Pest Management Guidelines |
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An Insecticide Dip for Tropical Cut Flowers and Foliage | ||
By: Victoria L. Tenbrink, Arnold H. Hara, Trent Y. Hata, and
Ben K. S. Hu
Department of Entomology, University of Hawaii, College of
Tropical Agriculture and Human Resources.
INTRODUCTION
Flowers and foliage exported from Hawai'i can be confiscated by
quarantine inspectors if insect pests are found. Field control of
insects is very important but rarely eliminates all pests. When
properly applied, a combination of insecticidal soap and a
pyrethroid in an after harvest dip is more effective for many
commodities than either one used alone.
MATERIALS
Of the insecticides tested, a soap pyrethroid combination at the
maximum label rate was most effective. Several pyrethroids and
insecticidal soaps are on the market. It is important to follow
the label rate because the concentrations of active ingredients
vary among the different brands. The pyrethroid selected must be
labeled for general ornamental use and its use as a dip must not
be prohibited. We tested a combination of Mavrik Aquaflow (active
ingredient: fluvalinate, Sandoz of Des Plaines, Illinois) and
insecticidal soap (active ingredient: potassium salts of fatty
acids) and found it effective against aphids, ants, soft scales,
and mealybugs.
METHOD
A 2 step method is recommended for commodities with scales, those
with cracks and crevices, and any highly infested material. The
first step is a wash in a mild cleaning solution, e.g., LOC
(Liquid Organic Cleaner, Amway of Ada, Michigan), in which tight
cracks and crevices are opened to expose insects and the
commodity is scrubbed to remove scales. The second step is a 5
minute dip in insecticidal soap and pyrethroid. Insecticidal soap
and a pyrethroid, such as Mavrik Aquaflow, are mixed with water
at the label rate and agitated to ensure even dispersal of the
chemicals. Flowers and foliage are submerged in the solution and
agitated for 10 or 20 seconds. Agitation is repeated at the end
of the soaking period. Total submersion should last at least 5
minutes. Longer submersion may damage plant material because of
overexposure to soap. Do not rinse. Allow flowers to air dry
before packing.
Based on scientific information on fluvalinate, the dip solution
should be protected from direct sunlight, which causes it to
break down rapidly. It should be replaced at least once a week.
PHYTOTOXICITY
We tested dips for safety on many cut flower and foliage
commodities. Insecticidal soap damaged these commodities:
dendrobium, anthurium, and cycads (including sago palm and
circinalis). These should be dipped in pyrethroid alone. The soap
pyrethroid dip tested nonphytotoxic for the following
commodities:
Anthurium Foliage Monstera
Bamboo Orchid Foliage Pothos
Bird of Paradise Foliage Green Ti
Calathea Foliage Green and White Ti
Dracaena Red Ti
Hala Uluhe
Lycopodium Whaleback
Soaps and detergents are phytotoxic to some commodities.
Phytotoxicity varies depending on exposure conditions. Testing
using a small sample of the crop is always recommended. After
dipping, the sample should be observed for a few days for wilting
or discoloration.
SAFETY FOR AFTER HARVEST DIP TREATMENT
Insecticidal soaps and Mavrik Aquaflow have the signal word
"CAUTION," which indicates the lowest level of the
three categories of risk to workers. Some pyrethroids are in
higher risk categories. Read labels carefully. Avoid breathing
vapors and contacting eyes, skin, or clothing. All safety
precautions on the label regarding protective clothing and
equipment must be followed. Eye protection, elbowlength rubber
gloves, rubber or plastic apron, and waterproof boots are
necessary because of possible exposure by splashing. The label
may have additional requirements. A locked cover over the dip
container when not in use will prevent animals and children from
contacting the pesticide solution.
DISPOSAL
Proper disposal of the chemicals must be considered in setting up
a dip operation. Used dip solutions should be disposed of by
applying to approved crops in accordance with all label
directions, including dilution rate and approved site. Contact
the Hawai'i Department of Agriculture, Pesticide Branch, if in
doubt about proper disposal.
PRECAUTIONARY STATEMENT
Use pesticides safely. Follow the pesticide label. Consult with
the Cooperative Extension Service or the Hawai'i State Department
of Agriculture for authorized special local need registrations or
additional information. The user is responsible for the proper
use, application, storage, and disposal of pesticides.
DISCLAIMER
Reference to a company or product name does not imply approval or
recommendation of the product by the College of Tropical
Agriculture and Human Resources, Cooperative Extension Service,
University of Hawai'i' i, or the United States Department of
Agriculture and does not imply its approval to the exclusion of
other products that may be suitable. All materials should be used
in accordance with label instructions or manufacturers'
directions.
REFERENCES
Hansen, J. D., A. H. Hara, and V. L. Tenbrink. 1992. Insecticidal
dips for disinfesting commercial tropical cut flowers and
foliage. Tropical Pest Management 38:245249.
Tenbrink, V. L., J. D. Hansen, and A. H. Hara. 1990. Postharvest
control of banana aphid using dips, 1989. Insecticide and
Acaricide Tests 15:338339.
--. 1991a. Postharvest control of mealybugs using dips, 1990.
Insecticide and Acaricide Tests 16:258.
--. 1991b. Phytotoxicity of Safer's Insecticidal Soap and Mavrik
Aquaflow as a postharvest dip, 1990. Insecticide and Acaricide
Tests 16:261262.
Issued in furtherance of cooperative Extension work, Acts of May
8 and June 30, 1914, in cooperation with the U.S. Department of
Agriculture. Noel P Kefford, Director of the Institute and Dean
of the College, cooperative Extension service, College of
Tropical Agriculture and Human Resources University of Hawai'i at
Manoa, Honolulu, Hawai'i 96822. An Equal Opportunity Employer
providing programs and services to citizens of Hawai'i without
regard to race, color, national origin, or sex. 12/93