UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

APR 1.6 Z014 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile (BCP) for Registration Review: Zoxamide (101702) 

FROM: 

THRU: 

Biological 

Carl Chen, 

Analysis 

Biologist 

Branch 

~ ~ 

Claire Paisley-Jones, Environmental Protection Specialist /' -~ L ~ Science Information and Analysis Branch L...--fJ --l ,. 

Economic 

Andrew Lee, 

Analysis 

Economist 

Branch 

af. 

(I 

c ~ Biological and Economic Analysis Division (7503P) 

Arnet Jones, Chief 

Biological Analysis Branch 

Diann Sims, Chief 

Science Information and Analysis Branch 

Timothy Kiely, Chief S}, 1~. Economic Analysis Branch ~ ~ Biological and Economic Anal sis Divi · (7503P) 

TO: Jill Bloom, Chemical Review Manager 

Pesticide Re-evaluation Division (7508P) 

Peer Review Panel date: February 26,2014 

Page 1 of9 
SUMMARY 

First registered in 2001, zoxamide is a fungicide used to control plant diseases including late 

blight on potatoes and tomatoes, buckeye rot on tomatoes, and downy mildew on cucurbits and 

grapes. Based on private market usage data from 2002-2012, zoxamide usage averaged 

approximately 11,000 pounds of active ingredient annually on approximately 80,000 acres of 

surveyed agricultural crops. The average a.i. rate during this time period was 0.14 pounds a.i. per 

acre. There are no registered non-agricultural uses. Idaho, North Dakota, Minnesota, 

Washington, Georgia, and Florida account for over 80% of total pounds applied. 

INTRODUCTION 

The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) 

provides an overview of the pest management roles and quantitative usage information 

for zoxamide. The BCP includes summaries of previous BEAD products and available 

public and/or private use and usage data for zoxamide to describe the role of this 

chemical in pest management. Additional information on use is available in the 

zoxamide PRD Label Data Report. Information provided in this BEAD Chemical Profile 

(BCP) may be used by stakeholders (e.g., users and registrants), OPP risk assessors, OPP 

risk managers, and the general public during the Registration Review process of this 

pesticide. 

USE SITES 

Zoxamide is registered for use on potatoes, tomatoes, cucurbits and grapes. There are no 

registered non-agricultural uses. 

FORMULATIONS 

Zoxamide is formulated as an 80% wettable powder in water soluble packets, and an 

8.3% water dispersible granule co-formulated with mancozeb (66.7%). 

APPLICATION METHODS 

Zoxamide can be applied with ground equipment, including chemigation, or by air. 

HISTORY OF ZOXAMIDE AND BEAD PRODUCTS 

Zoxamide is an oomycete fungicide first registered in the U.S. in 2001. A Screening 

Level Usage Analysis (SLUA) was prepared by BEAD for this chemical in 2013, which 

provided percent crop treated for crops treated between 2004 and 2011 (BEAD 2013). 

Page 2 of9 
Recently (2008- 2010), EPA issued several FIFRA section 18 emergency requests for 

use of zoxamide to control phytophthora cactorum blight on ginseng for Michigan and 

Wisconsin, indicating the potential value of the chemical for ginseng. 

USAGE 

Based on private market usage data from 2003- 2012, zoxamide usage averaged 

approximately 11,000 pounds of active ingredient annually on approximately 80,000 

acres of surveyed agricultural crops. The average a.i. rate during this time period was 

0.14 pounds a.i. per acre. Figure 1 presents zoxamide usage in pounds a.i. and total area 

treated from 2003-2012 (Proprietary Data 2003-2012). Both pounds of a.i. applied and 

the total area treated have fluctuated during this time, with no clear trend to indicate 

increased or decreased usefulness to growers over time. 

Total Area 

Treated 

("() 

0 

0 

N 

g 

N 

o.n 

g 

N 

1.0 

0 

0 

N 

" 0 

0 

N 

00 

0 

0 

N 

en 

0 

0 

N 

0 

..... 

0 

N 

Total Area Treated -Pounds AI 

..... 

..... 

0 

N 

N 

..... 

