that may limit it's availability for use by carrot growers. If
1,3-dichloropropene were not available to California growers, the
benefits of metam sodium could be as much as \$140 million because
production on the 23,000 acres currently using metam-sodium would not be
viable. BEAD estimates that the benefits of metam-sodium use in
Washington carrot production is at least \$250 thousand, resulting from
the higher production costs of using the metam-sodium alternative
dichloropropene and additional herbicide applications. However, benefits
could be as high as \$3.5 million if metam-sodium makes carrot
production viable these acres. These benefits are shared by carrot
producers in terms of higher returns, and consumers in terms of greater
supply and lower carrot prices.

**STATEMENT OF PURPOSE**

As part of the Reregistration Eligibility Decision (RED) process, EPA is
assessing the risks and benefits of the use of several soil fumigants as
a group: chloropicrin, metam-potassium, metam-sodium, and methyl
bromide. This document presents the assessment of the benefits to carrot
production that is provided by metam-sodium, the predominantly used
subject fumigant.

Conceptually, the benefits of a pesticide like a soil fumigant are
comprised of the improvements in production and/or reductions in cost
resulting from the pesticide use. The social benefits of a pesticide are
divided between the users of the pesticide, *e.g.*, carrot producers,
and consumers of carrots and carrot-containing products. Consumers
benefit because higher production and/or lower costs translate into a
cheaper and more abundant supply of carrot. The impact of fumigant
regulation on this consumer benefit is not explicitly evaluated in this
document.

In evaluating the benefits of soil fumigants, this document compares the
current situation in which fumigants are available for use, subject to
existing label restrictions, to the situation that is estimated to occur
were the fumigants not available. This is somewhat different from other
BEAD assessments of the impacts of regulation, in that no specific
regulatory scheme is considered.

**BACKGROUND**

This assessment focuses on carrot production in California and
Washington. California is included in this assessment because, in terms
of total carrot production, for both the fresh and processing markets,
and fumigant use in carrots, it is the most important state. Washington
is included in this assessment because it is the leading producer of
carrots for processing, in terms of acres harvested, and metam-sodium is
widely used in the Washington production system. Though there are other
important states that produce carrots for processing, fumigants are
either not used, or not covered by pesticide use reporting systems
available to EPA. This indicates that fumigant pest related issues are
less prominent in other growing regions. Nonetheless, we anticipate that
our findings will be generally relevant to all U.S. carrot production
where metam-sodium is used. This assessment is focused exclusively on
measuring the benefits of metam sodium. We are not assessing the
benefits of chloropicrin in carrot production, which is also being
considered by the Agency under a Reregistration Eligibility Decision.
This is because chloropicrin is used on only 3% of carrot acreage, is
used in combination with dichloropropene, and because we have little
information describing the carrot yield and quality benefits of
chloropicrin use in this scenario.

Carrots are a cool-season crop typically produced in deep, loose, and
well drained soils. The crop is typically irrigated with sprinkler or
furrow irrigation systems. The varieties planted depend upon the
specific intended fresh or processing markets. The crop is grown in
three to five year rotations with grains, potatoes, peppers, garlic,
melons, onions, tomatoes, or cotton. Many of these crops also depend on
the soil fumigation treatments applied prior to planting carrots. High
value crops like carrots also allow growers to rotate with lower value
crops. The major carrot pests, nematodes and diseases, typically cause
quality and yield losses.

Carrots are grown for either the fresh or processed markets. California
is the leading carrot producing state with approximately 80% of the
fresh market and about one third of the processed market. The San
Joaquin Valley accounts for more than half the state's carrot
acreage---though, to accommodate year round production, carrots are
grown in three other regions, low desert, high desert, and costal inland
valleys. Other important carrot producing states include Michigan and
Texas, where carrots for both the fresh and processed markets are grown.
Washington and Wisconsin produce significant quantities of carrot for
the processing market. On a national basis, there are an average of 85
and 16 thousand acres of carrots harvested for the fresh and processing
markets, respectively. Tables 1 and 2 provide detailed fresh and
processing market carrot production data for selected states and the
U.S.

