Resource Information |
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Postharvest Control of Thrips with Pyrethroids on Dendrobium, 1993 | ||
By: T. Y. Hata, A. H. Hara and Ben K.S. Hu
Beaumont Agri. Res. Center, University of Hawaii-Manoa, 461 W.
Lanikaula St., Hilo, Hawaii 96720, Phone (808) 935-2885
HOST: Dendrobium Orchid: Dendrobium 'Uniwai Princess'
TARGETED PESTS: Frankliniella occidentalis (Pergande), Western
flower thrips; Thrips palmi (Karny), Melon Thrips
EXPERIMENTAL PROCEDURE
Postharvest insecticidal treatments were evaluated from Jun
through Jul 1993 at the University of Hawaii, Waiakea Experiment
Station in Hilo, HI. Flowers used in this study were randomly
harvested from a commercial dendrobium farm in Kailua-Kona, HI.
Dendrobium plants were well established growing in 0.5 inch
crushed basalt rock under 30% polypropylene shade using standard
cultural practices. Treatments consisted of 4 replicates with 5
inflorescences per replicate. In study 1, inflorescences were
dipped floral end first into 5 gal buckets containing the
insecticide solutions (25.7oC). Inflorescence were submerged for
3 minutes, and gently agitated 10 times at emergence, at 1.5
minutes and again before removal for a total of 30 times. Control
flowers were dipped in water following the same procedure as
described. After dipping, inflorescences were held in buckets and
allowed to air dry. In study 2, the double insecticidal dip of
Mavrik Aquaflow consisted of immersing inflorescences (27.3oC) as
described above, followed by a 2 h waiting period and a second 3
min insecticide immersion. A 2.5 cubic meter chamber was used to
fumigate inflorescence with floragas (2 h exposure at 31.5oC).
Control flowers for the floragas were held in an identical
untreated chamber. Twenty-four hours after treatment, blossoms
were removed from the inflorescence, counted, and placed in
Berlese funnels heated with a 60 watt incandescent light bulb.
Thrips were collected in a 8:2:1:1 solution of ethanol, distilled
H2O, acetic acid and glycerin and the number of nymphs and adults
counted. Thrips counts were adjusted to the number of thrips per
blossom by dividing the total number of thrips recovered by the
total number of blossoms. Data were subjected to analysis of
variance (ANOVA).
RESULTS
Thrips identified in both studies were at a 8:2 ratio of T.
palmi/ F. occidentalis, respectively. In study 1, all treatments
significantly reduced the mean number of thrips per blossom as
compared with the control. There was no significant difference
between Talstar and Tempo. In study 2, the double insecticidal
dip was most effective significantly reducing the mean number of
thrips per blossom. Although floragas reduced the mean number of
thrips per blossom as compared with inflorescences held in a
untreated fumigation chamber there was no significant difference
between floragas fumigated inflorescences and inflorescences that
received no treatment.
Treatment (study 1) | AI (g/liter) | No. thrips/blossom |
Talstar F | 0.20 | 0.07c |
Tempo 2EC | 0.04 | 0.07c |
Tame 2.4EC | 0.20 | 0.29b |
Control | -- | 0.58a |
Treatment (study 2) | AI | No. thrips/blossom |
Double dip | 0.1 g/liter | 0.3c |
Floragas | 1.1 g/m3 | 0.6b |
Control for dipa | -- | 1.0 |
Control for fumigantb | -- | 1.3a |
Controlc | -- | 0.9ab |
Data transformed to log10(x+1) and subjected to ANOVA (P<
0.01). Means followed by different letters in a column are
significantly different by Waller-Duncan K-Ratio t test, k=100.
aDouble dip in water.
bFlowers in fumigation chamber without treatment.
cNo treatment.
PRODUCT INFORMATION
CAUTION
"Hawai'i pesticide law prohibits the use of many
insecticides as dips or drenches. Pesticide labels which prohibit
dip usage or state the amount of product to be used per acre
cannot be legally used as dips. Used dip solutions should be
disposed by applying to approved crops or site in accordance with
all label directions. Contact the Hawaii Department of
Agriculture, Pesticide Branch if in doubt about legal use and
proper disposal of insecticide dip solutions."
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 Hawaii, or the United State 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 manufacturer's
directions.
Product Name: Floragas
Manufacturer's Name: NZIG special gases
Address: PO Box 30-202, Lower Hutt
Composition: 2.0% permethrin, 0.1% pyrethrum
Product Name: Mavrik Aquaflow
Manufacturer's Name: Sandoz Crop Protection Corp.
Address: 1300 E. Touhy Ave., Des Plaines, IL 60018
Composition: fluvalinate 2.0 lb active per gallon
Product Name: Talstar Flowable
Manufacturer's Name: FMC Corp.
Address: 2000 Market Street, Philadelphia, PA 19103
Composition: bifenthrin 0.67 lb active per gallon
Product Name: Tame 2.4EC
Manufacturer's Name: Valent U.S.A. Corporation
Address: 1333 NO. California St., Walnut Creek, CA 94598
Composition: fenpropathrin 2.4 lb active per gallon
Product Name: Tempo 2EC
Manufacturer's Name: Miles Inc.
Address: P.O. Box 4913, 8400 Hawthorn Road, Kansas City, MO 64120
Composition: cyfluthrin 2.0 lb active per gallon