0 

N 

Total Pounds AI 

Applied 

Figure 1. Zoxamide Total Acres Treated and Total Pounds A.I. Applied (2003-2012). 

Source: Proprietary Data, 2003-2012 

Table 1 shows the crops with the highest use of zoxamide, as a percent of total pounds 

applied, from 2003-2007 and 2008-2012. Applications to potatoes account for the 

majority of usage in both periods. 

Page 3 of9 
Table 1. Comparison of Crops with Highest Use of Zoxamide- Percent of Total 

P d oun so fA . I A . ~pp. li e d b e tw een 2003 -2007 an d 2008 -2012 . 2003-2007 ZOO&l012 

., Av~rng!' = 12,000 lbs A,J. A:~mge = 11,000 lbs t,\..I. 

Cr.Qp_ %Lbs Crop %Lbs 

Potatoes 89 Potatoes 85 

Cucumbers 4 Cucumbers II 

Squash 4 Tomatoes 3 

Can tal opes 2 Pumpkins 1 

Watermelon 1 Watermelon 0.1 

Source: Proprietary Data, 2003-2012 

Another measure of pesticide usage, percent crop treated, indicates the potential 

importance of a chemical to a crop. Of the top crops listed in Table 1, an average of five 

percent of potatoes, cucumbers, and cantaloupe crops were treated with zoxamide. On 

average, less than two and a half percent of the remaining crops were treated with 

zoxamide. The percent crop treated of all observed crops from 2004 to 2011 can be found 

in the SLUA (BEAD 2013). Such low percent crop treated may indicate that zoxamide 

provides relatively low benefits to growers, or that there are less costly or more effective 

alternatives on the market. 

Table 2 shows the states with the highest use ofzoxamide, as a percent oftotal pounds 

applied, from 2003-2007 and 2008-2012. The states listed account for over 80 percent of 

total usage. Idaho, Minnesota, and North Dakota accounted for over 50 percent of usage 

in both time frames. Zoxamide usage in these states is driven solely by applications to 

potatoes. Because usage during both time periods is so low, apparently large 

fluctuations in percent of total pounds applied can be caused by relatively small changes 

in total pounds applied. 

Table 2. Comparison of States with Highest Use of Zoxamide- Percent of Total Lbs. 

A ~ppJ 1i e dB e tw een th e 2003 -2007 an d 2008 -2012 T' 1me f rames. ~ 2003:-2007 2008-2012 

Avyage S< 11,000 lbs A.l./YJ Average;:: 11,000 lbs A.I./YJ' 

" State %Lbs State %~bs 

Idaho 19 Idaho 28 

North Dakota 18 Minnesota 14 

Minnesota 18 North Dakota 14 

Washington 14 Wisconsin 9 

Georgia 8 Washington 8 

Florida 7 California 7 

Other* 16 Other* 20 

*Other States: ME, NY, WI, PA, TX, DE, MI, MA, *Other States: NC, FL, NY, OR, IN, PA, MI, ME, 

OH MD, DE 

Source: Proprietary Data, 2003-2012 

Application Rates 

Page 4 of9 
The average a.i. rate for all agricultural crops from 2008-2012 was 0.16lbs per acre. 

Table 3 shows average a.i. rates of top crops (crops with the greatest percent of total 

pounds a.i. applied as identified in Table 1). The top crops with the highest average a.i. 

rate are tomatoes and pumpkins both of which had rates above the overall average. The 

remaining top crops had a.i. rates at or below the overall average. 

T a e bl 3 Z . oxam1 "d e u se on T C op rops: A verage AIR .. a t e, 2008 -2012 

~op Average Pounds Average Total Ac~es Average A.L Ra~ 

A.L/y~ Treated /year 'If (lbs a.i./acre) 

Potatoes 9,100 68,800 0.13 

Cucumbers 1,200 7,100 0.16 

Tomatoes 300 1,600 0.17 

Pumpkins 100 800 0.17 

Watermelon 10 70 0.16 

*Total Acres Treated sums all acres treated for a crop, mcludmg those acres that receive multiple 

treatments. 