**Table 1. Carrots Grown For The Fresh Market, Yield, Price, Acreage,
Production, And Value, By Selected Region, 2001-2005 Average^1^.**

+-----------+------+-------+-------+---------+----------+----------+
| *         | **Y  | **    | **    | **Ha    | **Pr     | **Value  |
| *Region** | ield | Price | Value | rvested | oduction | of       |
|           | (CW  | per   | per   | Acres** | (1,000   | Prod     |
|           | T)** | CWT   | Acre  |         | CWT)**   | uction** |
|           |      | (     | (     |         |          |          |
|           |      | \$)** | \$)** |         |          | **(\$    |
|           |      |       |       |         |          | 1,000)** |
+-----------+------+-------+-------+---------+----------+----------+
| **Cal     | 298  | 20    | 6,079 | 67,900  | 20,228   | 412,814  |
| ifornia** |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+
| **M       | 318  | 13    | 4,204 | 4,280   | 1,364    | 18,037   |
| ichigan** |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+
| **Texas** | 285  | 25    | 7,051 | 2,420   | 689      | 17,281   |
+-----------+------+-------+-------+---------+----------+----------+
| **United  | 313  | 19    | 6,032 | 85,572  | 26,801   | 516,017  |
| States**  |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+

Sources: Crop Summary (USDA NASS, 2002-2006); Agricultural Prices (USDA
NASS, 2002-2006).

1\. Table values have been rounded.

**Table 2. Carrots Grown For The Processing Market, Yield, Price,
Acreage, Production, And Value, By Selected Region, 2001-2005
Average^1^.**

+-----------+------+-------+-------+---------+----------+----------+
| *         | **Y  | **    | **    | **Ha    | **Pr     | **Value  |
| *Region** | ield | Price | Value | rvested | oduction | of       |
|           | (ton | per   | per   | Acres** | (tons)** | Prod     |
|           | s)** | Ton   | Acre  |         |          | uction** |
|           |      | (     | (     |         |          |          |
|           |      | \$)** | \$)** |         |          | **(\$    |
|           |      |       |       |         |          | 1,000)** |
+-----------+------+-------+-------+---------+----------+----------+
| **Cal     | 31   | 98    | 3,093 | 3,460   | 110,222  | 10,721   |
| ifornia** |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+
| **M       | 23   | 66    | 1,518 | 1,520   | 34,920   | 2,311    |
| ichigan** |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+
| **Texas** | 17   | 62    | 1,044 | 1,400   | 24,148   | 1,423    |
+-----------+------+-------+-------+---------+----------+----------+
| **Was     | 30   | 69    | 2,096 | 4,760   | 144,512  | 9,975    |
| hington** |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+
| **Wi      | 23   | 63    | 1,449 | 3,980   | 90,210   | 5,693    |
| sconsin** |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+
| **United  | 27   | 74    | 1,987 | 16,232  | 431,598  | 32,169   |
| States**  |      |       |       |         |          |          |
+-----------+------+-------+-------+---------+----------+----------+

Sources: Crop Summary (USDA NASS, 2002-2006); Agricultural Prices (USDA
NASS, 2002-2006).

1\. Table values have been rounded.

**Fumigant Use**

The following section summarizes our understanding of the use of
fumigants in carrot production. In preparing this summary, we referred
to all available pesticide use data for the period 2001 to 2005. These
included data from the U.S. Department of Agriculture, National
Agricultural Statistics Service (NASS), The California Department of
Pesticide Regulation, Pesticide Use Reports (PUR), Phase 3 public
comments submitted to the Agency, communication with carrot producers,
and proprietary pesticide use, and usage data. It is worth noting that
these sources are frequently divergent. For this reason, we have
reviewed each of the sources carefully and have used what we concluded
to be the most appropriate and accurate information. Thus, the data
provided below reflects an element of professional judgment. It may
therefore be difficult to independently calculate the same estimates of
fumigant use. Nonetheless, the following data provides insight into the
extent and general importance of fumigants in carrot production.

As shown in Table 3, Carrots are commonly fumigated with dichloropropene
and metam-sodium, and to a small extent with chloropicrin. Over 6
million pounds of fumigants are used on carrots per year in the U.S.
Dichloropropene is used on approximately 20% of carrot acres and
Metam-sodium is used on about 30%. About 3% of carrot acreage are
treated with chloropicrin, which is applied in combination with
1,3-dichloropropene. In total, about one half of the U.S. carrot crop is
treated with one or more fumigant.

**Table 3. Annual fumigant Usage on Carrots, 2001-2005.**

Source: NASS Pesticide Use Reports, California PUR, and EPA proprietary
data.

Note, Percent crop treated data and pounds applied were taken from the
above data sources. Total area treated and pounds applied are calculated
in the table.

1\. Percent crop treated estimates apply to 70,360 acres of carrots
harvested in California, 4,760 acres of carrots harvested in Washington,
and 101,800 acres of carrots harvested in the U.S.

2\. A dash indicates that data are not available.

**FUMIGATION CHARACTERISTICS**

**Target Pests**

Fumigants are used alone or in combination in California and Washington
to control the following nematodes, weeds, and diseases in carrot
production.

