Methyl Bromide Alternatives in US/ California Dried Fruit and Nut Industries Gary Obenauf Agricultural Research Consulting Fresno, CA

Agricultural Research Consulting n Private Consultant n 1994 n Dried Fruits and Nuts since 1971

Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions n Chairman n Annually since 1994 n

Crop Protection Coalition n US n Users of Methyl Bromide n MBAO

California Organization n Postharvest n Preplant

Alternatives Currently n Postharvest n Preplant

Implications for Dried Fruits n Postharvest n Depends Upon Registrations, Competitors n Preplant n More problems, too many parameters to control

ImportsImports n Treatments ok currently n If US loses use-growers will demand imports stop n Quarantine and Preshipment

OrganicOrganic n Temperature-Freeze n Controlled Atmospheres-Nitrogen n Turn Fruit

Two Types of Alternatives n Chemical Alternatives n Non-chemical Alternatives

Chemical Alternatives n Phosphine n Carbonyl sulfide (COS) n Methyl Iodide (CH 3 I) n Surfuryl Fluoride (SO 2 F 2 ) n Propylene Oxide (C 3 H 6 O) n Ozone (O 3 ) n Others: Ethyl formate, Pressurized CO 2, and HCN

SO 2 F 2 – Sulfuryl Fluoride ProFume® n Physical Parameters: –Boiling Pt. = o C –Mol. Wt. = n Ease of Application: Applied as a gas from cylinders. n Advantages: Very good penetration. Chemically inert. Little sorption on commodity or packing materials. Aerates quickly. n Disadvantages: Not a good ovicide.

SO 2 F 2 n Relative Toxicity: More toxic to all stages of insects except the egg stage when compared to methyl bromide. n Post-fumigation phytotoxicity: phytotoxic to citrus fruit. n Registration: Already registered for structural fumigation (Vikane®). Needs food tolerance.

Testing Alternative Fumigants vs Codling Moth Diapausing Larvae in Walnuts

Non-Chemical Alternatives Heat Vacuum Mating Disruption Insect Pathogens Biological Control Compression

Preliminary field studies with almonds – Vacuum Bags Preparing test insects Sealing bags

Methyl Bromide Use in California from CDPR PUR database

MeBr Use in California from CDPR PUR database

Fumigant Use in California from CDPR PUR database

Fumigant Use for Trees and Vines

Accelerated CA PhaseOut of MeBr n Increased cost (due to limited availability) –tripled in 4 years –Some uses are now priced out (trees and vines, vegetables) n New CA Regulations on Use –Very large buffers for most uses (840’ for 10 acre field; 220 ft for 1 ac; requires multiple applications to reduce buffers) –Very intensive notification requirements –Very restrictive worker hours

Fumigant Costs Per lb. AI Per acre, applied Methyl Bromide $2.70 $1700 (350 lb/ac, broadcast shank, tarped) Chlorpicrin$2.40 $1600 (350 lb/ac, broadcast shank, tarped) Telone (1,3-D) $1.60 $650 (35 gal/ac, broadcast shank) Metam Sodium (MITC) $0.80 $320 (75 gal/ac, shanked, water seal)

Experimental (Unregistered) Fumigants n Iodomethane (Midas) (methyl iodide) n Propargyl Bromide n Sodium Azide n Propylene Oxide n Furfural n DMDS

Enns Nectarines 1 st Yr Growth

Drip Application Equipment Flow meter Static mixer Injection port Water meter Nitrogen cylinder