Source: Proprietary Data, 2008-2012 

Geographic Distribution of Zoxamide Use 

Figure 2 shows the geographic distribution ofzoxamide usage over 2008-2012, in terms 

ofpounds AI applied per 1,000 acres of state crop area grown (see Appendix A for 

interpretation ofthe map). This measure indicates the usage intensity in surveyed states 

(as opposed to percent of total pounds applied, which is presented in Table 2). Usage 

intensity is highest in Maine and Idaho followed by New York and Washington. Again, 

because of the relatively low usage of zoxamide, apparent differences in state usage may 

be caused by small changes in actual pounds applied. 

Page 5 of9 
Pounds Active Ingredient 

per 1,000 Crop Acres Grown 

CJNoData 

U <OD4 

(do.04-0.11 

- 012-0.14 

- >0.14 

Figure 2. Annual average agricultural use intensity of Zoxamide (2008-2012). 

CHEMICAL AND USE CHARACTERISTICS 

Zoxamide is a fungicide currently registered to control plant diseases including late blight 

on potatoes and tomatoes, buckeye rot on tomatoes, and downy mildew on cucurbits and 

grapes. One of its two end-use products registered under section 3 of the Federal 

Insecticide, Fungicide, and Rodenticide Act (FIFRA) is a single active ingredient 

product, Zoxium® 80WSP, which had no usage reported in Proprietary Data. The other 

product is Gavel® 75DF, a pre-mixture ofzoxamide and mancozeb. It is registered to 

control various diseases including early blight and leaf spot on potatoes and tomatoes, 

and bacterial speck or spot on tomatoes. 

Zoxamide belongs to the group o~ benzamides classified by the Fungicide Resistance 

Action Committee (FRAC) and coded as FRAC group 22 with a low to medium risk in 

resistance development, and FRAC states that resistance management is required (FRAC, 

2013). Mancozeb is at low risk of developing resistance (FRAC, 2013). Their 

combination product of Gavel® 75DF is a protectant fungicide that can be applied in a 

regularly scheduled preventative spray program without limitation on the number of 

Page 6 of9 
sequential application that is required when the single active ingredient product of 

zoxamide is used. Applications are made on a 1 0-14 day schedule during time of rapid 

vine growth (Idaho Potato Pulse, 2014). The label of Gavel® 75DF also states that, in 

addition to the foliar applications, "a single application for seed treatment may be made 

on crops that have registered seed treatment uses." These are interesting use 

characteristics of zoxamide that could have potential to increase its use in the future. 

ROLE OF ZOXAMIDE IN PEST MANAGEMENT 

The major agricultural use of zoxamide is on potatoes. Approximately 100,000 acres of 

potatoes were treated with zoxamide in 2012, including approximately 30,000 acres in 

Idaho (Proprietary Data, 2012). Other states that used zoxamide on potatoes in 2012 

included California, Florida, New York, and Washington. Gavel® 75DF that contains 

zoxamide has been recommended for use with its preventative nature to apply early in the 

season before the occurrence of disease in the region (Virginia Potato Profile, 2003). 

Standard protectants including Gavel® 75DF have resulted in very good late blight 

control when applied before an outbreak (Idaho Potato Pulse, 2014). 

Zoxamide was also used on other sites including cucurbits and tomatoes, with 

approximately five percent of cantaloupes and cucumbers and less than 2.5 percent of 

pumpkins, squash, and watermelons treated on average (SLUA, 2013). The disease on 

cucurbits that zoxamide was mainly used to control was downy mildew (Proprietary 

Data, 2001-2012). Although acreage treated is low, zoxamide has been used since 2011 

on tomatoes in California, as one of fungicides currently in consideration for use in this 

important tomato production region (Proprietary Data, 2001-2012). Zoxamide has been 

recommended for control of multiple diseases including late blight and early blight on 

tomatoes (New Jersey Tomato Profile, 2007). It has also been listed among fungicides 

available to Florida tomato grow~rs since 2006 (Florida Tomato Profile, 2006). 

