Available Reports

Agricultural Chemical Usage Vegetables, 1994 Summary.USDA National Agricultural Statistics Service and Economic Research Service. July 1995.

Pest and Pesticide Use Assessment and Personal Protective Equipment Use for Field Corn Production Systems in New York State for 1994.Cornell University, Ithaca, NY.

Potential Economic Impacts of the Delaney Clause Implementation on U.S. Agriculture. National Center for Food and Agricultural Policy.

Memorandum: Lists of Pesticide-Sensitive Individuals. State of Washington Department of Agriculture. June 15, 1995.

EPA reviews propargite

...Alan Schreiber

Propargite, the most widely applied miticide in the U.S., with about 5 million pounds used annually on over 2.6 million acres, is under scrutiny by the Environmental Protection Agency.

Current registered uses in Washington for the compound include bean, lima bean, field corn, popcorn, potato, alfalfa seed, clover seed, corn seed, carrot seed, mint, sweet corn, apple, non-bearing cherry, Christmas tree, conifer (nursery), hops, nurser y, ornamental, rose, strawberry, apricot, cherry, flower, grape, nectarine, peach, pear, plum, prune, non-bearing pear and walnut.

The EPA believes, but has not released its opinion publicly, that propargite may pose a cancer risk. The chemical was classified as a B2 , probable human carcinogen, in 1992. The manufacturer has presented new information to the EPA that could revise t he classification to C2, possible human carcinogen. This new data, if accepted by EPA, would reduce the potential risk estimate substantially.

Agency officials believe they have most of the information needed to make a regulatory decision and are negotiating the finer points of the risk assessment with the manufacturer, Uniroyal Chemical Company.

Uniroyal recently submitted additional toxicology and metabolism studies to the EPA, in order to better define the actual risk. The company met with EPA on August 17 to discuss the agency's concerns. Uniroyal believes that the agency's initial assessme nt overstates the risk and that a recent market basket survey proves that exposure to propargite residues is lower than expected.

According to the survey, no propargite residues were detected in samples of infant or adult apple juice, beef, milk, orange juice and oranges. Residues for other commodities sampled _ apples, applesauce, grapefruit, grapes, infant applesauce, infant pe aches, raisins, strawberries and peaches _ were less than 3 percent of allowable tolerance.

I plan to present additional information on the risk associated with the use of propargite. In this issue, I will describe some of the benefits associated with propargite use, as calculated recently by the USDA National Agricultural Pesticide Impact an d Assessment Program (NPIAP).

If propargite were banned, the annual economic loss would be approximately $240 million. The following table demonstrates the estimated losses by crop. According to the NAPIAP study, the most severely impacted commodities would be hops ($80.3 million), potatoes ($32.6 million), mint ($20.0 million), alfalfa seed ($16.5 million) and apples ($16.3 million). Each of these crops is important to the Northwest economy, and use of propargite is an important tool for their production.

Many crops on which the miticide is used have no effective alternatives. Crops on which propargite is used and are considered to have few or no alternatives include alfalfa seed, apricots, clover seed, corn, cranberry, peanuts, potatoes and strawberry.

Estimated economic losses per crop
based on cancellation of propargite uses

MCPA faces possible cancellations

MCPA is undergoing reregistration by EPA. MCPA is a widely used phenoxy herbicide similar to 2,4-D but with a different spectrum of control. The herbicide is used on a wide variety of sites, with 25 companies having 68 products registered in Washington State. The herbicide is important in controlling weeds on home lawns, commercial turf, golf courses, grassy noncropland, small grains, peas and other legume crops.

The primary registrants _ Akzo Nobel, BASF, DowElanco, A.H. Marks and Nufarm _ have formed a reregistration task force to maintain registration of the herbicide. Richard Otten, chair of the MCPA Task Force, on July 28 sent a letter describing potential unsupported uses of the pesticide to companies with MCPA registrations. In order to maintain economically viable registrations, the task force plans not to support registrations deemed too costly to reregister. Several unsupported MCPA uses, however, are important to weed control programs, and loss of these sites could hurt some growers.

