### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460



### MEMORAND UM Date: 05-May-2015 OFF I CE OF C H EM I CA L SAFETY AN D POLL UT IO N PR EVENT IO N



### S ubject: Prohexadione Ca lcium
. Sec tion 3 Registration for Use on Strawberry and Watercress. 

### Summary of Ana lytica l C hemi stry and Re s idue Data. PC Code: I 12600 DP Barcode: 0419981 Decision No.: 489681 Re istratio n No.: 7969-188 Petition No. : 4E8264 Re ulat o r Action: Section 3 Risk Assessment Ty e: NA Case No.: 7030 TXR No.: NA CAS No.: 127277-53-6 MRID Nos.: 4933900 I , 49339002 40 CFR: §180.547 

### From: William 

### 0. Wa sse ll , Chem ist Risk Assessment Branch I (RAB l) Health Effects Division (HED; 7509P) 

### Thro u g h: George F. Kramer , Ph.D. , Branch Sen io r Chemist**~41-t~~~ ~~** **~-a=:;;z_**

### __ RAB 1 / HED (7509P) 

### To: Barbara Madd e n / Laura No ll en, RM 05 Re g i strat ion Divi sion (RD; 7505P)


### Executive Summary Prohexadione calcium [calcium 3 -oxid o-5 -oxo -4- propionylc yclo h ex-3-e necarboxylate) is a plant growth regulator proposed for u se by the Interreg ional Res ea rch Proj ec t No. 4 (IR-4) on strawberry and watercress. The product reduces vegetative growth, shoot growth , and produces a larger stem diameter (waterc ress)
. Prohexadione calcium work s by inhibiting the biosynthesis of gibberellins, resulting in a decrease in ce ll elongation and a s low in g 

### .of cell growth
. Shoot reduction may cause positive benefits suc h as better light penetration , better fruit coloring , and bette r air flow within the plants. For watercress, prohexadione calcium may suppress growth for up to 14 days. For stra wbe rri es, vegeta tiv e growth suppress ion lasts for 2 to 5 weeks after app licati o n and does not affect vegetative growth th e fo ll owing year. Th e registered produ c t , Apogee ® Plant Growth Regulator (EPA Reg. No. 7969-188) , is formulated as a wettable granule ( WG) conta inin g 27.5% prohexadione calcium
. Tolerances are currently established under 40 CFR §I 80.547(a) for re s idues of prohexadione calcium inion pome fruit, peanu t , grass , cherry , and livestock commodities at levels ranging from 0.05 to 3.5 ppm. P age I of 13Prohexadione Calcium DP # : 4 19 981 

### The proposed to lerances for residues of proh ex ad ione calcium are: Strawberry
. ... .. .. .. . .... .. ....... . .. .. ...... .. .. .. .. ... .. .. . .... ... ...... 0
. 3 ppm W ate rc re ss .................................. .... .... ..... ...... ....... ... .2 ppm Based o n apple and p e anut metabolism s tudi es, the H E D Metabolism Assessment Review Co mmittee (MARC) concluded th at for th ese crops pare nt co mp ou nd is the on ly residue of co nc e rn for th e tol erance ex p r ession and diet a ry ri sk asse ss ment ( Memo , G
. Krame r, 4/ 07 / 00; DP # 263502). HED concludes that thi s decision may be translated to strawberry and wate rcress. For e n force m e nt of to le rances for prohexadione calcium in pome fruit , grass , peanut , and li vestock commod it ies ( reg iste r e d u se s) , the p e t it ioner used a re s idue analyti cal method (BASF Method 0 960 1) u sing gas c hro m at o g raph equipped w ith a ma ss-se lecti ve d e t ecto r (GC/ MSD). T h e m e thod was d esigned to mea s ure re s idu es of prohex adion e calcium as th e prohexadione met h y l este r. The repo rt ed le ve l of qu a ntitation ( LOQ) for prohexadione ca lcium i s 0.05 ppm for a ll apple, p ea r, and peanut commodities. Th e meth od was s uc cessfu ll y val id a t ed by the Age nc y A nal y tica l Chemistry Laboratorie s (A C L) at Fort Meade. Additi o na ll y , BASF Method 564/ 0 ha s bee n p roposed for e nforc emen t of prohexadione tolerances in/on che rri es . T he extractio n of res idu es are p e rformed in the same manner a s that of BASF Method No
. 09601
. Th e final detem1ination of prohexadione ca lcium is performed by liquid chromatography equipped with tandem mas s s pectromete rs (LC-MS/MS). The LOQ for residu es in cherries is 0.0 I ppm. This method has been deemed ad equ ate for e nforceme nt of tol eranc es for r es idu es in cherries. BASF A n a l ytical Method 0960 I , with min o r modification s , was utili zed for the de te rmin at ion of res idu es of pro hex ad ione ca lcium in watercress samples. T he method was validated prior to and in conjunctio n with the analysis of trea t e d sa mple s . The LOQ was validated t o be 0.1 ppn1 for residues in wat e rcr ess. BASF Method 564/ 0 was utilized fo r the determination of residue s of prohexadione calcium in s trawberry sa mple s. T h e method was validated prior to and in co njun ction w ith the analysis of treated samp les. The LOQ was val id at ed to be 0.0 I ppm for r es idu es in s trawb e rr y . H E O ha s de termined that BASF Analytical Method 0 9 60 l i s adequate for the determination of residues of prohexadione ca l c ium in/on wate rcress and Method 564/ 0 is adequate for the dete rmination of residues of proh exadi o ne calc ium in / o n strawberries
. Adequate crop fi eld trial data are available for proh exad io ne calcium o n strawberry and wate rcress. B ase d o n the r es ult s of th ese trial s , th e appropriate tolerance fo r re s idu es of prohexadione ca lc ium in/on strawberry is 0.3 ppm and i n/on waterc ress is 4.0 ppm. A re v i sed Sec ti o n F is re quir e d
. Reg ul a to ry R e comm e nd a tion s and Res idu e C h e mi s try Defi c i e nci es 

### Pe nd in g submission of rev ise d Section F (see requirem e nt s und e r Prop ose d To leranc es) an d an an a l ytical- grade s tandard (see req uir e me nts under S ubmittal of Analytical R efe ren ce Standards) , there a r e no res idu e chemistry iss ues that w o uld pre clude establi s hm ent of unconditional reg i stration s an d the foll ow ing pennanent tolerances for the growth re g ulator, prohexadione calc ium , including it s m etabo lites and degradates , in o r on the com m odi ti es in the table below. Co mpli a nc e with the to lera nce leve ls s pec i fied be l ow is to be de t e rm in e d by measuring on l y prohexadione calcium (calcium 3

- ox id o -5- oxo -4-p rop ion ylcy cl o hex - 3-enec arboxylate) , in or on th e fo ll owing commod i ti es : Page 2of13Prohexadione Calcium DP# : 419981 Strawberry
............................................... .... ..... .. ...... 0.30 ppm 

### Watercress
.................................................... . ........... 4.0 pp1n
860.1550 Propo sed Tol e ra nce s
• T he petitioner shou ld subm it a revised Secti on F reflectin g the I-J E D -recommended tolerance level specified above for residues in/on watercress. 860.1650 Subm itt al of Analyt ical Reference Stan dard s
• The analytical reference standard fo r prohexadione calc ium h as ex pired (perso n a l commu nic atio n w ith Theresa Cole , A n alyt ical C he mistry Branch (ACB) , 1230 / 20 14). The registrant must either recertify the l o t in the repos ito r y and se nd in an updated Ce rti ficate of A n alys is (COA) , or subm it new standards (differe nt lot # ) if th e previous lo t s will not be recertified. 

### If new standards are being sub mitted, they s h ou ld be sent to ACB, which is loca t e d at Fort Meade , to the att ention of either Theresa Co le at the fo ll owing address: USEPA Nati onal Pesticide Standards Repository/ A n a l yt ica l Chem istry Bra nch/OP P 701 Mapes R oad Fort George G
. Meade, MD 20755 -5 350 (Note that the mail wi ll be returned if the exte nd ed z ip code i s not used
. ) A human health ri s k assessment is forthcoming in a separate document. Ba c k g round Prohexadione ca lcium is a plant g r owth r eg ulator that works by inhibiting th e biosynthesis of gibbere llin s, resulting in a decrease in ce ll e longation and a slowing of cell growth. The chemica l structure and nomenclature of prohex adio ne ca lc ium is presented in Table 

### 1 . The physicochemica l properties of the technical g rade of prohexadione calc i um are presented in Table 2
.

Page 3of13Prohexadion e Calcium DP# : 419981 Table I. Test Compou nd Nomen cl ature. Compound**~** 

### -



## - 0**~** Cll 1 

### cl•

- a 0 0 0


# - - Common name Prohcxadione ca l cium Co mpany experimental name BAS 1 25 W IUPAC name ca lcium 3-oxido-5-oxo-4

-propionylcyclohex-3-enccarboxylatc CJ\S name calcium 3-oxido-5-oxo-4 -propiony l cyclohex-3

-e n ccarboxy l at

e CJ\S re g istry number 127277-53-6 End -u se product (E P) Apogee® Plant Growth Regulator (EPA Reg. No. 7969-188) Tab l e 2. P h ys i coc h e mi cal P r ope r t i es of P r o h exadio n e Calciu m . Parameter Value Reference Water solubi lity (20°C for 96 .6% 174 mg/Lin di s tilled water, 1602 mg/L in pll 5 Memo , H
. Podall , 5/18/99. 0253852 pure sa mple) bufTer
. 786 mg/L in pl I 7 bufTcr. and 665 m g/L in pll 9 buffer So lvent so lu bility (20°C for 0.038 m g/L in acetone 96.6% pure sample) 0.004 mg/L in toluen..: I. 11 m g/L in methanol 0. 1 05 mg/Lin iso propanol <

0 .003 m g/

L in n-hexanc Vapor pressure 1.00 x JO ·' torr at 20 ° C Di ssoc iation constant pK
. 5.15 Oc tanol /wa t cr partition coefficient lo g P = -2.9 at 20 

### • c, pH 7 l1ttQ : //

s item.hcrt s. ac.u k/acru ! footQrin t/cn / Reg orts/539.htm


### 860. 1200 D irect io n s for 

### Use Currently, prohexadione calcium is registered for use on pome fruit , peanut , grass, and cherry as a plant growth regulator. IR-4 has proposed to register Apogee® Plant Growth Re gu lat o r (E PA Reg . No. 7969-188) for us e on s trawberries and watercress. Informati o n pertaining to the registered/ proposed end-use product is presented in Tab le 3
. A summary of the proposed u se patterns is presented in Table 4.