**[Table 4. Key Carrot Pests, weeds, and diseases.]{.smallcaps}**

+------------+---------------------------------------------------------+
| **[R       | **[Key diseases, Pests and weeds]{.smallcaps}**         |
| egion]{.sm |                                                         |
| allcaps}** |                                                         |
+============+=========================================================+
| **Ca       | Nematodes (root-knot)                                   |
| lifornia** |                                                         |
|            | Nutsedge and Redroot Pigweed                            |
|            |                                                         |
|            | Pythium \[cavity spot\] and Rhizoctonia \[crown rot,    |
|            | violet root rot, seedling root rot\]                    |
+------------+---------------------------------------------------------+
| **Wa       | Nematodes (including root-knot & stubby-root            |
| shington** |                                                         |
|            | Volunteer Potatoes and Volunteer Wheat                  |
+------------+---------------------------------------------------------+

References: Nunez, 2006; USDA, 2000a; USDA 2000b.

**Use Characteristics**

[California]{.underline}

Metam-sodium is applied via sprinkler or flood, or as a soil injection
application prior to listing carrot beds. The soil is irrigated prior to
application. Approximately ten days later, metam-sodium is applied
(Grimmway Farms, 2005). Chloropicrin is applied in combination with
1,3-dichloropropene (i.e., Telone C-17) as a soil injection treatment.
Chloropicrin is not used alone.

The metam-sodium use rate for control of nematodes, diseases, and weeds
ranges from 162 - 213 pounds per acre (Bolthouse Farms 2005; Grimmway
Farms, 2005). The Average chloropicrin use rate is about 18 pounds per
acre and is only used in combination with 1,3-dichloropropene (Grimmway
Farms, 2005). The 1,3-dichloropropene use rate in the Telone C-17
product is 88.5 pounds per acre (Bolthouse Farms 2005; Grimmway Farms,
2005).

Carrot acres treated per day with all fumigants ranges from 40 to 80
acres and varies by application method (Grimmway Farms, 2005; Bolthouse
Farms 2005). According to the 2002 Census of Agriculture, there are 417
farms producing carrots in California at an average size of 164.6 acres.

A water seal is typically used for metam-sodium. Soil is compressed with
a bar when metam-sodium is injected. Listing of rows is done immediately
after injection treatments with chloropicrin plus dichloropropene or
dichloropropene alone (Bolthouse Farms 2005; Grimmway Farms, 2005). This
information is summarized in Table 5 below.

**Table 5. Selected Fumigation Application Information For Carrots Grown
In California.**

  -------------------- --------------------- --------------------- ------------------------
                       **Chloropicrin^1^**   **Dichloropropene**   **Metam-sodium**

  **Application Rate   18                    89 (in combination    162-213 (Average 170)
  (lb. ai/acre)**                            with chloropicrin);   
                                             121 (used alone)      

  **Acres Treated per  80 (soil injection)   80 (soil injection)   40-60 (flood, sprinkler
  Day**                                                            \[excluding center
                                                                   pivot\] drip), 80 (soil
                                                                   injection)

  **Time of            June-March, &         Year-round (varies    Year-round (varies with
  Fumigation**         September-November    with county)          county)

  **Application        Soil injection via    Soil injection        Soil injection, flood
  Method**             Telone product (i.e.,                       irrigation, drip
                       Telone C-17)                                irrigation, or sprinkler
                                                                   irrigation

  **Strip Application  All broadcast         All broadcast         Small percentage applied
  (% of Usage & % of                                               as a strip treatment,
  field area)**                                                    mostly broadcast

  **Soil Sealing       Soil (immediate       Soil (immediate       Water seal or pipe drag
  Procedures**         listing of beds after listing of beds after behind injection bar for
                       treatment)            treatment)            soil injection
                                                                   applications.
  -------------------- --------------------- --------------------- ------------------------

^1\ only\ used\ in\ combination\ with\ 1,3-Dichloropropene.^

[Washington]{.underline}

According to the 2002 Census of Agriculture, there are 141 carrot farms
in Washington and they average 74 acres each. Metam-sodium is applied
via center pivot irrigation systems in Washington. The circular treated
fields reportedly average around 125 acres and can be treated in a range
of 6 -- 35 hours (Crosby, 2007). The typical metam-sodium use rate in
Washington is 140 pounds per acre. This information is summarized in
Table 6 below.