Uses to be supported: MCPA Acid - turf MCPA Dimethylamine Salts - small grains (barley, oats, rye and wheat); small grains underseeded with alfalfa, clover, lespedeza, trefoil and vetch; pasture and rangeland grasses (including grasses grown for seed); turf and noncrop areas MCPA 2-Ethylhexyl Ester - small grains (barley, oats, rye and wheat); small grains underseeded with alfalfa, clover, lespedeza, trefoil and vetch; pasture and rangeland grasses (including grasses grown for seed); turf and noncrop a reas

MCPA uses not supported by the task force include all forestry uses; all aquatic food uses; all aquatic non-food uses; beans; peas; rice; sorghum; canary grass and flax. Those relying on these use patterns should contact their state IR-4 or PIAP repres entative. It appears these uses will be unavailable in the future, unless a user group expresses interest (and willingness to pay for outstanding data requirements) in keeping the uses. It may be possible to negotiate with either EPA, the MCPA Task Force or with a particular MCPA registrant to support a critical use for a time, during which a substitute herbicide could be developed.

MCPA on peas is a good example of a critical unsupported use. Washington produces about 60,000 acres of green peas and 98,000 acres of dry peas. In some pea-producing areas of the state, MCPA is considered critical to weed control programs. It is estim ated that the herbicide is used on about 75% of the irrigated peas (green peas) and to a lesser degree on dry peas in Washington. Alternative herbicides are less effective, or they interfere with rotation crops such as sweet corn. Loss of MCPA could resul t in increased use of less effective products, worse weed problems and decreased pea acreage.

The triazine wars continue

In November of last year, EPA placed the triazine herbicides, atrazine, simazine and cyanazine, under special review. The special review (the first new special review in about four years) was initiated based upon the agency's concern that long-term exp osure to these pesticides in food and drinking water may pose a risk of cancer.

The case against the herbicides exists, for the most part, on paper. The actual risk of cancer from the herbicides is relatively minimal when compared to other cancer risks. Cyanazine, for example, has been found in few situations at levels in excess o f the Health Advisory Level (HAL) established by EPA. However, at the current HAL for cyanazine of one part per billion, an individual would have to drink more than 350,000 eight-ounce glasses of water a day during a 70-year lifetime to reach a level of e xposure that could cause a negative health effect.

After a long and difficult process of negotiation with EPA, Du Pont has decided to phase out the use of cyanazine. Fred Degiorgio, manager of regulatory and environmental affairs for Du Pont, stated that, rather than fight EPA in the special review pro cess with little hope of winning, Du Pont decided to agree to a long-term phase-out in order to preserve use of the product as long as possible. This is a strategy similar to one used by Amvac when negotiating with EPA about mevinphos (Phosdrin).

Use of cyanazine products Bladex and Extrazine II will remain available without change through next year. After 1996, the maximum rate of cyanazine application will be reduced annually until 1997. The current maximum rate of application is 6.5 pounds o f active ingredient per acre. Incremental decreases in pounds per acre will be as follows: 1997 (5.0), 1998 (3.0), 1999 (1.0). Applications made after 1997 will require a closed cab during application. Existing stocks can be used through December, 2002.

The phase-out period is expected to give growers time to change to alternatives to cyanazine. Growers are not expected to incur additional costs as a result of this action.

Cyanazine is one of the most widely used herbicides and is registered for use on corn, cotton and sorghum. An estimated 95 percent of use is on corn, principally in the Midwest; use of the herbicide in the Northwest is insignificant.

On July 19, EPA and USDA met to discuss minor crops and the special review of the triazines in Washington, D.C. At that meeting, EPA stated that it would be willing to review any pertinent data that user groups provided regarding the importance of tria zine (actually simazine) use on minor crops.

Plant-pesticide approved
for use on field corn

The EPA has issued a conditional registration amendment approving full commercial use of a plant-pesticide to combat insect damage in field corn.

Ciba Seeds of Greensboro, N.C. and Mycogen Plant Sciences of San Diego, Calif. are the registrants and developers of the plant-pesticide that is produced when genetic material necessary to make a truncated version of the naturally occurring Baccillus t huringiensis (Bt) CryIA (b) insect toxin is transferred to corn.

