Resource Information |
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Postharvest Control of Thrips on Dendrobium, Hawaii, 1993 (2 articles) | ||
1: Post Harvest Control of Thrips on Dendrobium, Hawaii, 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 cv. Uniwai Princess
TARGETED PEST: Thrips palmi (Karny)
EXPERIMENTAL PROCEDURE
Decathlon 0.2 was evaluated as a postharvest insecticidal dip
from 26 Oct through 28 Oct 1993 at the University of Hawaii at
Manoa Waiakea Experiment Station in Hilo, Hawaii. Flowers used in
this study were randomly harvested from a commercial dendrobium
farm in Kailua-Kona, Hawaii. Dendrobium plants were well
established growing in 1.3 cm crushed basaltic rock under 30%
polypropylene shade using standard cultural practices. Treatments
consisted of 4 replicates with 5 inflorescences per replicate.
Inflorescences were dipped floral end first into 19 liter buckets
containing 11.4 liters of insecticide solution. Control flowers
were dipped in water. Inflorescences 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. After
dipping, inflorescences were held in buckets and allowed to air
dry. Twenty-four hours after treatment, blossoms were removed
from the inflorescences, 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.
Because the number of blossoms per inflorescences varied, 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 transformed to log10 (x+1). In addition,
fifteen inflorescences were randomly harvested and treated for
evaluation of vase life. Data were taken on the number of days
inflorescences remained intact (start of blossom wilt or
senescence) and end of vase life ( > 50% of blossoms
affected). Data were analyzed by t test.
RESULTS
Decathlon significantly reduced the number of thrips per blossom
as compared with the control. There was no significant difference
in vase life between treated and control inflorescences.
Treatment | AI (g/liter) | Thrips/blossom | Initiation of blossom drop | Vase life |
Decathlon | 0.03 | 0.2* | 12.2 | 18.9 |
Control | -- | 1.0 | 11.0 | 20.0 |
Data subjected to test. *, significant at P < 0.05.
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: Decathlon
Manufacturer's Name: Olympic Chemical Co., Inc.
Address: P.O. Box K, Mainland, PA 19451
Composition: cyfluthrin 20%
2: Post Harvest Control of Thrips on Dendrobium, Hawaii,
1993
By: T. Y. Hata, A H. Hara, Ben K.S. Hu, and V. L. Tenbrink.
Beaumont Agri. Res. Center, University of Hawaii, CTAHR, 461 W.
Lanikaula St.. Hilo, Hawaii 96720, (808) 9352885
Host: Dendrobium orchid, Dendrobium cv. Uniwai Princess
Targeted Pests: Frankliniella occidentalis (Pergande)
Thrips palmi (Karny)
HOST
Dendrobium orchid, Dendrobium cv. Uniwai Princess
TARGETED PESTS
Frankliniella occidentalis (Pergande)
Thrips palmi Karny
EXPERIMENTAL PROCEDURE
A postharvest insecticidal double dip and floragas postharvest
fumigant were evaluated for efficacy in June 1993 at the
University of Hawaii at Manoa Waiakea experiment station.
Inflorescences used in this study were randomly harvested from a
commercial dendrobium farm in Kailua-Kona, Hawaii from well
established plants growing in 1.3 cm crushed basalt rock under
30% polypropylene shade. Treatments consisted of 4 replicates
with 5 inflorescences per replicate. The double insecticidal dip
consisted of immersing inflorescences for 3 min with agitation
into 19 liter buckets containing 15 liters of insecticide
solution, followed by a 2 h waiting period and a second 3 min
insecticide immersion. Control flowers for the double dip were
immersed in water following the same procedure as described. A
2.5 cubic meter chamber was used to fumigate inflorescence with
floragas (2 h exposure). Control flowers for the floragas were
held in an identical untreated chamber. Twenty-four hours after
treatment, blossoms were removed from the inflorescences,
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. The
mean number of nymph and adult thrips per blossom was calculated
and analyzed by analysis of variance (ANOVA).
RESULTS
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 | AI (actual) | AI (formulated) | Thrips/blossom |
Double dip | fluvalinate 22.3 % | 0.1 g/liter | 0.3(c) |
Floragas | 2.0% permethrin, 0.1% pyrethrum | 1.1 gtm3 | 0.6(b) |
Control for dip(a) | -- | -- | 1 .O(a) |
Control for fumigant(b) | -- | -- | 1 .3(a) |
Control(c) | -- | -- | 0 9(ab) |
Data transformed to loglO(x+l) and subjected to ANOVA (P>
0.01). Means followed by different letters in a column are
significantly different by WallerDuncan KRatio t test, k=100.
(a)Double dip in water.
(b)Flowers in fumigation chamber without treatment.
(c)No treatment.
PRODUCT INFORMATION
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 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: Mavrik Aquaflow
Manufacturer's Name: Sandoz Crop Protection Corp.
Address: 1300 E. Touhy Ave., Des Plaines, IL 60018
Composition: fluvalinate 2.0 Ib active per gallon
Product Name: Floragas
Manufacturer's Name: NZIG special gases
Address: PO Box 30202, Lower Hutt
Composition: 2.0% permethrin, 0.1% pyrethrum