**Table 6. Fumigation Application Information For Carrots Grown In
Washington.**

  ---------------------------- ------------------------------------------
                               **Metam-sodium**

  **Application Rate (lb.      140
  ai/acre)**                   

  **Acres Treated per Day**    125 acre center pivot fields can be
                               treated in from 6 -- 35 hours (Crosby,
                               2007)

  **Time of Fumigation**       Fall

  **Application Method**       Via sprinkler irrigation

  **Strip Application**        All broadcast

  **Soil Sealing Procedures**  Water seal
  ---------------------------- ------------------------------------------

**PEST CONTROL PRACTICES**

The following section provides the cultural and chemical control
practices currently in use in California and Washington carrot
production. The available alternative control measures are also given
below.

**Cultural Control Practices**

Growers in both California and Washington utilize production practices
that identify types and levels of pests in individual fields, reduce
pest populations, determine which fields require treatment, and
determine the treatment of choice for individual fields. These practices
include soil sampling for target pests, deep plowing previous crop
residues, crop rotations, field selection, hand weeding, selective
irrigation timing, selective planting dates, and cover crops (Washington
State University, 2002; CMCC and CFCAB, 2005).

**Chemical Control Practices**

[California]{.underline}

**Metam-sodium**: Metam-sodium is applied for control of a wide range of
pests in California. It is used for low level root-knot nematode
infestations. It is used for pythium \[cavity spot\] and rhizoctonia
diseases \[crown rot, violet root rot, seedling root rot\]. Metam-sodium
is also used to control nutsedge and redroot pigweed. One gallon of 42%
active ingredient product contains 4.26 pounds of active ingredient.

**Chloropicrin + 1,3-dichloropropene (Telone C-17)**:
Chloropicrin-dichloropropene combination products are used to control
nematodes and some disease and weed pests. These products are used on a
limited basis in California carrot production due to their high cost.
Chloropicrin, used in combination with dichloropropene, reportedly
provides control of certain soil borne pathogens. Control of moderate to
high level root-knot nematode infestations, wireworms and symphylans is
provided by the dichloropropene ingredient (Bolthouse Farms, 2005 and
Grimmway Farms, 2005). One gallon of Telone C-17 contains 8.2 pounds of
1,3-dichloropropene plus 1.7 pounds of chloropicrin.

**1,3-dichloropropene:** When moderate to high nematode populations
exist prior to planting, growers will typically use a
1,3-dichloropropene alone product (e.g., Telone II), regardless of
disease or weed pests, because nematodes are the most damaging carrot
pests. Accordingly, the majority of 1,3-dichloropropene usage is in
these instances. It may be more advantageous to use a
chloropicrin-dichloropropene combination product (e.g., Telone C-17) but
the high cost of these products keeps usage to a minimum.

[Washington]{.underline}

**Metam-sodium**: Metam-sodium is used in Washington carrot production
mainly for control of low level root-knot nematode infestations. It is
also used to a lesser extent for the control of volunteer potatoes and
volunteer wheat. One gallon of 42% active ingredient product contains
4.26 pounds of active ingredient.

**Alternatives**

Specific control alternatives for the various carrot-pest combinations
associated with use of the subject fumigants in California and
Washington are as follows:

[California]{.underline}

**Nematodes (root-knot)**: major usage of metam-sodium and
dichloropropene (Telone); minor usage of chloropicrin reported. Use of
other registered pesticides was not reported in the usage data (EPA,
2007). Growers are already using a variety of non-chemical alternatives,
including crop rotation, field selection, and cover crops. These methods
alone do not ensure that carrots will not be adversely affected by
nematodes (USDA, 2000a). Metam-sodium is reportedly used to control low
nematode populations; whereas dichloropropene is suitable for
controlling moderate and high populations. Limitations to
dichloropropene use include buffer zones of 300 feet, township caps,
restricted use within the San Joaquin Air Basin during December and
January, and special permit requirements. Dichloropropene also must be
applied by injection by certified applicators.

**Nutsedge**: low usage of metam-sodium to control this pest. The
registered alternative linuron appears to be the alternative of choice
for this pest. Only low usage levels of the alternatives fluzifop and
trifluralin were reported in the available usage data (EPA, 2007).

**Redroot Pigweed**: minor usage of metam-sodium to control this pest.
The registered alternatives linuron and trifluralin appear to be the
alternatives of choice (EPA, 2007). The other registered alternatives
are carfentrazone-ethyl, metribuzin, glyphosate, and pyraflufen-ethyl.
Linuron and trifluralin are rated as excellent and fair/good,
respectively, for control of broadleaf weeds (CMCC and CFCAB, 2005).

