UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

UAY 1 3 2014 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

An Overview of the Benefits of Sulfur Use on Agricultural Crops (DP 417520) 

Tara Chandgoyal, Ph. D., Plant Pathologist 

Biological Analysis Branch 

Science 

Rafael A

Information 

. Prieto, Environme

and Analysis 

ntal Protection 

Branch 

Specialist 

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Monisha 

Andrew Lee

Kaul, 

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Lead 

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Enviro

Economist 

nmental Protection Specialist a (J (. ~t) ~ 

Economic Analysis Branch . 

Biological and Economic Analysis Division (7503P) 

Amet Jones, Chief /) - _fiA 

Biological Analysis Brand , J 

Diann Sims, Chief M. 

Science Information and Analysis Branch 

Timothy 

Economic 

Kiely, 

Analysis 

Chief 

Branch 

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Biological and Economic Anal is Division 3P) 

TO: Jose Gayoso, Chemical Review Manager 

Risk Management and Implementation Branch 2 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel: April30, 2014 

SUMMARY 

This document qualitatively characterizes the benefits of sulfur used on agricultural crops. 

Sulfur is registered for dozens of major and minor uses (field crops, vegetable crops, fruits/nuts 

and berries, and ornamentals) as a fungicide/miticide for the control of fungal diseases and mites. 

Historically, sulfur has been heavily used in the United States on grapes, tomatoes, peaches, 
oranges, apples, cherries, and carrots for control of fungal powdery mildew disease and mites. 

Sulfur is a valuable pesticide in managing plant diseases because of its low cost and good 

efficacy. It plays an important role in pest resistance management because no fungal pest has 

been reported to have resistance to sulfur. It plays an important role in integrated pest 

management in organic crop production. Sulfur has been used for decades on many crops giving 

growers extensive experience and knowledge of its use as a pesticide. 

BACKGROUND 

As part of the registration review process, the Environmental Fate and Effects Division (EFED) 

conducted a risk assessment that found some crops (some varieties of gooseberries, currants, 

apricots, raspberries, and cucurbits) may be adversely affected by sulfur applications. In addition, 

the risk assessment document also mentioned that there are five known incidents of 

unsubstantiated toxicity of sulfur to some crops (such as cucurbits and berries). This document 

provides an overview of the benefits of sulfur use on agricultural crops and its role in pest 

management. 

ANALYSIS 

In evaluating the benefits of a pesticide to the user, BEAD considers a number of factors. The 

most direct benefit of a pesticide is its ability to control pests that would otherwise damage a 

crop, reducing the yield and/or the quality of the produce. A pesticide might also provide value 

to a grower if it provides similar pest control at lower cost than other control measures. BEAD 

also considers less tangible benefits, including the role a pesticide may play in resistance 

management or in integrated pest management (IPM) programs. 

Sulfur is a natural element used for centuries to control plant diseases and mites (Browde and 

Ohmart, 2001). The top 10 (in terms of average lbs a.i. applied per year) sulfur use crops are 

listed in Table 1 (EPA BEAD, 2014). Sulfur is effective in controlling powdery mildew disease 

and mites on various crops. Powdery mildew and mites can cause heavy crop losses under pest 

favorable weather conditions and are the primary target pests for sulfur applications. Table 1 

also shows that sulfur is an inexpensive fungicide compared to most of its alternatives. Although 

comparative efficacy of alternatives was not considered in this analysis, the percent of crop 

treated with sulfur indicates grower reliance on it for pest management (Table 1 ). 

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Table 1: High Sulfur Use Crops with Disease/Pest Controlled (2004-2012) and Average 

Cost of Alternatives. 

-

Average Average Sulfur Alternatives 

Crop Major Pounds a.i. Percent Average Average Cost Diseases/Pests1 Crop Cost($) I Applied2 