Page 4of13Prohexadione Calcium DP# : 419981 Table 3. Summary of Regi s tered/Proposed End-Use Products. Prohexadione EPA File Calcium Fomrnlation Trade Name Symbol No. Concen trati on Type T arget Crops T arge t Pests Label Date Apogee® Strawberry Plant Growth 7969- 188 27.5% WG NA None Regulator Watercress
T able 4. Summary of Propo sed Direc tion s f o r Use of Proh exad ione Calcium. Applic. Timing, Trade Name ; Max. No. Max. Seasonal Type, and Formula ti on Applic. Rat e Applic. per Applic. Rate PHI Equipme nt [EPA R eg. No.] (lbai/A) Seaso n (lb ai/A) (days) S trawberry Fo li ar app licati on with gro und equipment. When 80 to 1 00% ofthe Apogee® Plant plants have 5 fully Growth Regula tor 0.034 3 1.02 21 expanded leaves and 27.5% WG before plants show first (7969-188] sig n of runner format io n . U

s e Direction s and Limitation s: Do not apply with airblast equipme nt or by airplane. Use a minimum of I O gallons of spray sol uti on per acre per ap plicat ion. Applications may be made at intervals o f 1 4 to 21 days. Use a standard sp ray adjuvan t, preferably a non-ionic su rfactant. Watercre ss Foliar with ground or sprinkler irrigation Apogee "" Plant systems. Apply when watercress has l eafed up Growth Regulator 0.1375 2 0.275 3 27.5% WG from the previou s (7969-188) harvest (5 to I0 days). Use Direction s a nd Limit at ion s: Apply ground applications through properly calibrated airblast equipment using a volume of I00 gallons per acre. Chemigati on app li cation s must be made as co nce ntrated as possible. For best results ap ply at 0.1 inch up to 0.15 inch (2,716 to 4,073 gallons) of water per acre. A second application ma y be made 7 days after the first application
. Do not tank mix with any other pe s ticid e products , adjuvants, liquid ferti lizer , nutrients, any other additives or anything ot her than water. 

### Conclusions: T h e s ubmitted use direction s for Apogee® Plant Growth Regulator are adequate to allow eva lu at ion of the residue data relativ e to the proposed u ses. 860.1300 Natu re of the Re s idue - P l a nts Memo, 11 / 22 /99, G. Kramer, D252547 Ba sed on apple and peanut m e taboli s m s tudie s, the HED MARC conc lud ed that for these c r ops parent compound i s the only re s idue of concern for the tolerance ex pression and dietary r i sk assessmen t (Memo, G. Kram e r , 4/ 07 / 00; OP# 263502). Prohexadione calcium i s rapidly m e tabolized to prohexadione and parent-like oxidativ e intermediat es a nd ultim a te ly to tric a rballylic acid, citri c acid , and other n atura l products fro m the p lant carbon pool. 

### HED concludes that this decision may be tran s lated to strawberry and watercress.

Page 5of13Prohexadione C alcium DP# : 419981 860.1300 Nature of the Residue -L ive stock Data re quirement s re g ardin g thi s g ui de lin e topic are not ge rman e to thi s petition because there are n o feedstuffs associated with the proposed u ses on s trawber r y and watercress. 860.1340 R es idu e A naly tic a l Me thod s DER R e f

ere nce: 4810670 l
. der.doc Memo , 03 11 0 / 200 I , G. Kramer, D2735 I 0 Memo, 06/ 02 / 20 1I , G. K ram e r, D384706 

### Exis ting Enfo rcemen t Methods: For enfo rcement of tole rances for proh exadione ca lc ium in pome fruit , grass, a nd pe a nut commodities ( reg istered use s) , th e p et iti oner u sed a res idu e analyt ical m e thod (BASF Method 0 960 1 ) using GC / MSD. Th e method was d esigned to m eas ur e res idu es of proh cxadi o n e ca lc ium as the prohe xadion e m e thy l este r. The rep orte d LOQ for prohexadione ca lc ium i s 0
. 05 ppm for all appl e , pear , a nd peanut co mm odit ies. T h e method was s ucces s fully va li dated by th e Ag e ncy AC L in Fo rt Meade. Ad diti o nall y , BA SF M e th od 564/ 0 has bee n pro pose d for enforcement of pro h exadione to le rances in/o n c h er ri es ( r eg i ste r ed u se). The extract io n of residues are p e rform ed in the sam e m a nn er as that of BASF Meth od No. D9601. Th e fina l determination of prohexadione calc ium i s performed by LC- MS / MS. The LOQ fo r re s idue s in c herri es i s 0.0 1 ppm . This m etho d h as been deemed adequate for e n force m e nt of tolerances for r es idue s in c h e rri es. BASF A nalyti ca l M e thod D960 1 , w ith minor modification s, was utili ze d for the d e termin a tion of res idu es of prohexadione calc ium in wa tercre s s samples
. The method was valid ated prior to a nd in conj u nction wi th th e a n a lys i s of tr eate d sa mpl es. T h e LO Q was validated to be 0.1 ppm for residue s in watercress. F or m ethod va lid a ti on , fortificatio n s ra n ged from 0.1 to 5.0 ppm w ith an ave ra ge recov e ry of 74 ± 3% (n = 9). For concurrent recoveries, fortification l evels ranged from 0.1 to 5.0 ppm with an average recovery of 8 0 ± 5 % ( n= 9). BASF Method 564/ 0 was utilized for th e det erm in a ti o n o f res idu es of prohexadione ca lcium in strawbe rr y samples. The m eth od was va lid a ted pri or to and in conju n ction w i th the analy s is of treated sampl es. Th e LOQ was validated to be 0.01 ppm for re s idues i n strawbeny. F o r method val id a ti on, forti fic at io n s ranged from 0.0 1 to 

### l.O ppm with an average recovery of 87 

### ± 9 % (n= 9)
. For conc urr e nt recov e ries , fort ifi catio n leve ls ra n ged fro m 

### O. l to 1 .0 ppm w ith a n average recovery of 92 ± 11 % ( n = 18). 

### Conclus ions: HED h as detenn i ned that B ASF A n alytic a l Method D 960 1 i s adeq u ate for th e determ in a ti on of res idue s of proh exadio n e calc ium in / o n waterc ress a nd Method 564/ 0 i s adequate fo r the d ete rmi nation of re s idues o f prohexad ione calcium in/on s trawbe rri es . 860.1360 Multiresi<.lue Method s Memo , 06/ 02 /20 1 1, G. Kram e r, D384706 Memo , G. Kram e r, 11 /30 /99 ; DP# 257930 The petition e r ha s prev ious ly submitted data concerning th e recovery o f re s idues of prohexadio n e and it s despropionyl metabolite using FDA M ulti residue Method protocols (PAM Vol. I). The se dat a we r e fo r warded to FD A for a co mpl ete eval u at ion ( Mem o, G
. Kramer , l l/30/ 99 ; DP # 257930). The petitioner reported that residues of p r ohexadione and th e despropionyl metabolite are n o t recov e re d u s in g FDA M ul tires idu e M etho d protoco ls. Pa ge 6of13Prohexadione Ca lc ium DP #: 419981 Additionally, the QuEChERS method has not been shown to a d equate l y quanti fy re s idu es of prohexadione calc i um. (http: // www.crl-pcst ic idcs.eu / I

i b rarv/ docs / fv/ CRLFV Mu i l i res idu e methods. pd 

### Q
. 86 0
. 13 80 S t o r age S t ab ili ty DER Refe r ence: 4933900 I .de r.doc (s trawb erry) DER Reference: 49339002.der.doc (wa tercress) The maximum frozen s torage i nt ervals from harvest to analysis for s trawberry samples was 390 days (

- I 3 m onth s) and for watercress sampl es was 794 da ys (-26 months). Storage stabi lity data fo r pro h exad io ne ca lci um in/on watercress and s tr awberry were ge n erated in conjunctio n with the crop field tria l s. The dat a d emo n strate that r esi du es inio n s trawb e rrie s a re stable for up to 422 days (- 14 month s); how eve r , th e dat a indicate residue s in /o n watercress d ec lined by about 34% during fro ze n storage. Th ese data are adequate to support the storage condit io ns and durat io n s of samp les fro m the cu rrent s tudi es. R es idu e dat a for watercress we r e a djust ed for d eg radation durin g sto r age. 

### 86 0
. 1 48 0 Meat, M ilk , P oult ry, a nd Eggs There are n o li vestock feedstuffs associated with the cro p s addressed herein. There fore, data requirements pertaining to m ea t , milk , poultry , and eggs are n o t re levan t to this tolerance pe ti t io n . 

### 860. l 500 C r o p F i el d T r i a ls DER Reference: 4933900 I .der.doc (strawbe rry) DER Ref erence: 49339002.der.doc (wate rcress) 

### S t r aw b e r ry : Nine field trials for proh exadi o n e calcium on strawb e rri es were conducted in Canada and the United States e ncompassing North American Free Trade Ag reemen t (NAFT A) G rowi n g Regions IA ( 1 in NS), 2 ( I in NJ), 3 ( I in FL ), S (I in 

### ON), SA (l in M I), SB (I in QC) , IO (2 in CA), an d 1 2 ( l B C) duri n g the 20 I 0 and 20 11 grow ing seaso n s. At eac h trial locat ion , prohexadione calcium, formulated as a WG, was app l ied to s trawb e r ri es as three folia r applications. The ra tes ran ge d from 36.0 g ai/ha (0.032 1 lb s a i/ A) to 40.8 g ai / ha (0.036 4 lbs ai / A), the re-treatment intervals (RT i s) were 8- 1 5 days , a nd the total ap plic a ti on rate was 110 g ai/ha ( 0
. 0990 lb s ai /A ). For eac h appl icat io n , a n o n-ioni c s urfa c tant was added in th e s pray m ixture at a 0.05% (v/ v) rate and am m onium s ulfat e was added a t a l: 1 ratio. Strawberrie s were h a rves ted a t preharvest interval s ( PHl s) of 16-25 day s. I n one trial (# 1 2 1) , sa mples were co ll ected a t diff e re nt time intervals (PHis of 1 3, 19 , 26, 31 da ys) to assess residue decl in e. I ndi vi du a l sa mpl e (a nd p e r-tri a l average) residu es i n s trawb e rries ra n ged from 0
. 03 ppm to 0.1 6 ppm (0 .03 pp m to 0.15 pp m ). Res id ue decline data s how that residu es of prohexadione calci um decrease in strawbe rri es with in c r eas in g PHl s.

Page 7of 1 3Prohexadione Calc ium DP#: 4 19981 T abl e 5. S umm arv o f R es idu es fro m S t rawberry F i e l d Tria l s w it h Pro h exa d io n e Calc ium
. Total R es idu es ( oom ) C rop App li catio n P HI Matrix Analyte Rate (days) N Min
. 1 Max. 1 LAFT2 HAFT2 Me di an 2 Mean 2 

### so 2 [g ai/ha) ( l

bs ai /A) S tr awbe rry Proh exadio ne 111-11 6 (0.0990

- 16-25 9 0.03 0. 1 6 0.03 0. 1 5 0.06 O.o? 0.038 fruit calcium 0. 104) 1 Values based o n to tal numb e r of sa mple s. 2 Values based on per- trial averages. LAFT = lowest average field trial. I I AFT = highe st average field tri al, SD = standard deviation. n = number of field trial s. 

### Conclusi ons : The s ubmitted field tri a l d ata for straw b e rry are adequate to fulfill data r e quirem e n ts. The num ber a nd locatio n s of th e tr ia ls are in ac c o rdan ce with OP P TS Guideline 860.1500 (Tab le 6).

T a bl e 6. Tri a l N um bers a n d Geogra phi ca l L oca t io n s . Crop No. Trials NAFTA Growing Zone Total I I A 2 3 4 5 5/\ SB 6 7 8 9 10 11 12 Straw- S ubmitt ed I I I 2 I 2 I 9 berry Req. 