**Pythium \[cavity spot\]**: moderate usage of metam-sodium for control
of this pest; low usage of chloropicrin and 1,3-dichloropropene used for
control of this pest. Mefenoxam appears to be the registered pesticide
of choice (EPA, 2007). Among the other registered alternatives there is
moderate usage of azoxystrobin and low usage of iprodione. The
California Crop Profile for Carrots (2000) states that "without
mefenoxam growers would incur 25% losses".

By planting carrots in a three-year rotation with crops other than
alfalfa, and maintaining proper irrigation, the incidence of cavity spot
can be reduced. Carrots should be harvested at the first sign of
maturity since older carrots are more susceptible. No Biological Control
methods have been established for cavity spot.

Mefenoxam is applied preplant incorporated or applied to the soil
surface and irrigated immediately after planting. Rates used are 0.03 to
0.06 pounds active ingredient per acre. Only crops with mefenoxam
registration can be planted back in treated soil within the next 12
months. Cercospora leaf blight is also reported to be controlled with
mefenoxam. Cavity spot is the most troublesome root disease in carrots.
All the other fungicide alternatives are rated as poor control measures
(CMCC and CFCAB, 2005).

**Rhizoctonia \[crown rot, violet root rot, seedling root rot\]**:
moderate usage of metam-sodium to control this pest. No usage of
registered alternatives detected in usage data (EPA, 2007). Registered
alternatives are azoxystrobin (root rot, crown rot, seedling root rot),
fludioxonil (seedling root rot), Bacillus subtilis strain QST 713 (low
pest pressure only, for unspecified Rhizoctonia disease) and mono- and
di-potassium salts of phosphorous acid (unspecified Rhizoctonia
disease). No information was located on the comparative efficacy of the
metam-sodium alternatives.

**California Alternatives Pest Control Summary**: Dichloropropene is the
only suitable fumigant for moderate and high nematode populations. It
also provides control of wireworms and symphylans. There are no
non-fumigant alternatives for control of nematodes. Nutsedge and redroot
pigweed are minor pests of metam-sodium in California carrot production.
There appears to be several adequate metam-sodium alternatives for these
pests, but linuron is the most prominent. Pythium and rhizoctonia are
moderately important pests of California carrots. Mefenoxam is a
suitable metam-sodium alternative for pythium control. Azoxystrobin and
iprodione can also be used. Cultural control measures are also available
to carrot producers. Alternative rhizoctonia controls include
azoxystrobin and fludioxonil. For lower infestation levels, *Bacillus
subtilis* strain QST 713 and mono- and di-potassium salts of phosphorous
acid provide adequate control.

[Washington]{.underline}

**Nematodes (including root-knot & stubby-root)**: major usage of
metam-sodium and dichloropropene for control of this pest (EPA, 2007).
According to the August 2000 Crop Profile for Carrots in Washington
State: cultural methods, crop rotation, cover crops, and field
selection, are reported as moderately effective controls; economic
thresholds are used by 43% of Washington state carrot growers to
determine when or whether to treat for nematodes; and more than
seventy-five percent of the acreage is treated with 1,3-dichloropropene
or metam-sodium.

Based on current use patterns, the non-fumigant oxamyl appears to be
unsuitable for controlling moderate and high nematode populations.
However, oxamyl is used in certain situations (dicer carrot crops,
fumigant buffer zones, where fumigants are not cost effective) and is
primarily applied via center pivot irrigation systems. It is
occasionally applied using other chemigation systems, or as a soil
treatment (preplant or postplant).

**Volunteer Potatoes** low acreage treated with metam-sodium. The
registered alternative linuron appears to be the control measure of
choice based on the usage data for this pest (EPA, 2007). Hand weeding
is practiced, but is expensive and impractical when high levels of this
pest are present.

**Volunteer wheat** low acreage treated with metam-sodium. Significant
usage of the alternatives clethodim, fluazifop, and glyphosate imply
that they are probably suitable metam-sodium alternatives (EPA, 2007).
No other information located on alternative control measures.

**Washington Alternatives Pest Control Summary**: Dichloropropene is the
only suitable fumigant for moderate and high nematode populations.
Dichloropropene is used in Washington carrot production for moderate to
high level root-knot nematode infestations. Dichloropropene also
controls wireworms (Washington State University, 2002). Registered
alternative oxamyl has very low usage and is reportedly used in addition
to fumigants much of the time and in special situations. Linuron is an
adequate control measure for volunteer potatoes, and clethodim,
fluazifop, and glyphosate appear to be adequate for controlling
volunteer wheat.

