Breaking insect-related citrus trade barriers using postharvest treatments

Transcription

1 Breaking insect-related citrus trade barriers using postharvest treatments Spencer S. Walse* J. Steve Tebbets David Obenland David Hall Joe Morse (UCR) Beth Grafton Cardwell (UCR) Michael Rogers (UF) Beth Mitcham (UCD) Dan Kuzmich (ARS) CA Citrus Update - Walse 1) Stand-alone -PH3 (Brevipalpus mites, red scale, Medfly) - MB (ACP in Miami last week of April) - cold treatment, fogging degreening rooms (FRB) - soaks/floods/dips 2) Systems-based (reduce need /requirements of #1) - mathematics of pre- & post- harvest factors - soaking (low WM organics) for FRB - ACP to AUS, brown rot w/ Adaskaveg 3) Regulatory - PH3 EPA off-gassing, OPP re-registration - EF report to organic board 1

2 Stand-alone fumigation: lab-scale phosphine, methyl bromide, ethyl formate CRS BT feasible standalone control option(s) ACP OFF/MF FRB benefit from system approach mites Asian citrus psyllid fumigation with MB ~ 70 mg h/l will control adult ACP ( 3 lbs, 50 F, 2 h) PH3 fumigations ongoing at CRF - UC Davis 2

3 Brevapalpus chilensis with MB ~ 152 mg h/l will control adult ACP at 40 F, 2.5 h > 2-fold more difficult than ACP Relative sorption of fumigants into naked fresh produce external versus internal feeders mites orange (0.51) OFF very important for short treatments (MB) 3

4 Brevipalpus chilensis with 1.3 ± 0.5 C B. species trade barrier to NZ?? B. californicus & B. lewisi - MB studies ongoing in Parlier/Kearney (G.-Cardwell) - PH3 studies ongoing in Parlier/Kearney (G.-Cardwell) - EF studies ongoing at CRF UC Davis (Mitcham) 4

5 Standalone FRB treatments 1) Fogging - Acetic acid 1% - Fruit growers & Smilanick (USDA-ARS) - 19% mortality 2) Cold-treatment - classic preshipment 22d at -0.5ºC (-5C for 5 d) - 34% mortality 3) IGR soaks w/ & w/out adjuvants ppm Imazalil back ground solution - 1:1 v/v spray-aid or 4.5% Prospect at 40 C 15 30s - Applaud 70DF, Esteem.86 EC, Micromite 80wgs - 50% control w/ spray-aid & Micromite 4) Lime sulfur soaks at 40 C - 44% control at 5% 30s exposures Standalone FRB treatments 5) Organic acid soaks w/ & w/out adjuvants - acetic acid, formic acid, ethyl formate, isopropyl formate, - ethanol, methanol, methyl formate - acetic acid 5 to10% (or more), 40 C, time, dry, rinse - No adjuvant - > 76% 90 s - 92% - 1:1 v/v spray-aid or 4.5% Prospect at 40 C - >97% 90s 5

6 Acetic acid soak commercial Bin drench ( room temp fruit) 40 C in 1:1 spray aid or 4.5% prospect food-grade acetic acid (~6% vinegar) dry bins in degreening room overnight Bin dump onto line to rinse and pack per usual commercial tests to start ASAP FDA POLICY ( Acetic acid is generally recognized as safe for use in foods if it is of "food-grade" and is used in accord with good manufacturing processes. FIFRA 25b exempt pesticides: malic acid, citric acid Opportunity to impact postharvest treatments PREPLANT PRODUCTION POSTHARVEST start finish SYSTEMS-BASED 6

7 General systems concept postharvest control systems Probit 9 efficacy production efforts OFF/MF FRB CRS >>>>>>>>>>>>>>>>>>>>>>> ACP Systems-based: Cumulative evaluation of processes Sample size estimation (Couey & Chew, ARS & UF, 1986) P General rule for the multiplication of independent probabilities (Finney, 1948; Rosenthal, 1978) ( 2 E1 E 2 En) 1 (1 P( E1))(1 P( E ))(1 P( En)) New rule for the multiplication of conditional probabilities P( Ea and Eb) P(Eb E a) (Eq. 2) P( Ea) 7

8 Dunking Soak tank Wall-o-water/Flooding Spraying Washing over brushes Brushes alone Washing over rollers Rollers alone Forced-hot air dryer (confirmatory Evaluation of events/processes 8

9 Systems evaluation: where we sit now Exceeding Probit 9 benchmark without postharvest fumigation Systems approach for FRB FRB 9

10 FRB egg physiology Evaluation of events/processes 10

11 Systems evaluation: where we sit now To exceed Probit 9 benchmark we need to string events Trade Barriers (we break em) Politics/regulatory economics $ X science 11

12 Egypt 1934 Phosphine Chronolgy: CO 2 Fumigatio n commercial test planned in CA First AlP fumigations 1953 AlP Tablets 1979 Mg 3 P 2 Tablets 1994 CO 2 + PH SYSTEMS- BASED final mitigation step Fosfoquim S.A. PH3 Generator Pure phosphine diluted in air Pure phosphine diluted in supra O2 air Other factors for Korea: Precedence Horn phosphine Fosfoqium S.A. 12

13 PH3 Applications: MB chambers, CA rooms Fruit Quality w/ Phosphine 42 F, 48 h, 1500 ppm David Obenland, USDA-ARS waxed field run control fumigated control fumigated 13

14 Other factors for Korea: Worker Safety Inhalation Exposure Fumigants off gas (i.e., depurate) uniformly from boxed fruit over the course of cold storage with loss that follows first-order kinetic approximations given the applied doses and corresponding treatment temperature utilized in this study. Other factors for Korea: Residues Ingestion Exposure Organic (i.e., gaseous) fumigant residues in fumigated fruit decreased uniformly over the course of cold-storage at 37 F and 34 F for oranges and grapes, respectively. Methyl bromide requires time-scales of days and phosphine requires timescales of hours to reach USEPA food tolerences for both methyl bromide and phosphine residues in fruit (dashed red lines). 14

15 THANK YOU 15