Treated2 Acre 3 ($) I Acre3.4 

Powdery Mildew, 

Grapes Bud Mite, Blister 38,900,000 80 3 22 

Mite 

Tomatoes Powdery Mildew, 8,900,000 60 10 15 Mites 

Powdery Mildew, 

Peaches Brown Rot, Leaf 2,400,000 60 5 20 

Spot, Silver Mite 

Oranges Mites 1,400,000 10 II 28 

Apples Powdery Mildew, 1,300,000 30 7 21 Scab, Blister Mite, 

Powdery Mildew, 

Cherries Brown Rot, Leaf 1,000,000 45 6 23 

Spot, Mite 

Carrots Powdery mildew, 1,000,000 45 7 13 Mites 

Grapefruit Mites 800,000 45 11 23 

Pistachios Citrus Flat Mite 700,000 30 11 25 

Strawberry Powdery Mildew, 600,000 50 3 44 Red Spider Mite 

1 Pest hsted as controlled by sulfur on product labels 

2 Data sources include: · 

USDA-NASS (United States Department of Agriculture's National Agricultural Statistics Service), 2004-2012 

EPA Proprietary Data, 2004-2012 

California DPR (Department of Pesticide Regulation), 2004-2012 

3 EPA Proprietary Data, 2008-20 12. 

4 Costs of alternatives are for target pest listed in this table. The costs of alternatives are a simple average across the 

nine years for the listed target pests. 

The Fungicide Resistance Action Committee (FRAC, 2012) has designated sulfur as FRAC 

Code M2 and is the only chemical in the group. Sulfur has multi-site contact activity -

belonging to the target site and code "multi-site contact activity," and group name and chemical 

group "inorganic". It is considered as a low risk group for resistance development, without any 

signs of resistance developing to this fungicide. 

The use of inorganic fungicides (such as sulfur, copper) has been well documented in the 

literature (Elis and Bradley, 1992). Beckman (2008) stated, "Sulfur is the oldest recorded 

fungicide and has been used for more than 2,000 years, early in agriculture history, the Greeks 

recognized its efficacy against rust on wheat. Sulfur can be used as a preventative fungicide 

against powdery mildew, rusts and other diseases. Sulfur prevents fungal spores from 

germinating, so it should be applied before the disease development". Sulfur label states that it 

can be phytotoxic to cucurbits and some varieties of berries when temperatures are high. 

Beckman (2008) and others recommend against using sulfur when temperatures are expected to 

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exceed 80°F to reduce the risk of plant phytotoxicity. This may be the reason for five known 

incidents of unsubstantiated toxicity of sulfur to crops as mentioned above. It is also 

documented that certain varieties of gooseberries, currants, apricots, raspberries, and cucurbits 

are susceptible to sulfur phytotoxicity. 

Sulfur has no known resistance by any pest. It plays an important role in integrated pest 

managment and resistance management. Sulfur is used by organic crop growers because it is 

effective in controlling fungal diseases and mite pests on various crops. Organic crop growers 

use sulfur in managing crop pests on different crops. Organic crop growers use various cultural 

practices to reduce pest pressure and they have a limited number of compounds (such as copper 

based fungicides, potassium bicarbonate, and biological fungicides such as Ampelomyces 

quisqualis) for controlling pests (Anomynous, 2014). Therefore, sulfur plays an important role in 

the integrated management of pests in organic production of different crops. 

CONCLUSION 

Sulfur is an inorgani·c pesticide that plays an important role in plant disease/pest management on 

many major and minor use crops because it provides effective control of both fungal diseases 

and mites at low cost. It also plays an important role in pest resistance management because no 

pest has been reported to be resistant to sulfur and can be rotated with other compounds that are 

prone to resistance. Sulfur is important for the organic growers because of a limited number of 

compounds available (such as copper and biologicals) for controlling pests on these crops. 

REFERENCES 

Anomynous, 2014. Accessed May 1, 2014. http://www.oardc.ohiostate.edu/fruitpathology/organic/.fungicidesystems.htm 

Beckerman, J. 2008. Using Organic Fungicides. Disease Management Strategies. Purdue 

Extension BP-69-W. 

Browde, J and Ohmart, C. 2001. Improving sulfur management. Accessed on February 3, 2014. 

http://www.practicalwinery.com/mayjunO 1 p ll.htm 

Ellis, B. W and Bradley, F .M. 1992. The organic Gardner's Handbook ofNaturallnset and 

Disease Control, Rodale Press. Emmaus, PA. 534pp. 

EPA BEAD, 2014. Screening Level Usage Analysis (SLUA). Biological and Economic 

Analysis Division, Unpublished EPA report. 

FRAC. 2012. Accessed on February 4, 2014. 

http://www.frac.info/frac/publicationlanhang/FRAC code List 201 O.pdf 

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