Schedule J. Ethylene dibromide (EDB) fumigation of fresh fruit

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Ethylene dibromide (EDB) is effective against the stages of certain fruit flies (Diptera, family Trypetidae). Species found susceptible to the treatments given below are:

Anastrepha ludens (Loew). Mexican fruit fly
A. mombinpraeoptans Sein. West Indian fruit fly
A. suspense (Loew).
Ceratatitis capitata (Wied). Mediterranean fruit fly
Dacus dorsalis Hendel. Oriental fruit fly
Rhaqoletis cinqulats (Loew). Cherry fruit fly
R. pomonella (Walsh). Apple maggot

Alternative treatments - low temperature and vapour heat treatments are also used for control of these insects in fruit (see USDA, 1976).

TREATMENT FOR HAWAIIAN FRUIT

TREATMENT FOR MANGOES

Dosage

TREATMENT OF FRUIT TO CONTROL MEXICAN FRUIT FLY

Found effective on oranges, grapefruit, tangerines, plums and mangoes.

Dosage - Ethylene dibromide in g/m³ (oz/l 000 ft³) for 2 h.

MEDITERRANEAN FRUIT FLY IN FLORIDA

Treatments based on the foregoing schedule were used in the campaign against the Mediterranean fruit fly in Florida, beginning in May 1956 (Richardson, 1958).

Authority - U.S. Department of Agriculture, Agricultural Research Service, Plant Quarantine Division, Supplement to Quarantine 56. No.319.56 - 2 e, February 1959.

APPLE MAGGOT IN CANADIAN APPLES

Fumigation of apples with EDB at fruit and air temperatures above 16°C in approved chambers or under gas proof sheets to control larvae of the apple maggot Rhanoletis pomonella.

Dosage - EDB 6 mg/l (6 (oz/l 000 ft³) for 2 h (Sanford, 1962a, b). (At temperatures below 10°C there may be considerable persistence of EDB vapours.)

GENERAL NOTES CONCERNING TREATMENT OF FRUIT WITH EDB

1. The ethylene dibromide must be volatilized as quickly as possible by means of pans on hot plates or by other effective vaporizing devices.

2. The fumigation period required begins when all the fumigant is known to have evaporated. (This time may be determined by experiment or by observation through glass ports.)

3. Circulation of the fumigant/air mixture by means of fans or blowers must continue throughout the exposure period.

4. Thorough aeration of the fruit is essential before it is released for human consumption. This is especially important in the fruit temperature range of 10 to 27°C.

TOLERANCE OF FRUIT TO EDB FUMIGATION

The tolerance of the fruit listed below was determined by exposure to 16 g/m³ (16 (oz/l 000 ft³) for 2 h at 21°C unless otherwise stated. Therefore, these fruits should be tolerant under normal circumstances to any of the schedules given above.

IMPORTANT. The information on tolerance is based on fruit reaction only and is given for guidance. It is not implied that the fumigant is necessarily effective under the given conditions against all pests found in or on the fruit. As suggested before, tests should always be made to deal with specific problems under local conditions.

TOLERANT FRUITS

Apples, numerous United States varieties (a, 9, j). Apples, 5 Canadian varieties (k). (Apples appear to be generally tolerant to EDB.)

Apricots (3 varieties)(a)

Avocados (a). No injury at 0.5 to 3 lb/1 000 ft³ (c); no injury to Fuerte avocados at 1 to 3 lb ( f); MacArthur, Anaheim and El Tropico were injured at 2 lb/1 000 ft³ for 2 h; 3 lb caused severe injury(f).

Bananas, Cavendish (i)

Cherries (3 varieties) (a, d)

Citrus: grapefruit, lemons, oranges and tangerines are tolerant if recommendations are followed (c,e). Overloading the chamber may result in peel injury, especially in grapefruit.

Figs (2 varieties) (a)

Grapes (6 varieties) (a)

Mangoes (c, h). Tolerant at 1 lb/1 000 ft³ for 2 h at 25°C (c, l) Nectarines (6 varieties) (a)

Papayas (e)

Peaches (13 varieties) (a, j) Pears (6 varieties) (a, j)

Pineapples (e)

Plums (16 varieties) (a, j)

NON TOLERANT FRUITS

Avocados (some varieties)
Persimmons (5 varieties) (a)

RESIDUES

For details of residues see Tanada et al (1953), Dumas (1962), Coggiola and Huelin (1964), Alumot et al (1965) and the general reviews of Lindgren et al (1968) and Dumas and Bond (1975).

REFERENCES

General references - USDA (1967b) and USDA (1976) with periodic revisions.

Schedule K. Ethylene dibromide(EDB) fumigation of fresh vegetables

Ethylene dibromide (EDB) is effective against the stages of certain fruit flies (Diptera, family Trypetidae) which may be found in certain vegetables.

