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Cyhalofop - butyl FOCUS meeting, July 11, 2014 Michelle Ranville - author Attendees: Jolene Trujillo, Jill Bloom (PRD); Michelle Ranville, Bill Phillips, Rafael Prieto (BEAD); Jean Holmes, Richard Shamblen ( EFED ); Doug Dotson, Margarita Collantes (HED); Nneka Breaux, Rafael Herrera, Rick Man n , Glenda Gordon (Dow AgroScience) Meeting Notes: DAS presented a powerpoint that contained answers to many of EPA’s questions about cyhalofop butyl usage in rice. Those responses + additional comments are contained in these notes, but there was some other background in the powerpoint that is not in these notes. That PPT is saved as “DAS_EPA_FOCUS Meeting.pptx” at G: \ ~Registration Review

\ Chemicals

\ Cyhalofop

- butyl EPA Question: Where is cyhalofop - butyl used in dry - and wet - seeded rice in the U.S.? DAS Response: Cyhalofop - butyl is used in Arkansas, California, Louisiana, Mississippi, Missouri, and Texas.

- CA is 99% water - seeded

- LA and AK also have water - seeded rice but much lower levels

- MS, MO, and TX have minimal or zero water - seeded rice. EPA Question: Discuss the spectrum of plants that are affected by the mechanism of action for this chemical. DAS Response: Cyhalofop - butyl only affects grasses. It h as no activity against broadleave s or sedges.

- There is a buffer for peaches of 2 - 4 miles because they are allergic to the AI. DAS did tests to find out the appropriate buffers. This is only a concern in CA because peaches are not grown in the other rice - growing regions

- It is necessary to add an adjuvant to cyhalofop - b utyl or it would not have efficacy against grasses. It needs the adjuvant to penetrate the waxy coating on weeds. Many post - emergent herbicides use an adjuvant for this reason EPA Question: Discuss DowAgroSciences plan for wild rice DAS Response: DAS does not plan to label wild rice and will remove the use from existing unstamped labels EPA Question: Can Dow clarify the term “post - flood?” For example, in water - seeded rice, is the “post - flood” application the period after the flood for seeding, or application period after permanent flood? DAS Response: Post - flood refers to any time after seeding that the fields are flooded with water and that grass weeds would be present in the rice. Thus, post flood can be both of the examples provided.2

EPA Question: Why can the granule formulations be only applied to “water - seeded” rice? It seems that the granule co uld be applied to “dry - seeded” rice since the granule is applied to flooded waters. DAS Response: The Clincher granule can only be used to control grasses that are completely (>80%) submerged at the 1 - 3 leaf vegetative stage. In water seeded rice, the rice is flooded the whole time and grass weeds can be controlled while they are still submerged at the 1 - 3 leaf stage. In dry se eded rice, the permanent flood is only established once the rice tillers, typically 4 - 6 weeks after planting. Once you flood the fi

eld at this stage, grasses are typically tillered (advanced growth stage) and are NOT submerged. Thus the granule cannot be used to control the grass weeds due to their large size and little foliage under water for herbicide uptake.

- If you wait for perma nent flood, the weeds would be 80% out of water and granules would not work. The granules are broadcast over the water and dissolve killing the small weeds.

- Clincher also cannot be applied under drought stress (i.e., after pre - flood and before permanent f

lood), so liquid formula may be applied after permanent flood.

- Normally growers don’t like to drain water, but 80% must be exposed for liquid foliar application to work. So if there is rain, they would have to lower the water prior to application.

- A “fl ush” just means that water is entered into one end of the field until the field is soaked. The water is not drained.

- The rice field has a levy around it that is 12 - 18 inches high, so there is no way for water to drain naturally. Also, the soil is very c ompacted so water is not lost.

- Liquid is basically a “rescue” application, only used if weeds poke through. EPA Question: How is clincher used in the ratoon rice production process? DAS Response: In Louisiana, very little Clincher is used in ratoon rice. An estimated 50 gallons per season is applied which – at the 13 oz/acre rate – would treat less than 500 acres. It is typically used as a spot spray, not broadcast, to control patches of grass we eds.

- Almost all ratoon rice is grown in LA, at least as far as DAS knows because that is the only place they see Clincher applied to ratoon rice.

- After the first crop is harvested, the field is drained and plowed. Then flooded again and ratoon crop might provide small second harvest. It would not be worth much to spray with herbicide and it would have to be planned well to meet the 60 - day PHI

- Only 20% or less of rice gets Clincher application, in general, so probably very small amount in ratoon rice. EPA Question: How are buffer zones established? Buffer distances for the same commodity vary among labels. In particular, for endangered species, the RebelEX has a smaller distance for the Southern States than California .3

DAS Response: Buffer zones are estab lished with modeling and actual drift studies. An additional safety margin was applied for the products used in CA because of the local conditions.

- In products with multiple AIs, the buffer zone was based on the more toxic (Clincher)

- In CA, timing of other crops relative to rice matters, e.g., young wheat nearby in CA at time of Clincher application versus older wheat in LA which is not as susceptible

- Also, Rebel X (with smaller buffers) is labeled for use in CA but not marketed there. EPA Question: T here are two 24c labels for CA with higher application rate for one - time even. DAS Response: They want to keep this use.