### u.s. 1 Il l 11 0 Il l 1 11 3/2 I ll 8 1 6 Req. Ca n. 2 I I I I I 5 1 As per Table 5 of 860.1500 for strawberry: the second number reOects a 25% reduction in th e number of field tri als allowed for th e crop as a represe ntativ e commodity in su ppo rt of a crop gro up/s ubgroup tolerance o r when applica ti on re su lts in no quantifiable residues. 2 As per Tabl e 1. 2 of PMRA R eg ul atory Directive D IR20 10

- 05. The re sid ue data for s trawb e r ry were e nte re d into the Organi z ation fo r Economic Co -op e rati o n and De ve lopm ent ( OE C D ) maximum residue limit (M RL) Calculator. Ba s ed o n th e results of the se tri a ls, th e appropriate tolerance for residues of proh exad ione calc ium inion strawberry is 0.30 ppm. 

### W ate r cress: The IR-4 has s ubmitted field trial dat a for prohexadion e calcium on watercress from thre e fi e ld trial s conducted in th e United S ta te s during the 2009 grow in g seasons in th e NA FT A Growing Zo nes 2 (M O ; 1 tri a l) a nd 3 ( FL ; 2 trials ). Eac h trial con s isted of o ne untreated plot and one treated pl ot ( p o nd ) w ith the ex ception of Trial FL 24 , w hich had t wo treated plots se t up in differ e nt p on d s . For purposes of thi s revie w , the se cond plot will be treated as a se parate tri al h e rein . A t eac h tri a l on e treated plot rece i ve d four fol i ar bro adcas t app l ic at ion s of a 27.5% WO formulation of prohexadion e ca lcium ( Apo g ee® Pl a nt G rowt h Re g ulat or) at 0.135-0. 143 lb a i / A/ application , with two applicat io n s eac h mad e before th e fir s t and seco nd cutt in gs for total rates of 0. 272

- 0.2 8 4 lb ai / A for each cuttin g. After the first harv es t , th e wate rcress was c ut and allowed to r egrow b efore the seco nd set of applications
. At Tr ia l FL24 , a seco nd tr eate d plot recei ve d fo ur fo li ar overhead ch e mi gation a pplicati o ns at 0.140 lb ai/ A/application as a bove for total rates of 0
. 28 0 lb ai/ A for eac h cutting. Th e s pra y mi x tur es for the c hemi ga ti o n application s a ls o in c lud ed a tebuconazo le e nd

- u se product as part of a nothe r study. Dat a and inform atio n pert ain in g to teb uconazo le are not ad dre ssed further in thi s summary document. Applications we re mad e at R T i s of 6-7 days betwee n first and seco nd and third and fou11h applicatio n s; RTi s we re 15- 24 days be t\.v ee n th e se cond and third applicat ion s . Ap pli cati ons were mad e in sp ra y vo lumes of 29.4

- 59.2 gal/A Pa ge 8of 1 3Prohexadione Calcium DP # : 41998 1 u s in g g ro un d eq uipment for folia r broadca st applicati o n s a nd in s pra y vo lum es of l 06.8- 25 0. 5 gal/A for chemigation applications. A no ni on ic su rfac t a nt 

### (NlS) was adde d to th e spray mixture for all applicat ions. Sample s o f wat ercress from each cutt in g were harvested at maturity at a 3

- day P HI. In wa t erc ress har ves ted at th e proposed PH I of 3 da ys fo ll owi ng the la s t of tw o broadca s t fo li ar or four c hemi gation app li cations of the 27.5% WG fo rmulation of prohexadione ca lc ium at a total rate of 0.272-0 .28 4 lb ai / A, individual sam pl e (a nd p er - trial average) residues o f prohexadione calc ium were 0.298 -2.0 0 (0.32 1

- 1. 72) ppm. Re sidues were generally lo wer in seco nd

- ha r vest sample s than they were in first -h arvest samp les, and residue s we re l owe r followi ng chemigation applications th an they were follow in g foliar applicati ons: overa ll average residues were 0.347 ppm fo ll owing chemigati on app li cati ons vs. 1 .30 ppm fo ll ow in g foliar applications. Res idue declin e was not eva lu ated
.

Tab l e 7. S um mary of R esid u es fr o m W ate r c r es s Fi e ld T r ia l s w it h Pr o h exa cli o n e C alcium
. Total Application Piii Re sidues (ppm Prohexadione calcium) Crop Matrix Rate (lb ai / A) (days) n ' Min
. 2 M ax. 2 LAfT 1 HAFT 3 Mcdian 3 Mean 3 As Found Watercress
. I " cutting 0.272-0.284 3 3 0.203 1.32 0.2 12 1.14 0.933 0.760 Watercress, 2nd cutting 0.277-0.280 3 3 0. 1 97 0.725 0.246 0.7 11 0.654 0.537 Watercress combined 0.272-0 .2 84 3 3 0. 1 97 1.32 0.2 12 1.1.t 0.683 0.649 Corrected for Decline in Storage Watercress. I•1 cutting 0.272-0.284 3 3 0 .3 07 2.00 0.32 1 1.72 1.41 1.15 Watercress, 2"d cutting 0.277-0.280 3 3 0.298 I. I 0 0.373 1. 08 0.99 1 0.8 14 Wntercrcss combined 0
. 272-0
. 284 3 3 0
. 298 2.00 0
. 32 1 1. 72 1.03 0.983 1 n 

### = number or field trials
. 2 Values based on t o tal number or sa mple s. 3 V a lues based on per-trial averages. LAFT = lowest average field tri al. I IAFT =highe s t average field trial, SD= standard deviation
. SD 3 0.486 0.253 0.367 0.736 0.384 0.557



### Conclus ions: The s ubmitt ed field tri a l data fo r wate rcress are adequat e to fulfill data requirements. The n umber and locat ions of the trial s are in accordance with OPPT S Guideline 860. 1 500 (Tab le 6). Ta bl e 8. T r i a l N umb ers a n d Geograp h ica l Locatio n s. 0. NAFT A Growing Zone Crop Trial s I 2 3 4 5 6 7 8 9 10 11 12 Watercress Sub. I 2 Rcq. 1 1 As per fab l e I of 860
. 1500. Geo graph i c di s tribution 1 s not speci lied for crops requirin g three or fewer trial s. The residue data for watercress were e nt ered into the OECD MRL Calcu lator. B ased on the results of th ese trials , the appropriate tol erance for residues of prohexadione calcium in/on wa t e rc ress is 4.0 ppm. 

### 860. 1 520 P r oce ss ed Foo d a nd Feed To tal 3 2

There i s no crop assoc i ate d with thi s p e titi o n for w hi c h H ED requ ires residu e data fo r proc essed fractions.

Page 9of1 3Prohexadione Calcium DP# : 419981 860
. 1650 

### S u bmitta l of Ana lytical Reference Standards The analytical reference standard for prohexadione calcium has expired (personal communication w ith Theresa Co le, ACB, 12/30/20 1 4). The regis trant must e ither recertify the lot in the repository and send in an updated COA, or subm it new standards (d ifferent lot#) 

### if th e previous lot s will not be recertified. 

### If new standards are being submitted , they should be sent to the ACL, which is located at Fort Meade, to the attention of eithe r Theresa Cole at th e following address: USEPA National Pestic id e Standards Re pository/ Analytical C he mi stry Branch /O PP 70 I Mapes Road Fort George G
. Meade, MD 20755-5350 (Note that the mail will be returned if the extended zip code is not used.) 860.1850/860.1900 

### Confined/Fie l d Accumu l a tion in Rotational Crops Rotational crop s tudies are not ge rmane to thi s petition as the proposed crops are not rotated with other crops. 860.1550 

### Propo se d To lerances T o lerances are currentl y estab li s hed under 40 CFR 

### § l 80.547(a) for res idu es of prohexadione calcium in/on pome fruit , peanut, grass, and livestock commodities at level s ranging from 0.05 to 3.5 ppm. HED concludes 40 CFR 

### § l 80.547(a) should be revised to include the following tolerances: Tab le 9. To l era n ce S umm a r 1 for Pro h exa dione Ca lcium
. Commodity Proposed H ED-Recommendcd Correct Commodity Definition Tolerance (ppm) Tolerance (ppm) Strawberry 0.3 0.3 Watercress 2 4 A revised Section F is required to revi sed the requested tolerance level for residues in/on watercress. An International Residue Limit (IRL) Status Fonn is appended to this document. There are cu rr ently no establis hed Codex, Can adian, or Mexican MRLs for prohexadione calcium in/on strawberr i es and watercress. The use on strawberry i s a joint review between the U.S. EPA and Health Canada Pest Management Regulatory Age ncy (PMRA)
. The tolerance expression and level for pro hexad ione calc ium in /o n s trawberry is harmoni zed with PMRA.

cc: W
. Wassell (RAB I ) RO I : RABI C hemi sts(Ol / 07 /20 1 5) Template Vers io n September 2005

Page 1 0of13Proh exadione Calcium DP # : 419981 A ppendix I. Inte rn a ti o n a l R es idu e Limit ( IRL ) S tatu s Form
Prohexadione Ca l c ium (112600; 12/ 29/ 2014) Summary of US and I nternationa l To lera nces and Maximum R esidue Limits R esidue Definiti o n: 

## us Canada Mexico 2 C od ex 4 0 C FR § 180.547 calcium 3 , 5-dio x o-4-( I- None Pl a nt/ Liv es tock : oxopropy l) cycl ohexa nccarbox y la ca lcium 3-o x id o -5-oxo - 4

- te propion y lc ycloh ex - 3

- e nec arb o xy late Comm od it y 1 Toleran ce (p om ) / M

cui11111111 R es idue limit (m f! / k f!.) 

## us C anada Mexico 2 C od e x S trawberry 0.3 Watercress 4.0 Compl eted: M
. Negussi e; 1 2

/ 30/1 4 1 In c lude s only commoditi es of mterest for this action
. Tolerance va lues should b e th e HE D recommendations and n ot th os e propo s ed by the appli c ant. 2 Mex ic o ad o pts US tol e ran ces a nd/o r Codex MRL s for it s ex po rt purp oses .

Pa ge 1 1 of 13Proh exadi o n e C al c ium 

### A pp e ndi x II . T o le r an ce - Assess m e n t Ca lcul a tio ns . Prohexadione

Strawberry Foliar application 0.0321

- 0.0364 lbs ai/A (36

- 41 g ai/ha) Total nwnber of data (n) Percentage of censored data Nwnber of non - censored data Lowest residue (LR) Highest residue (HR) Median re sidue (STMR) Mean Standard deviation (SD) Correction factor for censoring (CF) Proposed MRL estimate Unrounded Rounded to the next MRL class Prohexadione Strawberry Foliar application 0.0321

- 0.0364 lbs ai/A (36

- 41 g ai/ha) Residues (mg/kg) 0
. 040 0
. 090 0.080 0.100 0
. 040 0
. 060 0
. 050 0
. 150 0.030 0.070

Page 1 2of 13 DP ll : 4 19981

10 0% 10 0.030 0.150 0.06 5 0
. 071 0
. 03 6 1
. 000

0.21 5

0.3Pro h exa di o n e Calci um

Total number of data (n) Percentage of censored data Number of non-censored data Lowest residue (LR) Highest residue (HR) Median residue (STMR) Mean Standard deviation (SD) Prohexadione Watercress Foliar application Total Rate: 0.272-0.284 lb ai/A

Correction factor for censoring (CF) Proposed MRL e stimate Unrounded Rounded to the next MRL class High uncertainty of MRL estimate due to small dataset
. 