Species of insects found susceptible are listed in Schedule J together with general notes on ethylene dibromide fumigation of perishable materials.

TREATMENT

A standard treatment, effective against the oriental fruit fly, Dacus dorsalis, is EDB at a dosage 8 g/m³ (8 (oz/1 000 ft³) for 2 h with a minimum temperature of 21°C in any part of the system. The load factor given for Mexican fruit fly in Schedule J could be applied.

TOLERANCE OF FRESH VEGETABLES TO EDB

The reactions listed below are based on Pratt et al (1953) with the treatment given above.

IMPORTANT. The information on tolerance is based on vegetable reaction only and is given for guidance. It is not implied that the fumigant is necessarily effective under the given conditions against all pests found in or on the vegetable. As suggested before, tests should always be made to deal with specific problems under local conditions.

TOLERANT CROPS

Beans, lima and snap
Broccoli
Cucumbers
Melons (cantaloupe, casaba, honeydew, Persian, watermelon)
Peppers, bell
Squash (summer and winter varieties)

NON TOLERANT CROPS

Artichokes. Discoloration and decay Cauliflower. Darkening and spotting of curds; killing of leaves Eggplant. Severe general injury Melon, Crenshaw Peppers, chill). Injury to calyx and off-colour of fruit Tomatoes (4 varieties)

RESIDUE TOLERANCES

The general review of Lindgren et al (1968) discusses official United States tolerances for ethylene dibromide used on a number of vegetables.

Schedule L. Hydrogen cyanide (HCN) fumigation of fresh fruit and vegetables

Some fruits are tolerant to HCN and, if applied according to directions, the fumigant may be used on them without danger to the consumer. Applications recommended for certain quarantine purposes are given here.

ATMOSPHERIC FUMIGATION WITH HCN

The fumigant volatilized from the liquid is applied at the rate of 6 g/m³ (6 (oz/l 000 ft³ ) for one hour at a temperature above 10°C. Fan circulation (explosion-proof motors) must be maintained throughout the treatment. The fruit must be dry, otherwise serious burning may result.

Avocados, packed for shipment, to control latania scale, Hemiberlesia lataniae (Sign.)

Citrus fruit (oranges, lemons, limes, grapefruit) to control scale insects and thrips and possibly other external pests such as citrus whitefly and blackfly. For control of bean thrips, Hercothrips fasciatus (Perg.), exposure period may be reduced to 35 minutes (Harper, 1942 - 57; Richardson and Balock, 1959).

HCN is used extensively in Japan for fumigation of bananas and citrus fruit infested with scale insects (Mori, 1980). Application is conducted through a dispenser unit consisting of a vaporizer and blower and the gas is circulated to facilitate even distribution. After fumigation, the remaining gas is removed through an HCN gas scrubber. The recommended dosage is 2 g/m³ for 30 min.

VACUUM FUMIGATION WITH HCN (Harper, 1942 - 57)

Dosage 6 g/m³. The fumigant introduced into intial vacuum of 125 mm (about 5 in) absolute pressure with stream of air (simultaneous introduction) until atmospheric pressure is reached. Exposure period: 1 hour. Temperature not less than 15°C.

For control of mealybugs, Pseudococcus sp., in persimmons packed for export

Schedule M. Hydrogen cyanide (HCN) fumigation of dormant nursery stock

Balled nursery stock should be held for 10 to 14 days after digging before fumigation. Avoid free moisture on plants. After fumigation, all plants should be gently but thoroughly washed by sprinkling with water. They should be protected from sunlight and wind for 48 h following treatment.

ATMOSPHERIC FUMIGATION WITH HCN

Fumigation of imported nursery stock to prevent introduction of San Jose scale, Aspidiotus perniciosus Comst. Dosage HCN 6 g/m³ (6 oz/l 000 ft³ ). Temperature not below 4 C. Fumigant is introduced with stream of air. After this, continuous recirculation of fumigant/air mixture in the chamber at a rate per hour equivalent to 40 times the cubic capacity of the chamber. Exposure period: 30 min.

The above is based on information supplied by the Netherlands Ministry of Agriculture, Plant Protection Service (Personal communication P.H. Van de Pol, 17 March 1959).

If the above rate of circulation of fumigant/air mixture cannot be attained, apply the treatment used for many years to control scale insects and woolly aphids before the introduction of Yacuum fumigation or high velocity circulation. Dosage of HCN, 10 g/m³ (10 oz/l 000 ft³). Temperature not less than 4 C. Exposure period: 45 min to 1 h. Continuous circulation of air/fumigant mixture is advisable. If fans or blowers are used, they should be of the shielded, nonexplosive type.

