Thrips Control Onion, 2013

Abstract

The objective of the study was to evaluate the efficacy of insecticides for control of onion thrips (OT) and western flower thrips on dehydrator onions under desert growing conditions. Dehydrator onion “White Creole” was direct seeded into six row beds on 40-inch centers on 19 October 2012 at the University of California Desert Research and Extension Center, El Centro, CA. Stand establishment was achieved using overhead sprinkler irrigation initiated on 22 October 2012. Sprinklers were used until January 2013, and furrow irrigation was utilized thereafter. Plots were four beds 13.3 ft in width by 50 ft in length and bordered by one untreated bed. The experiment included 11 insecticidal treatments and an untreated check. Four replications of each treatment were arranged in an RCB design. Insecticidal compounds, formulations, and application rates, along with treatment dates, are provided in Table 1. All insecticide treatments were foliar sprays applied with a four-row sprayer (Lee Spider Spray TracTractor) with three TJ-60 11003VS nozzles per bed, a total of 12 nozzles that delivered 53 gpa at 30 psi. The adjuvant, DyneAmic (Helena Chemical Co.), was added to all insecticidal spray mixtures at 0.25% vol/vol. Thrips were sampled by …