### Prohexadione Watercress Foliar application Total Rate: 0.272-0.284 lb ai/A Residues (mg/kg) 1. 

### 720 0.991 0
. 321 

### 0.373 1.410 1. 

### 080

Page 13of 1 3 DP# : 4 1 99 81

6 0% 6 0
. 321 1
. 720 1. 036 0
. 983 0.556 1
. 000

3
. 206 4Prohexadionc calcium [ P C Code I I 2600]ffhe Interregional Re searc h Proje ct No. 4 ( IR -4) [BAS 125 W] 05-May

- 2015 B .7.6
B.7 .6. J B.7. 6 .1.2 Docum e nt ID: R e port :
Gu id e lin es: Re si du es Re s ultin g fr om S upervi sed Trials (A nnex IIA 6.3 ; Annex IIIA 8.3) Residue s in Tar ge t Cro p s Waterc re ss MR ID No. 49339002 Corley , 

### J. (2012) Prohexadione Calciwn: Magnitude of the Residue on Watercress. IR -4 S tud y N umb e r : 101 5 1. U npubli s he d s tud y prepa r ed by IR-4
. 1 64 p. E PA OCS PP Harmonized Test Guideline 860.1500 Crop Fie ld Tria l s (Aug u st 1996) PMRA R egul a tory Direc tiv e DIR98

- 02

- Residue C hemi st r y Guid e li nes , Section 9

- C rop Field Trials P MRA Regulatory Dir ec ti ve DIR2010- 05

- Re vis io ns to th e Re s idu e C hemi stry Crop Fie ld Tria l R eq uire m ents OECD Guide li ne 509 Crop Fie ld Trial (Septe m be r 2009) GLP C ompliance: No deviations from re g ul ato r y requirements (Good Laboratory Pr ac tic e R eq uir emen t s of 40 CFR 

### § 1 60) were r eporte d w hi c h wo uld have a n impact on the va li dity of the study. Acce p ta bili ty:
Eva lu a tor : T he s tu dy is considered sc ie n t ifically acceptab le. Th e accep tability of this s tud y fo r reg ul atory purposes i s add ressed in the forth comin g U.S. EPA Residue Che mi s try Summary Document , DP# 419981. William D. Wa sse ll ,**mi ,Jf~Jf1** **th** Effec ivision/Risk Assess m e nt Bran ch 1 ( HED/ RAB I ) 

# itl(jf)<flhltNote : This Data Eva luation Record (DER) was originally prepared und er con tract b Versar, Inc. (6850 Versar Center, S prin gfie ld , VA 22 1 5 1 ; submitted 9 / 05114). The DER has been reviewed by 1IED and revised to reneet current Offic e of Pesticide Program s (OP P ) policies. 

### EXECU TIVE SUMMARY The I nterregional Research Project Number 4 ( IR

- 4) has submitted field trial d ata fo r prohexadione ca lcium o n waterc r ess from three fi e ld tri a ls cond u cte d in th e United States durin g the 2009 grow in g seasons in the Nort h America n Fr ee Trade Agreement (NAFT A) Growing Zones 2 (M D ; 1 trial) and 3 (FL; 2 trials). Th e three trials reflected herein includ e two pa i rs of tri a l s co nduct ed i n MD a nd FL th at H E D h as d e t e rmin ed to be rep li cate tri a ls and a th ird s ide

- byside trial that was co n ducted at the same locat ion in FL but reflected a different u se pattern (c hemigation vs. foliar b roadcas t app l ication). Each trial consisted of one untreated p lot and one treated plot (pon d) with the exce ption of Tr i a l FL24, which had two treated plots set up in diff e rent ponds. For purposes of this review, th e seco nd plot wi ll b e tr eate d a s a se parate tri a l here in
. A t eac h trial o ne treated p lot receiv ed four fo li ar broadcast applications of a 27 .5% water-di spe rsible granule (WO) fo rmul a ti on of

EPA MRJD # : 49339002 Page I of8Prohexadione calcium [PC Code l I2600]ffhe Interregiona l Research Project No. 4 ( IR-4) [BAS 125 W) prohexadione calci um (Apogee® Plant Growth R egulator) at 0.135-0.143 lb ai / Napp lication , w ith two app lic ations each made before the first and seco nd cuttings for total rates of 0.272

- 0.284 lb ai/ A for each cutting. After the fir st harvest , the watercress was cut and allowed to regrow before the second set of applications. At Tria l FL24, a second treated plot received four foliar ove rh ead c hemigat ion applications at 0.140 lb ai/Napp lication as above for total rates of 0.280 lb ai / A for each cutting. The spray mixtures for the chemigation appl ications also included a tebuconazole end-use product as pai1 of another st ud y. Dat a and information pertaining to tebucona zo le were n ot addressed further in the study. Applications were made at retreatment intervals (R Tis) of 6- 7 days between first and second and third and fourth applications; RTis were 15-24 days between the second and third applications. Applications were made in spray vo lume s of29.4-59.2 gal / A usin g ground equ ipme nt for foliar broadcast applications and in spray volumes of l 06.8

- 250.5 gal/ A for chemigation applications. A nonionic surfactant (NIS) was added to the spray mixture for all app li cation s . Samp les of watercress from each cutting were harv ested at maturity at a 3-day preharvest interval (P HI ). All samp les were maintained frozen at the testing facility, during shipment to the laboratory, and were stored fro ze n until ana lysis. Th e maximum storage interval for samples between h a rve s t and ext ra ctio n for analysis was 794 days (26. l months). Samples were analyzed within l day of extraction. To support sample storage durations , a concurrent storage stabi l ity study was conducted with the field trial study. No 0-day data were provided. The data demon s trate that residues of prohexadione calc ium declined in / on watercress during frozen storage for up to 792 days (recovery of 66%). Reported residues we r e corrected for loss on storage. These data are acceptable to support the storage conditions and durations of the samples from the subm itted field trials; how eve r , storage stability stud ies should always include a 0-day sampling interval to estab li sh the residue levels present at th e time samp le s are placed into storage [see OCSPP 860.1380( d)(6)(i)]. Samples were analyzed for residues of prohexadione calcium using a gas chromatography method with mass-spectrometry detection (GC/MS), BASF Method No. 0960 I with minor modifications. The limit of quantitation (LOQ; determined as the lowest le vel of method validation , LL MV) was 0.10 ppm for wate rcress. Acceptable m e th od validation and concurrent re coveries were reported for watercress samples a t fortification levels of 

### O. l 0-5 .0 ppm, thus va li dating the method. The fortification levels were adequate to bracket expected residue levels. In waterc ress harvested at PHi s of 3 days following the last of two broadcast foliar or chemigation applications of the 27.5% WG formulation of prohexadione calcium at a total rat e of0.272-0.284 lb ai / A, individual sample (and per-trial average) residues of prohexadione calcium were 0.298-2.00 (0.32 1-1.72 ) ppm. Residues were generally lower in second -h arvest samp les than they we re in first-harvest samples, and residues were l ower following chem igation applications th an the y were following foliar applications: overall average residues were 0.347 ppm following chemigation app li cations vs. 1.30 ppm following foliar applications. R esidue decline was not eva luated
. 

### I. 

### MATERIALS AND METHODS

EPA MRJD # : 49339002 Page 2 of8Prohexadione ca l ci um [P C Co de l 12600 ] ffhe I nterre gio nal Research Projec t No. 4 (IR-4 ) [BAS 1 25 W] 

### A
. MAT E RIALS

T ab l e B .7.6. 1. 2- 1. No m e n cl at u re fo r P r oh exadio n c Ca lcium
. Common name Pr ohexadionc calcium I U

PAC name Calcium 3

- ox id o -5- oxo -4-prop io n ylcyc lohex-3

-enecarboxylate C AS n o . 1272 77-53-6 Co mp a ny ex p e rim e nta l n a me BA S 125 W O th er sy n o ny m s (i f a p p l icab le) NA



### - -

# ~ CHJ 

### , . Ca 0 0 0 '- 

### - B
. S t u dy D es ig n 1. 

### T e s t Proc ed u r e Thre e re s idue trials were conducted on wat e rc ress w i th a 27.5% WG formu lation of prohexadione calcium durin g the 2009 grow in g seaso n (Tab le B.7.6. 1. 2

- 2). T wo pairs of trial s we re conducted at the same locatio n s and reflected the same use pattern. HE D has det e rmin ed that the se trial s s hould be cons idered r ep li ca t es as detailed in the table b e low . Ind ependen t Tri al Dcte rminati o n 1 Tri al Nos. Di fforcn ccs De c isio n FL24

- 02 and FL25 Same l ocati on Replic ate Variety : B& W #4 7 vs. B& \V # I Tri als were conducted in separate ponds *No other differences in guidance crit e ri a. MD02 and M0 03 Same locati o n and varietv R ep li ca t e Tri a l s were co nducted in se parate ponds *N o oth e r diffe r e nces in g uid an ce c rite ri a. 1 All assess m en ts are based on th e replic a t e trial guidance presented 111 drafi memo 568_Cn t e n a for Ind epe nd enc e ofTri al s 04 / 23120 13 (EPA and PMRA). Ta bl e B.7.6. 1. 2-2. Tri a l Nu mbe r s a nd Geograp h ic a l L ocat io n s. Crop No. NAFTA Growin g Zo ne To ta l Trials I 2 3 4 5 6 7 8 9 10 II 12 W

aterc r ess S ub
. I 2 3 R

eq. 1 2 1 As per Table I of 860. 1 500
. Geographic distribution is not spec i lied for crops requi rin g three or fewe r trials. 

### Locatio n s a nd detailed u se p att e rns for th e tri a l s are provid e d in Table B.7.6
. 1 .2-3.

EPA MRID #: 49339002 Pa ge 3 of8Proh exa dione calcium [ P C Co de I I2600]ffhe Interregional R esearch P roject No. 4 (IR-4 ) (BAS 125 W] T a bl e B. 7.6. 1. 2-3
. S tu d y Us e P a tt e rn . Location : End -u se Plot M e th od of Application/ Timing County / Ci ty. Product' of Appli ca tion S tate; Yea r (Tri a l ID) Indi an Ri ve r 27. 5 % 0 2 I. foliar broadcast before I " County, FL ; WG cu tt in g; vegetative 2009 2. Fo liar broadcast befo r e I " (F L24- 02) cutting: vegetati ve 3
. Foliar broadcas t before 2 nd cu tt in g: vegetativ e 4. Foliar broadcas t before 2 nd cutting: vege tati ve (FL24-03) 27.5% 03 I
. foliar overhead chemigation WG befo r e I " c uttin g; vege t at ive 2
. Foli ar overhead chemigation before 15 ' cutting: vegeta ti ve 3. Fol i ar overhead che migation before 2nd cuttin g ; vegetat ive 4. foli ar ove rhead che mi gation before 2nd cuttin g; vege tati ve Indian River 27.5% NA I
. fo liar broa dcas t before I " Co unty. FL: WG cuttin g; vegetative 2009 (FL 25) 2. Foliar broadcas t befo r e I " cuttin g: vegetative 3. Fo li ar broadca s t before 2nd cuttin g: vege tati ve 4
. Foli a r broadcas t befo re 2nd c uttin g; vege ta tive C learsp rin g. 27.5% NA I
. Fo liar broadc as t before I " MD: 2009 WG cuttin g: pre -bloom ( MD 02) 2. Foliar broadca st befo re I " cu tt ing; p r e- b l oom ; fi rs t bud s 3. Foliar broadca st befo r e 2nd cutting: pre -bloom 4. Foliar broadca st before 2nd cuttin g; pre- b l oom C learsprin g . 27.5% NA I. Foliar broadcast before 151 MD; 2009 WG cuttin g; pre- bloom (MD03) 2. F o liar broadcas t befo r e I " cutting : pre -bl oo m: fir s t bud s 3
. Foliar broadcast before 2nd cuttin g; pre-blo o m 4
. Foliar broadcas t be fore 2nd cutting ; pre -bloom