For discussion of technical problems in the fumigation of plant material with HCN, see Be ran (1946) and Van de Pol and Rauws (1957).

VACUUM FUMIGATION WITH HCN (Harper 1942 - 57)

Fumigation of balled citrus plants to control scale insects, specifically the Californian red scale, Aonidiella aurantii (Mask.). Dosage of HCN 5 g/m³ (5 oz/l 000 ft³ ). Temperature not less than 10°C. Initial vacuum 100 mm (4 in) of Hg absolute pressure. Fumigant is introduced with stream of air until atmospheric pressure is restored. Exposure period: 1 h.

Schedule N. Fumigation of flower bulbs and corms

This schedule covers flower bulbs and corms, including bulbous iris, gladioli, lilies (including Easter lilies), narcissus, tulips and many other kinds.

VACUUM TREATMENTS

Some varieties may be affected by sustained vacuum and produce shortstemmed plants or retarded growth. Initial vacuum treatments followed by restoration of atmospheric pressure after or during the introduction of the fumigant are usually effective and less injurious to bulbs.

1. For aphids (tulip bulb aphid, Anuraphis tulipae (Fonsc.), and other species).

(a) HCN. 10°C and above; 2 g/m³ (2 oz/l 000 ft³) for 2 h under atmospheric pressure.

(b) Methyl bromide. See schedule for mites. Aphids are easily killed by methyl bromide but stronger treatment will also control postembryonic mites.

2. For bulb flies, narcissus bulb fly, Lampetia equestris (F.), and lesser bulb fly, Eumerus tuberculatus Rond.).

(a) HCN. 18°C and above: 6 g/m³ for 6 h under atmospheric pressure (recommended by the Netherlands Ministry of Agriculture).

(b) Methyl bromide. 15 to 20°C: 48 g/m³ for 5 h under atmospheric pressure, or 48 g/m³ for 3 h under preliminary vacuum.

21°C and above: 48 g/m³ for 4 h under atmospheric pressure or 48 g/m³ for 2.5 h under preliminary vacuum.

Below 15°C: not recommended for atmospheric fumigation (Andison and Cram, 1952).

3. For mites (bulb mite, Rhizoalyphus echinopus (F. & R.), bulb scale mite, Steneotarsonemus laticeps (Halb.), eriophyid mites). Methyl bromide treatment should be repeated after 10 to 14 days in order to kill eggs (Mackie et al, 1942; Monro, 1937 - 40). Eriophyid mites, Eriophyes spp., may sometimes be controlled by milder treatments with HCN or methyl bromide.

(a) HCN. 18°C and above: 6 g/m³ for 24 h (recommended by the Netherlands Ministry of Agriculture).

(b) Methyl bromide. 15 to 21°C: 48 g/m³ for 2.5 h under atmos pheric pressure, or 48 g/m³ for 2 h under preliminary vacuum.

21 to 27°C: 48 g/m³ for 2 h under atmospheric pressure, or 48 g/m for 1.5 h under preliminary vacuum.

27°C and above: 40 g/m³ for 2 h under atmospheric pressure, or 40 g/m³ for 1.5 h under preliminary vacuum.

4. For thrips (gladiolus thrips, Taeniothrips simplex (Mor.) and lily bulb thrips. Liothrips vaneeckei Pries.). With methyl bromide against thrips, temperature is an important factor in obtaining complete control of the insects in all stages, including eggs. It is advisable, wherever possible, to fumigate at or above 20°C (Steinweden et al (1942).

Methyl bromide. 21 to 27°C: 48 g/m³ for 3 h under atmospheric pressure, or 48 g/m³ for 2 h under preliminary vacuum.

27°C and above: 48 g/m³ for 2 h under atmospheric pressure, or 40 g/m³ for 2 h under preliminary vacuum.

General reference - USDA (1976) with periodic revisions.

Schedule O. Methyl bromide fumigation of cut flowers and greenery

THRIPS

Methyl bromide at the rate of 16 g/m³ (16 oz/l 000 ft³) for 1.5 h may be applied to cut flowers of rose, tulip and carnation at atmospheric pressure at temperatures of 29 to 31°C for the control of thrips, Rhiphiphorothrips cruentatus H., without injuring the blooms (Junaid and Nasir, 1956).

Chrysanthemums (aphids only), methyl bromide 12 g/m³ (12 oz/l 000 ft³) for 2 h at 21 C or above.

SURFACE FEEDERS, LEAF MINER, THRIPS.

Methyl bromide At atmospheric pressure exposure period 2 hours

Concentrations should be at least 75 percent of the applied dosage at 30 min and 50 percent at 2h.

BORERS, SOFT SCALES (Vacuum fumiqation - 380 mm)

The prior consent of the importer should be obtained for vacuum fumigation.

See USDA (1976) for further information on these treatments.

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