**BENEFITS OF FUMIGATION**

**Yield and Quality**

In both California and Washington, 1,3-dichloropropene plus an
additional herbicide application (and an additional fungicide in
California) appears to be a suitable alternative for all pests
controlled by metam-sodium. Though we have limited data, we do not
anticipate yield losses when these alternatives are available and used.
However, in California, there are numerous restrictions that apply to
dichloropropene, the primary alternative for nematode control. These
restrictions may limit the use of dichloropropene on that part of the
carrot crop that is currently treated with metam-sodium. Where neither
metam-sodium nor dichloropropene are available, we assume that growers
will experience 25% yield losses. An estimate of the portion of the
carrot crop that would fall in this range is not available. This yield
loss estimate is based on information provided by the California Carrot
Board (California Carrot Board, 2006). Based on correspondents with
Washington carrot production experts and limited reported usage, we also
assume that oxamyl is not as efficacious in controlling nematodes as
metam-sodium (Crosby 2007 and EPA 2007). Based on this information, we
estimate a minimum of a 10% yield loss for Washington carrot acreage
currently using metam-sodium that switches to oxamyl.

**Economic Benefits**

In the following section we value the benefit of the use of the fumigant
metam-sodium in carrot production, the predominantly used subject soil
fumigant. This is done by comparing current carrot production to carrot
production without the use of fumigants, the result of which is reduced
yields and changed production costs. BEAD's estimates of the benefits of
the soil fumigants, conceptually, are the improvements in production
and/or reductions in cost resulting from the fumigants use. The benefits
of fumigant use are shared between users of the pesticide and consumers
of carrot where consumers benefit because higher production and/or lower
costs may translate into a cheaper and more abundant supply of carrot.

In the following section we evaluate the impact of estimated carrot
yield losses on the economic viability of carrot producers. BEAD uses a
partial budget analysis to estimate the impacts of changes in
production. That is, we evaluate the consequences on a typical acre of
the crop grown, rather than attempt to assess the impacts in the context
of a whole enterprise, which could include multiple crops under
cultivation. This approach allows the Agency to compare losses to net
operating revenue, which is defined as the difference between gross
revenue and variable operating costs, on a per-acre basis. The analysis
ignores fixed costs, which are highly dependent on land ownership and
the size and diversity of the grower's operation, and therefore
difficult to define on a per-acre basis. As such, this analysis may
understate the benefits of fumigation with metam-sodium as a percentage
of the grower's income.

Estimated benefits of metam-sodium use in California and Washington
carrot production are summarized in Tables 7 and 8.

[California]{.underline}

The best alternative control for metam-sodium in California carrot
production is dichloropropene plus linuron, mefenoxam, and azoxystrobin.
Alternative controls would add \$146 in operating costs, and would lead
to a reduction of 17% in net operating revenues, from \$869 to \$723.
Spread across the approximate 23,000 acres of California carrot acres
where metam-sodium is applied, this reduction is valued at approximately
\$3.5 million. However, if acres currently treated with metam-sodium
could not be treated with dichloropropene, due to regulatory
restrictions, we anticipate yield losses of 25% and increased production
costs. These would combine for losses in net revenues of 166%. This
represents unsustainable losses to these carrot producers and would lead
them to stop carrot production on these acres. This equals a reduction
in the value of California carrot production of about \$140 million.

BEAD estimates that the value of metam-sodium use in California carrot
production ranges from \$3.5 to \$140 million, depending on the
availability of 1,3-dichloropropene. These acres could be put to a
different use, such as producing a different crop, so these losses could
ultimately be less.

**Table 7. Per Acre Gross Revenue, Operating Costs, and Net Operating
Revenues, Metam-sodium and Alternatives, California Carrot Production,
Fresh Market Utilization.**

  ------------------------- ------------------ --------------------- ------------------
                            **Metam-Sodium**   **Dichloropropene +   **No Fumigant +
                                               Linuron + Mefenoxam + Linuron +
                                               Azoxystrobin**        Mefenoxam +
                                                                     Azoxystrobin**

  Yield (CWT)               298                298                   224

  Estimated Yield Loss      0%                 0%                    25%

  Price per CWT             \$20               \$20                  \$20

  Gross Revenue             \$6,079            \$6,079               \$4,559

  Fumigation costs          \$152^1^           \$220                 \$0
  (nematodes + soil borne                                            
  disease + weeds)                                                   

  Additional Weed Control   \$0                \$18                  \$18
  Costs^2^                                                           

  Additional Disease        \$0                \$60                  \$60
  Control Costs^3^                                                   

  Other Land Preparation    \$258              \$258                 \$258
  Costs                                                              

  Land Preparation Costs    \$410              \$556                 \$336

  Growing Period Costs      \$800              \$800                 \$800

  Harvest Costs2            \$4,000            \$4,000               \$4,000

  Total Operating Costs     \$5,210            \$5,356               \$5,136

  Net Operating Revenue     \$869              \$723                 (\$577)

  Percentage Change in Net  0%                 17%                   166%
  Operating Revenue                                                  
  ------------------------- ------------------ --------------------- ------------------

Source: U.C. Cooperative Extension, Sample Costs to Establish and
Produce Market Carrots Imperial County -- 2004, Prepared by Herman S
Meister,
<http://www.agecon.ucdavis.edu/uploads/cost_return_articles/carrotsmkt04.pdf>.