### . 1 27 .:>% WG formulation (A p ogcclll Plant Gro wth R egulator) . 2 Total rate after eac h cu tti ng . 3 N I S = no nioni c surfac tant. Volum e Rate per R etreatme nt To ta l (ga l / A) App lication Int e r va l Rat e2 (lb ai //\) (days) (lb ai /A) 30
. 24 0
. 14 2 

## -- 0.282 29
. 85 0. 1 40 7 29.80 0. 14 0 24 0.278 29 .37 0.138 7 214.12 0.140 

### -- 0.280 123
. 94 0.140 7 106
. 76 0. 1 40 24 0.2 80 25 0.52 0
. 14 0 7 30. 1 7 0. 14 1 

## -- 0.279 29
. 36 0.138 7 29.73 0. 139 24 0
. 278 29 .63 0. 139 7 58
. 13 0. 1 35
- · 0.272 59
. 19 0.137 7 59 .22 0.140 15 0.277 57.93 0. 137 6 46 .22 0.141 

## -· 0.28 4 47
. 02 0. 143 7 41 .07 0. 139 1 5 0.279 4 1.1 3 0
. 1 40 6 Surfactant/ Adjuvan t3
NIS

NIS

NI

S

NIS

NIS

Watercress was grow n a nd m ain ta in ed acco rd in g to typ i cal ag ri cu lt ural practices. No u n u s ual weathe r c onditi o n s we re r e p o rt e d to h ave affec te d c rop g ro wth o r deve lo pm e nt dur in g th e s tud y.

EPA MRID # : 49 33 9002 Page 4 of8Prohexadione calcium [PC Code I I 2600)rrhe Interregional Research Project No. 4 ( IR -4 ) [BAS 125 W] Sa mple Handling and Preparation Duplicate control and treated samples of watercress were collected at maturity (3-day PHI) after the last applicati on. All samples were placed in to frozen storage with in

- 6 hours of collection and were stored frozen (< 0-10 °F) at the field s ites for 5-26 days before shipment v ia ACOS freezer truck to the University of Florida Food and Env ironm en tal Toxicology Laboratory (Gainesville , FL). At the analytical laboratory , samples were hom ogenized in the presence of dry ice and were stored at
- 37 to 7 °C until extraction for analysis. 2. D esc ription of Ana lytica l Proc e dure s Samples were ana l yzed fo r prohexad ione ca lc ium u s ing a previou s ly validated GC/MS, BASF Method No. 09601 with minor mod ifi cations (Memo, 3/ 1 0/01, G
. Kramer , 0273510 , MRID 48 106701 )
. A comp lete description of the method was inc luded in the s ubmi ss i on. Briefly, sampl es were extracted twice w ith acetonitrile (ACN): 1.5 M sulfuric ac id (9: 1, v:v) , then homogenized with 0.05 M sodium acetate a nd filtered. The comb in ed extract was applied to an ENV + soli d-pha se extraction (S PE) cartridge , and residues were e l uted with methanol. Sulfuric acid was added to the e lu ate , and the mixture was refluxed to convert prohexadione carboxylic acid to methyl prohexadione carboxylate. The r esul tin g extract was applied to an ENV+ SPE cart ridge. Re sidues were eluted with 0
. 01% oxalic acid in acetone (w/v) , a nd the e luate was r ed uced und er nitrogen for ana l ysis by GC / MS. The m e thod det e rmin es resi dues of prohexadione calcium as the m ethyl ester, m ethy l prohexadione carboxylate. Residues of methyl prohexadione carboxylate were converted to prohexadione acid equivalents by the petitioner using a molecular weight conversion factor of 0. 93 8 , and the se residues were reported incorrectly as pro hexadione calcium in the study. The reported re s idu es of prohexadione acid were converted to prohexadione calcium equivalents by the study reviewer using a molecular weight conversion factor of 1.179. The LOQ (determined as the LLMV) was 0.10 ppm. We note that th e petitioner a lso p r esented ca lcu l ated valu es fo r the limit of detectio n (LOO) and LOQ based on recoveries obtained at the 

### O. l 0-ppm fortificat i on level. The LOD was calculated by multiplying the sta ndard dev iat ion of recovery measurements at the L LMV by the one-tailed t-statistic (confidence level not reported) for 6 replicates, and the LOQ was defined as 3x the LOO. The calculated LOD a nd LOQ were 0.015 ppm a nd 0.046 ppm , respectively.

EPA MRJD # : 49339002 Page 5 of8Prohexadione calcium [PC Code I I 2600]ffhe Int erregional Research Project No. 4 ( I R-4) [BAS 125 W] 

### II. RESULTS AND DISCUSSION Method performance was evaluated during method validation and by use of concurrent recovery samples. For method validat ion , nine samples of untreated watercress were fortified with prohexadione calcium at 0.10 , 0.50, and 5.0 ppm ; individual recove ri es were 70-78 % with a standard deviation of 2.8%. For concurrent rec ove ry , nine samp les of untreated watercress were fortified at 0.10, 0.50 and 5.0 ppm; individual recoveries were 69 -87 % with a standard d eviation of 5 .6%. Recoveries were generall y within the acceptable range of 70%-120%; therefore , the method was considered valid for the analy s is of res idue s of prohexadione calcium in watercress matrices. The fortification levels bracketed the measured residues. Concurrent recoveries were not corrected for appare nt residues in controls. The detector response was linear (coefficient of determination , 

## r2 2:0.979 1) with in the ran ge of 0.0204

- 0.143 ng/mL. Representative chromatograms of control samp les , fort ified samples and tr eated samp les were provided. The control chromatograms generally had no peaks of interest above th e c hromato grap hic background. The fort ifi ed samp le chromat ogra ms contained only the analyte of interest , and peaks were symmetrical and well defined. Apparent residues in controls were below the LOQ (< 0.10 ppm). The reported residue values were not corrected for apparent residues in controls. The reported residues of prohexadione acid were converted to prohexadione calcium eq ui va l ents by the s tud y reviewer u s ing a molecular we ight convers i on factor of 1.179. Tab l e B.7.6.1.1-4. S umm ary of Method Validation a nd Conc urr en t Recoverie s of Prohexadione (free acid) fr o m Watercress . Matrix Fortification Level Recoverie s Mean ± Std. Dev. ( oom) (%) (%) Meth od Va lid atio n R ecoveries Watercres s 0. 1 73, 75, 74 74 ± 0
. 8 0.5 7 1 , 78, 78 76 ± 3 5
. 0 72. 75. 70 72 ± 2 Ove r all Rane e: 70 to 78 74 ± 3 Conc urr en t ll.ccoverie s \.\latercre ss 0.1 76, 78, 85 80 ± 4 0.5 69 , 84 , 84.80 79 ± 6 5 .0 79.87 83 Overall Ran2e: 69 t o 88 80±5 

### The field residue samples were stored frozen a maximum of 794 days (26.1 months) from harvest to extraction for analysis (Tab le B. 7 .6. l.2-5a). Freezer storage stabi lity data were generated concurrently with the watercress field trials; the results are presented in Table B.7.6. l
. 2-5b. No 0-day data were provided. The data demon strate that residue s of prohexadione calcium declined in/on watercress for up to 792 days (26
. l months) of frozen storage. Reported residues were corrected for loss on storage. The se data are acceptable to suppo11 th e storage conditions and durations of th e samp l es from the subm itted field trials; however , storage stabil ity stud i es should always include a 0-day samp ling interval to es tablish the res idue leve ls present at the time samples are placed into storage [see OC S PP 860. l 380(d)(6)(i)).

EPA MRID # : 49339002 Pag e 6 of8Prohexadione calciu m [ PC Code 112600)ffhe Interregional Researc h Project No. 4 ( IR-4 ) [BAS 125 W] Tab l e B.7
. 6.1.2-Sa
. Su mm a r y of Storage Conditions. Matrix Storage Temperature ( 0 C) Actual Storage In terval of Demonstrated Storage Stabi li ty (RJ\C or Extract) Duration ' (days/months) (days/ months) Watercress 0- 1 0 ° F at the field s ites; 700

- 794 days Residues declined by

- 34% following storage -37 to 7 °C at the laboratory (23.0

- 26.1 month s) for 792 days . 2 1 Interval from harvest to extraction. Samples were analyzed within 0-1 days of extraction. 2 Based on concurrent storage stability study. Sec Tab l e 7.6 . I . 2-5b. Tab le B. 7 .6.1.2-Sb. Stabi li ty of Prohexadione Calcium Residues in Watercress. Commodity Spike Storage Fresh Fortification Stored Sample Recoveries Mean Recovery Corrected% Level Int erval Recoveries( %) (%) (%) Recovery• (ppm) (days) Waterc ress 0.5 792 80 52 , 48 , 58 53 66 1 Co rrec ted for recovery in fre s h l y fortified sa mples. 

### The resu lts from the s ubmitted field tri a ls are presented in Tab les B
. 7
. 6
. 1.2-6 and B.7.6.1.2

- 7
. In watercress har ves t e d at PHis of 3 da ys following the la st of two broadca s t foliar or chemigation application s of the 27.5% WG formulation of prohexadione calcium at a total rate of 0.272-0. 284 lb a i / A , individual sample (and per-trial average) re s idues of prohexadione ca lcium were 0.298

- 2
. 00 (0
. 321-1.72) ppm . Residue s were generally lower in second-harvest s ample s than they were in first-harvest samp l es, and residue s were lowe r following chemigation app li cations than th ey were fo llowing foliar applications: overall average residues were 0.347 ppm following chemigation applications vs. 1 .30 ppm following foliar applications. Residue decline was not evaluated
.