Zoxamide may also have potential for use on diseases or sites that are not listed on the 

label. A FIFRA section 2(ee) recommendation for Gavel® 75DF, a pre-packaged 

combination product containing zoxamide, has been issued in New York so growers have 

another fungicide for managing Phytophthora blight in most cucurbit crops (New 

Fungicide on Cucurbits, 2014). Zoxamide was also needed to control Phytophthora 

blight under emergency exemptions through FIFRA section 18 and was used on ginseng 

in Michigan and Wisconsin. 

DATA NEEDS 

The Agency currently does not have certain important information on zoxamide. 

Obtaining the following information may improve future assessments conducted by the 

Agency related to the use and importance of zoxamide. 

• Any future use/usage data on some important crops such as grapes, which 

currently have no usage reported in Proprietary Data. 

Page 7 of9 
REFERENCES 

BEAD. 2013. Zoxamide Screening Level Usage Analysis (SLUA). 

Florida Tomato Profile. 2006. 

http://www. ipmcenters.org/cropprofiles/ docs/FL tomatoes. pdf accessed 

online January 2014. 

FRAC. 2013. Fungicide Resistance Action Committee. 

http://www .frac. info/frac /index.htm 

accessed online January 2014. 

Idaho Potato Pulse. 2014. Idaho Potato Commission. 

http://industry.idahopotato.com/?page=potato pulse detail&id= 126&is popup= 1 

accessed online February 2014. 

New Fungicide on Cucurbits. 2014. Zoxamide use for control ofPhytophthora blight on 

cucurbits: a 

FIFRA 2(ee) recommendation of Gavel® 75DF in New York. Vegetable MD 

Online. Cornell University. 

http ://vegetablemdonline. ppath.comell.edu/N ewsArticles/Cuc Gavel.htm 

accessed online January 2014 

New Jersey Tomato Profile. 2007. 

http://www.ipmcenters.org/cropprofiles/docs/NJtomatoes.pdf 

accessed online January 2014. 

Proprietary Data. 2001-2012. (pesticide usage data) 

Virginia Potato Profile. 2003. http://www.ipmcenters.org/cropprofiles/docsN Apotato.pdf 

accessed online January 2014 

Page 8 of9 
APPENDIX A 

The map included herein is primarily for the use of the risk assessors in the 

Environmental Fate and Effects Division. The map provides a very broad geographical 

view of the average annual amount (in pounds) of the active ingredient applied per 1,000 

acres of crop acres grown. These data are included in the maps because risk assessors are 

interested in the amount of a pesticide used across agricultural land. The calculated 

values presented in the map are not equivalent to an application rate (lb ai/ A). 

The data used to make these maps have several limitations. Any interpretation ofthe 

maps should consider the underlying data and the associated limitations carefully. 

The numerator (annual average pounds applied) is based on private market surveys of 

pesticide use in agriculture averaged over the last five years (Proprietary Data, 2008-

2012). These surveys cover about 60 crops and are targeted in states that produce the 

majority of the crop. Although the surveys capture most of the use of a particular active 

ingredient in agriculture, there are several limitations to these surveys. 

• States with minor production of a surveyed crop are not sampled 

• Not all types of pesticides are surveyed in every crop in every year 

• Many specialty crops with very small acreages are not included in the survey 

The result of these limitations is that states that show no usage may actually have a small 

amount ofthe active ingredient being used. In some cases the displayed use intensity 

may be distorted because the surveyed crops and the reported pesticide usage may not 

accurately represent the actual pesticide usage on the crops produced in the state. 

The denominator (1,000 crop acres grown) was also obtained from the same private 

market survey database. The "Crop Acres Grown" variable represents the total acres 

grown in a given state of all of the surveyed crops. This value is independent of pesticide 

usage and pesticide registration. It is important to note that the surveyed crops (about 60) 

are sampled from states that are major producers of each crop. Therefore, there are cases 

where the actual crop acreage in a state is higher than that reported by crop acres grown 

in the survey because either that state and/or crop was not included in the survey. 

The reader should pay particular attention to the figure legends and realize that a map 

prepared for a particular chemical is not directly comparable to a map prepared for a 

different chemical as the legend bins will likely be different. 

Page 9 of9