Thrips Control on Pepper, 1996

The study was conducted on Waikele Farms, Inc. located at Kunia, HI. The field was set up in a RCB design with seven treatments and four replications (blocks). Each treatment plot consisted of two rows of plants 30 ft long. Each plot was separated by a 5.5-ft spacing. Blocks were separated by 10-ft spacing. Plants were planted at 18-inch spacing. Total field size was 0.17 acre. Treatments were applied at 40 psi with an output of 60 gpa using a compressed CO2 sprayer. One TJ60 8006 spray nozzle was used per row. Treatments were applied at 7-day intervals on 13, 20, 27 Sep, and 10 Oct. Surveys were made on a bi-weekly basis for a total of two post-treatment surveys. At each survey, two stages of the plant were sampled: flowers and young fruit approximately 1-2" in diameter. Ten randomly selected flowers and fruits were sampled from each treatment plot and separately placed in plastic zip-lock bags. Each sample was washed separately with a detergent solution and the thrips were collected on a 150-mesh sieve. Thrips were recorded by developmental stages; first-instar larvae (LI), second-instar larvae (LII), and adults (A). At harvest, mature fruits were examined and ranked on a scale of 0-5. A rating of “0” indicated no damage on the fruit. The maximum rank of “5” was assigned to a fruit showing 50% or more of its surface scarred with thrips damage. Each rated fruit was also rated as ‘marketable’ or ‘unmarketable’ based on established grading criteria.