Table B.7.6.1.2-6. Res idue Data from Watercress Field Trials w ith P r o h exa dion e Ca lcium. 1 Locatio n : Zone Crop/ Matrix Rate PHI Residues 2 (ppm prohexadione Co unt y/C ity, State; Variety (lb ai / A) (days) calc ium) [/\ veragel Year (Trial ID) As found Corrected for decl in e on sto ra ge Indian River County , 3 Watercress/ Leaves and s tems ; 0.279

- 0.282 3 1.32, 1 .26, 2.00 , l.9I , FL ; 2009 (FL24-02) B & W # 47 1 SI cutting 0.968, 0.993 1 .47, 1 .50 a nd Indian River and [ 1.1 4 ] [I. 72] County, FL: 2009 B& W# l Leaves and stems; 0.278 3 0. 705 , 0.59 1 , 1.07 , 0.895 , (FL25) 2 nd cutti ng 0.626, 0.696 0.949, 1.05 [ 0.654) [0.99 I] In dian River County. 3 Watercress/ Leaves and ste ms: 0.280 3 0.220. 0.203 0.334 , 0.307 FL; 2009 (FL24 -03) B& W#l I SI cutting [Chcmigation] [0.2121 [0.321] Leaves and s tem s; 0
. 280 3 0. 1 97,0.296 0.298, 0.448 2"d cutting [Chemigation] [0.246 ) [0.373] C l

earspr ing , MD; 2 Watercress/ Leaves and stems ; 0.272-0.284 3 1. 06, 1. 00 , 1.61 , 1.52 , 2009 (MD02) and B & W #47 ISi cutting 0.81 I , 0.856 1 .23, 1.30 Clearspring, MD: [0.933] [ 1.41] 2009 (MD03) L eaves and s tems ; 0
. 277

-0.279 3 0.686. 0.710, 1.04, 1.08

2nd cutting 0.723, 0.725 I. I O , 1.1 0 [0.71 I] [ 1.08] 1 The 27.5 % WO formulation {Apogee® Pl ant Growth Regulator) wa s used. 2 Re sidues of pro hcxad ionc calcium were determined as meth y l prohcxad ionc carboxylatc by the method
. Residue s were converted to pro hexad ione acid equivalents by the petitioner u s ing a molecu lar weight conversion factor of0.938, and these residue s were reported incorrectl y as prohcxadione calcium in the MRID. The reported residues of prohcxadione acid were converted to prohexadione ca l cium equivalents by the st ud y reviewer using a molecula r weig ht conversion factor of I .179 and arc presented above "As found." These residues were then corrected for decline on s tora ge (

- 34%) by th e study reviewer
.

EPA MR10 # : 49339002 Pa ge 7 of8Pro hexa di o ne ca lcium [P C C od e I 1 2 600] ffhe Int e rreg ional Resea r c h Pro ject N o . 4 ( I R-4 ) [BA S 125 W) T a b l e B
. 7 .6
. t. 2 -7
. Su mma r y o f Re s idu es fro m W a t erc r ess Fie ld Tri a l s w ith P r o h ex a dio n e Ca lcium
. Cro p Matrix Total Appli ca ti o n P iii n ' R es idue s ( ppm Proh e xadi o nc ca lcium ) R

ate ( lb ai /A

) (days) Mi n . 2 M ax. 2 LAFT 1 H AFT 3 M c dia n 3 Mean 3 As F o un d W

at

e r

c re ss . 1 st c uttin g 0. 272

- 0. 28 4 3 3 0
. 20 3 1.32 0
. 2 1 2 1.1 4 0.933 0.760 W

at

er

c r

ess . 2nc1 cuttin g 0
. 277

- 0
. 280 3 3 0. 197 0. 725 0. 24 6 0
. 7 11 0
. 65 4 0
. 53 7 W

at

e rcress combined 0
. 272

- 0. 284 3 3 0
. 19 7 1.32 0
. 212 1.14 0.6 8 3 0 .64 9 Co rre ct ed fo r decl in e o n s toragt: Wat e rcres s . I st cu tt ing 0.272-0
. 28 4 3 3 0
. 307 2
. 00 0
. 32 1 1. 72 1 .4 1 1. 15 W

at

e r

c r

ess . 2 "d cuttin g 0.277

- 0
. 28 0 3 3 0
. 298 1. 10 0
. 3 7 3 1. 08 0
. 99 1 0.8 14 W

at

e r

c r

ess combin ed 0
. 272

- 0. 284 3 3 0
. 2 9 8 2
. 00 0 .3 2 1 1.72 1. 03 0 .9 83 1 n = numb er o f field tri al s. 2 Va lue s bas ed on tota l nu m be r of samp les. 3 Va lu e s bas ed o n pe r- tri al ave ra ge s. LAFT = lo w es t avera ge field tri al, I I AFT = hi g h

e st average fi e l d tri al, S D = s ta nd ar d dev i ati o n. 

### Ill. C O NCL US I O NS 

### s oi
0 .48 6 0
. 253 0
. 367 0.7 3 6 0 .384 0
. 5 57

Th e wa t e rcre ss fi e ld tria ls are c ons id ere d sc ie ntifically acc e ptab le. In wate r cress h ar v ested at PH I s of 3 d ays fo ll o win g th e l a st of two b roa dc a s t fo liar o r chemi ga tio n appli ca ti o n s of th e 2 7 .5 % W G formul ati o n of p ro hex adi o ne calc ium at a to ta l ra te o f 0.272

- 0
. 2 84 l b ai/ A, indi v id ua l sam pl e (and p e r- tr ia l av era ge) res idue s o fp ro he xadi o n e ca lcium we re 0. 2 98- 2
. 00 (0
. 32 1

- 1. 72) ppm . Res idu es w e re gen e rall y lowe r in s e co nd-harv e s t s amp les than they w e re in fir s t-h a r ves t sa mp les , a nd r es idu es we re lowe r follo w in g c he mi g at io n a ppl icati o n s than they we re fo ll ow in g fo li ar appli ca tio n s: ov e ra ll ave r age r es i d ues we re 0.34 7 pp m fo ll ow i ng c h emi gati o n appli cati ons vs. 1 .30 ppm fo ll ow in g fo li ar applic ati o n s. Res idu e d e clin e was n ot eva l u ated. An acce ptabl e m e thod wa s u se d for res idu e qu an t ita tio n , and ad e qu ate s tora g e s ta bili ty dat a we re s u b mitte d to s up po rt s ampl e s t o ra g e dur a ti o n s and c o nditi o n s. 

### RE FE REN CES N on e

EPA MRJO # : 493 3 9002 Page 8 o f8Prohexadione calcium [PCB)/ BASF Canada Inc
. [BAZ] OS-May-20 l S 

### B. 7 . 6 Res i d u es R es ultin g fr o m S up e rvi se d T ri a ls (A nn e x 

### II A 6.3 ; A nn ex III A 

### 8
. 3 ) B . 7. 6.l Res idu es i n Target C r o ps B. 7.6. 1.l Str a wb e r ri es Doc u me n t ID : PMRA No. 237S772 MRID No. 49339001 

### R e port:
G u id e lin es: Liu , S
. (2013). " P rohexadione Calcium: Magnitude of the Res idue on Strawberry". Study Numbe r: AAFCI0-016R. Unpub l ished study prepared by Agriculture and Agri-Food Canada , Ottawa, ON , Canada. 27S pages . EPA OCSPP Harmonized Test Guide l ine 860
. 1SOO Crop Field Trials (August 1996) PMRA Regu l atory D i rective DIR98

- 02

- Res i due Chemistry Guide l ines , Section 9

- Crop F i e ld Tr i a ls PMRA Regulatory Di r ective DIR2010-0S

- Revisions to t he Residue Chemistry Crop F i e ld Tri al Requirements OECD Guideline S09 Crop F ield Trial (September 2009) 

### GLP Co mpli a nc e: No deviations from regulatory requirements were reported which would 

### Acce p ta bili ty : Eva lu a tor : have an impact on the validity of the study. The study is considered scientifically acceptab l e. Pamela Chu , Evaluation Officer, MUAS, HED William D. Wassell ,**Chemis f** ealth**ffe** i vis ion/Risk Assessment Branch I (HED/ RAB 

### 1) 

# /f/Vjf/) 

# t
. JVt EXECUT IVE SUMMA R Y Nine fie ld tria ls for prohexadione calc i um on strawberries were conducted in Canada and the United States encompassing North American F ree Trade Agreement (NAFT A) Growing Regions I A 

### (l in NS), 2 

### (l in NJ), 3 ( 1 in FL), S (1 in ON) , SA (1 in M I ), SB (1 in QC), 10 (2 in CA), and 12 (1 BC) during the 2010 and 2011 grow ing seasons . • At each trial location , prohexadione calcium , formu l ated as a wettab l e granule , was applied to strawb e rries as three foliar app li cations
. The rate ranged from 36.0 g ai/ha (0
. 0321 lbs ai/ A) to 40.8 g ai /ha (0
. 0364 l bs ai / A) , the re - treatment intervals (RTis) were 8-lS days, and the total application rate was 110 g ai/ha (0.0990 lbs a i / A). For each application, a non-ion i c surfactant was added in the spray mixture at a 0.05% (v/ v) ra t e and ammon ium sulfate was added at a 1: 1 rat io. Strawberri es were harvested at preharvest i nterva ls (PHis) of 16-25 days
. In one trial (# 121 ) , samp l es were co ll ected at different time intervals (PHIs of 13 , 19, 26 , 31 days) to assess re sidue decline behaviour. All samples were maintained frozen at the testi ng fac ili ty, dur ing s hi ppi ng to t he laboratory , and were stored frozen until ana lysis
. The maximum storage interval for samples between harvest
Pa e I of 8 EPA MRID No.49339001Prohexadione calc i um [PCB] / BASF Canada Inc. [BAZ] and ana lysis was 390 days (

- 13 months). Residues of prohexadione have been shown to be stable in strawberries for up to 422 days (

- 14 months) under frozen conditions. Adequate sto rage stab ility data are therefore available to support the storage conditions and interva ls for samples in th e current trials. Samples in the cur rent study were analyzed for residues of prohexadione calcium using a highperformance liquid chromatography method with tandem mass spectrometry detection (LC / MS/MS) work in g meth od based on Method 564/ 0 entitled , "Va li dation of the analytical method 564/ 0: M ethod for the determination of prohexadione-Ca in plant and an imal matrices , " ( PMRA# 1525282 , MRID No. 4810670 l ) to d e termine residues of prohexadione ca lcium. This method has been previously reviewed and deemed acceptable for data gat herin g and enforcement (S2007-8864/-8867; PMRA# 1 628696; Memo, 11/22/99, G. Kramer , 0252547). Acceptable method validation and concu rrent recoveries were r e port ed for r esidues of proh exad ione ca lc ium in/on strawberry fruit samples at fortification levels of 0.01 , 0.1, and l.O ppm thus validating the method. The limit of quantitation (LOQ ) was 0.01 ppm for prohexadione in strawberry fruits. In dividual samp le (and per-trial average) r esidues in s tr awberries ranged from 0.03 ppm to 0.16 ppm (0.03 ppm t o 0.15 ppm). Residue decline data show that re s idu es of prohexadione calcium decrease in strawberr ies with increasing PH i s. 

### I
. MA TERIAL S AND M ET HODS A
. MATERIALS

Tab le B
. 7.6. 1.1

- 1. No menclatur e fo r Pr o h exad io n e calc ium
. Co mm o n n a me Prohcxadionc ca l cium I UPAC Calcium 3-oxido-5-oxo-4-propion y l cyc loh ex -3-cnccarb oxy latc CAS no . 1272 77 -53-6 Com pan y experi me n ta l n ame BA S 125 W Ot h er sy non yms (if a p p li cab le) NA**~** 

### - 

# #' " • ,. C a 0 0 0**~** 

### - B. S tud y D es i g n 1. 

### Test Proc e dure A total of nine residue trials on strawbe rri es were conducted with a wettab le granule formulation in Canada and the United States during the 2010

- 2011 growing season (Table 

### 8. 7 .6. l.1-2).

Paoc 2 of8 EPA MRID No.49339001P ro h exa di o n e ca lcium [P C B ) / BASF C a nada Inc
. [BAZ] Table B.7.6. 1.1 -2. Tria l N umb e r s a n d G eogra phi ca l L ocat i o n s .

