Resource Information

     
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