1\. Metam-sodium application costs vary by application methods. Sprinkle
injection costs are assumed to be representative. When applied by flood,
the total cost is \$189, cost of metam-sodium (\$145.00) and the cost of
two field floods (\$25.95 for the first and \$17.95 for the second).
Application costs using sprinklers are \$152 per acre. Applied by soil
injection, total costs are \$177 per acre.

2\. Additional weed control costs are \$18, based on estimated cost of
linuron at 0.75 pounds of active ingredient per acre. Does not include
application costs.

3\. Additional soil borne disease costs are \$25 for azoxystrobin at
0.22 pounds or active ingredient per acre, and mefenoxam at \$35 at 0.20
pounds of active ingredient per acre.

[Washington]{.underline}

The best alternative control for metam-sodium in Washington carrot
production is dichloropropene plus linuron and clethodim. The use of
these compounds would result in no yield losses, but would increase
costs by \$150 per acre. This would result in a reduction of net
operating revenue of 26%. Given that net operating revenue does not
include fixed costs, a 26% reduction in net operating revenue may be
unsustainable for many Washington processing carrot producers.
Washington carrot producers also have oxamyl plus linuron and clethodim
available as an alternative to metam-sodium. This combination would
result in losses in net operating revenue of a minimum of 36%, and is
not likely a viable alternative to metam-sodium.

BEAD estimates that the value of metam-sodium to Washington carrot
production that currently uses metam-sodium (1,800 acres) ranges from
\$250 thousand (using dichloropropene plus linuron and clethodim) to
\$3.5 million (no carrot production on those acres currently using
metam-sodium). This range depends on whether producers can maintain
profitability with the higher cost of dichloropropene plus linuron and
clethodim. If they can not, BEAD assumes that they will cease carrot
production with the resulting loss being the total value of production
on those acres, \$3.5 million. These 1,800 acres could be put to a
different use, such as producing a different crop, so these losses may
ultimately be less.

**Table 8. Per Acre Gross Revenue, Operating Costs, and Net Operating
Revenues, Metam-sodium and Alternatives, Washington Carrot Production.**

+-----------------------+-----------+-----------------+---------------+
|                       | **Metam   | **Di            | **Oxamyl +    |
|                       | -Sodium** | chloropropene + | Linuron**     |
|                       |           | Linuron +       |               |
|                       |           | Clethodim**     | **+           |
|                       |           |                 | Clethodim**   |
+-----------------------+-----------+-----------------+---------------+
| Yield (tons)          | 30        | 30              | 27            |
+-----------------------+-----------+-----------------+---------------+
| Estimated Yield Loss  | 0%        | 0%              | 10%           |
+-----------------------+-----------+-----------------+---------------+
| Price per Ton         | \$69      | \$69            | \$69          |
+-----------------------+-----------+-----------------+---------------+
| Gross Revenue         | \$2,096   | \$2,096         | \$1,886       |
+-----------------------+-----------+-----------------+---------------+
| Nematode Control      | \$100     | \$220           | \$66          |
| Costs^1^              |           |                 |               |
+-----------------------+-----------+-----------------+---------------+
| Additional Weed       | \$0       | \$30            | \$30          |
| Control Costs         |           |                 |               |
+-----------------------+-----------+-----------------+---------------+
| Total Operating       | \$1,523   | \$1,673         | \$1,519       |
| Costs^2^              |           |                 |               |
+-----------------------+-----------+-----------------+---------------+
| Net Operating Revenue | \$573     | \$423           | \$367         |
+-----------------------+-----------+-----------------+---------------+
| Percentage Change in  | 0%        | 26%             | 36%           |
| Net Operating Revenue |           |                 |               |
+-----------------------+-----------+-----------------+---------------+

Source: Washington State University Cooperative Extension, 2000 Carrot
Enterprise Budgets Columbia Basin, Washington State, Prepared by Herbert
Hinman, Erik Sorensen, and Gary Pelter.

Note: Harvesting is assumed to be done by growers and is not itemized in
the crop budgets.