C r op No. Tria ls NA IT A Grow in g Zo n e T ota l I I A 2 3 4 

### s SA SB 6 7 8 9 1 0 11 1 2 S t raw - Submitted I I I 2 I 2 I 9 berry Req. U
. S
. 1 Il l 110 Il l I ll 312 Il l 8 1 6 Req
. Can. 2 1 I I I I 5 1 As per Table 5 of 860. 1 500 fo r s t rawbe rry; th e s e co nd num be r re fl ects a 25% red u c t io n in th e num be r o f fi e ld tri a ls a ll owed fo r the crop as a repn.:sen l a ti ve co mm od ity in s uppo rt of a cro p gro up/s ubgroup t o l

era nce o r w he n a ppli ca ti o n r es ult s in no quan ti fiab l e resid ues . 2 J\s per Tab l e 1 .2 of P MRA Reg ul a tory Directi ve DIR2 0 I 0

- 05. Lo cat ion s and detail e d use patterns for the trials a re provided in Table B.7.6.1.1-3
. Tab l e B. 7.6. 1.1 -3. S t ud · v Use Pattern. Loca ti o n : C it y. V o lum e Rat e pe r Rctrealmenl Total Ra te S tate/ Prov in ce: End-u se Pro du ct/ M e thod of Appli ca ti o n / I U h a l Ap p li ca ti o n Int e r va l [ g ai / ha] Surfa c ta nt/ Year For mul ati o n (% ai ) Timin g o f Appli ca ti o n (ga l / A ) [g a i / ha] ( days) (lb s ai/ A ) Adju van t (T ri a l I D) (l bs ai/A) Ken tvil l e. NS / 20 I0 A p ogee/ I
. Fo liar / Gree n b erri es. 306 37.9 N I A 11 1 Ac ti va t e Plu s Trial ID # 11 9 We tt ab l e Gra nul es runn e r s s ta rt ed (33. 7) (0.0338) (0.099) 0.05% (v/ v). (27 .4 %) 2
. Fo li ar / Fru it i ng 293 36.3 14 A mm o ni um (32.2) (0.032 4 ) su l fa t e ( I : I ) 3. Fo l iar / F rui ting 297 36
. 7 1 3 (32.7) (0.0327) I Iarrow. ON / 20 I 0 Apogee / I
. Fo l iar / Some 330 -1 0.8 N I A 11 6 Agral 90 0.05 % Trial ID # 1 20 Wettable Granules flowe ri ng (36.3) (0.0364) (0. 1 0 3 ) (v/ v)
. (27.4%) 2. Fol i ar / F l owering 313 38.7 1 3 A m mo n ium (3 4 .4) (0.0346) s u lfa te ( I : I ) 3. Fo liar / F rui ti ng 298 36
. 9 1 3 (32.8) (0.0329) Frel i ghsburg. Apogee/ I
. Fo lia r / S tarted 3 10 38.4 N I A 114 Agra l 90 0
. 05% QC/ 20 10 We tt ab l e Gra nule s fl o w ering (34. 1) (0.03 4 3) (0. 10 2 ) (v/ v), T r ia l ID # 1 2 1 (27. 4 %) 2
. Foliar / S tartin g to 307 38. 1 1 3 Amm o nium fruit and fl o w erin g (3 3
. 8 ) (0.03 4 0) s ul fa te ( I : I ) 3
. Fo liar / Fruitin g and 3 03 37.5 15 flowering (33
. 3) ( 0
. 0 33 5) L

a ng l ey. B C/ 20 I 0 Apo g e e/ I
. Foliar / BBCH 15 294 36 .4 N I A 111 Agral 90 0
. 0 5% T ri a l ID fl 122 We tt a bl e Granul es (V ege tative s ta ge) (3 2
. 3) (0. 0 325) ( 0
. 099 ) ( v/v), ( 27
.4 %) 2
. Foli a r / Vege t a tiv e 3 0 1 37.3 1 3 Amm o nium (33. 1 ) (0.0333) s ul fa te( l : I ) 3
. Fo liar / Flowe rin g 299 37.2 14 (32.9) (0
. 0332) C ream Ridge. A p ogee/ I. F o li ar / Bl oo m 307 37.9 N I A 112 A ttach, 0.05% NJ / 20 1 0 We tt ab le G ra nul es (33
. 8 ) (0.0338) (0.09 9 9 ) (v/ v) , Tria l ID # 170 (27.4%) 2. Fo li ar / Sma ll g reen 297 36.7 9 Ammonium frui t (32. 7 ) (0.0327) sulfate ( I : I ) 3
. Foliar / Fru iting 300 37
. 1 8 (33.0) (0.033 1 ) Parlier. CN 20 10 Apogee/ I
. Foliar broadcast/ 307 38
. 1 NIA 11 4 Induce. 0.05 % Trial ID # 17 1 We ttable Granu l es Vege tative/b l ooming (33.8) (0.03 4 ) (0. 1 02) (v/ v). (27.4%) 2
. Fo liar broadcast/ 306 37
. 9 14 A mm onium Fruitin g/b l oo min g (33.7) (0.0338) s ul fa t e ( I: I ) 3
. Fo liar bro ad cast/ 303 37.6 1 2 Fruitin !t (33.3) (0.0336) ll o ll , M 1 / 20 I 0- Apogee/ I
. Fo liar / Vege ta ti ve 29 1 36.0 N I A 111 Ac ti va to r 90. 20 11 W e ll a bl e Granul es (32. 0 ) (0.032 1) ( 0.099 ) 0
. 0 5 % (v / v).
Pa o e 3 of8 E PA MRlD N o. 4 933 9001Prohexadione calcium [PC B] / BASF Canada In c. [ BAZ] Table 8. 7.6.1. 1-3
. Study U se Pattern.

Location : City, Vo lum e Rate per Retrcatmcnt Total Rate Stat e/ Province: End-u s e Product/ Method of Application / I Uha J App li ca ti on Interval [g ai/ ha] Surfa c 1an t/ Year Formulation (% ai) Tim in g of Application [ g ai/ ha l Adjuvant (Trial ID) (ga l / A) ( lb s ai/ A) (day s ) (lbs ai / A) Trial ID # 233 (27.4 % ) 2. Foliar / Early 300 37.1 1 3 Ammonium nowering (33
. 0) (0.0331) sulfate ( l : I ) 3
. Foliar / 309 38.2 14 Flowerin g/ fruiting ( 34
. 0 ) ( 0.0341 ) B a lm. F l/ 2010

- Ap ogee / I
. Foliar broad cast/ 3 0 4 37
. 6 NIA 113 De - F ae 82 0
. 20 11 Wett able G ranul es Bloom to fruiting ( 33.4 ) ( 0.0336 ) (0 .101 ) 0. 05 % (v / v)
. Tri al ID # 234 ( 27
. 4 %) 2
. Foliar broadcast/ 8 1 0 307 38.0 14 Amm o nium 11 cm (33.8) (0.0339) sulfate ( I : I ) 3. Foliar broadcas t/ 305 37.8 15 Bloom to fruiting (33
.6) (0.0338) S a lin a s . CA/20 1 0 Apogee/ I. Foliar / F l owers and 295 36.5 NI A 111 R-11. 0.05 % Tr ial ID #235 Wettable Grnnulcs fruiting (32.5) (0.0326) (0
. 099) (v/ v). ( 27
.4 %) 2. Foliar / Flower s and 308 37.2 14 Ammonium fruiting (3 3
. 9) (0.0332) s ulfate ( I : I ) 3
. Foliar / Flowers and 3 03 37.2 13 fruiting ( 33.3 ) ( 0
. 0332 ) 

### Strawbe rries were grown and maintained according to typical agricultural practices. Irrigation was u sed at all trial s ites except trial IDs 120 a nd 233. No unusual weather co nditions were r epo rted during the study
. Temperatures were within 4.4 ° C (7
. 9°F) of normal a nd precipitation was within 114.1 mm (4.49 in) of norma l. Trial ID s# 119 , 120 , and 233 rece ived more rainfall than normal while Trial ID s# 122 , 170 , and 234 received significant ly less precipitat io n. 

### Sa mple Handling a nd Preparation Two untreated and two treated samples of mature strawberries were hand-picked 20

- 23 days after final applicat ion. H oweve r , only one sampl e was collected from each plot in Trial ID # 170 due to early rip eni ng and in Trial ID # 120 , 122 , and 170 , sampling dates were modified ( 16, 25 , and 17 days, respect iv e ly) to ensure collection of rep re se ntativ e mature strawberries. Untr eated sa mpl es were collected fir st or by a different person to avoid contamination. Ends and edges of plots were avoided. Each sa mple surpassed the minimum target weight of 1 kg except Trial ID s # 121 and 170 where sample sizes were reduced due to wildlife interference and/or early fruit ripening. Samples were placed in bags then placed in coolers where they were s hipp ed to site fac ility freezers within 4 hours and 33 minutes of harvest. All samples were stored frozen in the freezers 

### (S -l 8 ° C/**-0.4 F)**  

### until shipment to the analytical laboratory (ADPEN Lab oratories Inc ., FL). All sampl es a rri ved frozen and in good condition at the analytical laboratory and stored frozen ( -29 to 3 ° C/ -20.2 to 37.4 ° F) until maceration and extraction. The maximum temperature (3 ° C/ 37.4°F) was due to a temporary freezer malfunct i on, however the study report indicates that the samples remained frozen during this period. Strawberry samp les were homogenized w ith a Hobart food proc esso r with dry ice and kept frozen until analysis. 

### 2. De sc ription of Analytica l Procedur es Samples of strawberries were analyzed for residues of prohexadione ca lc ium , detem1ined as prohexadione (free ac id ) , using an LC/MS / MS workjng method based on th e reference method 564/ 0: " Validat ion of the analyt ical method 564/ 0: Method for th e determination of prohexadione-Ca in plant and animal matri ces ," (PMRA# 1525282 , MRlD No. 4810670 l )
. This Pa e4of8 EPA MRID No.49339001Proh exa dione ca lc ium [ PC B] / BASF Ca nad a Inc. [BAZ]
m e th od ha s been pre v ious l y rev iewed a nd d ee m e d acceptab le fo r data gatheri ng a nd e n force m ent ( S2007-8864/ -8867 ; PMRA# 1628696 ; Memo , 3/ 10 / 01 , G. Kramer , D273510). Minor modification s were made to the method: addi ti onal standards w e r e a dd ed to the ca librati o n curve a nd ex tra c t s were ce ntrifu ge d lo nger at a sl ightl y lowe r rpm. Briefl y, sampl es were e xtracted w i th acetonitr il e : 2M H 2 S04 so lution. Extracts we r e cl eaned up using solid -ph ase extrac ti on (SPE) col umn elute d wi th ace tonitril e : m eth a nol : fo rmic acid. MS/MS detection in positive ionization mode monitored ion tran s itions from 

### m l z**~** 157 for prohe xad ione . A molecular we ight convers io n factor ( l .179) was u sed to express the fre e ac id as prohexadione ca lc ium equ iv a le nt. Th e LOQ was 0.0 l pp m fo r pro hexad io ne and the limi t of detectio n ( LOD ) estimated to be 0.003 pp m . 

