Border plants species and alternative treatments on the control of thrips and the incidence of its predator (Toxomerus spp.) on onion

Abstract

Two experiments were carried out at Epagri/Experiment Station of Ituporanga, SC, Brazil, in order to evaluate the effect of border plants on onion associated or not to alternative compounds to control thrips (Thrips tabaci) and its effect on syrphid predators (Toxomerus spp.). The treatments in both experiments did not reduce the incidence of onion thrips and did not affect the population of syrphid predators. Commercial yield and
onion bulb weight were not increased by sprays of any tested substances. Treatments with extracts of buck wheat and fodder radish 10% and onion bordered with weeds were superior in onion bulb weight compared to onion bordered with fodder radish and buck wheat in the experiment 2.