1\. Typical costs for dichloropropene, metam-sodium, and oxamyl are
about \$220, \$100, and \$14-\$66 per acre, respectively.
Dichloropropene costs are comprised of a \$37 application fee for soil
injection, and \$10.18 per gallon for 18 gallons (Crosby, 2007).

2\. Costs of production vary widely across Washington. The costs in the
table represent those for carrot production in the South Columbia Basin.

**CONCLUSIONS**

There are approximately 102,000 acres of carrots grown in the U.S.
annually. Metam-sodium, the primary fumigant used in carrot production,
is applied to about 30% or 30 thousand acres. Metam-sodium is currently
relied on for disease, weed and nematode control.

BEAD estimates the benefit of metam-sodium in California carrot
production to be about \$3.5 million annually in reduced production
costs compared to fumigation with 1,3-dichloropropene and applications
of other herbicides and fungicides. However, 1,3-dichloropropene is
subject to regulatory restrictions in California that may limit it's
availability for use by carrot growers. If 1,3-dichloropropene were not
available to California growers, the benefits of metam sodium could be
as much as \$140 million because production on the 23,000 acres
currently using metam-sodium would not be viable. BEAD estimates that
the benefits of metam-sodium use in Washington carrot production is at
least \$250 thousand annually, resulting from the higher production
costs of using dichloropropene and additional herbicides. However,
losses could be as high as \$3.5 million if carrot production cannot
continue on these acres due to these higher production costs. These
benefits are shared by carrot producers in terms of higher returns, and
consumers in terms of greater supply and lower carrot prices.

**Limitations to assessment**

This document presents the assessment of the benefits provided by the
soil fumigants in the production of carrots. The following are
limitations of this analysis:

-   The assessment does not account for transition to new agronomic
    practices such as introduction of new growing areas or the
    introduction of newer as yet unregistered fumigants.

-   The assessment is based on partial budget analysis and does not
    account for price or income distribution effects resulting from
    changes in supply.

-   Yield losses based on grower experiences and crop specialist
    opinion.

-   Benefits to rotational crops are not assessed.

**REFERENCES**

Bolthouse Farms, 2005, Response to EPA Request for Soil fumigant Use and
Benefit Information

California Carrot Board, 2006, "Comments Issued By The California Carrot
Board And The California Tomato Commission Regarding The Metam Sodium
(EPA-HQ-OPP-2005-0125 And 1,3-Dichloropropene (EPA-HQ-2005-0124) Risk
Assessments." December 13, 2006.

CMCC and CFCAB, 2005, A Pest Management Strategic Plan for Fresh Carrot
Production in California, California Minor Crops Council and California
Fresh Carrot Advisory Board,
<http://www.ipmcenters.org/pmsp/pdf/CACarrot.pdf>.

Crosby, T., 2007, personal communication with Richard Michell, January
9, 2007.

EPA, 2007, EPA Proprietary Data.

Grimmway Farms. 2005, Response to EPA Request for Soil fumigant Use and
Benefit Information

Nunez, J., 2006, E-mail Communication regarding California fumigant
target pests with Richard Michell, December 18, 2006.

USDA, 2000a, Crop Profile for Carrots in California 2000,
<http://www.ipmcenters.org/cropprofiles/docs/cacarrots.html>.

USDA, 2000b, Crop Profile for Carrots in Washington State 2000,

<http://cipm.ncsu.edu/cropprofiles/docs/wacarrot.html>

USDA NASS. 2002. Census of Agriculture. U.S. Department of Agriculture,
at <http://www.nass.usda.gov/Census_of_Agriculture/index.asp>.

USDA NASS. 2002-2006a. Agricultural Prices, Summary. National
Agricultural Statistics Service, U.S. Department of Agriculture, July,
at
<http://usda.mannlib.cornell.edu/MannUsda/viewDocumentInfo.do?documentID=1003>.

USDA NASS. 2002-2006b. Crop Production, Summary. National Agricultural
Statistics Service, U.S. Department of Agriculture, January, at
<http://usda.mannlib.cornell.edu/MannUsda/viewDocumentInfo.do?documentID=1047>.

USDA NASS. 2005. Agricultural Chemical Usage, 2004 Field Crops Summary.
National Agricultural Statistics Service, U.S. Department of
Agriculture, May, at
<http://usda.mannlib.cornell.edu/usda/nass/AgriChemUsFC//2000s/2005/AgriChemUsFC-05-18-2005.pdf>.

Washington State University, 2002, Crop Profile for Carrots in
Washington, <http://cru84.cahe.wsu.edu/cgi-bin/pubs/MISC0361E.html>.