### II. RESULT S AND DISCUSSION Method performance was evaluated during m ethod va lid a ti on by fortifying strawbe rry fruit with prohexadione at 0.0 I , 0. 1 , and 1 .0 ppm. N ine samp le s of strawbe rry fr u it we re fort ifi ed w ith proh e x a dion e ( three s amples were fortified at each spiking le v e l)
. Method validat ion rec ove ries at s pik in g leve ls of 0.0 I ppm , 0. 1 ppm, a nd 1.0 ppm ranged from 88% to 107 % (S. D. ± 10%) , 87 % to 89% (S .D
. ± 1% ) , and 75-79% (S .D
. ± 2 % ) , re spect ive ly. The method was a l so validated concurrentl y b y sp i king co n trol strawberr y fruit sample s with 0.0 I a nd 1. 0 ppm of proh exad ione. Recoveries at the 0.01 ppm and 1.0 ppm spik in g leve ls ra nged from 71-108 % ( n = 9 , S.D. ± 1 2%) and 76- 110 % ( n = 9, S. D. ± 10 %) , re spectively. All recoveries were w ithin th e acc e ptab l e range of 70 % to 120 %. Therefore , the m ethod was con s idered v alid for the analy s is of prohexadi o ne residu e s in strawberry matrices (Table B.7.6 .1. 1-4 )
. Th e fo rtifi cat ion leve l s did bracket th e m ea s ured r e s idu es. Th e d e tector r e sponse was lin ea r (corre la ti o n coefficien t , r 

### 2: 0.9923) within th e r ange of 0.0625- 25 ng/ mL. Representative chromatograms of co ntro l samples , fo rtifi ed samp l es and treated s ampl es w ere provid e d. The control chro m atograms g e ne ra ll y had no peaks of i nt erest above th e chromatograp hi c background. T h e fort ifi ed samp le chromatograms cont a ined only the analyte of in tere s t , and peaks we re sym m etrical and we ll defined. The reported residue values in fortified sampl es were corrected for app a rent re s idues i n co ntro ls . Tabl e B .7 .6. 1. l-4
. S ummar y o f Method Validation and Co ncurr e nt Rec ov eri es o f Pro h exa dion e (free acid) fr o m St ra w b e rr y Fruit. Matrix Fo rtifi c ation Leve l R ecoveries Mean :!: S td. D ev . (oom) ( % ) (%) Method V a li d ation Recove rie s Strawberry f ru it 0.0 1 88. 107. 92 96± 10 0. 1 88. 89
. 87 88 ± 1 1.0 76. 7 9. 75 77 ± 2 Conc urre nt Recove ri es S t rawberry f ru i t 0.0 1 I 0 0
. I 0 8. 96
. 85 . 7 1. 98 , 9 4
. I07 , I 08 96 ± 12 1. 0 85. 86. 83 , 76
. 78. 11 0. 90. 93. 86 87 ± 1 0 Th e fi e ld re s idue samp les w e re s tored frozen a max imu m of 390 day s (

- 13 month s ) from harvest to extraction (Tab le B .7.6. 1.1- 5)
. Samp l es we re a nal yzed w ithin I day of ex tra ct io n.

Pa e 5 of 8 EPA MRJD No.4 933 900 IProhexadio ne ca lcium [PCB)/ BASF Ca nad a Inc . [BAZ] 

### Free ze r storage stabi l ity data were ge n e rated co ncur rentl y w ith th e strawberry field trial s. On e untreated sample , three fo rtifi e d s tora ge samples , and thr ee fres hly fo rtifi ed sample s were a naly zed at eac h s t o rag e interval. Th e co ncurrent freezer s t orage stabi lity data indi cate th at r es idu es of prohexadione were s tabl e whe n s tored fro z en at ca.**-l** 

### 8 °C**(~ 0.4** **F)** 

### in s tra wbe rries fo r up to 422 days. There are no co nce rn s w i th the s tability of resi du es o f prohexadione in/on tre ated s trawb e rry samp les from thi s s tudy
.

Ta b l e B.7.6.2. 1-3. S tabilit y of Pro h exa di o n e R es idu es in St ra wberr i es During S tora l!e at ca.**°C.** Storage Fortification Reco vered Mean Mean Mean Co mm odity Dura tion Level Re s idue s Rec overy Co ncurrent Co rrected (days/ m on th s Recovery Recovery ' ) (ppm) (ppm) (%) (%) (%) 0.0795 0 0.0822 82.5 93 89 0.0858 0.0966 30 0.0922 92.6 1 00.6 93 0.0890 0.0869 1 20 0.0277* 83
. 7 76
. 9 109 0 .0 805 0.0880 Strawberry fruit 2 10 0
. 100 0.0929 91.2 97.5 94 0.0928 0.0903 300 0.0853 86
. 9 98
. 7 88 0.0852 0
. 0826 390 0.0753 76 .6 97.0 79 0.07 18 0.0875 422 0.0797 84
. 3 88 .9 95 0.0858 1 Co rrected for concu rren t recover y if below 100%. • The s tudy rep ort indicates that thi s value was determined t o be an outlier by the Grubbs and Dixon te st and was excluded in the calcu lation of the m ean recovery . No exp la nat i o n was provided for thi s very low recovery. Table 8.7.6.1.1-5. S umm a r y of S torage Co nditi o n s. Matrix S t orage Tempera ture Actual Storage Duration In terval of Demonstrated Storage Stability 

### r o q ( RAC or Extract) ( O r) (days) (da ys) A free ze r storage stabil it y s tud y was conducted co ncurrentl y with the anal ytical portion of the S trawberry fru it - 29 to 3 390* re s idue trial study. The data (sec Table (- 20
. 2 to 37.4) B.7
. 6
. 2
. 1- 3) indicate th at prohcxadione r es idue s are stable when stored froze n for up to .t 22 days. •From harvest to extraction. Samples were analy zed for re sidues within I day of ex t raction
. 

### The re s ult s from these trials s howe d th at w hen h arvested 16- 25 days after th e las t of thr ee ap pli cation s a t a seaso n al rate of 111-1 1 6 g a i /h a (0.0990-0. 104 lbs ai / A), re s idue s of prohexadione calcium in s trawb e rri es ranged from 0.03 ppm to 0.16 ppm (Tables B
. 7.6.1.1 - 6 

### and 8.7.6.1.1 - 7).

Pa e6of8 EPA M RlD No.4933900 1Prohexadione calcium [PCB] / BA SF Canada In c. [BAZ] 

### J n the r es idue declin e trials , mean residu e level decreased from 0. IO ppm to 0.04 ppm in s trawberry fruit betwe en PHi s of 13 and 3 1 day s. T a bl e B .7.6. 1.1 -6. Re s idue D a ta from S tr aw b erry F i e ld Trial s w i th Prohexad ion e Ca lcium
.

Location : C ity , Rate To ta l State/Pro v inc e : Reg io n C rop/ Matri x End-Use rg ai/ha] Pill Proh exa dione ca l cium' (per-trial Year Variety Product (days) (ppm) ( Trial ID) ( lbs ai / A) average) Kentvillc. Strawberry / 0.04 NS / 2010 I A Seascape Fruit Apogee 111 2 1 0 .0 4 Trial ID fl 11 9 ( Day- W G (0.0990) neutral ) O.QJ Strawberry / 0.09 I I

arrow , ON / 20 I 0 5 H oneoye Fruit Apogee 116 1 6 0.09 T ri a l ID fl 1 20 (Jun1:- WG (0. 104) 0.09 bearing) 13 0.09 0. 1 0 0. 10 19 0.08 0 .0 8 0.08 Frelighsburg. S trawberry / 2 1 0. 10 0. 10 QC/ 2010 SB Seascape Fruit Apogee 114 0. 1 0 Tria lI D # 121 (Day

- WG (0
. I 02) 0.08 neutra l) 26 0.o7 0.08 0.04 31 0.04 0.04 Strawberry/ O.oJ Langley. B C/ 20 I 0 12 Albion Fruit Apogee 111 25 0.0 4 Trial ID # 1 22 ( D ay- \VG (0.0990) neutral) 0.04 C ream Ri dge. Strawberry / NJ / 2010 2 Earliglow Fruit Apogee 112 17 0.06 0.06 Trial ID # 170 (June- WG (0.0999) bearin g) S trawb e rry/ 0.05 P a rlier. CN20 I 0 10 Albion Fruit Apogee 114 2 1 0.05 Trial ID # 17 1 (Day- WG (0.102) neutral) 0.05 ll o lt , M l/20 1 0

- S trawb e rr y/ 0
. 1 6 20 11 5 Jewe l Fruit Apogee 111 20 0
. 1 5 Trial ID # 233 (June- WG (0.0990) 0. 13 bearing) Balm , F L/20 1 0

- S trawb er ry/ 0.03 20 11 3 Treas ure Fruit Apogee 113 2 1 0.03 Trial ID # 234 (June- WG (0. 101) 0.03 bearing) Sa linas, CN20 10 S trawberry / 0.06 Tria l ID 11235 A l bion Apogee 1 11 10 (Day- Fruit WG (0.0990) 23 0.07 neutral ) 0.08 'E xpressed as prohexadione ca l cium equivalents

Pa e7o f8 EPA MRIO No.4933900 IPro hexadione ca lcium [PCB] / BASF Canada In c. [BA Z ] Tab l e B. 7 .6.1.1 -7
. Summary o f Residue s fr o m Strawberry Fie ld Trial s wit h Pro h exa d io n e Calc ium
. Total Re sid u e s (ppm) Crop Application PHI Matrix Ana lyte Rate (days) n Min
. 1 Max. 1 LAFT 2 HAF T 2 Mcdian 2 Mean 2 

### so 2 [g ai / ha] (lb s ai/ A) Strawbcrr Pro hexadionc 111

- 116

y fruit ca lcium (0.0990

- 1 6-25 9 0.03 0
. 16 0.03 0. 1 5 0.06 0.07 0.038 0.1 04) 1 Values based on to ta l num be r of s amples. 2 Value s based on per-t rial averag e s. LAFT = lowe st averag e field trial. HAFT = highe s t avera ge fi eld trial, SD = s tandard dcviation
. For c o mputati o n of th e LAFT. HAFT. median, mean . and s tand a rd de v iation. va lue s< LOQ ar e ass um ed to be at the LOQ (0.0 I ppm ). n = numb er of li c ld trial s. 

### III. CONCLUS ION S The s trawberry field trial s are cons id e re d sc i e ntifically acceptable
. Th e result s of the study s h owed tha t fo llowin g a to tal ap plicati on of 

### 111-11 6 g ai/ ha 

### (0.0990-0. l 

### 04 l bs ai / A) in s trawb e rry sa mpl es co ll ected at PI-Ils of 

### 1 6

-25 day s, residues of proh exadion e calc ium ranged from 

### 0.03 ppm to 

### 0. 16 ppm. A decline stud y indicates th at the leve l ofprohexadione calcium res idu es in strawberries d ecrea ses with tim e. Adequate s torage s tability dat a has been provided to suppo rt samp le s torage durations and conditions. 

### REFERENCES PMRA # 

### 1 525282. MRJD No. 

### 48 l 

### 06701. Lclunann , A. and Mackenroth , C. 

### (2005). "Va lidati on of th e ana lyti cal m e thod 

### 56 4/ 0: Metho d for the d ete rmin a ti o n of Prohex adion e -C a in plant and a nim a l m atri ces"
. S tudy co d e : 

### 84609. BASF Doc 10 

### 2005/100758 1
. U np ubl ish ed s tud y prepared by B AS F Akti engese ll sc haft , Limb urgerhof , G erm an y. 

### 63 pages.

Pa e8of8 EPA MRID No.4933900 I