Abstract
Abstract The insecticides were evaluated at the Kula Research Station, Maui Agricultural Park, from May to June. The field was set up in a RCB design with six treatments and four replications (blocks). Each treatment plot measured 70 ft by 7.5 ft. It consisted of four rows of cabbage on 36 in. centers and 18 in. in-row spacing. Adjacent rows were offset to allow equidistant plant spacing between rows. Treatment plots in each block were separated by a 4.5 ft row spacing. Blocks were separated by a 10 ft. wide space that allowed sprayer access. Total field size was 150 ft. by 109 ft. Treatments were applied using a tractor mounted with a PTO driven spray pump equipped with a 30 ft. boom. The boom was set with three banks nozzles that coincided with row spacing. Each group of nozzles had its own line from the main tank; therefore, spray output to specific treatment plots could be easily controlled by the sprayer operator. The first treatment was applied using hollow cone TX-18 (Spraying Systems) nozzles at 100 psi. Due to excessive drift caused by the small droplet size, the nozzles were changed to TX-26 for the second to fifth treatment application. The pressure was reduced to 45 psi to give an output of 100 gallons per acre. For the last two treatments, the twin jet TJ-60 8006 nozzles at 25 psi were used for an output of 100 gallons per acre. The first treatment was made on 16 May, 12 days after transplanting. Subsequent applications were made on the following dates: 23 and 30 May, 6, 13, 20, and 27 June.
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