Use of the product is expected to increase corn yields 10 to 15 percent and to help eliminate the application of more toxic pesticides used to control insects on corn plants. The primary target of the toxin is the European corn borer.

The product registration is limited currently to commercial field corn production; sweet corn and popcorn currently remain registered for seed corn propagation only. EPA's initial registration in late March for this plant-pesticide allowed planting of limited acreage for seed corn.

The EPA has reviewed and approved the resistance management plan for the Bacillus thuringiensis corn plant-pesticide. The management plan includes, among numerous actions, close monitoring of the plant-pesticide to determine if resistance is developing in target insects.

The agency concluded that the resistance plan submitted by the registrants would reduce the possibility of resistance developing for three to five years following application of the corn plant-pesticide.

Washington minor crops book
soon to be available

Washington Minor Crops, a reference book on the minor crops of Washington State, is in press and should be available in early September.

The 330-page book, co-authored by Dr. Alan Schreiber, Agrichemical and Environmental Education Specialist and Laura Ritchie, editor (former), Washington State University, describes more than 200 of the commercially grown minor use food, feed and seed c rops in the state of Washington. It mentions the common pests of these crops and 112 pesticides.

Minor crops are generally those for which the crop acreage and the volume of pesticide required are insufficient to make registration cost effective for a pesticide manufacturer. In Washington, these crops include such well-known commodities as apples, hops, grapes and potatoes and such exotic commodities as evening primrose, pepino, currants and Belgian endive. The only food and feed crops not covered are alfalfa, barley, corn, oats and wheat.

The book is divided into four parts: a five-page introduction, a 21-page description by county of Washington agriculture, a four-page table listing crops grown by county and a 283-page crop-by-crop description of Washington agriculture.

Also included is a list of crop synonyms (a linkage of a commonly used crop name such as broccoli raab with the crop's less common names of Chinese flowering cabbage, choy sum and rapini), tables relating common names and brand names of pesticides and indices by crop, county and pesticides.

The general layout of information contained in the book is similar to that shown on the following two pages. First on the page is a box containing production statistics, such as the number of acres on which the crop is grown, the number of growers and the value of the crop. Then, separate sections provide description of the crop, the key pests, the pesticides used commonly on the crop, a discussion of the key pest control issues, listings of expert contacts and sources, and a map showing where the crop is grown in the state.

Officially Unofficial

Officially Unofficial is a regular feature that may include information considered politically inappropriate by some.

**Gallo Brothers once was the largest organic grower in the world. In 1994, I toured a 5,000-acre-plus organic vineyard in California. Their operation at the time seemed impressive. In total, Gallo had over 10,000 acres of organic grapes. Due to th e difficulty in producing organic grapes on a large scale, the company has largely switched back to conventional production of grapes.

**I recently became aware of a very interesting and challenging pesticide issue in Washington. The historical use of lead arsenate, primarily in orchards, may become one of the more pressing and thorny problems for the Department of Ecology, the lead state agency on the issue. Use of lead arsenate on more than 100,000 acres in the first half of the century has left thousands of acres of land in Washington with residues above the levels considered by the state as safe. The astronomical cost of cl eaning up the sites prevents DOE from accomplishing its clean up goals.

**There is a draft plan circulating around EPA to radically change the manner in which the cancer risk from pesticides is calculated. The current method utilizes a risk quotient called Q-star. Explaining what a Q-star is is too complicated for t his column. EPA is considering use of a different method to improve the risk characterization of propargite and other pesticides suspected of being carcinogens. This new method, which uses an ED10 (the effective dose that affects 10 percent of the populat ion exposed to the chemical) could significantly change cancer risk characterization. The entire risk/benefit equation for propargite would change (possibly for the better) If this new method is adopted. If the new plan is adopted, It would do away with t he designations of B1, B2 and C carcinogens. This would have some profound implications, with one potential change being the delisting of some pesticides as Delaney chemicals. Pretty interesting....

State Issues

Special Local Needs (Section 24c)

Label restrictions for Special Local Needs in Washington: The following pesticide uses have been granted label registrations by the Washington State Department of Agriculture under the provisions of Section 24 (c) amended FIFRA.

Federal Issues

Emergency Exemptions (Section 18)

A crisis exemption has been granted for the following use: